Biomedical subjects

J W Kasckow

Publications and source records attributed to J W Kasckow.

36 records · Page 2Linked to original sources

PubMed1999

Regulation of corticotropin-releasing factor-binding protein expression in amygdalar neuronal cultures.

Corticotropin-releasing factor-binding protein (CRF-BP) is known to regulate the bioavailability of CRF and may also play a role in stress behaviours. CRF-BP has been localized in the pituitary as well as central nervous system (CNS) limbic and cortical areas, including the amygdala. The signal transduction pathways which regulate amygdalar CRF-BP are not well understood. In this report, we have examined the effect of protein kinase A and C activators, CRF, dexamethasone and interleukin-6 (IL6) on CRF-BP mRNA and protein expression in dissociated fetal amygdalar cultures. CRF-BP mRNA levels were determined by Northern analysis following 12 h treatment with the following agents: forskolin (1-30 microM), CRF (1-1000 nM), phorbol-12-myristate-13-acetate (TPA; 1-50 nM), dexamethasone (1-100 nM) and IL6 (10-500 pM). Significant increases in CRF-BP mRNA were observed in response to forskolin (30 mM), CRF (100, 1000 nM), IL6 (100, 500 pM), TPA (50 nM) and dexamethasone (100 nM; P<0.05 for all; n=3-6 for all). We extended our observations of CRF-BP expression to the protein level by performing semiquantitative Western analysis of total cellular protein after treatment with the same agents. Twenty-four hour treatment with 30 microM forskolin, 1000 nM CRF, 50 nM TPA, 100 pM IL6 or 100 nM dexamethasone significantly increased CRF-BP expression (P<0.05, n=3 for each treatment). The primary cultures were then transfected with a rat CRF-BP-reporter construct containing 3500 base pairs of CRF-BP 5' flanking DNA. Treatment with all five agents produced statistically significant increases above control (P<0.05; n=3 for each). The results suggest that CRF-BP in the amygdala is stimulated by numerous pathways which may play a significant role in promoting behavioural changes.

5' Untranslated Regions↗

PubMed1999

Serial CSF corticotropin-releasing hormone levels and adrenocortical activity in combat veterans with posttraumatic stress disorder.

OBJECTIVE: The authors sought to carefully test, by using a technique of continuous CSF sampling, the hypothesis that basal elevations in CSF corticotropin-releasing hormone (CRH) concentrations exist in patients with posttraumatic stress disorder (PTSD). They also sought to assess the relationship among PTSD symptoms, adrenocortical activity, and CSF CRH levels. METHOD: CSF was withdrawn by means of a flexible, indwelling subarachnoid catheter over a 6-hour period, and hourly CSF concentrations of CRH were determined for 11 well-characterized combat veterans with PTSD and 12 matched normal volunteers. Twenty-four-hour urinary-free cortisol excretion was also determined. PTSD and depressive symptoms were correlated with the neuroendocrine data. RESULTS: Mean CSF CRH levels were significantly greater in PTSD patients than in normal subjects (55.2 [SD = 16.4] versus 42.3 pg/ml [SD = 15.6]). No correlation was found between CSF CRH concentrations and PTSD symptoms. While there was no significant difference between groups in 24-hour urinary-free cortisol excretion, the correlation between 24-hour urinary-free cortisol excretion and PTSD symptoms was negative and significant. CONCLUSIONS: By using a serial CSF sampling technique, the authors found high basal CSF CRH concentrations and normal 24-hour urinary-free cortisol excretion in combat veterans with PTSD, a combination that appears to be unique among psychiatric conditions studied to date.

Adrenal Cortex↗

PubMed1999

Coordinate and divergent regulation of corticotropin-releasing factor (CRF) and CRF-binding protein expression in an immortalized amygdalar neuronal cell line.

CRF is a 41-amino acid neuropeptide best known for its hypophysiotropic actions. CRF is widely distributed in the central nervous system in areas beyond the hypothalamus. CRF-binding protein (CRF-BP) regulates the bioavailability of CRF, and knowledge of the regulation of CRF-BP synthesis is an integral component of understanding the actions of CRF. To better study the regulation of CRF and CRF-BP, primary amygdalar cultures were immortalized by transfection with the SV 40 large T antigen. A clonal line that expresses CRF immunoreactivity and messenger RNA was selected. The production of CRF peptide and message by this line is regulated in a manner indistinguishable from primary cultures. We also observed that the immortalized cells express CRF-BP immunoreactivity and messenger RNA. The expression of both CRF and CRF-BP is positively regulated by forskolin and interleukin-6. Unlike CRF, the expression of CRF-BP message and peptide was increased by phorbol 12-myristate 13-acetate or dexamethasone. These results demonstrate that the synthesis of CRF and CRF-BP in this clonal cell line may be regulated in parallel by some agents but not by others. These data also suggest that dexamethasone may decrease the biological availability of CRF in the amygdala by increasing the expression of CRF-BP, rather than by decreasing CRF expression.

Amygdala↗

PubMed1998

NPY messenger RNA is increased in medial hypothalamus of anorectic tumor-bearing rats.

Previous investigations suggest that neuropeptide Y (NPY) feeding mechanisms and corticotropin releasing factor (CRF) are altered in anorectic tumor-bearing (TB) rats. To better determine the relationship of NPY and CRF synthesis to cancer anorexia we measured mRNA for these peptides in medial and lateral hypothalamus of TB and control rats. NPY and CRF mRNA were reliably detected by Northern blot analysis only in medial hypothalamus, where NPY message was elevated significantly in TB rats. CRF mRNA tended to be reduced in both pair-fed (PF) and TB rats, but did not reach statistical significance. Concentrations of NPY or CRF were not altered significantly in either the lateral or medial hypothalamus of TB or PF rats. These results suggest that the transcription of NPY is elevated in PF rats and is increased further in anorectic TB rats. The lack of significant increases in levels of peptides may be related to dilution, due to measuring a relatively large block of hypothalamic tissue. Alternatively, translation of the signal for NPY production may be inhibited, or degradation of peptide levels may be increased.

Animals↗

PubMed1998

Interleukin-1 regulation of corticotropin-releasing factor (CRF), glucocorticoid receptor, c-fos and c-jun messenger RNA in the NPLC-KC cell line.

The NPLC-KC human hepatoma cell line expresses corticotropin-releasing factor (CRF) and it has been demonstrated that CRF secretion and synthesis in this cell line increases in response to activators of the protein kinase A (PKA) and C (PKC) pathways as well as interleukin-1 (IL1). CRF expression with all three agents can be inhibited with the synthetic steroid-dexamethasone (DEX). In this report, we have examined the effect of IL1 (beta form) in the presence and absence of DEX on CRF mRNA (mRNA) expression as well as the expression of human glucocorticoid receptor (GR) mRNA and the mRNA of the proto-oncogenes (c-jun and c-fos) that have been implicated in CRF regulation. NPLC-KC cells were incubated with picomolar concentrations of IL1. Following this total RNA was extracted from the cells and Northern Blots were probed with 32P-labelled human DNA probes for the CRF, GR, c-jun and c-fos genes. Levels of mRNA expression were measured using a PhosphoImager and were normalized to mRNA levels of control probe glyceraldehyde-3-phosphate dehydrogenase (GAPD). CRF mRNA was significantly increased with IL1 treatment in a time and concentration dependent manner. CRF mRNA expression increased with increasing concentrations of IL1 over the range of 1-100 pM; expression of CRF mRNA also peaked after 24 h of 100 pM IL1 treatment and reached a level of expression approximately seven times higher than control. This pattern of expression was significantly inhibited in the presence of 100 nM DEX. Levels of the GR, c-fos and c-jun mRNAs were also significantly increased in the presence of IL1 and inhibited when DEX was co-incubated with IL1. The results reveal that IL1 stimulation of CRF mRNA expression by IL1 in the NPLC-KC cell line is accompanied by activation of GR mRNA as well as the mRNA of the immediate early genes--c-fos and c-jun. The results also demonstrate that this cell line may serve as a model system for the molecular mechanisms by which IL1 regulates CRF in central nervous system (CNS) neurons.

Carcinoma, Hepatocellular↗

PubMed1997

Regulation of corticotropin-releasing factor (CRF) messenger ribonucleic acid and CRF peptide in the amygdala: studies in primary amygdalar cultures.

Amygdalar CRF has been implicated in the mediation of stress behaviors. The signal transduction pathways that regulate amygdalar CRF are not well understood. In this report, we have examined the effect of protein kinase A and C activators, dexamethasone, and interleukin 6 on CRF messenger RNA (mRNA) and CRF peptide expression in dissociated amygdalar cultures. The amygdala from E19 rat pups was dissected out bilaterally and dissociated in 0.25% trypsin for 10-15 min and plated. On day 17 in culture, CRF mRNA and peptide were measured following treatment with the following agents: forskolin, the phorbol ester-phorbol 12 myristate 13-acetate (TPA), dexamethasone, and interleukin-6 (IL6). Both forskolin and IL6, but not TPA, increased CRF mRNA in a time- and dose-dependent manner. Secretion and intracellular content of the CRF peptide also increased with both forskolin and IL6 treatment but not with TPA. Dexamethasone treatment did not alter the expression of CRF message or peptide. Transfection of the primary cultures with a rat CRF promoter-luciferase reporter construct followed by treatment with all four agents produced alterations in luciferase expression that were consistent with changes observed at the level of CRF mRNA and peptide. The results suggest that CRF regulation in the amygdala differs from that known to occur in the hypothalamus, and that elevation of IL6 levels within the central nervous system may directly act to stimulate CRF production and secretion from limbic structures such as the amygdala, to promote subsequent behavioral changes.

Amygdala↗

PubMed1997

Uncoupling of serotonergic and noradrenergic systems in depression: preliminary evidence from continuous cerebrospinal fluid sampling.

We used the technique of continuous cerebrospinal fluid (CSF) sampling to test the following hypotheses regarding CNS monoaminergic systems in depression: (1) absolute concentrations of the informational substances tryptophan and 5-hydroxyindoleacetic acid (5-HIAA) are altered in the CNS of depressed patients (2) abnormal rhythms of tryptophan and/or 5-HIAA, or defective conversion of tryptophan to serotonin (5HT), exist in the CNS of depressed patients, and (3) the relationship between the CNS 5HT and norepinephrine (NE) systems is disrupted in depressed patients. We obtained 6-h concentration time series of tryptophan, 5-HIAA, NE, and 3-methoxy-4-hydroxyphenylglycol (MHPG) in the CSF of 10 patients with major depression and in 10 normal volunteers. No significant differences in CSF tryptophan, 5-HIAA, NE, or MHPG concentrations or rhythms were observed between normal volunteers and depressed patients. Neither were there differences in the mean tryptophan-to-serotonin ratio. However, a negative linear relationship was observed between mean concentrations of 5-HIAA and NE in the CSF of the normal volunteers (r = 0.916 [r2 = 0.839], df = 9, P < 0.001) while, in contrast, depressed patients showed no such relationship (r = +0.094 [r2 = 0.00877], df = 9, n.s.). Furthermore, the correlation coefficients expressing the relationship between CSF MHPG and CSF 5-HIAA within the normal and depressed groups were significantly different. These data support the hypothesis that a disturbance in the interaction between the serotonergic and noradrenergic systems can exist in depressive illness in the absence of any simple 5HT or NE deficit or surplus.

Adult↗

PubMed1996

Substance use: a powerful predictor of relapse in schizophrenia.

This study examined substance use among a group of 37 schizophrenia patients participating in a year-long fluphenazine decanoate (FD; Prolixin) dosage reduction study (Inderbitzin et al. (1994) Am. J. Psychiatry 151, 1753-1759). Ten (50%) of the 20 FD dose-reduced patients, and 6 (35%) of the 17 control group patients were identified as substance users. The dose-reduced and control groups did not differ significantly in substance use. We examine here the 37 patients regrouped by substance users (n = 16) versus non-users (n = 21) to determine the effects of substance use. In addition to identifying substance users and types of substances used, we hypothesize that substance users differ demographically from non-users, have worse symptomatology, worse compliance, higher rates of relapse, and therefore, can confound studies. Clinical and demographic data were obtained. At least half of the substance users were using alcohol or cocaine. The substance use group had a significantly higher severity of illness score on the BPRS at study onset. We found no significant differences between the two groups on other rating scales. The non-use group lived more independently, and the substance use group was younger. The substance use group had nearly twice as many hospitalizations in the 2 years prior to the study, a greater rate of missed appointments in the year before and during the study, and 4 times as many relapses during the year of the study than the non-use group. The key finding was that among 9 of the 37 patients who relapsed in the year of the study, 7 of the 9 had a history of substance use. Substance use was found to be a better predictor of relapse and hospitalization than gradual 50% dosage reduction of FD in the related study. Substance use among schizophrenia patients is a major complicating factor.

Adult↗

PubMed1995

Exposure to an antisense oligonucleotide decreases corticotropin-releasing factor receptor binding in rat pituitary cultures.

Corticotropin-releasing factor (CRF) appears to integrate the endocrine, autonomic, immunologic, and behavioral responses of mammals to stress. To investigate further the role of CRF in the CNS, we have begun investigating the usefulness of "antisense knockdown" strategies directed against the CRF receptor using rat anterior pituitary gland primary cell cultures. The 15-mer antisense (5' CTG-CGG-GCG-CCG-TCC 3') and "scrambled" control (5' CGT-CCG-CGC-GCT-GCG 3') oligonucleotides were synthesized based on the rat CRF receptor sequence just downstream of the initiation codon. In each of four separate experiments, exposure to 10 mumol/L of antisense oligonucleotide for 40-67 h resulted in significant (17-36%) decreases in 125I-ovine CRF binding to pituitary cells as compared with either control (no oligonucleotide) or 10 mumol/L of "scrambled" oligonucleotide. Moreover, compared with scrambled oligonucleotide, exposure to 10 mumol/L of antisense oligonucleotide, which produced a 22% decrease in CRF receptor binding, also resulted in a significant attenuation of the adrenocorticotrophic hormone response following a 30-min challenge with 100 pmol/L of CRF. Thus, CRF receptor antisense oligonucleotides apparently reduce functional expression of CRF receptors. This technique may be useful in studying the kinetics of CRF receptor production and the physiological functions of CRF receptors within the CNS.

Adrenocorticotropic Hormone↗

PubMed1995

Regulation of corticotropin-releasing factor secretion and synthesis in the human neuroblastoma clones- BE(2)-M17 and BE(2)-C.

The BE(2)-M17 and BE(2)-C human neuroblastoma cell lines have been shown to synthesize and secrete corticotropin-releasing factor (CRF) following retinoic acid treatment. It has been demonstrated that CRF secretion and intracellular synthesis increases in response to forskolin treatment. In this report, we have further characterized these cells in response to protein kinase C activators, dexamethasone, interleukin-1 alpha, as well as various neurotransmitters and peptides. Nanomolar concentrations of the phorbol ester--phorbol 12 myristate 13--acetate (TPA), increased intracellular CRF content in both cell lines while increasing secretion only in the BE(2)-M17 cell. Nanomolar concentrations of dexamethasone were not able to alter basal levels of secretion and content in either cell type. However, in the BE(2)-M17 cell but not the BE(2)-C cell, the same concentrations of dexamethasone added to 30 microM forskolin augmented levels of CRF secretion and content. Likewise, the same augmented response in CRF secretion and content was seen only in the BE(2)-M17 cell line when nanomolar concentrations of dexamethasone were added to 20 nM TPA. Furthermore, only in the BE(2)-M17 cell line were micromolar levels of the biogenic amine serotonin able to increase levels of CRF secretion and content. No effects on CRF in both cell lines were demonstrable with picomolar levels of interleukin-1 alpha as well as micromolar levels of acetylcholine, norepinephrine, arginine-vasopressin, oxytocin, and angiotensin-II. The potential usefulness of these cells as models of central nervous system or placental CRF-containing neurons is discussed.

Colforsin↗

PubMed1994

The BE (2)-M17 neuroblastoma cell line synthesizes and secretes corticotropin-releasing factor.

The BE (2)-M17 human neuroblastoma has previously been shown to express corticotropin-releasing factor (CRF) mRNA following retinoic acid treatment. It is demonstrated in this report that both cell extracts and cell incubation medium of retinoic acid-treated BE (2)-M17 cells were shown to contain CRF-like immunoreactivity (CRF-LI) by RIA. CRF-LI secretion and content were also dose-dependently increased by forskolin. In addition, cell extracts were applied to a C18 Vydac column and peak CRF-LI from the collected fractions was shown to coincide in time of elution with peak immunoreactivity seen with oxidized synthetic CRF standard. Thus, in containing the CRF peptide, the BE (2)-M17 cells are useful models for further study of CRF cellular and genetic regulation.

Brain Neoplasms↗

PubMed1994

Interleukin-1 alpha induces corticotropin-releasing factor secretion and synthesis from NPLC-KC cells through various second messenger pathways.

Interleukin-1 (IL1) is a key messenger implicated in endocrine and immune systems that interact to mediate the stress response. Corticotropin-releasing factor (CRF) secretion and synthesis in the NPLC-KC human hepatoma cell line has been shown to respond to IL1 stimulation. We have studied how various inhibitors of second messenger pathways alter this IL1 effect. NPLC-KC cells were grown in six-well Costar plates and treated for 12 or 24 h with or without 500 pM IL1 (alpha form) in the presence of various inhibitors of second messenger pathways. Inhibitors included the protein kinase C (PKC) inhibitor, H-7; the protein kinase A inhibitor, IP20; or the cyclooxygenase inhibitor indomethacin (IND). Both cell extracts and secretion media were assayed for CRF-like immunoreactivity by radioimmunoassay. IP20, H-7, and IND all reduced basal CRF secretion at 24 h but not at 12 h. No effects were seen on basal CRF synthesis with these inhibitors. The three inhibitors also reduced IL1 effects on CRF secretion at 12 and 24 h. The reduction seen with all three inhibitors was statistically significant (P < 0.05) at 12 h. Although a reduction was seen with all three inhibitors at 24 h, a statistically significant reduction (P < 0.05) was demonstrable only for H-7. IL1 stimulated CRF synthesis in the NPLC-KC cells appears to only involve PKC pathways. Only the PKC inhibitor H-7 reduced the augmentation that IL1 produces on CRF synthesis. This effect was statistically significant at 12 and 24 h (P < 0.05).

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1994

Corticotropin-releasing factor is secreted in the BE(2)-C neuroblastoma cell and is responsive to forskolin.

The BE(2)-C human neuroblastoma has been shown to express corticotropin-releasing factor (CRF) messenger RNA. In this study, BE(2)-C cells were treated 5 days with 5 microM retinoic acid. Cell extracts were also applied onto a C18 Vydac column and fractions were assayed for CRF-like immunoreactivity (CRF-LI) which coincided in time of elution with oxidized or non-oxidized CRF synthetic CRF standard. With forskolin treatment, secretion media and cell extract CRF-LI increased in a concentration-dependent fashion. Thus, this cell line synthesizes and secretes CRF and is a good model for studying CRF regulation.

Colforsin↗

PubMed1992

Expression of GABAA receptor polypeptides in clonal rat cell lines.

The neuronal-like cell lines, B35, B65, B103, and B104, previously reported to possess high affinity GABA binding, were analyzed for various cellular properties. They possessed peripheral but lacked central benzodiazepine binding. Only B65 cells possessed [3H-]muscimol binding; none bound [35S]TBPS. None of the cells exhibited GABA-stimulated chloride conductance with patch clamp recordings. By Western blots the cells possessed alpha subunits. Northern blot and polymerase chain reaction analysis showed that out of alpha 1, alpha 4, beta 1 and gamma 2 subunits, only alpha 1 subunit mRNA was present. Thus, GABAA-receptor binding without associated central benzodiazepine receptor sites and without functional chloride channels appears to result from expression of an incomplete subunit composition.

Animals↗

PubMed1986

Mechanism of phospholipase A2-induced conduction block in bullfrog sciatic nerve. I. Electrophysiology and morphology.

The effects of exogenously added phospholipase A2 (PLA2) and its hydrolytic products in isolated bullfrog sciatic nerve were investigated. Nerves were pretreated for 3 h with a dose of trypsin which did not affect conduction in order to enhance penetration of the added agents. Treatment of nerves with beta-glucosidase, neuraminidase or chymotrypsin had no effect on conduction. Whereas incubation of the nerves with normal Ringers for 2 h had no significant effect on conduction, incubation with PLA2 in Ringers caused decrements in the height of the compound action potential in a dose-related manner. In addition, incubation of the nerves with 10 mg/ml lysolecithin, arachidonic acid, or docosahexaenoic acid caused marked decrements in the height of the compound action potential. Electron microscopic analysis of nerves after each treatment which caused conduction block revealed varying levels of myelin damage. Although myelin was damaged at the paranodal and/or internodal region, depending on the agents used, the axonal membrane appeared to be intact at the ultrastructural level. It was concluded that the block in conduction resulting from PLA2 was due to the formation of lysolecithin and long chain polyunsaturated fatty acids.

Animals↗

PubMed1986

Mechanism of phospholipase A2-induced conduction block in bullfrog sciatic nerve. II. Biochemistry.

The biochemical changes associated with conduction block following exogenous application of purified phospholipase A2 to bullfrog sciatic nerves were investigated. Nerves were treated with concentrations of phospholipase A2 needed to produce at least a 50% decrease in the compound action potential after a 2-2 1/2 h incubation. This phospholipase A2-induced conduction block was associated with lipid hydrolysis, depletion of high energy phosphates and decreases in [3H]saxitoxin binding. Forty-two percent of the nerve phosphatidylcholine and 45% of the nerve phosphatidylethanolamine were hydrolyzed. [3H]Saxitoxin binding was decreased by 85% in association with conduction block attained with phospholipase A2 incubation. There were significant decrements in adenosine triphosphate levels (-58%) and in phosphocreatine levels (-78%), but no difference in the specific activities of these phosphate compounds. It is concluded that a number of mechanisms can account for the conduction failure resulting from phospholipase A2, including disruption of sodium channels needed for propagation of regenerative nerve impulses and the depletion of high energy phosphates needed to maintain ionic gradients.

Adenine Nucleotides↗

PubMed1981

Experimental allergic encephalomyelitis: suppression with SD-170, a new synthetic drug.

SD-170 is a new drug synthesized by Umezawa and associates. The clinical, pathological, and immunologic effects of this drug on acute EAE were investigated. In guinea pigs immunized with 5 micrograms MBP in CFA, SD-170 diminished the clinical severity as well as delaying the onset of death in acute EAE. All clinical observations were supported by histologic findings. On the contrary in animals immunized with spinal cord homogenate SD-170 did not suppress acute EAE. In SD-170 treated animals there seemed to be a lowered cellular response to MBP by the lymphocyte proliferative response test; there also seemed to be a lowered humoral antibody response to MBP. We conclude that SD-170 is an immunosuppressive of acute EAE.

Animals↗

PubMedDate not supplied

The use of novel antipsychotics in the older patient with neurodegenerative disorders in the long-term care setting.

Treating older patients with neurodegenerative disorders involves numerous challenges. The older patient population is expected to increase appreciably in the coming years; thus, there will be increasing numbers of these individuals requiring treatment. As a result, the appropriate choice of psychopharmacologic agents becomes an important decision in treating older patients with atypical antipsychotics. The atypical antipsychotic medications are replacing the high-potency conventional antipsychotics in the long-term care setting because of the lower risks of side effects. For instance, atypical antipsychotics have lower rates of extrapyramidal side effects and tardive dyskinesia. Double-blind placebo-controlled trials examining the use of risperidone and olanzapine have been published and indicate that both agents safely and effectively reduce agitation symptoms in long-term care patients with neurodegenerative disorders. For instance, based on these studies, the doses that appear efficacious in treating behavioral agitation in dementia are 0.5 to 1.5 mg per day of risperidone and 5 to 10 mg per day of olanzapine. In addition, there are open-label studies examining the use of quetiapine, which suggest that this agent is also safe and efficacious in patients with dementia. Doses used range approximately from 25 to 350 mg per day. Very few studies are available examining the newest atypical antipsychotics, ziprasidone and aripiprazole, in patients with neurodegenerative disorders. These studies do suggest that ziprasidone and aripiprazole are worth further study in the long-term care setting.

Aged↗