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1.
Int J Gynaecol Obstet ; 94(3): 333-42, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16857201

ABSTRACT

Cervical cancer kills over a quarter of a million women worldwide on an annual basis, with 80% of these deaths occurring in developing countries. Cytology-based screening programs, widely used in industrialized countries, are difficult to implement in low-resource settings. Non-cytological methods for screening and treatment have been developed and studied over the last decade. Given the barriers to widespread, good quality screening and early treatment, the most promising new prevention strategy will be the introduction of a vaccine to prevent human papillomavirus infection, the cause of cervical cancer. Understanding women's health-seeking behaviors is critical to successful dissemination and uptake of both screening and vaccine prevention strategies.


Subject(s)
Mass Screening/methods , Uterine Cervical Neoplasms/diagnosis , Developing Countries , Female , Health Services Accessibility , Humans , Papillomavirus Vaccines/administration & dosage , Uterine Cervical Neoplasms/mortality , Uterine Cervical Neoplasms/prevention & control , Women's Health , Women's Rights
2.
Int J Gynaecol Obstet ; 89 Suppl 2: S55-9, 2005 May.
Article in English | MEDLINE | ID: mdl-15823268

ABSTRACT

The Alliance for Cervical Cancer Prevention (ACCP) came together in 1999 to answer key research questions and to advocate for greater global and national interest in reducing the heavy burden of morbidity and mortality caused by this preventable disease. Visual inspection with acetic acid (VIA), visual inspection with Lugol's iodine (VILI), and human papillomavirus (HPV) tests have been shown to be viable alternatives to traditional cytology. ACCP experience confirmed that cryotherapy is a safe and effective method that is acceptable to women and can be delivered by a range of health providers, including nonphysicians. Programs can maximize coverage by accommodating local needs and involving community leaders and women in planning and implementation. Advocacy efforts have led to significant policy changes and galvanized support for cervical cancer prevention. Despite the prospect of new HPV vaccines, screening will be needed for at least the next 30-40 years. Our experience has shown that with creativity, flexibility, and well-focused use of resources, the inequitable burden of cervical cancer borne by women in poor countries can be sharply reduced.


Subject(s)
Health Resources/trends , Health Services Accessibility , Uterine Cervical Dysplasia/prevention & control , Uterine Cervical Neoplasms/prevention & control , Women's Health Services/trends , Community-Institutional Relations , Consumer Advocacy , Developing Countries , Female , Health Services Accessibility/trends , Humans , Poverty , Uterine Cervical Neoplasms/diagnosis , Uterine Cervical Neoplasms/therapy , Uterine Cervical Dysplasia/diagnosis , Uterine Cervical Dysplasia/therapy
3.
Neuroscience ; 68(3): 721-8, 1995 Oct.
Article in English | MEDLINE | ID: mdl-8577368

ABSTRACT

Adenosine antagonists potentiate dopamine-mediated behaviours. A2a adenosine and D2 dopamine receptors are abundantly co-expressed within the striatopallidal subset of striatal neurons, suggesting that this is the site of interaction between A2a and D2 receptors. We show that the D2-dependent induction of the immediate early gene c-Fos occurs in striatopallidal neurons 3 h following injection of reserpine (10 mg/kg). We used this paradigm to test whether adenosine antagonists modulate D2-dependent activation of striatopallidal neurons. The non-selective A1-A2 adenosine antagonists theophylline (25 mg/kg) or 3,7-dimethyl-1-propargylxanthine (25 mg/kg) potentiated the effect of a submaximal dose of the D2 dopamine agonist quinpirole (0.05 mg/kg) to prevent the induction of striatal c-Fos following reserpine. Co-administration of the A2a receptor antagonist 8-(3-chlorostyryl) caffeine (5 mg/kg) with quinpirole (0.05 mg/kg) also attenuated striatal c-Fos induction following reserpine to a greater extent than 0.05 mg/kg quinpirole alone. When administered prior to reserpine, theophylline (25 mg/kg) or 3,7-dimethyl-1-propargylxanthine (25 mg/kg) partially attenuate the induction of striatal c-fos. These results demonstrate that systemic administration of adenosine antagonists enhance D2 dopamine receptor-dependent regulation of c-Fos in the striatopallidal pathway. These results support a functional interaction between A2a adenosine and D2 dopamine receptors in striatopallidal neurons.


Subject(s)
Adenosine/antagonists & inhibitors , Dopamine Agonists/pharmacology , Genes, fos/drug effects , Globus Pallidus/metabolism , Neostriatum/metabolism , Receptors, Dopamine D2/agonists , Adrenergic Uptake Inhibitors/pharmacology , Animals , Caffeine/analogs & derivatives , Caffeine/pharmacology , Ergolines/pharmacology , Globus Pallidus/drug effects , Immunohistochemistry , Male , Neostriatum/drug effects , Neural Pathways/drug effects , Neural Pathways/metabolism , Phosphodiesterase Inhibitors/pharmacology , Quinpirole , Rats , Rats, Sprague-Dawley , Reserpine/pharmacology , Theobromine/analogs & derivatives , Theobromine/pharmacology , Theophylline/pharmacology
4.
Neuroscience ; 94(2): 505-14, 1999.
Article in English | MEDLINE | ID: mdl-10579212

ABSTRACT

Repeated dopamine agonist administration to rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway potentiates behavioral and neuronal activation in response to subsequent dopamine agonist treatment. This response sensitization has been termed "priming" or "reverse-tolerance". Our prior work has shown that three pretreatment injections of the mixed D1/D2 agonist apomorphine (0.5 mg/kg) into 6-hydroxydopamine-lesioned rats permits a previously inactive dose of the D2 agonist quinpirole (0.25 mg/kg) to induce robust contralateral rotation and striatal Fos expression in striatoentopeduncular "direct" pathway neurons. These striatal neurons typically express D1 but not D2 receptors. Because apomorphine acts as an agonist at both D1 and D2 receptors, the present study sought to determine whether D1, D2, or concomitant D1/D2 receptor stimulation was required to prime D2-mediated contralateral rotation and striatal Fos expression. Twenty-one days following unilateral stereotaxic injection of 6-hydroxydopamine into the medial forebrain bundle, rats received three pretreatment injections, at three- to six-day intervals, with either: the mixed D1/D2 agonist apomorphine, the D1 agonist SKF38393, the D2 agonist quinpirole, or a combination of SKF38393 + quinpirole. Ten days following the third pretreatment injection, 6-hydroxydopamine-lesioned rats were challenged with the D2 agonist quinpirole (0.25 mg/kg). Pretreatment with SKF38393 (10 mg/kg), quinpirole (1 mg/kg) or SKF38393 (1 mg/kg) + quinpirole (0.25 mg/kg) permitted an otherwise inactive dose of quinpirole (0.25 mg/kg) to induce robust contralateral rotation which was similar in magnitude to that observed following apomorphine priming. However, only pretreatment with SKF38393 (10 mg/kg) or SKF38393 (1 mg/kg) + quinpirole (0.25 mg/kg) permitted the same dose of quinpirole (0.25 mg/kg) to induce striatal Fos expression. These results demonstrate that while prior stimulation of D1, D2 or D1/D2 receptors can effectively prime D2-mediated contralateral rotation, prior stimulation of D1 receptors is required to prime D2-mediated striatal Fos expression. This study demonstrates that priming of 6-hydroxydopamine-lesioned rats with a D1 agonist permits a subsequent challenge with a D2 agonist to produce robust rotational behavior that is accompanied by induction of immediate-early gene expression in neurons that comprise the "direct" striatal output pathway. These responses are equivalent to the changes observed in apomorphine-primed 6-hydroxydopamine-lesioned rats challenged with D2 agonist. In contrast, D2 agonist priming was not associated with D2-mediated induction of striatal immediate-early gene expression even though priming of D2-mediated rotational behavior was not different from that observed following priming with apomorphine or D1 agonist. Therefore, while priming-induced alterations in D2-mediated immediate early gene expression in the "direct" striatal output pathway may contribute to the enhanced motor behavior observed, such changes in striatal gene expression do not appear to be required for this potentiated motor response in dopamine-depleted rats.


Subject(s)
Apomorphine/pharmacology , Corpus Striatum/metabolism , Dopamine Agonists/pharmacology , Genes, fos , Proto-Oncogene Proteins c-fos/genetics , Quinpirole/pharmacology , Receptors, Dopamine D1/physiology , Receptors, Dopamine D2/physiology , 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Animals , Corpus Striatum/drug effects , Corpus Striatum/pathology , Dopamine/metabolism , Gene Expression Regulation , Male , Motor Activity/drug effects , Oxidopamine/toxicity , Proto-Oncogene Proteins c-fos/analysis , Rats , Rats, Sprague-Dawley , Receptors, Dopamine D1/drug effects , Rotation
5.
Neuroscience ; 79(1): 79-93, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9178866

ABSTRACT

Chronic treatment with dopaminergic agonists is associated with response fluctuations to L-dihydroxyphenylalanine in Parkinson's disease and enhanced motor activity to D1 and D2 dopamine agonists in rats with 6-hydroxydopamine lesions of the nigrostriatal pathway. In dopamine-depleted rodents this phenomenon has been referred to as "priming" or reverse tolerance. The neurochemical changes that underlie "priming" of dopaminergic agonist responses are poorly understood. Some aspects of priming of D1 agonist-mediated rotation in the 6-hydroxydopamine-lesioned rat have been characterized, but priming of D2-agonist-dependent motor responses has been less thoroughly studied. In this study, examination of rotational behaviour and induction of Fos-like immunoreactivity were used to investigate changes in the striatal outflow systems in response to treatment with the D2 agonist quinpirole in 6-hydroxydopamine-lesioned rats that had been primed with apomorphine. Administration of apomorphine (0.5 mg/kg; three injections at three to six day intervals) permitted an otherwise inactive dose of quinpirole (0.25 mg/kg) to produce robust contralateral rotation and to induce the expression of Fos in striatal neurons belonging to the striato-nigro-entopeduncular ("direct") pathway. The increase in contralateral rotation and ipsilateral striatal Fos expression following administration of quinpirole to apomorphine-primed rats was mediated by a D2-like receptor and did not appear to be due to a change in sensitivity of D2 receptors. Apomorphine priming also enhanced the ability of quinpirole to induce Fos expression in the globus pallidus, a target of the striatopallidal ("indirect") pathway. Western blot analysis confirmed that treatment with quinpirole induced the expression of c-Fos protein with no change in the expression of 35-37,000 mol. wt Fos-related antigens in apomorphine-primed rats treated with water or quinpirole. Induction of Fos expression in the striatum generally results from blockade of D2 receptors and the striato-nigro-entopeduncular pathway preferentially expresses D1 receptors. Thus, the quinpirole-dependent induction of striatal Fos in apomorphine-primed 6-hydroxydopamine-lesioned rats represents a qualitative alteration in striatal outflow. These studies demonstrate that pretreatment of 6-hydroxydopamine-lesioned rats with apomorphine increases the activity of the "direct" and "indirect" striatal outflow pathways in response to D2 receptor stimulation. These changes have the net result of enhancing thalamocortical activity and likely underlie the enhanced contralateral rotation produced by quinpirole in apomorphine-primed rats. Changes in striatal outflow, particularly in the striato-nigro-entopeduncular pathway, may contribute to alterations in D2-dependent motor responses observed after chronic dopaminergic stimulation in the dopamine-depleted striatum.


Subject(s)
Apomorphine/pharmacology , Corpus Striatum/physiology , Dopamine Agonists/pharmacology , Motor Activity/physiology , Neurons/physiology , Quinpirole/pharmacology , Receptors, Dopamine D2/physiology , Animals , Axonal Transport , Basal Ganglia/physiology , Benzazepines/pharmacology , Corpus Striatum/drug effects , Corpus Striatum/pathology , Functional Laterality , Gold Colloid , Male , Models, Neurological , Motor Activity/drug effects , Neurons/cytology , Neurons/drug effects , Oxidopamine , Proto-Oncogene Proteins c-fos/biosynthesis , Rats , Rats, Sprague-Dawley , Receptors, Dopamine D2/agonists , Rotation , Salicylamides/pharmacology , Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate
6.
Brain Res Mol Brain Res ; 13(1-2): 35-41, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1315917

ABSTRACT

The effect of administration of the muscarinic antagonist scopolamine on the increase in striatal preproenkephalin (PPE) mRNA following a 6-hydroxydopamine (6-OHDA) lesion or chronic D2 dopamine (DA) antagonist treatment was examined by dot-blot hybridization. Administration of scopolamine dose-dependently attenuated the 6-OHDA lesion-induced increase in striatal PPE mRNA. Administration of the D2 DA antagonist eticlopride to naive rats increased striatal PPE mRNA in a dose- and time-dependent fashion. Chronic coadministration of scopolamine attenuated the eticlopride-induced increase in striatal PPE mRNA. Chronic administration of scopolamine alone did not alter striatal PPE mRNA levels. In contrast, chronic administration of eticlopride, scopolamine or the two combined decreased striatal preprotachykinin (PPT) mRNA to the same extent, suggesting that there was no direct interaction between D2 dopaminergic and cholinergic mechanisms in the regulation of striatal PPT mRNA. These data indicate that DA differentially regulates striatal PPE and PPT mRNA and suggest that dopaminergic regulation of striatal PPE mRNA is mediated in part through D2 DA effects on striatal cholinergic neurons.


Subject(s)
Corpus Striatum/physiology , Enkephalins/genetics , Interneurons/physiology , Oxidopamine/pharmacology , Protein Precursors/genetics , RNA, Messenger/metabolism , Receptors, Dopamine/physiology , Salicylamides/pharmacology , Scopolamine/pharmacology , Acetylcholine/pharmacology , Animals , Blotting, Northern , Dose-Response Relationship, Drug , Interneurons/drug effects , Kinetics , Male , Models, Neurological , Nucleic Acid Hybridization , Oligonucleotide Probes , Phosphorus Radioisotopes , RNA, Messenger/genetics , Rats , Rats, Inbred Strains , Receptors, Dopamine/drug effects , Receptors, Dopamine D2
7.
Brain Res Mol Brain Res ; 12(1-3): 111-9, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1312196

ABSTRACT

The effect of administration of subtype selective dopamine (DA) agonists on the 6-hydroxydopamine (6-OHDA) lesion-induced increase of striatal preproenkephalin (PPE) mRNA was examined by dot-blot hybridization. Eight days following a unilateral 6-OHDA lesion of the substantia nigra pars compacta (SNc), PPE mRNA levels in the ipsilateral striatum were increased approximately two-fold. Administration of the D2 DA agonist, quinpirole, dose-dependently attenuated the 6-OHDA lesion-induced increase in striatal PPE mRNA. The effect of quinpirole was blocked by coadministration of the D2 DA antagonist eticlopride. In contrast, administration of the D1 DA agonist, SKF 38393, either dose-dependently augmented or had no effect on the 6-OHDA lesion-induced increase in striatal PPE mRNA. In the contralateral striatum, administration of quinpirole decreased PPE mRNA, while administration of SKF 38393 increased PPE mRNA compared to sham lesioned control levels. These data suggest the action of DA at D1 and D2 DA receptors differentially regulates striatal PPE mRNA levels and the apparent inhibition of ENK biosynthesis by DA is mediated via an interaction with D2 DA receptors.


Subject(s)
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Corpus Striatum/physiology , Desipramine/pharmacology , Dopamine/metabolism , Enkephalins/genetics , Ergolines/pharmacology , Gene Expression Regulation , Oxidopamine/pharmacology , Protein Precursors/genetics , RNA, Messenger/metabolism , Receptors, Dopamine/physiology , Salicylamides/pharmacology , Animals , Blotting, Northern , Corpus Striatum/drug effects , Enkephalins/metabolism , Gene Expression Regulation/drug effects , Kinetics , Male , Nucleic Acid Hybridization , Oligonucleotide Probes , Oxidopamine/administration & dosage , Protein Precursors/metabolism , Quinpirole , RNA, Messenger/genetics , Rats , Rats, Inbred Strains , Receptors, Dopamine/drug effects , Receptors, Dopamine D1 , Receptors, Dopamine D2 , Reference Values , Stereotaxic Techniques
8.
Brain Res Mol Brain Res ; 14(3): 186-95, 1992 Jul.
Article in English | MEDLINE | ID: mdl-1279342

ABSTRACT

A cDNA fragment homologous to other G protein-coupled receptors was isolated from rat brain using the PCR method and demonstrated to be abundantly expressed in striatum. Using this fragment as a probe, a 2.1 kb full-length cDNA was isolated from a rat striatal cDNA library. This cDNA encodes a protein of 410 amino acids and is highly homologous to previously isolated adenosine receptor cDNAs. Expression of this cDNA in COS cells revealed high affinity (Kd = 38.6 nM) and saturable binding of the A2 adenosine receptor-selective ligand [3H]CGS 21680. Agonist displacement profile of [3H]CGS 21680 binding was consistent with an adenosine receptor of the A2 subtype (NECA greater than (R)-PIA greater than CPA greater than (S)-PIA). In situ hybridization demonstrated that rat A2 adenosine receptor mRNA was co-expressed in the same striatal neurons as D2 dopamine receptor mRNA, and never co-expressed with striatal D1 dopamine receptor mRNA. Several lines of evidence have previously suggested that dopamine-induced changes in motor behavior can be modulated by adenosine analogs acting at the A2 subtype of adenosine receptor in the forebrain. The co-expression of D2 dopamine and A2 adenosine receptors in a subset of striatal cells provides an anatomical basis for dopaminergic-adenosinergic interactions on motor behavior.


Subject(s)
Corpus Striatum/physiology , Hypothalamus, Middle/physiology , Receptors, Dopamine D2/genetics , Receptors, Purinergic/genetics , Adenosine/analogs & derivatives , Adenosine/metabolism , Amino Acid Sequence , Animals , Antihypertensive Agents/metabolism , Base Sequence , Blotting, Northern , Caudate Nucleus/physiology , Cell Line , Cloning, Molecular , Dogs , Gene Library , Kinetics , Molecular Sequence Data , Oligodeoxyribonucleotides , Phenethylamines/metabolism , Poly A/genetics , Poly A/isolation & purification , Polymerase Chain Reaction , Putamen/physiology , RNA/genetics , RNA/isolation & purification , RNA, Messenger/analysis , RNA, Messenger/metabolism , Rats , Receptors, Purinergic/metabolism , Sequence Homology , Transfection
9.
Obstet Gynecol ; 89(2): 168-73, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9015015

ABSTRACT

OBJECTIVE: To evaluate the "U" technique versus the manufacturer-recommended technique for Norplant removal. METHODS: We conducted a randomized comparison of the manufacturer-recommended method of removal and the "U" technique. The latter involves an incision between and parallel to the third and fourth implants and uses a modified vasectomy clamp to remove the implants by pulling perpendicular to the implant's axis. RESULTS: Twenty-one physicians (three experienced, 18 inexperienced) performed 200 Norplant removals. Inexperienced physicians took significantly less time for removal using the "U" technique than the standard technique (7.9 versus 10.5 minutes), even after controlling for other factors. Experienced physicians also required less time for removal using the "U" technique (3.1 versus 3.7 minutes), but the difference was not statistically significant after controlling for other factors. Both experienced and inexperienced physicians broke implants more frequently using the standard technique, although the difference was significant only for experienced physicians (relative risk 3.6, 95% confidence interval 1.2, 10.8). No differences were noted between the techniques with respect to tissue damage or patient reports of pain during or after removal. CONCLUSIONS: These results suggest that the "U" technique is an improvement over the standard technique, particularly for personnel who are not highly experienced in Norplant removal.


Subject(s)
Contraceptive Agents, Female/administration & dosage , Levonorgestrel/administration & dosage , Adult , Contraception/methods , Drug Implants/administration & dosage , Female , Humans
10.
Urology ; 52(4): 685-91, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9763094

ABSTRACT

OBJECTIVES: Currently, no surveillance system collects data on the numbers and characteristics of vasectomies performed annually in the United States. This study provides nationwide data on the numbers of vasectomies and the use of no-scalpel vasectomy, various occlusion methods, fascial interposition, and protocols for analyzing semen after vasectomy. METHODS: A retrospective mail survey (with telephone follow-up) was conducted of 1800 urology, family practice, and general surgery practices drawn from the American Medical Association's Physician Master File and stratified by specialty and census region. Mail survey and telephone follow-up yielded an 88% response rate. RESULTS: In 1995, approximately 494,000 vasectomies are estimated to have been performed by 15,800 physicians in the United States. Urologists performed 76% of all vasectomies, and nearly all (93%) urology practices performed vasectomies in 1995. Nearly one third (29%) of vasectomies in 1995 were no-scalpel vasectomies, and 37% of physicians performing no-scalpel vasectomies taught themselves the procedure. The most common occlusion method in 1995 (used for 38% of all vasectomies) was concurrent use of ligation and cautery. In 1995, slightly less than half (48%) of all physicians surveyed interposed the fascial sheath over one end of the vas when performing a vasectomy. Protocols for ensuring azoospermia varied: 56% of physicians required one postvasectomy semen specimen; 39% required two, and 5%, three or more. CONCLUSIONS: No-scalpel vasectomy, used by nearly one third of U.S. physicians, has become an accepted part of urologic care. Physicians' variations in occlusion methods, use of fascial interposition, and postvasectomy protocols underscore the need for large scale, controlled, and statistically valid studies to determine the efficacy of occlusion methods and fascial interposition, as well as whether azoospermia is the only determination of a successful vasectomy.


Subject(s)
Vasectomy/methods , Vasectomy/statistics & numerical data , Adult , Data Collection , Humans , Middle Aged , Retrospective Studies , Semen , United States
11.
Brain Res ; 827(1-2): 160-8, 1999 May 08.
Article in English | MEDLINE | ID: mdl-10320705

ABSTRACT

Administration of dopamine agonists to 6-hydroxydopamine (6-OHDA) lesioned rats enhances the rotational response to subsequent administration of dopamine agonist, an effect called 'priming'. Previously, we have shown that 6-OHDA rats primed with three injections of the D1/D2 dopamine agonist apomorphine (0.5 mg/kg) permitted a challenge with an otherwise inactive dose of the D2 agonist quinpirole (0.25 mg/kg) to elicit robust rotational behavior and to induce Fos expression in striatoentopeduncular neurons. In this study, the time-course and role of N-methyl-d-aspartate (NMDA) glutamate receptors on apomorphine-priming of these D2 responses were investigated. The enhanced rotational behavior and striatal Fos expression observed following challenge with quinpirole (0.25 mg/kg) peaked 1 day following the third apomorphine priming injection and persisted, in reduced form, for at least 4 months. Pretreatment with the NMDA antagonists MK-801 or 3-[(+)-2-carboxypiperazin-4-yl]-propyl-1-phosphonate (CPP) dose-dependently attenuated apomorphine-priming of quinpirole-mediated rotational behavior and striatal Fos induction compared to 6-OHDA rats primed with apomorphine alone. Taken together, these data suggest that priming of these D2-mediated responses in 6-OHDA rats develops rapidly, persists for several months, and is dependent on concomitant NMDA receptor stimulation. Since this priming effect resembles response fluctuations observed in patients with Parkinson's disease receiving long-term l-dihydroxyphenylalanine therapy, the results of the present study suggest that interventions that prevent the development of this enhanced response, such as NMDA antagonists, could prove useful in reducing the incidence these response fluctuations.


Subject(s)
Behavior, Animal/physiology , Corpus Striatum/chemistry , Proto-Oncogene Proteins c-fos/biosynthesis , Receptors, Dopamine D2/physiology , Receptors, N-Methyl-D-Aspartate/physiology , Animals , Apomorphine/pharmacology , Behavior, Animal/drug effects , Brain Chemistry/drug effects , Brain Chemistry/physiology , Corpus Striatum/metabolism , Dizocilpine Maleate/pharmacology , Dopamine Agonists/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Male , Nerve Degeneration/chemically induced , Oxidopamine , Piperazines/pharmacology , Quinpirole/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, Dopamine D2/agonists , Rotation , Sympatholytics , Time Factors
12.
Brain Res ; 897(1-2): 213-6, 2001 Apr 06.
Article in English | MEDLINE | ID: mdl-11282380

ABSTRACT

Three priming injections with the D1/D2 dopamine agonist apomorphine permits a challenge with the D2 agonist quinpirole to elicit robust contralateral rotation and ipsilateral striatal Fos expression in 6-hydroxydopamine lesioned rats. Pretreatment with NMDA glutamate antagonists MK-801 or CPP dose-dependently attenuates these quinpirole-mediated responses. These findings suggest that concomitant NMDA receptor stimulation is required for the expression of D2-mediated responses in apomorphine primed dopamine-depleted rats.


Subject(s)
Apomorphine/pharmacology , Dopamine Agonists/pharmacology , Receptors, Dopamine D2/metabolism , Receptors, N-Methyl-D-Aspartate/metabolism , Animals , Behavior, Animal/drug effects , Brain Chemistry/drug effects , Denervation , Dizocilpine Maleate/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Male , Oxidopamine , Parkinson Disease/drug therapy , Parkinson Disease/metabolism , Piperazines/pharmacology , Proto-Oncogene Proteins c-fos/metabolism , Rats , Rats, Sprague-Dawley , Receptors, Dopamine D2/biosynthesis , Sympatholytics
13.
Brain Res ; 743(1-2): 124-30, 1996 Dec 16.
Article in English | MEDLINE | ID: mdl-9017239

ABSTRACT

The interaction between adenosine and D1 dopamine systems in regulating motor behavior and striatal c-Fos expression was examined in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions. These results were compared to the synergistic interaction between D1 and D2 dopamine systems in 6-OHDA rats. Coadministration of the adenosine antagonist 3,7-dimethyl-1-propargylxanthine (DMPX: 10 mg/kg) and the D1 dopamine agonist SKF38393 (0.5 mg/kg) to 6-OHDA-lesioned rats produced significant contralateral rotation and c-Fos expression in the ipsilateral striatum compared to 6-OHDA rats treated with either drug alone. However, the regional pattern of striatal c-Fos activation following treatment of 6-OHDA rats with SKF38393 and DMPX was different from the dorsolateral pattern of striatal c-Fos induction observed after coadministration of D1 and D2 dopamine agonists (SKF38393: 0.5 mg/kg + quinpirole: 0.05 mg/kg). These data are consistent with a functional interaction between D1 dopamine and adenosine systems in the striatum, but suggest that activation of different subsets of striatal neurons underlie the behavioral synergy observed following combined adenosine antagonist-D1 dopamine agonist and combined D1 dopamine agonist-D2 dopamine agonist treatment.


Subject(s)
Corpus Striatum/drug effects , Dopamine Agonists/pharmacology , Motor Activity/drug effects , Proto-Oncogene Proteins c-fos/biosynthesis , Purinergic P1 Receptor Antagonists , Receptors, Dopamine D1/agonists , 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Animals , Corpus Striatum/metabolism , Drug Synergism , Functional Laterality/physiology , Male , Neurotoxins , Oxidopamine , Rats , Rats, Sprague-Dawley , Rotation , Theobromine/analogs & derivatives , Theobromine/pharmacology
14.
Brain Res ; 707(1): 75-80, 1996 Jan 22.
Article in English | MEDLINE | ID: mdl-8866715

ABSTRACT

Low to moderate doses of amphetamine produce locomotion which is dependent on release of dopamine in the anteromedial striatum and nucleus accumbens. The effects of selective adenosine A1 and A2a receptor agonists on locomotion and c-Fos induction following a moderate dose of amphetamine was assessed in rats. Pretreatment with the adenosine A1 receptor agonist N6-cyclohexyladenosine (CHA) or the adenosine A2a receptor agonist 2-[(2-aminoethylamino)carbonylethylphenylethylamino]-5'-N- ethylcarboxamidoadenosine (APEC) inhibited locomotion following an injection of amphetamine (1.5 mg/kg). This dose of amphetamine induced Fos-like immunoreactivity in an antero-dorsomedial distribution in the caudate-putamen and uniformly in the core and shell of the nucleus accumbens. Pretreatment with the adenosine A2a receptor agonist APEC, but not the adenosine A1 receptor agonist CHA, attenuated c-Fos induction in caudate-putamen and nucleus accumbens by amphetamine. These findings indicate that amphetamine-induced behavior is subject to modulation by adenosine receptors through mechanisms which are both related to and independent of c-Fos induction.


Subject(s)
Amphetamine/pharmacology , Corpus Striatum/drug effects , Locomotion/drug effects , Nucleus Accumbens/drug effects , Proto-Oncogene Proteins c-fos/drug effects , Purinergic P1 Receptor Agonists , Adenosine/pharmacology , Animals , Cell Count/drug effects , Male , Rats , Rats, Sprague-Dawley
15.
Brain Res ; 749(1): 120-6, 1997 Feb 21.
Article in English | MEDLINE | ID: mdl-9070635

ABSTRACT

Expression in striatum of c-Fos, a 35 kDa Fos-related antigen (FRA) and the phosphorylated form of cyclic AMP response element binding protein (phosphoCREB) was assessed using Western blots in rats that developed behavioral sensitization following repeated amphetamine administration. Treatment with d-amphetamine (5 mg/kg) for 5 consecutive days produced behavioral sensitization. Similar to previous observations using chronic cocaine administration, amphetamine sensitized animals had decreased c-Fos and increased FRA proteins in striatum. Supershift analysis with antisera to c-Fos and FRA proteins demonstrated that 4-Fos and the 35 kDa FRA are components of the striatal AP-1 binding complex from sensitized rats. Thus, amphetamine sensitization is accompanied by alterations in the composition of the AP-1 DNA binding complex. An increased amount of phosphoCREB protein was also present in the striatum of amphetamine sensitized rats. These results suggest that alterations in Fos, FRA and CREB transcription factors are common neuronal responses to chronic psychostimulant administration and may contribute to regulation of genes important to the neuroplastic changes underlying psychostimulant sensitization.


Subject(s)
Amphetamine/pharmacology , Antigens/biosynthesis , Central Nervous System Stimulants/pharmacology , Cyclic AMP Response Element-Binding Protein/metabolism , Neostriatum/metabolism , Proto-Oncogene Proteins c-fos/biosynthesis , Transcription Factors/metabolism , Activating Transcription Factor 2 , Animals , Behavior, Animal/drug effects , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Humans , Infant , Male , Neostriatum/drug effects , Oligonucleotides/metabolism , Phosphorylation , Proto-Oncogene Proteins c-fos/immunology , Rats , Rats, Sprague-Dawley , Transcription Factor AP-1/biosynthesis
16.
Brain Res ; 631(1): 161-6, 1993 Dec 17.
Article in English | MEDLINE | ID: mdl-8298989

ABSTRACT

We have used the suicide transport agent volkensin to produce selective lesions of striatonigral neurons. By in situ hybridization histochemistry unilateral volkensin injections in the substantia nigra decreased the number of D1 receptor mRNA-expressing neurons in the ipsilateral striatum but did not change the number of D2 receptor and A2a adenosine receptor mRNA-expressing neurons. These findings confirm that striatonigral neurons express D1 receptors and suggest that D2-A2a receptor expressing neurons are predominantly localized to other neuronal populations within the striatum.


Subject(s)
Corpus Striatum/metabolism , Glycoproteins , N-Glycosyl Hydrolases , Plant Lectins , RNA, Messenger/metabolism , Receptors, Dopamine D1/genetics , Receptors, Dopamine D2/genetics , Receptors, Purinergic P1/genetics , Animals , Autoradiography , Corpus Striatum/pathology , Corpus Striatum/physiology , Efferent Pathways/metabolism , Histocytochemistry , In Situ Hybridization , Male , Neurons/drug effects , Neurons/physiology , Plant Proteins/pharmacology , Rats , Rats, Sprague-Dawley , Ribosome Inactivating Proteins, Type 2 , Substantia Nigra/metabolism , Substantia Nigra/pathology , Substantia Nigra/physiology , Tissue Distribution , Toxins, Biological/pharmacology
17.
Brain Res ; 818(2): 543-7, 1999 Feb 13.
Article in English | MEDLINE | ID: mdl-10082844

ABSTRACT

Acute administration of reserpine induces Fos expression in striatopallidal neurons, an effect blocked by pretreatment with the D2 dopamine agonist quinpirole. Pretreatment with the NMDA antagonists (+)MK-801 or CPP attenuated reserpine-mediated striatal Fos induction whereas pretreatment with ketamine or the inactive isomer (-)MK-801 did not. These results support a role of NMDA glutamate receptors in regulating the activity of the striatopallidal pathway.


Subject(s)
Corpus Striatum/metabolism , Globus Pallidus/metabolism , Proto-Oncogene Proteins c-fos/biosynthesis , Receptors, Dopamine D2/physiology , Receptors, N-Methyl-D-Aspartate/physiology , Animals , Dizocilpine Maleate/pharmacology , Dopamine Agonists/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Ketamine/pharmacology , Male , Quinpirole/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Reserpine/pharmacology
18.
Life Sci ; 41(4): 385-90, 1987 Jul 27.
Article in English | MEDLINE | ID: mdl-3037224

ABSTRACT

The binding of the opiate antagonist 3H-naloxone was examined in rat whole brain homogenates and in crude subcellular fractions of these homogenates (nuclear, synaptosomal, and mitochondrial fractions) using buffers that approximated intra- (low sodium concentration) and extracellular (high sodium concentration) fluids. Saturation studies showed a two-fold decrease in the dissociation constant (Kd) in all subcellular fractions examined in extracellular buffer compared to intracellular buffer. In contrast, there was no significant effect of the buffers on the Bmax. Thus, 3H-naloxone did not distinguish between binding sites present on cell surface and intracellular tissues in these two buffers. These results show that the "sodium effect" of opiate antagonist binding is probably not a function of altered selection of intra- and extracellular binding sites.


Subject(s)
Brain/metabolism , Naloxone/metabolism , Receptors, Opioid/metabolism , Sodium/pharmacology , Animals , Cell Membrane/metabolism , Cell Nucleus/metabolism , Kinetics , Mitochondria/metabolism , Rats , Receptors, Opioid/drug effects , Synaptosomes/metabolism
19.
Contraception ; 59(6): 363-7, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10518230

ABSTRACT

Associations between Depo-Provera (injectable, progesterone-only contraceptive) use and visible disruption of cervical epithelium and cervical ectopy were investigated using data collected as part of a cervical cancer screening study in periurban Cape Town, South Africa. Women were interviewed about their contraceptive use, and underwent a gynecologic examination that included two 35-mm photographs of the cervix after application of 5% acetic acid. Photographs of 723 subjects were reviewed (blind to clinical information and using systematic criteria developed before review) for evidence of atrophy and epithelial disruption, including inflammation and ulceration. The percentage of the cervix covered with columnar epithelium (ectopy) was also estimated from the photographs. A random sample of 85 photographs was reviewed again for reliability. A total of 121 current users of Depo-Provera were no more likely to have evidence of epithelial disruption (38%) than 574 nonusers (39%), odds ratio (OR) = 1.37, 95% CI: 0.89-2.11 adjusting for age and parity. The prevalence of significant ectopy (columnar epithelium covering > 10% of the cervix) was also no different among current Depo-Provera users (OR = 1.22, 95% CI: 0.80-1.86 adjusting for age and parity). Reliability of visual scoring of epithelial disruption and ectopy was excellent (kappa = 0.8). Although the underlying prevalence of visible disruption of cervical epithelium was very high, current use of Depo-Provera was not associated with increased prevalence of visible disruption of the cervical epithelium or with ectopy in this sample of African women.


PIP: The relationship between cervical epithelium disorders and cervical ectopy and Depo-Provera use was investigated among African women. The women, aged 35-65 years, had gynecologic examinations, which included various cervical cancer screening tests including two 35-mm colored photographs of the cervix. Cervical photographs from 723 participants were reexamined for the signs of disruption. Results showed that among 121 current Depo-Provera users, 38% showed no steady increase in epithelial disruption compared with 34% of past users and 49% of nonusers. There was no difference in the odds ratio (OR = 1.37; 95% CI: 0.89-2.11). The percentage of women with significant ectopy was higher in current and past users of Depo-Provera, but no trends remain after age adjustment and parity (OR = 1.22; 95% CI: 0.80-1.86). The credibility of the diagnosis of cervical disruption combined (either ulceration, inflammation, or athropy) was excellent (K = 0.8). However, the results were doubtful in light of the concept that simple epithelial thinning may account for putative effects of Depo-Provera. The validity of this method needs further investigations.


Subject(s)
Cervix Uteri/pathology , Contraceptive Agents, Female/adverse effects , Medroxyprogesterone Acetate/adverse effects , Uterine Cervical Diseases/chemically induced , Adult , Aged , Aging , Atrophy , Epithelium/pathology , Female , Humans , Middle Aged , Odds Ratio , Parity , South Africa , Ulcer , Uterine Cervical Diseases/pathology , Uterine Cervicitis/chemically induced
20.
Contraception ; 56(4): 215-22, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9408702

ABSTRACT

In a joint pilot study by Family Health International (FHI), AVSC International, and the Instituto Mexicano del Seguro Social (IMSS), information was gathered on the determinants of azoospermia following vasectomy on 38 healthy men who chose vasectomy for contraception. The time and number of ejaculations associated with loss of sperm motility and loss of sperm eosin vital staining were also evaluated. "Azoospermia" was defined on the basis of two consecutive azoospermic semen samples collected at least 3 days apart. The single decrement life table method was used to calculate weekly gross cumulative life table rates for the time to azoospermia, zero motility, and zero viability. The Kaplan-Meier method was used to calculate the product-limit estimates of the cumulative rates for the total number of ejaculations to azoospermia, 0% motility and 0% viability. The median time to azoospermia was 10 weeks and at the end of week 20, the life table rate (+/- standard error) was 93.0 (+/- 6.30) weeks/100 men. The median number of ejaculations to azoospermia was between 25 and 30, and the cumulative rate (+/- standard error) at 60 ejaculations reached 94.5 (+/- 5.16)/100 men.


PIP: The time and number of ejaculations to azoospermia after vasectomy were investigated in a prospective pilot study of 38 vasectomy acceptors conducted by Family Health International and the Instituto Mexicano del Seguro Social. Two consecutive azoospermic semen samples collected at least 3 days apart were required for azoospermia to be declared. 25 men (65.8%) demonstrated azoospermia during the 24-week follow-up period; however, 9 (23.7%) discontinued prior to the study's end or before achieving azoospermia. The median time to azoospermia was 10 weeks. At the end of week 20, the single decrement life table rate was 93.0 +or- 6.30 weeks per 100 men. The median number of ejaculations to azoospermia was 25-30 and the cumulative rate of azoospermia at 60 ejaculations was 94.5 +or- 5.16 per 100 men. It took approximately 5 weeks longer for men with fewer than three ejaculations per week to reach azoospermia than their counterparts with a higher number of ejaculations. The median time to sperm motility was 3 weeks, while that to 0% viability was 9 weeks. There were two pregnancies, one of which involved a man who had been declared azoospermic. An expanded study based on this pilot study is underway.


Subject(s)
Oligospermia , Vasectomy , Adult , Follow-Up Studies , Humans , Life Tables , Male , Mexico , Pilot Projects , Prospective Studies , Time Factors
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