Discovery of cis-N-(1-(4-(methylamino)cyclohexyl)indolin-6-yl)thiophene-2-carboximidamide: a 1,6-disubstituted indoline derivative as a highly selective inhibitor of human neuronal nitric oxide synthase (nNOS) without any cardiovascular liabilities

A series of 1,6-disubstituted indoline derivatives were synthesized and evaluated as inhibitors of human nitric oxide synthase (NOS) designed to mitigate the cardiovascular liabilities associated with previously reported tetrahydroquinoline-based selective neuronal NOS inhibitors due to higher lipophilicity ( J. Med. Chem. 2011 , 54 , 5562 - 5575 ). This new series produced similar potency and selectivity among the NOS isoforms and was devoid of any cardiovascular liabilities associated with QT prolongation due to hERG activity or endothelial NOS mediated vasoconstriction effect. The SAR studies led to the identification of cis-45, which was shown to reverse thermal hyperalgesia in vivo in the spinal nerve ligation model of neuropathic pain with excellent safety profile (off-target activities at 80 CNS related receptors/ion channels/transporters). The results presented in this report make cis-45 as an ideal tool for evaluating the potential role of selective nNOS inhibitors in CNS related disorders where excess NO produced by nNOS is thought to play a crucial role.

Discovery of N-(3-(1-methyl-1,2,3,6-tetrahydropyridin-4-yl)-1H-indol-6-yl) thiophene-2-carboximidamide as a selective inhibitor of human neuronal nitric oxide synthase (nNOS) for the treatment of pain

3,6-Disubstituted indole derivatives were designed, synthesized, and evaluated as inhibitors of human nitric oxide synthase (NOS). Bulky amine containing substitution on the 3-position of the indole ring such as an azabicyclic system showed better selectivity over 5- and 6-membered cyclic amine substitutions. Compound (-)-19 showed the best selectivity for neuronal NOS over endothelial NOS (90-fold) and inducible NOS (309-fold) among the current series. Compounds 16 and (-)-19 were shown to be either inactive or very weak inhibitors of human cytochrome P450 enzymes, indicating a low potential for drug-drug interactions. Compound 16 was shown to reverse thermal hyperalgesia in vivo in the Chung model of neuropathic pain. Compound 16 was also devoid of any significant vasoconstrictive effect in human coronary arteries, associated with the inhibition of human eNOS. These results suggest that 16 may be a useful tool for evaluating the potential role of selective nNOS inhibitors in the treatment of pain such as migraine and CTTH.

Development of a competency-based curriculum in global child health

Resident interest in global health is increasing; however, a paucity of literature on competency-based curricula in global child health is available. A collaborative group including members from the University of Minnesota (UMN) Department of Pediatrics, the UMN College of Education and Human Development, and the Makerere University Department of Paediatrics and Child Health in Kampala, Uganda, developed a competency-based global child health curriculum for pediatrics residents at UMN. The group defined competencies for each of the Accreditation Council for Graduate Medical Education competency domains and developed the curriculum via six steps: (1) defining competencies specific to global child health, (2) authoring goals and objectives for each competency, (3) assigning appropriate postgraduate training levels to each competency, (4) determining intended resident groups for each competency, (5) aligning the program with the existing residency education program, and (6) developing methods to evaluate acquisition of each competency. Faculty implemented the competency-based curriculum in 2009, and the curriculum is now freely available online for adaptation and use by other residency programs. Faculty are currently introducing evaluation methods, which will allow them, for the first time, to assess a trainee's competency in global child health by the end of his or her residency. The authors believe that the development of this curriculum represents an important step forward in global health education for pediatric residents and that other residency programs, including those of nonpediatric specialties, can use the process as a model to develop global health curricula.

Triptan-induced enhancement of neuronal nitric oxide synthase in trigeminal ganglion dural afferents underlies increased responsiveness to potential migraine triggers

Migraine is a common neurological disorder often treated with triptans. Triptan overuse can lead to increased frequency of headache in some patients, a phenomenon termed medication overuse headache. Previous preclinical studies have demonstrated that repeated or sustained triptan administration for several days can elicit persistent neural adaptations in trigeminal ganglion cells innervating the dura, prominently characterized by increased labelling of neuronal profiles for calcitonin gene related peptide. Additionally, triptan administration elicited a behavioural syndrome of enhanced sensitivity to surrogate triggers of migraine that was maintained for weeks following discontinuation of drug, a phenomenon termed 'triptan-induced latent sensitization'. Here, we demonstrate that triptan administration elicits a long-lasting increase in identified rat trigeminal dural afferents labelled for neuronal nitric oxide synthase in the trigeminal ganglion. Cutaneous allodynia observed during the period of triptan administration was reversed by NXN-323, a selective inhibitor of neuronal nitric oxide synthase. Additionally, neuronal nitric oxide synthase inhibition prevented environmental stress-induced hypersensitivity in the post-triptan administration period. Co-administration of NXN-323 with sumatriptan over several days prevented the expression of allodynia and enhanced sensitivity to stress observed following latent sensitization, but not the triptan-induced increased labelling of neuronal nitric oxide synthase in dural afferents. Triptan administration thus promotes increased expression of neuronal nitric oxide synthase in dural afferents, which is critical for enhanced sensitivity to environmental stress. These data provide a biological basis for increased frequency of headache following triptans and highlight the potential clinical utility of neuronal nitric oxide synthase inhibition in preventing or treating medication overuse headache.

Novel 2-aminobenzothiazoles as selective neuronal nitric oxide synthase inhibitors

A series of substituted 2-aminobenzothiazole compounds have been synthesized and evaluated as nitric oxide synthase (NOS) inhibitors. Compound 14 shows activity in the nM range and is selective for the human neuronal NOS isoform. We have also evaluated the compounds against the rat NOS isoforms. For some of the compounds, there are significant differences in NOS inhibitory activities between the human and rat enzymes. For example, compound 10b has nM activity against the rat nNOS while low microM activity against the human nNOS.

The differential effects of atypical antipsychotics on prolactin elevation are explained by their differential blood-brain disposition: a pharmacological analysis in rats

All atypical antipsychotics avoid extrapyramidal side-effects yet differ in their propensity to cause other side-effects, like prolactin elevation. We proposed that the atypical antipsychotics with a propensity for prolactin elevation would show a higher pituitary versus striatal D2 receptor occupancy. To investigate this hypothesis, we tested four atypical antipsychotics, two that are commonly associated with prolactin elevation (amisulpride and risperidone) and two that are less frequently associated (quetiapine and olanzapine). In particular, we calculated their ED(50) values to increase plasma prolactin and block peripheral pituitary D2 receptors to their ED(50) values to antagonize apomorphine-induced stereotypy and occupy central striatal D2 receptors. All antipsychotics dose dependently increased prolactin levels and antagonized apomorphine-induced stereotypy. However, the central to peripheral potency (ED(50) for apomorphine antagonism to ED(50) for prolactin elevation) differed remarkably across these drugs: amisulpride (21764), risperidone (14), quetiapine (10), and olanzapine (1.7). Compounds displaying a higher peripheral potency brought about higher prolactin levels for a given level of functional central antagonism. This dissociation between central and peripheral effects was explained by the differential occupancy of D2 receptors in the striatum versus in the pituitary [ratio of striatal/pituitary ED(50) values (milligram per kilogram) for D2 occupancy): amisulpride (17/0.026 = 654), risperidone (0.89/0.081 = 14), quetiapine (24/4.1 = 6), olanzapine (0.30/0.43 = 0.7). These results indicate that dissociation between central and peripheral D2 receptor occupancy is a major determinant of the degree of prolactin elevation observed at therapeutic doses.

Acne therapy: a methodologic review

BACKGROUND

Acne is a very common problem with significant physical and psychological morbidity. The evidence basis for its treatment had not been systematically reviewed. Therefore, we performed an evidence review to provide researchers a basis for further studies, and to provide clinicians the background needed to interpret current and future clinical studies.

OBJECTIVE

We summarize the methodologic state of the acne literature in patients with acne who do not have complicating co-morbidities.

METHODS

This was an expert-advised literature synthesis. We used a structured literature search for English-language controlled trials in Cochrane CENTRAL, MEDLINE, OLDMEDLINE, HSTAT, CINAHL, and PsychInfo. Results underwent a structured data abstraction process, with review by at least 2 reviewers.

RESULTS

Out of 1588 unique articles, 250 articles (274 controlled trials) over the past 50 years were reviewed: 57 (21%) trials had at least one major weakness and no strengths; 125 (47%) trials had at least one major strength and at least one major weakness; 48 (18%) trials had at least one major strength, and no major weaknesses. The remaining 16 (6%) were of intermediate quality or did not provide enough information to make a determination. One fourth of studies did not report patient age; one fourth did not report on patient gender. Only 8% mentioned patient race; only 2% mentioned skin type; 0.4% mentioned diet; none scored sexual maturity or insurance status. There were 1237 outcomes. There were more than 25 methods of assessing acne severity and more than 19 methods for counting lesions. There were only two trials that formally assessed psychological outcomes. More than 140 treatments were tested in 251 comparisons.

CONCLUSION

Ranging over 50 years of research, the acne literature evidences great heterogeneity at all levels: patient characteristics, acne severity, outcome assessments, treatments, and comparisons. A list of methodologic recommendations is provided.

Effects of improved access to safety counseling, products, and home visits on parents' safety practices: results of a randomized trial

OBJECTIVE

To present the results of an intervention trial to enhance parents' home-safety practices through pediatric safety counseling, home visits, and an on-site children's safety center where parents receive personalized education and can purchase reduced-cost products.

DESIGN

Pediatricians were randomized to a standard- or an enhanced-intervention group. Parents of their patients were enrolled when the patient was 6 months or younger and observed until 12 to 18 months of age.

SETTING

A hospital-based pediatric resident continuity clinic that serves families living in low-income, inner-city neighborhoods.

PARTICIPANTS

First- and second-year pediatric residents and their patient-parent dyads.

INTERVENTIONS

Parents in the standard-intervention group received safety counseling and referral to the children's safety center from their pediatrician. Parents in the enhanced-intervention group received the standard services plus a home-safety visit by a community health worker.

OUTCOMES

Home observers assessed the following safety practices: reduction of hot-water temperature, poison storage, and presence of smoke alarms, safety gates for stairs, and ipecac syrup.

RESULTS

The prevalence of safety practices ranged from 11% of parents who stored poisons safely to 82% who had a working smoke alarm. No significant differences in safety practices were found between study groups. However, families who visited the children's safety center compared with those who did not had a significantly greater number of safety practices (34% vs 17% had > or 3).

CONCLUSIONS

Home visiting was not effective in improving parents' safety practices. Counseling coupled with convenient access to reduced-cost products appears to be an effective strategy for promoting children's home safety.

Randomized trial of enhanced anticipatory guidance for injury prevention

OBJECTIVE

To develop and evaluate an injury prevention anticipatory guidance training program for pediatric residents.

DESIGN

Thirty-one residents were randomly assigned to an intervention or control group. Both groups attended a 1-hour seminar about injury prevention and the American Academy of Pediatrics TIPP (The Injury Prevention Program) materials. The intervention group also received 5 hours of experiential instruction on injury prevention content and counseling skills (SAFE Counseling Framework). Families with infants from birth to age 6 months were enrolled in the study (N = 196); they were followed up until the child was aged 12 to 18 months. Data were collected by means of baseline and follow-up interviews, audiotapes of medical visits, parent exit surveys, and home observations.

SETTING

A hospital-based continuity clinic that serves families living in low-income, inner-city neighborhoods.

OUTCOMES

Physician counseling and parent satisfaction, knowledge, beliefs, and behaviors.

RESULTS

Parents seen by physicians in the intervention group received significantly more injury prevention counseling for 5 of the 6 safety practices, and they were significantly more satisfied with the help their physicians provided on safety topics. They were no less satisfied with their physicians' counseling on other anticipatory guidance topics. Parents' knowledge, beliefs, and home safety behaviors did not differ between the 2 groups.

CONCLUSIONS

The frequency and impact of pediatric counseling can be enhanced by experiential training that targets specific injury hazards. Because low-income families face many barriers to carrying out the recommended safety practices, supplemental strategies are needed to ensure safer homes.

Rehospitalization of children with asthma

BACKGROUND

Although some children with asthma experience multiple admissions, asthma is considered a preventable cause of hospitalization.

OBJECTIVE

To assess whether components of medical histories, ambulatory care prior to hospitalization, or ambulatory care after discharge are associated with repeated hospitalizations for children admitted with asthma.

DESIGN

Nested case-control study of a cohort of children hospitalized for asthma, comparing those who were rehospitalized within 1 year with those not rehospitalized.

SETTING

Urban pediatric primary care clinic.

PARTICIPANTS AND METHODS

Subjects were 119 children, aged 0 to 14 years, who had an inpatient admission with a diagnosis of asthma between July 1, 1993, and June 30, 1995 (index hospitalization). Data sources included medical charts, computerized patient records, and administrative data. Use of health care services was compared among children who were rehospitalized within 1 year of the index admission and those who were not.

MAIN OUTCOME MEASURE

Repeated hospitalizations.

RESULTS

The proportions of children who received general pediatric, allergy, or pulmonary care in the year prior to the index hospitalization were 86%, 7%, and 8%, respectively. By report, half of all children did not receive prescribed therapies, more than half were exposed to cigarette smoke at home, and one fourth were not up-to-date with immunizations at the time of admission. Thirty-five of the 119 children hospitalized with asthma were subsequently readmitted with asthma within 1 year of the index hospitalization. Children readmitted did not differ from those with a single admission in terms of the above characteristics. However, significantly more children subsequently readmitted had a pulmonary consultation during the index admission (23% vs 4%; P = .001) or in the year following discharge (37% vs 12%; P = .002). In addition, children readmitted were more likely to have other chronic conditions (69% vs 49%; P= .048).

CONCLUSION

Among low-income urban children, readmission for asthma is not associated with receipt of prescribed therapies or pediatric care.

Haloperidol-induced within-session response decrement patterns and catalepsy in rats: behavioural dissociation

The typical antipsychotic haloperidol is known to induce extra-pyramidal side-effects (EPS). Catalepsy in rats is generally regarded as a valid model for detecting the EPS liability of compounds in humans. Together with its antipsychotic and cataleptogenic actions, haloperidol causes an attenuation of instrumental responding which becomes larger in the course of a session: a within-session response decrement. The present study compared the time-course of haloperidol-induced catalepsy, measured by a bar test, to the haloperidol-induced within-session response decrements, measured by operant behaviour under a fixed ratio 10 schedule of reinforcement. Rats were trained to press a lever on a Fixed Ratio 10 schedule of food reinforcement during sessions of 15 min. When responding was stable, saline or haloperidol in 0.03 mg/kg, 0.1 mg/kg, or 0.3 mg/kg was administered intra-peritoneally either 30, 90 or 180 min prior to behavioural testing. The number of lever presses, food tray visits and latency to press the lever and to visit the food tray were analysed in five successive blocks of 3 min. Catalepsy was tested 30, 60, 90, 120, and 180 min. after injection, by placing a rat with its forepaws on a horizontal bar. The latency to remove both forepaws from the bar was scored. Within-session response decrements were present at 0.1 mg/kg and at 0.3 mg/kg, from 30 min after administration onward. At these doses, latency to press the lever was increased after 30 and 90 min, but not significantly after 180 min. Latency to visit the tray was affected only after 30 min, at 0.3 mg/kg. Haloperidol induced a dose-dependent increase in catalepsy from 60 min onwards, with maximal effect after 120 min. A dissociation between the time-course of occurrence of within-session response decrement and the cataleptogenic action of haloperidol, as well as between the latter and both latency measures, was found. Consequently, the present data suggest that within-session response decrements are not obviously caused by catalepsy-related impairments.