The global distribution of oral and maxillofacial surgeons: a mixed-methods study.

Despite its role in treating the most dominant non-communicable diseases worldwide, the global workforce of oral and maxillofacial (OM) surgeons is not well-characterized. To address the current deficit in understanding of the global OM surgeon workforce and to elevate oral and maxillofacial surgery (OMS) in the global health discourse, we join other surgical specialties in evaluating global surgical capacity with a descriptive analysis of the distribution of OM surgeons worldwide. A mixed-methods study was implemented using a combination of literature review, in-country contacts, internet searches, and survey data. The survey was distributed globally from January to June 2022. Data regarding OM surgeon workforce estimates were obtained for 104 of 195 United Nations-recognized countries (53.3%). Among countries with available estimates, the median global workforce density was 0.518 OM surgeons per 100,000 population. Twenty-eight countries (26.9%) were reported to have two or fewer OM surgeons. The median OM surgeon workforce density for low-income countries was 0.015 surgeons per 100,000 population, compared to 1.087 surgeons per 100,000 population in high-income countries. low and middle-income countries countries have the least workforce density as well as the least data coverage. More work is needed to better understand the capacity of the global OM surgeon workforce and access to OMS care.

Establishment of feline in-house reference intervals for hematologic and biochemical parameters and potential age-related differences.

Reference intervals (RIs) are one of the essential elements in the procedure of disease diagnosis. This is especially true for feline species in which RI is less available than in canine species. RIs are affected by biological, geographical and instrumental factors, yet published RIs with incomplete background are popularly used. Inappropriate interpretations of RIs may affect classification of disease and subsequent treatment. In this study, we demonstrated the step-by-step establishment of feline RIs following the American Society for Veterinary Clinical Pathology (ASVCP) reference interval guideline. A total of 51 parameters were examined, including 20 hematology and 31 biochemistry parameters, and the results were compared to one local RI and two foreign RIs. Overall, about 29% (10/35) of tested parameters were different form local RIs and 60% (30/50) were different from the two foreign RIs, highlighting geographical variations. A higher upper reference limit (URL) in red blood cell count (RBC), hematocrit (Hct), Hemoglobin (Hgb), albumin, creatinine and lower URL in potassium and white blood cell count (WBC) were identified, which may impact the interpretation. In addition, statistical analysis of age and gender were factored separately and indicated that 10 parameters were significantly higher in the adult group. For the impact of gender, percentage of basophil and total iron-binding capacity (TIBC) were lower in female and male cats, respectively. In conclusion, we have demonstrated that it is desirable to establish in-house RIs or RIs of local sources. An age specific RI for the geriatric feline population is advisable for better diagnosis and monitoring the disease.

Short-term dipeptidyl peptidase-4 inhibitor use increases the risk of herpes zoster infection in Asian patients with diabetes.

BACKGROUND: We aimed to evaluate whether patients with diabetes who use dipeptidyl peptidase (DPP)-4 inhibitors are at a higher risk of developing a herpes zoster (HZ) infection. METHODS: We used a subset of the Longitudinal Health Insurance Database 2000 containing all inpatient and outpatient medical claims of ∼1 million people who were randomly sampled from the National Health Insurance Research Database. Patients who were newly diagnosed with Type 2 diabetes International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM 250.x0 and 250.x2) who used antidiabetic medications were divided into two cohorts based on their use of DPP-4 inhibitors between 2009 and 2011. Cox proportion hazard regression models were used to assess the effects of DPP-4 inhibitors on the incidence of HZ compared with the non-DPP-4-inhibitor-exposed cohort. RESULTS: Patients in DPP-4-inhibitor-exposed cohort with diabetes and HZ infections revealed an incidence density of 4.20 per 1000 person-years compared with 3.50 per 1000 person-years for the non-DPP-4-inhibitor-exposed cohort (adjusted hazard ratio [HR] = 1.19, 95% confidence interval [CI] = 0.70-1.99). Furthermore, high-dose DPP-4-inhibitor treatment was associated with a significantly higher risk of HZ (adjusted HR = 2.46, 95% CI = 1.16-5.19 for a defined daily dose [DDD] ≥ 360). In addition, short-term DPP-4-inhibitor treatment was associated with a significantly higher risk of HZ (adjusted HR = 2.04, 95% CI = 1.03-4.04 for a DDD ≥ 360 days). CONCLUSION: These results suggest that Asian patients with diabetes who use short-term DPP-4 inhibitors might be at a higher risk of developing HZ.

Adaptive Phase-Field Modeling of Anisotropic Wetting with Line Tension at the Triple Junction.

Line tension could affect the contact angle at triple junction, especially in micro- to nanoscale wetting. We have developed an adaptive phase-field model to consider the line tension quantitatively. This model is coupled to the smoothed boundary method for treating the contact line with the solid phase, while the volume constraint is imposed. Our calculated contact angles are in good agreement with the modified Young's equation. Further examples are illustrated for the anisotropic wetting on hydrophilic/hydrophobic stripes and rectangular grooves.

Statins can increase the risk of herpes zoster infection in Asia.

This study evaluated whether statin therapy increases the risk of herpes zoster (HZ) infection in Asia. This retrospective cohort study used the Longitudinal Health Insurance Database (LHID2000). From the LHID2000, patients aged 20 years were divided into two cohorts according to their statin use and were matched at a 1:1 ratio according to propensity scores, which were calculated using a logistic regression for estimating the probability of treatment assignment. The primary outcome was HZ infection. All patients were followed from the index date until the date of HZ infection, withdrawal from the insurance system, or the end of 2011. The study included 53,069 patients receiving statin therapy as a statin cohort and 53,069 patients without statin therapy as a nonstatin cohort. The mean follow-up durations for the statin cohort and nonstatin cohort were 4.89 [standard deviation (SD) = 2.86] years and 4.75 (SD = 2.90) years, respectively. The patients in the statin cohort had a 21 % higher risk of contracting HZ infection than the patients in the nonstatin cohort [95 % confidence interval (CI) = 1.13-1.29]. The incidence of HZ infection increased with the Charlson comorbidity index (CCI) score in both cohorts. A high mean defined daily dose of the six types of statins considered in this study was associated with a significantly increased risk of HZ infection. Statin therapy can increase HZ infection in Asia. More benefit-risk evaluations for statin use are necessary in Asia.

Increased depression, diabetes and diabetic complications in Graves' disease patients in Asia.

BACKGROUND: This study aimed to evaluate the risk of depression and other cardiovascular comorbidities in Graves' disease (GD) patients in Asia. METHODS: The study patients were all newly diagnosed with GD [International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) 242.0] from January 1998 to December 2008. Patients aged <20 years or those with preexisting mental disorder (ICD-9-CM 290-319) were excluded from analyses. Control patients were randomly selected for the non-GD cohort, 1:4 frequency matched to the GD cohort according to sex, age and index year. The same exclusion criteria applied to the GD cohort were applied to the non-GD cohort. The GD cohort contained 4195 patients and the non-GD cohort contained 16 780 patients. RESULTS: The GD patients were more likely to have diabetes (8.03% vs. 4.48%, P < 0.0001), hypertension (18.1% vs. 13.5%, P < 0.0001), hyperlipidemia (11.9% vs. 9.09%, P < 0.0001) and coronary artery disease (10.3% vs. 5.86%, P < 0.0001) than the control patients were. The GD patients were also associated with significantly higher risk of depression than the control patients were (hazard ratio = 1.69, 95% confidence interval = 1.45-1.96). CONCLUSION: GD and GD treatment are associated with increased risk of depression diabetes and diabetic complications in Asian patients.

ENU-induced mutation in the DNA-binding domain of KLF3 reveals important roles for KLF3 in cardiovascular development and function in mice.

KLF3 is a Krüppel family zinc finger transcription factor with widespread tissue expression and no previously known role in heart development. In a screen for dominant mutations affecting cardiovascular function in N-ethyl-N-nitrosourea (ENU) mutagenized mice, we identified a missense mutation in the Klf3 gene that caused aortic valvular stenosis and partially penetrant perinatal lethality in heterozygotes. All homozygotes died as embryos. In the first of three zinc fingers, a point mutation changed a highly conserved histidine at amino acid 275 to arginine (Klf3(H275R) ). This change impaired binding of the mutant protein to KLF3's canonical DNA binding sequence. Heterozygous Klf3(H275R) mutants that died as neonates had marked biventricular cardiac hypertrophy with diminished cardiac chambers. Adult survivors exhibited hypotension, cardiac hypertrophy with enlarged cardiac chambers, and aortic valvular stenosis. A dominant negative effect on protein function was inferred by the similarity in phenotype between heterozygous Klf3(H275R) mutants and homozygous Klf3 null mice. However, the existence of divergent traits suggested the involvement of additional interactions. We conclude that KLF3 plays diverse and important roles in cardiovascular development and function in mice, and that amino acid 275 is critical for normal KLF3 protein function. Future exploration of the KLF3 pathway provides a new avenue for investigating causative factors contributing to cardiovascular disorders in humans.

Identification and characterization of androgen receptor associated coregulators in prostate cancer cells.

The androgen receptor (AR) is a member of the nuclear receptor (NR) superfamily that mediates the effects of androgens on target tissues. Over the last decade, it has become apparent that NRs require accessory factors for optimal activation of target gene expression. Numerous NR coregulators have been identified, with diverse structures and potential mechanisms of coregulation, creating an increasingly complicated picture of NR action. Due to the expanding complexity of the coregulator field, this review will focus on the AR ligand-binding domain (LBD) and N-terminal interacting proteins identified by our lab. The LBD-interacting proteins ARA70, ARA55 and ARA54 were first characterized and ARA70 was found to have a relatively higher specificity for the AR in human prostate cancer DU145 cells. Characterization of the functional relationship between the AR and these coregulators indicated that ARA70 and ARA55 could enhance the androgenic effects of 17beta-estradiol (E2) and hydroxyflutamide (HF), an antiandrogen commonly used in the treatment of prostate cancer. ARA160, an AR N-terminal interacting protein also known as TATA element modulatory factor (TMF), was subsequently shown to cooperate with ARA70 in enhancing AR activity. Another AR N-terminal interacting protein, ARA24, interacted with the poly-Q tract, a region within the N-terminus of the AR linked to Kennedy's disease (X-linked spinal and bulbar muscular atrophy). More recently, our lab has identified ARA267, a SET domain containing protein, and supervillin, an F-actin binding protein, as AR coregulators. Collectively, the data from these studies indicate that these coregulators are necessary for optimal AR transactivation. Interruption of the interaction between AR and these proteins may serve as a new therapeutic target in the treatment of prostate cancer.

Effects of antihistamines on 3, 4-methylenedioxymethamphetamine-induced depletion of serotonin in rats.

This study investigated the effects of chlorpheniramine (CPA, 10-25 mg/kg), diphenhydramine (DIPH, 20 mg/kg), tripelennamine (TRIP, 20 mg/kg), and pyrilamine (PYRI, 20 mg/kg) on 3, 4-methylenedioxymethamphetamine (MDMA, 20 mg/kg x 2)-induced hyperthermia and depletion of indoles in rat brains, on the uptake of serotonin and dopamine into rat synaptosomes, on the binding affinity of CPA for biogenic amine transporters in the synaptosomes of rat brain, and on the scavenging hydroxyl free radicals activity. Rats were treated with two injections of MDMA, CPA, DIPH, TRIP, PYRI, and saline, alone or in combination of MDMA with one of the antihistamines, 6 h apart and sacrificed 5 days later. Rectal temperature was measured prior to and hourly following the drug injections for 13 h. As compared to saline controls, MDMA increased body temperature and decreased levels of indoles, measured by HPLC, in several brain regions of rats. CPA attenuated and DIPH had no effect on MDMA-induced hyperthermia, yet both attenuated the depletion of indoles, whereas PYRI and TRIP potentiated these effects. CPA inhibited the binding of [(3)H]paroxetine and [(3)H]nisoxetine to the synaptosomes of cerebral cortex and of [(3)H]win 35,428 to the synaptosomes of striatum. CPA, DIPH, TRIP, and PYRI inhibited [(3)H]serotonin uptake. CPA, PYRI, and TRIP, but not DIPH, scavenge hydroxyl radicals. Possible mechanisms of the different effects of the antihistamines on MDMA-induced hyperthermia and depletion of serotonin are discussed. Published 1999 Wiley-Liss, Inc.

Effects of antihistamines on fenfluramine-induced depletion of indoles in the brain of rats.

Various effects of chlorpheniramine (CPA), diphenhydramine (DIPH), tripelennamine (TRIP), and pyrilamine (PYRI) on fenfluramine (FEN)-induced depletion of serotonin in the brain of rats were observed to be dependent on body temperature. Levels of 5-HT and 5-HIAA in the frontal cortex, hippocampus, and striatum of rats treated with FEN (10 mg/kg, once or twice daily x 4 days) decreased to approximately 30% (P < 0.01) that of controls with no significant changes after CPA, DIPH, TRIP, and PYRI. Treatment with FEN plus CPA (5, 10, 20 mg/kg) and FEN plus DIPH (20 mg/kg), but not FEN plus TRIP (20 mg/kg) and FEN plus PYRI (20 mg/kg), increased brain serotonin levels 2- to 3-fold more than those treated with FEN plus saline. Treatment with FEN plus CPA and FEN plus DIPH, but not FEN plus TRIP and FEN plus PYRI, decreased rectal temperature with no significant change after FEN. The antihistamines alone decreased temperature at a 1-hour period and enhanced FEN-induced reduction in body weight. Possible mechanisms of the different effects of antihistamines on FEN-induced depletion of serotonin are discussed.

N-tert-butyl-alpha-phenylnitrone protects against 3,4-methylenedioxymethamphetamine-induced depletion of serotonin in rats.

The present study examined the effect of N-tert-butyl-alpha-phenylnitrone (PBN) on 3,4-methylenedioxmathamphetamine (MDMA)-induced depletion of serotonin in the CNS. Rats were treated with two concurrent injections of MDMA (20 mg/kg, s.c.), PBN (50-400 mg/kg dissolved in ethanol, 50 mg/ml of 25% ethanol, i.p.), saline or 25% ethanol, alone or in combination, 6 h apart, and sacrificed 5 days later. Rectal temperature was measured prior to and hourly following the drug injection for 5 h. Monoamine levels in the tissue were measured by HPLC. Density of the 5-HT transporters was assayed by [3H]paroxetine binding. Rectal temperature of rats increased after MDMA, decreased after PBN, ethanol, PBN plus ethanol, and MDMA plus ethanol, and was not significantly altered after MDMA plus PBN. Levels of 5-HT and 5-HIAA in the frontal cortex, hippocampus, striatum, and brain stem of rats decreased significantly after MDMA or MDMA plus ethanol, but not after MDMA plus PBN, PBN plus ethanol (PBN dissolved in ethanol), or ethanol as compared to the saline controls. Levels of 5-HT and 5-HIAA in the brain tissues of rats treated with MDMA plus PBN were elevated as compared to those treated with MDMA plus saline. Similar results were observed in the density of 5-HT transporters in the frontal cortex and hippocampus. These results indicate that scavenging of free radicals of MDMA metabolites or reactive oxygen species by PBN and with lowering of body temperature protected against MDMA-induced depletion of serotonin transmitter.

Comparative anorectic effects of metaraminol and phenylephrine in rats.

Structure-anorectic activity relationship of two substituted amphetamines has been investigated in this study. Literature reports showed conflicting results in their anorectic activities in spite of the similarity in chemical structures of metaraminol and phenylephrine. Hence, the effects of alpha-carbon atom substitution and primary (metaraminol) and secondary amine (phenylephrine) moieties of these substituted amphetamines on the anorexia of rats were investigated in this study in nonfood- and food-deprived rats. Food intake at 1, 3, 14, and 24 h intervals, water intake at a 24-h interval, and body weight alteration for 10 days were monitored after daily drug administration for 3 consecutive days. Both metaraminol and phenylephrine were found to be potent anorectic. The relative anorectic potencies of phenylephrine were 0.54 and 0.81 of that of metaraminol at 1- and 3-h intervals, respectively. Body weight of rats treated with metaraminol (5.0 mg/kg) and phenylephrine (10 mg/kg) decreased significantly from Days 1 to 9.

Effects of salicylate on 3,4-methylenedioxymethamphetamine (MDMA)-induced neurotoxicity in rats.

The drug 3,4-methylenedioxymethamphetamine (MDMA) is a serotonergic neurotoxicant that causes hyperthermia and depletion of serotonin (5-HT) and 5-hydroxy-indole-3-acetic acid (5-HIAA) in the central nervous system. Formation of neurotoxic metabolites of MDMA, e.g., 2,4,5-trihydroxy-methamphetamine and 2,4,5-trihydroxyamphetamine, involves hydroxyl and/or superoxide free radicals. The present study was designed to determine whether the hydroxyl free-radical-trapping agent salicylate could provide protection against MDMA neurotoxicity in rats. In the acute studies, sodium salicylate (12.5-400 mg/kg, calculated as free acid) was injected interperitoneally (i.p.) 1 h before subcutaneous (s.c.) injections of MDMA (20 mg/kg as base). In the chronic studies, sodium salicylate (3.1-100 mg/kg) was injected i.p. 1 h before repeated s.c. injections of MDMA (10 mg/kg as base, twice daily, at 0830 and 1730 h for 4 consecutive days). Repeated MDMA administration depleted contents of 5-HT and 5-HIAA in the frontal cortex, hippocampus and striatum. Coadministration of salicylate plus MDMA did not significantly alter MDMA-induced depletion of 5-HT and 5-HIAA in these tissues. Thus, salicylate, a hydroxyl free-radical-trapping agent, does not protect against MDMA-induced hyperthermia and depletion of 5-HT and 5-HIAA. These observations suggest that MDMA-induced neurotoxicity may occur mainly through the production of superoxide or other radicals rather than hydroxyl free radicals. Salicylate actually potentiated MDMA-induced hyperthermia and lethality, findings that might be of clinical relevance.

Identification of 3',5'-cyclic adenosine monophosphate response element and other cis-acting elements in the human androgen receptor gene promoter.

Androgen and androgen receptor (AR) play an important role in sexual differentiation and prostate proliferation. To investigate AR gene transcriptional regulation, a 2.3-kilobase AR gene promoter region was isolated, sequenced, and characterized. Chloramphenicol acetyltransferase (CAT) assay and sequence homology search of AR gene promoter among human, rat, and mouse revealed some potential cis-acting elements, including a GC box, a suppressor region, and a purine-rich element. Deletion analysis and gel retardation assay using a 50-base pair (bp) double-strand purine-rich element showed that this purine-rich element can bind to specific proteins in nuclear extract of LNCaP and HeLa cells and may be essential for AR gene transcription. Furthermore, to investigate the effect of cAMP on AR gene transcription, we treated LNCaP and HeLa cells with 10 mM (Bu)2cAMP after transfection with CAT gene reporter plasmids linked to the AR gene promoter. This treatment induced several folds of CAT activity in LNCaP cells only, and the induction was further confirmed at AR mRNA level by Northern blot analysis and reverse transcription-polymerase chain reaction assay. Deletion analysis of the AR gene promoter showed that a region between 530 bp and 380 bp upstream of AR gene transcription initiation site, which includes one potential cAMP response element (CRE), is responsible for cAMP induction. Gel retardation analysis using this CRE (AR/CRE1) showed that AR/CRE1 can bind to specific proteins in nuclear extract of LNCaP cells, which appears to form a different binding complex compared to somatostatin/CRE.

Vitamin A, Vitamin E or beta-carotene status and hepatitis B-related hepatocellular carcinoma.

A case-control study was carried out in 59 patients with newly diagnosed hepatocellular carcinoma and 101 control subjects, who were all male hepatitis B carriers. The odds ratios of hepatocellular carcinoma occurring among hepatitis B carriers in the lowest quartile and those highest quartile of dietary and serum status were 5.3 (1.9 to 15.0) and 86.9 (20.0 to 377.2), respectively. The odds ratios for hepatitis B carriers in the lowest quartile and those in the highest quartile of dietary and serum beta-carotene status were 1.7 (0.7 to 4.1) and 5.0 (1.9 to 13.2). Vitamin E status did not differ in case patients and control subjects. Low education level, heavy consumption of alcohol, and smoking status were also associated with increased odds of hepatocellular carcinoma. Serum retinol, positively associated with dietary retinol, demonstrated an independent effect on hepatocellular carcinoma. This effect may reflect changes in the physiologic condition of the patients at the time of entering the hospital.

Prevalence of Chlamydia trachomatis infection in pregnant patients.

Chlamydia is a sexually transmitted disease of epidemic proportions, infecting an estimated 4 million people a year. It results not only in infertility and ectopic pregnancy but also in infant morbidity and mortality. Ectopic pregnancy is responsible for 11 percent of maternal deaths. About 60 percent of infected women can transmit the bacteria at birth to their infants. Early detection and treatment of chlamydia in both men and women, especially prenatal women, is critical. Chlamydia trachomatis infection of the cervix was found in 8.1 percent of a group of 1,004 pregnant women at a hospital prenatal clinic by means of a direct fluorescent antibody test. The prevalence of C. trachomatis was only 0.7 percent in 277 pregnant women receiving prenatal care from private practitioners. All patients between 27 and 30 weeks gestation who tested positive were treated with oral erythromycin. Their partners were treated with tetracycline. The outcome of pregnancy in patients treated for chlamydial infection was compared with a control group of noninfected mothers from the same population. The frequency of premature rupture of the membranes, prematurity, and low Apgar scores among the treated women were not significantly different from those in the control group. There was a significant difference, however, between the two groups in the incidence of low mean birth weight infants and the presence of meconium. Children can acquire a chlamydial infection at birth from contact with infected cervico-vaginal secretions. If not detected and treated, these infected infants may develop conjunctivitis, bronchiolitis, and pneumonia. It is suggested, therefore, that all patients at prenatal clinics be screened for chlamydial cervicitis. Those testing positive and their partners should be treated.

Metabolic profile of tripelennamine in humans.

Volunteers were injected im with 100 mg of tripelennamine (pyribenzamine).HCl dissolved in saline. Timed urine was collected. Tripelennamine and its metabolites were identified by GC/MS. Amounts of free tripelennamine excreted in the 0-2-, 2-4-, 4-8-, 8-12-, and 12-24-h urine samples were found to be 0.30, 0.56, 0.17, 0.21, and 0.0%, respectively, of the administered dose. In the same time periods, total tripelennamine (free plus conjugated) amounts were found to be 0.92, 1.20, 0.96, 1.30, and 1.31%, respectively, and total amounts 2-[alpha-hydroxybenzyl(2-dimethylaminoethyl)amino]pyridine(alpha- hydroxytripelennamine) plus an unidentified metabolite were found to be 0.16, 3.35, 3.06, 7.46, and 8.85% of the dose, respectively.

Cocaine-induced locomotor activity in rats.

Rats were injected SC or IP with a dose of cocaine at 20 mg/kg twice daily or saline (2 ml/kg) for 15 consecutive doses. Horizontal (including ambulatory and repetitive activity) and ambulatory locomotor activities were assessed following the first (acute) and the 15th (chronic) injections. Total locomotor activity (area under curve, AUC) following the acute and the chronic administration of cocaine were comparable, regardless of the route of drug administration. However, the temporal patterns of activity were significantly different; the peak of locomotor activity occurred earlier (chronic vs. acute, 20 vs. 40 min after IP; 130 vs. 180 min after SC) following chronic cocaine administration. Furthermore, the peak activity was significantly higher (3-fold after IP and 50% after SC) in chronically than in acutely treated rats, providing evidence for sensitization. In contrast, activity in the late session (240-280 min after SC) was significantly lower following the chronic SC cocaine administration, providing evidence for desensitization. The absolute slope values of the ascending phase and the descending phase were significantly larger following chronic administration of cocaine than that following the acute dosing. The possibility of changes in locomotor activity with alteration of pharmacokinetics on chronic cocaine treatment is discussed.

The neurochemical and stimulatory effects of putative metabolites of 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine in rats.

Rats were injected SC with a dose of 10 mg/kg (as base) of 3,4-methylenedioxyamphetamine (MDA), or 3,4-methylenedioxymethamphetamine (MDMA), 4-hydroxy-3-methoxyamphetamine, alpha-methyldopamine and alpha-methylnorepinephrine, metabolites of MDA, and alpha-methylepinephrine, a putative metabolite of MDMA, twice daily for either 5 or 7 consecutive doses. The rats were killed 24 h after the last injection and monoamines in discrete brain regions were assayed. MDA, MDMA, 4-hydroxy-3-methoxyamphetamine and alpha-methyldopamine, but not alpha-methylepinephrine, decreased the concentration of serotonin (5-HT) in the frontal cortex. MDA and MDMA, but not 4-hydroxy-3-methoxyamphetamine, alpha-methyldopamine and alpha-methylepinephrine, also decreased the concentration of 5-hydroxyindoleacetic acid (5-HIAA) in the frontal cortexes. In stimulatory studies, MDA and MDMA, but not their metabolites except alpha-methylepinephrine, which increased activity at 15 and 30 min, increased locomotor activity from 15 to 180 min following the drug administration.

Lack of neurochemical evidence for neurotoxic effects of repeated cocaine administration in rats on brain monoamine neurons.

Rats were injected with cocaine (20 mg/kg, s.c. or i.p. twice daily for 8 days) or saline and killed at 1, 8, 15 or 48 days after the last injection. The concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and their metabolites, assayed by HPLC-EC, in frontal cortex, hippocampus, striatum, hypothalamus, midbrain, pons-medulla and spinal cord were not significantly different from those in the saline-injected controls at any of the time points examined. These data suggest that the repeated cocaine administration in rats does not produce any long-term depletion in brain catecholamine and 5-HT content suggesting no neurotoxic effects of the drug.