Implications of retinal effects observed in chronic toxicity studies on the clinical development of a CNS-active drug candidate

The development path described for JNJ-26489112 provides perspectives on interpretation of retinal effects observed in nonclinical studies and their implications for clinical development. JNJ-26489112 is a CNS-active investigational drug that has potential as a novel treatment for treatment-resistant and bipolar depression, epilepsy, and neuropathic/inflammatory pain. In a 6-month toxicity study in albino rats, retinal atrophy was observed at supratherapeutic exposures to JNJ-26489112. The histopathological changes and topography of the lesions were characteristic of light-induced damage specific to albino rats. The species/strain specificity is supported by an absence of any ocular effects in dogs and in pigmented and albino rats, housed under standard and reduced lighting, respectively. To further evaluate its potential to cause ocular effects, in vivo functional and structural ocular analyses were included in a 9-month monkey toxicity study. Reductions in rod- and cone-mediated electroretinograms were observed at supratherapeutic exposures but without any histopathologic changes. These data suggested that the effects of JNJ-26489112 in monkeys were neuromodulatory and not neurotoxic. Taken together, data related to the light-induced atrophy in albino rats and reversible neuromodulatory effects in monkeys, supported the safe evaluation of JNJ-26489112 in a clinical proof-of-concept study that included comprehensive functional and structural ocular monitoring.     

Prolactin (PRL) induction of cyclooxygenase 2 (COX2) expression and prostaglandin (PG) production in hamster Leydig cells

Serum prolactin (PRL) variations play a crucial role in the photoperiodic-induced testicular regression-recrudescence transition in hamsters. We have previously shown that cyclooxygenase 2 (COX2), a key enzyme in the biosynthesis of prostaglandins (PGs), is expressed mostly in Leydig cells of reproductively active hamsters with considerable circulating and pituitary levels of PRL. In this study, we describe a stimulatory effect of PRL on COX2/PGs in hamster Leydig cells, which is mediated by IL-1β and prevented by P38-MAPK and JAK2 inhibitors. Furthermore, by preparative isoelectric focusing (IEF), we isolated PRL charge analogues from pituitaries of active [isoelectric points (pI): 5.16, 4.61, and 4.34] and regressed (pI: 5.44) hamsters. More acidic PRL charge analogues strongly induced COX2 expression, while less acidic ones had no effect.Our studies suggest that PRL induces COX2/PGs in hamster Leydig cells through IL-1β and activation of P38-MAPK and JAK2. PRL microheterogeneity detected in active/inactive hamsters may be responsible for the photoperiodic variations of COX2 expression in Leydig cells.     

Angina pectoris in patients with HIV/AIDS: prevalence and risk factors

IntroductionThe incidence of ischemic heart disease is higher in patients with HIV/AIDS. However, the frequency of angina pectoris in these patients is still not known. Literature about this subject is still scarce.ObjectiveTo evaluate the prevalence of angina pectoris and risk factors for coronary disease and to examine the association between traditional risk factors and HIV-related risk factors and angina pectoris.MethodAn epidemiological cross-sectional study, analyzed as case-control study, involving 584 patients with HIV/AIDS. Angina pectoris was identified by Rose questionnaire, classified as definite or possible. Information regarding risk factors was obtained through a questionnaire, biochemical laboratory tests, medical records and anthropometric measures taken during consultations at AIDS treatment clinics in Pernambuco, Brazil, from June 2007 to February 2008. To adjust the effect of each factor in relation to others, multiple logistic regression was used.ResultsThere was a preponderance of men (63.2%); mean ages were 39.8 years for men, 36.8 years for women. The prevalence of definite and possible angina were 11% and 9.4%, respectively, totaling 20.4%, with independent associations between angina and smoking (OR = 2.88; 95% CI: 1.69-4.90), obesity (OR = 1.62; 95% CI: 0.97-2.70), family history of heart attack (OR = 1.70; 95% CI: 1.00-2.88), low schooling (OR = 2.11; 95% CI: 1.24-3.59), and low monthly income (OR = 2.93; 95% CI: 1.18-7.22), even after adjustment for age.ConclusionThis study suggests that angina pectoris is underdiagnosed, even in patients with medical monitoring, revealing lost opportunities in identification and prevention of cardiovascular morbidity.     

Prediction of Whole-Body and Segmental Body Composition by Bioelectrical Impedance in Morbidly Obese Subjects

Background  

Validated equations for body composition analysis using bioelectrical impedance (BIA) in morbidly obese (MO) subjects are scarce. Thus, our aim was to develop new equations from physical and BIA parameters to estimate whole-body and segmental body composition in MO subjects, with dual-energy X-ray absorptiometry (DXA) as the reference method.     

The Impact of IFN-γ Receptor on SLPI Expression in Active Tuberculosis: Association with Disease Severity

Interferon (IFN)-γ displays a critical role in tuberculosis (TB), modulating the innate and adaptive immune responses. Previously, we reported that secretory leukocyte protease inhibitor (SLPI) is a pattern recognition receptor with anti-mycobacterial activity against Mycobacterium tuberculosis (Mtb). Herein, we determined whether IFN-γ modulated the levels of SLPI in TB patients. Plasma levels of SLPI and IFN-γ were studied in healthy donors (HDs) and TB patients. Peripheral blood mononuclear cells from HDs and patients with TB or defective IFN-γ receptor 1* were stimulated with Mtb antigen and SLPI, and IFN-γR expression levels were measured. Both SLPI and IFN-γ were significantly enhanced in plasma from those with TB compared with HDs. A direct association between SLPI levels and the severity of TB was detected. In addition, Mtb antigen stimulation decreased the SLPI produced by peripheral blood mononuclear cells from HDs, but not from TB or IFN-γR patients. Neutralization of IFN-γ reversed the inhibition of SLPI induced by Mtb antigen in HDs, but not in TB patients. Furthermore, recombinant IFN-γ was unable to modify the expression of SLPI in TB patients. Finally, IFN-γR expression was lower in TB compared with HD peripheral blood mononuclear cells. These results show that Mtb-induced IFN-γ down-modulated SLPI levels by signaling through the IFN-γR in HDs. This inhibitory mechanism was not observed in TB, probably because of the low expression of IFN-γR detected in these individuals.Tuberculosis (TB) is among the most common causes of morbidity and mortality in patients with HIV infection. Although protective immunological mechanisms against Mycobacterium tuberculosis (Mtb) are not fully understood, resistance to mycobacterial infections is primarily mediated by the interaction of antigen-specific T cells and macrophages.^1,2 This interaction depends on the cross talk of cytokines produced by these cells, and interferon (IFN)-γ is essential for protection.^2,3 Thus, during the immune response of the host against Mtb, IFN-γ produced by type 1 helper T cells is recognized by its receptor on macrophages. The IFN-γ receptor (IFN-γR) is composed of two ligand-binding IFNGR1 chains associated with two signal-transducing IFNGR2 chains, and an associated signaling machinery.^2–5 IFN-γ binds to its receptor and activates macrophages to efficient killing of intracellular mycobacteria. In humans, the loss-of-function mutations in IFNGR1 or IFNGR2 genes are closely associated with severe susceptibility to poorly virulent mycobacteria highlighted in childhood.^4,6,7Secretory leukocyte protease inhibitor (SLPI) is a serine protease inhibitor secreted by inflammatory and epithelial cells, mainly in the respiratory tract mucosa, and it is primarily active against neutrophilic elastase, cathepsin G, trypsin, and chymotrypsin.⁸ The expression and secretion of SLPI are down-modulated during chronic obstructive pulmonary disease.^9–11 In addition, cathepsins B, L, and S and cigarette smoke exposure result in the cleavage and inactivation of SLPI.^12,13 Moreover, it has been demonstrated that IFN-γ is a prominent stimulator of cathepsins and matrix metalloproteinase-12 and an inhibitor of SLPI.¹⁴ Remarkably, SLPI may also function as an endogenous immunomodulatory, anti-inflammatory, and/or antimicrobial substance.^15–18 The antimicrobial effects of SLPI against several bacteria have been demonstrated.¹⁵ In particular, Nishimura et al¹⁷ described that recombinant mouse SLPI inhibited the growth of bacillus Calmette-Guérin (BCG) and Mtb through the disruption of the mycobacterial cell wall structure. Furthermore, we reported that human SLPI is a secreted pattern recognition receptor for mycobacteria that increases both the phagocytosis and killing of the pathogen.¹⁸ Remarkably, exposure of murine peritoneal macrophages to Mtb led to an increase in SLPI secretion.¹⁹ Thus, given the anti-inflammatory and anti-mycobacterial roles of SLPI in humans and taking into account the fact that SLPI is inhibited by IFN-γ,²⁰ a crucial cytokine in the protective immunity against Mtb, herein we studied the effect of IFN-γ on the expression of SLPI during human active disease.