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Healthcare (Basel, Switzerland) May 2023So far, neuroendocrine studies conducted in schizophrenic patients have yielded conflicting results. Many of these discrepancies may be explained by the diversity of... (Review)
Review
So far, neuroendocrine studies conducted in schizophrenic patients have yielded conflicting results. Many of these discrepancies may be explained by the diversity of factors that influence the hormonal levels (at baseline and in response to pharmacological stimuli), the heterogeneity of the populations studied, the absence of standardization of test challenges and the confounding and long-lasting effects of previous treatments. Numerous studies have used apomorphine (APO) in the evaluation of dopaminergic (DA) function in schizophrenic patients. APO, a direct acting DA receptor agonist, decreases prolactin (PRL) and stimulates growth hormone (GH), adrenocorticotropic hormone (ACTH) and cortisol secretion. Therefore, the magnitude of hormonal responses to APO is an indirect assessment of the functionality of DA receptors at the hypothalamic-pituitary level. This review provides an update on the applications of the APO test in schizophrenia in clinical, pathophysiological and therapeutic fields.
PubMed: 37239772
DOI: 10.3390/healthcare11101487 -
Cureus Feb 2023The management of dopamine agonist (DA)-resistant prolactinomas unresponsive to second and third-line treatment is challenging and requires alternative medical therapy.... (Review)
Review
The management of dopamine agonist (DA)-resistant prolactinomas unresponsive to second and third-line treatment is challenging and requires alternative medical therapy. The presence of estrogen receptors on pituitary tumors, and the variable behavior of pituitary tumors in the presence of estrogen, prompted investigation of the role of anti-estrogen in the treatment of DA-resistant prolactinomas. The goal of this paper is to perform a systematic review of the role of tamoxifen in the treatment of DA-resistant prolactinomas. A systematic review was conducted. Inclusion criteria were case reports, case series, and experimental studies using tamoxifen in DA-resistant prolactinomas. Exclusion criteria included review articles, DA-sensitive prolactinomas, and those that were not previously treated with DA. Data were analyzed using descriptive statistics. For continuous data, the mean was used. For dichotomous data, frequencies and percentages were used. Data on 22 patients were extracted from the seven included studies. Twenty patients (90.9%) responded positively to the use of tamoxifen with a mean reduction in prolactin levels of 57.4%. Ten patients (45.5%) showed normalization of prolactin post-tamoxifen administration. Regression of tumor size and stability of tumor growth were reported in four out of 22 cases (18.2%). Combination therapy with DA and tamoxifen increased DA sensitivity and had a clinically significant inhibitory effect on prolactin secretion. Furthermore, tamoxifen may be considered an effective adjuvant for tumor size control. Therefore, further studies are needed to draw more clinically and statistically robust conclusions.
PubMed: 36950000
DOI: 10.7759/cureus.35171 -
Cephalalgia : An International Journal... Feb 2023To systemically review clinical studies investigating the role of prolactin and its receptors in headache and migraine. (Review)
Review
OBJECTIVE
To systemically review clinical studies investigating the role of prolactin and its receptors in headache and migraine.
BACKGROUND
Migraine prevalence is more common in women compared to men. As prolactin is a crucial regulator of the hypothalamus-pituitary-gonadal axis, prolactin and its receptors might contribute to signaling mechanisms underlying migraine.
METHODS
In this systematic review, we searched PubMed and EMBASE with the terms: prolactin, hyperprolactinemia, macroprolactinemia, hypoprolactinemia, migraine, headache, head pain and trigeminal pain pathway for clinical studies investigating prolactin signaling in headache and migraine. Two reviewers independently screened 841 articles for population, intervention, comparison, outcome, and study design. Studies were restricted to the English language and were excluded if they had a nonexperimental methodology.
RESULTS
Nineteen clinical studies met the inclusion criteria and were included in the qualitative and quantitative analysis. The main findings were that serum prolactin levels were found to be higher in individuals with migraine compared to healthy controls, and prolactinomas (prolactin-secreting pituitary adenomas) were correlated with higher incidence of headache in otherwise healthy individuals and migraine attacks in individuals with migraine.
CONCLUSION
Considerable evidence suggests a key role of prolactin and its receptors in migraine pathophysiology. Further randomized and placebo-controlled clinical studies targeting prolactin signaling are needed to further clarify influences of prolactin in migraine attack initiation.
Topics: Male; Humans; Female; Prolactin; Headache; Prolactinoma; Migraine Disorders; Hyperprolactinemia; Pituitary Neoplasms
PubMed: 36718026
DOI: 10.1177/03331024221136286 -
NPJ Schizophrenia May 2021Early intervention is essential for favorable long-term outcomes in schizophrenia. However, there is limited guidance in the scientific literature on how best to choose... (Review)
Review
Early intervention is essential for favorable long-term outcomes in schizophrenia. However, there is limited guidance in the scientific literature on how best to choose between dopamine D receptor (DR) partial agonists and DR antagonists in early stages of schizophrenia. The aim of this meta-analysis was to directly compare DR partial agonists with DR antagonists for efficacy and tolerability, using randomized controlled trials (RCTs) that involved participants diagnosed with first-episode psychosis, schizophrenia, or related psychotic disorders with a duration of illness ≤5 years. Fourteen RCTs, involving 2494 patients, were included in the meta-analysis. Aripiprazole was the only identified DR partial agonist, and was not significantly different from pooled DR antagonists for overall symptom reduction or all-cause discontinuation. However, aripiprazole was more favorable than pooled DR antagonists for depressive symptoms, prolactin levels, and triglyceride levels. Specifically, aripiprazole was more favorable than paliperidone for triglyceride levels and more favorable than risperidone and olanzapine, but less favorable than ziprasidone, for weight gain. In addition, aripiprazole was less favorable for akathisia compared with second-generation DR antagonists, in particular olanzapine and quetiapine, and less favorable for discontinuation due to inefficacy than risperidone. Lastly, aripiprazole was more favorable than haloperidol for various efficacy and tolerability outcomes. In conclusion, aripiprazole's efficacy did not differ substantially from DR antagonists in the early course of schizophrenia, whereas differential tolerability profiles were noted. More double-blind RCTs are required comparing the efficacy and tolerability of aripiprazole as well as other DR partial agonists with DR antagonists in early stages of schizophrenia.
PubMed: 34035313
DOI: 10.1038/s41537-021-00158-z -
Frontiers in Cellular Neuroscience 2016Oligodendrogenesis and oligodendrocyte precursor maturation are essential processes during the course of central nervous system development, and lead to the myelination... (Review)
Review
Oligodendrogenesis and oligodendrocyte precursor maturation are essential processes during the course of central nervous system development, and lead to the myelination of axons. Cells of the oligodendrocyte lineage are generated in the germinal zone from migratory bipolar oligodendrocyte precursor cells (OPCs), and acquire cell surface markers as they mature and respond specifically to factors which regulate proliferation, migration, differentiation, and survival. Loss of myelin underlies a wide range of neurological disorders, some of an autoimmune nature-multiple sclerosis probably being the most prominent. Current therapies are based on the use of immunomodulatory agents which are likely to promote myelin repair (remyelination) indirectly by subverting the inflammatory response, aspects of which impair the differentiation of OPCs. Cells of the oligodendrocyte lineage express and are capable of responding to a diverse array of ligand-receptor pairs, including neurotransmitters and nuclear receptors such as γ-aminobutyric acid, glutamate, adenosine triphosphate, serotonin, acetylcholine, nitric oxide, opioids, prostaglandins, prolactin, and cannabinoids. The intent of this review is to provide the reader with a synopsis of our present state of knowledge concerning the pharmacological properties of the oligodendrocyte lineage, with particular attention to these receptor-ligand (i.e., neurotransmitters and nuclear receptor) interactions that can influence oligodendrocyte migration, proliferation, differentiation, and myelination, and an appraisal of their therapeutic potential. For example, many promising mediators work through Ca(2+) signaling, and the balance between Ca(2+) influx and efflux can determine the temporal and spatial properties of oligodendrocytes (OLs). Moreover, Ca(2+) signaling in OPCs can influence not only differentiation and myelination, but also process extension and migration, as well as cell death in mature mouse OLs. There is also evidence that oligodendroglia exhibit Ca(2+) transients in response to electrical activity of axons for activity-dependent myelination. Cholinergic antagonists, as well as endocannabinoid-related lipid-signaling molecules target OLs. An understanding of such pharmacological pathways may thus lay the foundation to allow its leverage for therapeutic benefit in diseases of demyelination.
PubMed: 26903812
DOI: 10.3389/fncel.2016.00027 -
International Journal of Clinical... Sep 2015To describe the efficacy, tolerability and safety of brexpiprazole for the treatment of schizophrenia and as adjunct for major depressive disorder (MDD). (Review)
Review
Brexpiprazole for schizophrenia and as adjunct for major depressive disorder: a systematic review of the efficacy and safety profile for this newly approved antipsychotic - what is the number needed to treat, number needed to harm and likelihood to be helped or harmed?
OBJECTIVE
To describe the efficacy, tolerability and safety of brexpiprazole for the treatment of schizophrenia and as adjunct for major depressive disorder (MDD).
DATA SOURCES
The pivotal registration trials were accessed by querying http://www.ncbi.nlm.nih.gov/pubmed/ and http://www.clinicaltrials.gov, for the search terms 'brexpiprazole' OR 'OPC-34712', and by also querying the EMBASE (Elsevier) commercial database for clinical poster abstracts, and by asking the manufacturer for copies of posters presented at congresses. Product labelling provided additional information.
STUDY SELECTION
All available clinical reports of studies were identified.
DATA EXTRACTION
Descriptions of the principal results and calculation of number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the available study reports and other sources of information.
DATA SYNTHESIS
Brexpiprazole is a new dopamine D2 receptor partial agonist that received approval for the treatment of schizophrenia and for adjunctive use for the treatment of MDD based on a clinical trial development programme that included two pivotal Phase III trials of brexpiprazole monotherapy in acute schizophrenia, and two pivotal Phase III trials of adjunctive brexpiprazole in acute MDD in patients who demonstrated inadequate response to standard antidepressant therapy. In addition, results from a 52-week relapse prevention/maintenance randomised placebo-controlled withdrawal study in patients with schizophrenia are available. In these trials, brexpiprazole was administered once daily and titrated to target doses. The recommended dose for the treatment of schizophrenia is 2-4 mg/day and that for MDD, 2 mg/day. Pooling together all the available data for the recommended target dose of brexpiprazole for acute schizophrenia from the above studies, the percentage of responders is 45.5% vs. 31.0% for placebo, yielding a NNT of 7 (95% CI 5-12). In the relapse prevention/maintenance trial, significantly fewer patients relapsed in the brexpiprazole group compared with placebo (13.5% vs. 38.5%), resulting in a NNT of 4 (95% CI 3-8). When the results for brexpiprazole 1, 2 and 3 mg from the two Phase III MDD trials are pooled together, 23.2% of the patients receiving brexpiprazole were responders, vs. 14.5% for placebo, yielding a NNT of 12 (95% CI 8-26). Brexpiprazole was well tolerated - for schizophrenia, discontinuation rates because of an adverse event (AE) were overall lower for patients receiving brexpiprazole vs. placebo, and for MDD a total of 3% of brexpiprazole-treated patients and 1% of placebo-treated patients discontinued because of AEs, resulting in a NNH of 53 (95% CI 30-235). Although the most commonly encountered AE noted in product labelling was akathisia (5.5% in the acute schizophrenia trials and 8.6% in the MDD trials), differences from placebo were small, generating a non-significant NNH of 112 for patients with schizophrenia and a modest NNH of 15 (95% CI 11-23) for patients with MDD. Short-term weight gain appears modest; however, more outliers with an increase of ≥ 7% of body weight were evident in open-label 52-week safety studies. Effects on glucose and lipids were small. Minimal effects on prolactin were observed, and no clinically relevant effects on the ECG QT interval were evident.
CONCLUSIONS
Clinical trials of brexpiprazole support its efficacy at the recommended target dose of 2-4 mg/day for the treatment of schizophrenia, and at the recommended target dose of 2 mg/day as adjunct to antidepressant medication for the treatment of MDD. Head-to-head comparisons with other available agents among patients with schizophrenia and MDD in the 'real world' are needed.
Topics: Antidepressive Agents; Antipsychotic Agents; Chemotherapy, Adjuvant; Clinical Trials as Topic; Depressive Disorder, Major; Dopamine Agonists; Humans; Quinolones; Schizophrenia; Thiophenes
PubMed: 26250067
DOI: 10.1111/ijcp.12714 -
Frontiers in Microbiology 2014Toxoplasma gondii is the causal agent of toxoplasmosis in which one third of the world's population has been infected. In pregnant women, it may cause abortion and... (Review)
Review
BACKGROUND
Toxoplasma gondii is the causal agent of toxoplasmosis in which one third of the world's population has been infected. In pregnant women, it may cause abortion and severe damage to the fetal central nervous system. During pregnancy, the prevalence of toxoplasmosis increases throughout the second and third quarter of gestation, simultaneously progesterone and 17β-estradiol also increase. Thus, it has been suggested that these hormones can aggravate or reduce parasite reproduction. The aim of this study was reviewing the relationship between hormones and infection caused by T. gondii in several experimental animal models and humans, focused mainly on: (a) congenital transmission, (b) parasite reproduction, (c) strain virulence, (d) levels of hormone in host induced by T. gondii infection, and (e) participation of hormone receptors in T. gondii infection. Are the hormones specific modulators of T. gondii infection? A systematic review methodology was used to consult several databases (Pub Med, Lilacs, Medline, Science direct, Scielo, Ebsco, Sprinker, Wiley, and Google Scholar) dated from September, 2013 to March, 2014.
RESULTS
Thirty studies were included; eight studies in humans and 22 in animals and cell cultures. In the human studies, the most studied hormones were testosterone, progesterone, prolactin, and 17β-estradiol. Type I (RH and BK) and Type II (Prugniaud, SC, ME49, T45, P78, and T38) were the most frequent experimental strains.
CONCLUSIONS
Thirty-five years have passed since the first studies regarding T. gondii infection and its relationship with hormones. This systematic review suggests that hormones modulate T. gondii infection in different animal models. However, given that data were not comparable, further studies are required to determine the mechanism of hormone action in the T. gondii infectious process.
PubMed: 25346725
DOI: 10.3389/fmicb.2014.00503 -
Evidence Report/technology Assessment Nov 2010The purpose of this report is to systematically examine the possible causal mechanism(s) that may explain the association between alcohol (ethanol) consumption and the... (Review)
Review
OBJECTIVES
The purpose of this report is to systematically examine the possible causal mechanism(s) that may explain the association between alcohol (ethanol) consumption and the risk of developing breast and colorectal cancers.
DATA SOURCES
We searched 11 external databases, including PubMed® and Embase, for studies on possible mechanisms. These searches used Medical Subject Headings and free text words to identify relevant evidence.
REVIEW METHODS
Two reviewers independently screened search results, selected studies to be included, and reviewed each trial for inclusion. We manually examined the bibliographies of included studies, scanned the content of new issues of selected journals, and reviewed relevant gray literature for potential additional articles.
RESULTS
Breast Cancer. Five human and 15 animal studies identified in our searches point to a connection between alcohol intake and changes in important metabolic pathways that when altered may increase the risk of developing breast cancer. Alterations in blood hormone levels, especially elevated estrogen-related hormones, have been reported in humans. Several cell line studies suggest that the estrogen receptor pathways may be altered by ethanol. Increased estrogen levels may increase the risk of breast cancer through increases in cell proliferation and alterations in estrogen receptors. Human studies have also suggested a connection with prolactin and with biomarkers of oxidative stress. Of 15 animal studies, six reported increased mammary tumorigenesis (four administered a co-carcinogen and two did not). Other animal studies reported conversion of ethanol to acetaldehyde in mammary tissue as having a significant effect on the progression of tumor development. Fifteen cell line studies suggested the following mechanisms: Increased hormonal receptor levels. Increased cell proliferation. A direct stimulatory effect. DNA adduct formation. Increase cyclic adenosine monophosphate (camp). Change in potassium channels. Modulation of gene expression. Colorectal Cancer. One human tissue study, 19 animal studies (of which 12 administered a co-carcinogen and seven did not), and 10 cell line studies indicate that ethanol and acetaldehyde may alter metabolic pathways and cell structures that increase the risk of developing colon cancer. Exposure of human colonic biopsies to acetaldehyde suggests that acetaldehyde disrupts epithelial tight junctions. Among 19 animal studies the mechanisms considered included: Mucosal damage after ethanol consumption. Increased degradation of folate. Stimulation of rectal carcinogenesis. Increased cell proliferation. Increased effect of carcinogens. Ten cell line studies suggested: Folate uptake modulation. Tumor necrosis factor modulation. Inflammation and cell death. DNA adduct formation. Cell differentiation. Modulation of gene expression. One study used a combination of animal and cell line and suggested intestinal cell proliferation and disruption of cellular signals as possible mechanisms.
CONCLUSIONS
Based on our systematic review of the literature, many potential mechanisms by which alcohol may influence the development of breast or colorectal cancers have been explored but the exact connection or connections remain unclear. The evidence points in several directions but the importance of any one mechanism is not apparent at this time.
Topics: Alcohol Drinking; Animals; Breast Neoplasms; Cell Proliferation; Colorectal Neoplasms; Estrogens; Ethanol; Female; Humans; Male; Mammary Neoplasms, Animal; Oxidative Stress; Prolactin; Receptors, Estrogen; Risk
PubMed: 23126574
DOI: No ID Found -
Endocrine Reviews Feb 2010Opioid abuse has increased in the last decade, primarily as a result of increased access to prescription opioids. Physicians are also increasingly administering opioid... (Review)
Review
Opioid abuse has increased in the last decade, primarily as a result of increased access to prescription opioids. Physicians are also increasingly administering opioid analgesics for noncancer chronic pain. Thus, knowledge of the long-term consequences of opioid use/abuse has important implications for fully evaluating the clinical usefulness of opioid medications. Many studies have examined the effect of opioids on the endocrine system; however, a systematic review of the endocrine actions of opioids in both humans and animals has, to our knowledge, not been published since 1984. Thus, we reviewed the literature on the effect of opioids on the endocrine system. We included both acute and chronic effects of opioids, with the majority of the studies done on the acute effects although chronic effects are more physiologically relevant. In humans and laboratory animals, opioids generally increase GH and prolactin and decrease LH, testosterone, estradiol, and oxytocin. In humans, opioids increase TSH, whereas in rodents, TSH is decreased. In both rodents and humans, the reports of effects of opioids on arginine vasopressin and ACTH are conflicting. Opioids act preferentially at different receptor sites leading to stimulatory or inhibitory effects on hormone release. Increasing opioid abuse primarily leads to hypogonadism but may also affect the secretion of other pituitary hormones. The potential consequences of hypogonadism include decreased libido and erectile dysfunction in men, oligomenorrhea or amenorrhea in women, and bone loss or infertility in both sexes. Opioids may increase or decrease food intake, depending on the type of opioid and the duration of action. Additionally, opioids may act through the sympathetic nervous system to cause hyperglycemia and impaired insulin secretion. In this review, recent information regarding endocrine disorders among opioid abusers is presented.
Topics: Analgesics, Opioid; Animals; Endocrine System; Endocrine System Diseases; Female; Humans; Hypogonadism; Male; Opiate Alkaloids; Opioid-Related Disorders
PubMed: 19903933
DOI: 10.1210/er.2009-0009