Cannabinoid action depends on phosphorylation of dopamine- and cAMP-regulated phosphoprotein of 32 kDa at the protein kinase A site in striatal projection neurons

Herbal cannabis, smoked in the form of marihuana or hashish, is the most common illicit drug consumed in the Western world. In the brain, cannabinoids interact with neuronal CB1 receptors, thereby producing a marked reduction of motor activity. Here, we report that the motor depressant effect produced by the cannabinoid receptor agonist (-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]trans-4-(3-hydroxypropyl)cyclohexanol (CP55,940) is attenuated by genetic inactivation of the dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32), which is abundantly expressed in the medium spiny neurons of the striatum. Point mutation of Thr34, the protein kinase A (PKA) phosphorylation site of DARPP-32, produces a similar reduction in the effect of the CB1 agonist. In contrast, point mutation of Thr75, a site on DARPP-32 specifically phosphorylated by cyclin-dependent kinase 5, does not affect the behavioral response to CP55,940. Activation of CB1 receptors, either by an agonist or by inhibition of reuptake of endogenous cannabinoids, stimulates phosphorylation at Thr34, thereby converting DARPP-32 into an inhibitor of protein phosphatase-1. Genetic inactivation either of dopamine D2 receptors or of adenosine A2A receptors reduces the phosphorylation of DARPP-32 at Thr34 and the motor depression produced by CP55,940. Our data indicate that a considerable proportion of the psychomotor effect of cannabinoids can be accounted for by a signaling cascade in striatal projection neurons involving PKA-dependent phosphorylation of DARPP-32, achieved via modulation of dopamine D2 and adenosine A2A transmission.     

The efficacy of pentamidine combined with allopurinol and immunotherapy for the treatment of patients with diffuse cutaneous leishmaniasis

A new treatment regimen was tested on patients with incurable diffuse cutaneous leshmaniasis (DCL) infected with Leishmania mexicana mexicana in Mexico. Two patients with advanced stages of the disease were treated with polychemotherapy (pentamidine and allopurinol) combined with recombinant human interferon-γ (rIFN-γ). For determination of the best medication, parasites isolated from patient lesions were exposed to available drugs both as promastigotes and as intracellular amastigotes. A synergistic effect was observed in vitro for the combination of pentamidine and allopurinol. Both patients were treated and recovered rapidly, but one of them developed insulin-dependent type I diabetes because of pentamidine toxicity. The complication was controlled and both patients were discharged with an apparent parasitologic cure, but after 3 months the two patients began to relapse. Our results suggest that allopurinol-pentamidine polychemotherapy, involving reduced dosage of pentamidine, combined with rIFN-γ is an alternative for DCL patients infected with L. m. mexicana. Received: 24 June 1998 / Accepted: 27 July 1998     

Ovulation induction in a poor responder with panhypopituitarism: a case report and review of the literature.

BACKGROUND: Most women with panhypopituitarism will undergo successful ovulation induction with gonadotropin therapy. Few proven treatment options exist for those who respond poorly to such therapy. A poor response may indicate diminished ovarian reserve, or reflect a deficiency of other key components for ovarian function. CASE: A 31-year-old female with panhypopituitarism and a poor response to gonadotropin therapy took growth hormone (GH) replacement for 4 months prior to restarting gonadotropins. When the serum level of insulin-like growth factor-I normalized, she began ovulation induction with gonadotropins with transdermal estradiol. After 63 days of gonadotropin therapy, she had a leading follicle of 18 mm, followed by follicles of 16.5 mm and 15.5 mm. The serum estradiol was 796 pg/ml, and human chorionic gonadotropin was administered. The patient conceived with timed intercourse. A prior attempt at ovulation induction with gonadotropins alone failed to produce follicular development. CONCLUSION: Prolonged gonadotropin treatment may be necessary to achieve ovulation and avoid the misdiagnosis of ovarian failure. Co-treatment with GH and estrogen may improve the follicular response in a poor responder with panhypopituitarism.     

Peritonitis in Latin America.

Peritoneal dialysis has a high acceptance rate in Latin America, thus the knowledge concerning complication patterns is of great relevance. This work reviews Latin American data on peritonitis, the most serious complication of peritoneal dialysis. The incidence of peritonitis has been reduced over time, concomitantly with the incorporation of safer exchange systems and the use of prophylactic measurements. Today, rates lower than 1 episode per 24 patient-months are commonly reported. Furthermore, changes in causative organisms have been observed, with predominance of Staphylococcus aureus up through the mid-1990s, as well as increases in coagulase-negative staphylococcus and participation of gram negatives. However, the prevalence of S. aureus is still high, due possibly to climatic conditions and the elevated prevalence of carriers. Resolution rate varies from 55% to 78%, transfer to hemodialysis from 10.9% to 15.4%, and death in 3% to 9.9% of cases. Outcome is worse in S. aureus episodes compared to those with coagulase-negative staphylococcus, despite the higher percentage of oxacillin-resistant strains among the former. In general, despite socioeconomic or climatic conditions, our results are similar to those in developed countries, perhaps as a consequence of technological improvements and/or center expertise.     

Influence of residual renal function on dietary protein and caloric intake in patients on incremental peritoneal dialysis.

OBJECTIVE: To evaluate protein and caloric intake in peritoneal dialysis (PD) patients on an incremental dialysis schedule, in an attempt to discriminate the influence of residual renal function (RRF) on these nutritional parameters. DESIGN: Prospective observational study. PATIENTS: Nine patients who had significant RRF at the beginning of PD therapy, which permitted a schedule of incremental PD (i.e., the number of peritoneal exchanges was increased as the RRF fell) in order to maintain the sum of renal and peritoneal clearance (weekly Kt/V urea) at approximately 2. METHODS: The mean adequacy parameters (urine and peritoneal Kt/V urea and creatinine clearance) along with the mean dietary energy (DEI) and protein intake (DPI) estimated by 3-day diet histories, were determined 6 and 9 months after the beginning of PD, when patients had RRF (period 1), and 6 and 9 months after the loss of RRF (period 2). The mean data obtained in both periods were compared. The best determinants for the changes in DEI and DPI after the loss of RRF were also investigated. RESULTS: Mean total Kt/V urea was very similar in both periods (2.16+/-0.32 vs 2.15+/-0.18), although creatinine clearance decreased significantly after the loss of RRF (74.41+/-12.28 L/week/1.73 m2 vs 56.78+/-11.77 L/week/1.73 m2, p = 0.0001). Absolute and normalized DPI values for actual body weight decreased after the loss of RRF (68.21+/-11.87 g/kg vs 59.27+/-13.66 g/kg, p = 0.02; and 1.17+/-0.32 g/kg/day vs 0.97+/-0.32 g/kg/day, p = 0.01). Although the energy delivered by peritoneal glucose uptake increased significantly after the loss of RRF, the mean total energy intake (DEI plus peritoneal glucose uptake) was very similar in both periods (2141+/-339 kcal/day vs 2010+/-303 kcal/day, p = 0.13). However, the mean total energy intake normalized for actual body weight decreased significantly after the loss of RRF (37.5+/-10.1 kcal/kg/day vs 32.8+/-8.9 kcal/kg/day, p = 0.02). The changes in DEI and DPI between periods 1 and 2 correlated negatively with the difference of the energy delivered by peritoneal glucose uptake (r = 0.65, p = 0.05, and r = 0.88, p = 0.001, respectively). The magnitude of DPI changes between both periods correlated significantly with the magnitude of urinary Kt/V urea changes (r = 0.77, p = 0.01). However, there was no correlation between the changes in DPI and the changes in total Kt/V urea, total or renal creatinine clearance, or the length of time on PD. CONCLUSIONS: The loss of RRF led to a reduction in dietary caloric and protein intake. The magnitude of the reduction in the DPI was strongly correlated with the increase in the energy delivered by peritoneal glucose uptake and with the decrease in the urinary Kt/V urea, but not with the total Kt/V urea.     

1-(2,3,4-trimethoxyphenyl)-3-(3-(2-chloroquinolinyl))-2-propen-1-one, a chalcone derivative with analgesic, anti-inflammatory and immunomodulatory properties

OBJECTIVE AND DESIGN: The synthetic chalcone derivative 1-(2,3,4-trimethoxyphenyl)-3-(3-(2-chloroquinolinyl))-2-propen-1-one (TQ) was evaluated for its immunomodulatory and anti-inflammatory efficacy in vitro and in vivo. MATERIAL AND SUBJECTS: Human neutrophils and lymphocytes from healthy volunteers and RAW 264.7 murine macrophages. Swiss mice and Lewis rats were randomly divided into groups of six animals. TREATMENT: TQ was orally administered in all in vivo assays (10-30 mg/kg). METHODS: Elastase, superoxide and LTB(4) release were assayed in human neutrophils, NO/PGE(2) production and NF-kappaB activation in RAW 264.7, and (3)H thymidine incorporation in human lymphocytes. Zymosan-stimulated air pouches, DNFB-DTH, PBQ-induced writhings and formalin-induced pain were assayed in mice. Adjuvant-induced arthritis was tested in rats. Dunnett's t-test was employed for statistical analysis. RESULTS: Human T-cell proliferation, neutrophil functions and NO/PGE(2) production in murine macrophages were inhibited by TQ (IC(50) in the microM range), which showed anti-inflammatory, immunomodulatory and analgesic effects. CONCLUSIONS: Our findings indicate the potential interest of TQ in the modulation of some immune and inflammatory responses probably by NF-kappaB inhibition.     

Enterococcus cecorum septicemia in a malnourished adult patient

Enterococcus cecorum, a species typically isolated from chicken, pigs, calves, horses, ducks, cats, dogs, and canaries, was isolated from the blood of a patient with severe septicemia. The isolate was identified by conventional biochemical tests. Identity asEnterococcus cecorum was confirmed by SDS-PAGE analysis of whole cell protein. This is the first report of the isolation ofEnterococcus cecorum in a clinical setting.