Mapping grey matter reductions in schizophrenia: an anatomical likelihood estimation analysis of voxel-based morphometry studies

Voxel-based morphometry (VBM) is a popular tool for mapping neuroanatomical changes in schizophrenia patients. Several recent meta-analyses have identified the brain regions in which patients most consistently show grey matter reductions, although they have not examined whether such changes reflect differences in grey matter concentration (GMC) or grey matter volume (GMV). These measures assess different aspects of grey matter integrity, and may therefore reflect different pathological processes. In this study, we used the Anatomical Likelihood Estimation procedure to analyse significant differences reported in 37 VBM studies of schizophrenia patients, incorporating data from 1646 patients and 1690 controls, and compared the findings of studies using either GMC or GMV to index grey matter differences. Analysis of all studies combined indicated that grey matter reductions in a network of frontal, temporal, thalamic and striatal regions are among the most frequently reported in literature. GMC reductions were generally larger and more consistent than GMV reductions, and were more frequent in the insula, medial prefrontal, medial temporal and striatal regions. GMV reductions were more frequent in dorso-medial frontal cortex, and lateral and orbital frontal areas. These findings support the primacy of frontal, limbic, and subcortical dysfunction in the pathophysiology of schizophrenia, and suggest that the grey matter changes observed with MRI may not necessarily result from a unitary pathological process.

Macrophage inflammatory protein-1alpha (not T helper type 2 cytokines) is associated with severe forms of respiratory syncytial virus bronchiolitis

It has been suggested that the pathogenesis of respiratory syncytial virus (RSV) infection is related to the development of T helper (Th) type 2 cytokine responses. The presence of Th1 and Th2 cytokines and the chemokines macrophage inflammatory protein (MIP)-1alpha and monocyte chemotactic protein (MCP)-1 were assessed by ELISA in nasopharyngeal secretions of infants with RSV infection. Infants with mild bronchiolitis had increased Th1 cytokines and reduced Th2 cytokines, compared with infants with upper respiratory tract illness alone. Severe bronchiolitis was characterized by a more balanced Th1-Th2 response that did not differ from that of infants with upper respiratory tract illness alone. In contrast, MIP-1alpha was markedly increased in infants with severe bronchiolitis. MIP-1alpha and MCP-1 levels also were inversely related to oxygen saturation (P<.005). Thus, the severity of RSV bronchiolitis appears to be related more to chemokine release than to Th2 cytokine production.

Multicenter study to assess safety and efficacy of INH-A21, a donor-selected human staphylococcal immunoglobulin, for prevention of nosocomial infections in very low birth weight infants

BACKGROUND

Prophylactic administration of intravenous immunoglobulin has been inconsistent in reducing the risk of sepsis in very low birth weight (VLBW) infants presumably because of varying titers of organism specific IgG antibodies. INH-A21 is an intravenous immunoglobulin from donors with high titers of antistaphylococcal antibodies. This dose-ranging study explored safety and preliminary activity of INH-A21 for prevention of staphylococcal sepsis in VLBW infants.

METHODS

This was a multicenter, double blind, group-sequential study. Infants with birth weights 500-1250 g were randomized to receive up to 4 doses of placebo, 250 mg/kg, 500 mg/kg or 750 mg/kg INH-A21. Safety and frequencies of sepsis were compared across treatment groups.

RESULTS

All treatment groups had similar mean gestational age, birth weight, Apgar score and maternal use of antibiotics. Randomizations to 250 mg/kg (N = 94) and 500 mg/kg (N = 96) doses were terminated after interim analyses demonstrated a low probability of finding a difference when compared with placebo. Infants randomized to the INH-A21 750 mg/kg group (N = 157) had fewer episodes of Staphylococcus aureus sepsis [relative risk (RR), 0.37; 95% confidence interval (CI), 0.12-1.12; P = 0.14], candidemia (RR 0.34; 95% CI 0.09-1.22; P = 0.09) and mortality (RR 0.64; 95% CI 0.25-1.61; P = 0.27) when compared with the placebo-treated cohort (N = 158). No dose-related trends were observed for adverse events or morbidities associated with prematurity.

CONCLUSIONS

INH-A21 750 mg/kg demonstrated potential to reduce sepsis caused by S. aureus, candidemia and mortality in VLBW infants. Although statistical significance was not reached, based on the magnitude of the estimated differences, the efficacy and safety of INH-A21 750 mg/kg should be evaluated in an adequately powered, well-controlled study.

Current status of heparin dissolution of gallstones. Experimental and clinical observations

Investigation of the use of heparin in bile indicates that it has the ability to disperse suspended particles. Clinical experience using a heparinized saline flush in forty-three patients with retained gallstones demonstrated disappearance of the stones in thirty-one of the patients. On this basis we would recommend this treatment for further clinical trials in patients with retained common duct stones.

Development of an allosteric inhibitor class blocking RNA elongation by the respiratory syncytial virus polymerase complex

Respiratory syncytial virus (RSV) represents a significant health threat to infants and to elderly or immunocompromised individuals. There are currently no vaccines available to prevent RSV infections, and disease management is largely limited to supportive care, making the identification and development of effective antiviral therapeutics against RSV a priority. To identify effective chemical scaffolds for managing RSV disease, we conducted a high-throughput anti-RSV screen of a 57,000-compound library. We identified a hit compound that specifically blocked activity of the RSV RNA-dependent RNA polymerase (RdRp) complex, initially with moderate low-micromolar potency. Mechanistic characterization in an in vitro RSV RdRp assay indicated that representatives of this compound class block elongation of RSV RNA products after initial extension by up to three nucleotides. Synthetic hit-to-lead exploration yielded an informative 3D quantitative structure-activity relationship (3D-QSAR) model and resulted in analogs with more than 20-fold improved potency and selectivity indices (SIs) of >1,000. However, first-generation leads exhibited limited water solubility and poor metabolic stability. A second optimization strategy informed by the 3D-QSAR model combined with in silico pharmacokinetics (PK) predictions yielded an advanced lead, AVG-233, that demonstrated nanomolar activity against both laboratory-adapted RSV strains and clinical RSV isolates. This anti-RSV activity extended to infection of established cell lines and primary human airway cells. PK profiling in mice revealed 34% oral bioavailability of AVG-233 and sustained high drug levels in the circulation after a single oral dose of 20 mg/kg. This promising first-in-class lead warrants further development as an anti-RSV drug.

Multicenter study to determine antibody concentrations and assess the safety of administration of INH-A21, a donor-selected human Staphylococcal immune globulin, in low-birth-weight infants

Nosocomial or late-onset sepsis is a common complication among premature infants, with a frequency inversely correlated with birth weight. Increased susceptibility to infection is due in part to an immature humoral (antibody-mediated) immune response. This study investigated the pharmacokinetics (PKs) and safety of a donor-selected specific intravenous immune globulin (IVIG) preparation, INH-A21 (Veronate), for prevention of sepsis in premature infants. Thirty-six infants weighing between 500 and 1,250 g during the first postnatal week were eligible to begin a series of up to four intravenous infusions of 500 or 750 mg/kg of body weight INH-A21. Blood samples were analyzed for antibodies against the Ser-Asp dipeptide repeat G (SdrG) and clumping factor A (ClfA) surface proteins of staphylococci. Sparse sampling and population PK analyses were performed to derive PK parameters. Following administration of the 500- and 750-mg/kg doses, the estimated average steady-state levels of anti-ClfA were 6.1 U/ml and 9.2 U/ml, respectively, and those of anti-SdrG were 5.2 U/ml and 7.7 U/ml, respectively. The elimination half-lives for anti-ClfA and anti-SdrG were 719 h and 701 h, respectively, and the clearances were 0.18 ml/h and 0.21 ml/h, respectively. In the final model, the values of the PK parameters were independent of gestational age. Both doses of INH-A21 were well tolerated, and the safety profile was similar to those of other IVIG preparations. These results suggest that a shorter dosing interval should be utilized between the first and second doses to achieve and maintain higher titers of anti-ClfA and anti-SdrG antibodies. Further studies examining INH-A21 for the prevention of late-onset sepsis in infants within the weight range studied are warranted.

Orally efficacious lead of the AVG inhibitor series targeting a dynamic interface in the respiratory syncytial virus polymerase

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory infections in infants and the immunocompromised, yet no efficient therapeutic exists. We have identified the AVG class of allosteric inhibitors of RSV RNA synthesis. Here, we demonstrate through biolayer interferometry and in vitro RNA-dependent RNA polymerase (RdRP) assays that AVG compounds bind to the viral polymerase, stalling the polymerase in initiation conformation. Resistance profiling revealed a unique escape pattern, suggesting a discrete docking pose. Affinity mapping using photoreactive AVG analogs identified the interface of polymerase core, capping, and connector domains as a molecular target site. A first-generation lead showed nanomolar potency against RSV in human airway epithelium organoids but lacked in vivo efficacy. Docking pose-informed synthetic optimization generated orally efficacious AVG-388, which showed potent efficacy in the RSV mouse model when administered therapeutically. This study maps a druggable target in the RSV RdRP and establishes clinical potential of the AVG chemotype against RSV disease.

The relationship of cholecystectomy and taurocholic acid feeding to bile composition and hepatocyte function in prairie dogs

The prairie dog was used as a model for human gallstone formation. Stones formed in the gallbladder of all animals on a lithogenic diet. Hepatic bile was nonlithogenic, whereas gallbladder bile promoted cholesterol precipitation. Addition of taurocholate to the diet reduced the number of stones and lithogenicity. Cholecystectomy resulted in an increased bile flow and reduced secretion of cholesterol in the animals on a high cholesterol diet. Reduction of cholesterol and bile acid synthesis by negative feedback was demonstrated in isolated hepatocyte culture. The shift of bile salt production to chenodeoxycholates on a high cholesterol intake was demonstrated both in vivo and in vitro. A theory of gallstone formation is presented which hypothesizes a defect in hepatocyte storage of cholesterol rather than bile acid synthesis as the primary effect, relegating the problems to one of a disease of lipid metabolism.

Effect of triiodothyronine and reserpine on induction and growth of mammary tumors in rats by 3-methylcholanthrene

This study was designed to investigate the effects of exogenous L-triiodothyronine (LT3) and reserpine administration on the induction and stimulation of 3-methylcholanthrene (3-MC) mammary tumors. Two hundred-fifty-eight 30-day-old virgin 100 gm Sprague Dawley rats were divided into eight groups. Groups I-IV received either reserpine, LT3, both, or saline 22 days after tumor induction with 3-MC. Groups V-VIII were pretreated with either reserpine, LT3, or both for 29 days prior to tumor induction, and treatment was continued after tumor induction in all except Group VII. All rats were observed for tumor growth and sacrificed at seven months. Reserpine administration resulted in a protective effect against tumor induction in all groups in which it was used, with the most striking effects observed in the pretreated groups. Early LT3 stimulation of tumor formation was reversed by simultaneous administration of reserpine. Prolonged administration was unnecessary when both agents were administered prior to 3-methylcholanthrene.

Synthesis and evaluation against hepatitis C virus of 7-deaza analogues of 2'-C-methyl-6-O-methyl guanosine nucleoside and L-Alanine ester phosphoramidates

7-Deazapurines are known to possess broad antiviral activity, however the 2'-C-methylguanosine analogue displays poor cell permeation and limited phosphorylation, thus is not an efficient inhibitor of hepatitis C virus (HCV) replication. We previously reported the 6-O-methyl entity as a prodrug moiety to increase liphophilicity of guanine nucleosides and the ProTide approach applied to 2'-C-methyl-6-O-methylguanosine has lead to potent HCV inhibitors now in clinical trials. In this Letter, we report the synthesis and biological evaluation of 2'-C-methyl-6-O-methyl-7-deaza guanosine and ProTide derivatives. In contrast to prior studies, removal of the N-7 of the nucleobase entirely negates anti-HCV activity compared to the 2'-C-methyl-6-O-methylguanosine analogues. To understand better this significant loss of activity, enzymatic assays and molecular modeling were carried out and suggested 2'-C-methyl-6-O-methyl-7-deaza guanosine and related ProTides do not act as efficient prodrugs of the free nucleotide, in marked contrast to the case of the parent guanine analogue.

The effect of sodium benzoate and taurocholic acid feeding on human bile composition

Four patients were fed sodium benzoate after stabilization following common bile duct exploration. Bile collections revealed no change in the output of glycine conjugated bile acids. Three patients had taurocholic acid added to the regimen after 3 days and demonstrated a significant increase in total and taurine conjugated bile acid output with marked reduction of the G/T ratio. These latter changes are similar to those produced by taurocholic acid feeding alone and therefore no benefit of the combination of drugs on bile salt excretion or conjugation ratio was demonstrated.

Dislocation of the sternoclavicular joint. Evaluation using paraxial computed tomographic reconstruction

Sternoclavicular dislocations are relatively infrequent, constituting less than 1% of somatic dislocations. Despite the fact that the sternoclavicular joint is the only articulation between the upper extremity and the axial skeleton, it possesses the least amount of osseous stability of any joint in the body. Sternoclavicular dislocations are generally divided into anterior and posterior disruptions, the former being the most common. An unusual case of an anterior dislocation of the sternoclavicular joint with a large superior component is described. It was found that coronal paraxial computed tomographic reconstruction of the joint was quite useful in evaluating this injury.

Streetside support

Five years ago a small group of employees (health professionals and others) from Saint Joseph's Hospital, Atlanta, volunteered to prepare a meal for the homeless at one of the city's shelters. The experience led to a group decision to volunteer time to provide basic healthcare to the homeless. This soon led to the hospital-based Mercy Mobile Health Project, which, with community involvement, eventually became the Atlanta Community Health Program for the Homeless. Although the Saint Joseph's Mercy Care Corporation sponsors the program, a number of public and private agencies and professional groups are involved. All strive to expand efforts to address the problems of the homeless, to break the cycle of homelessness, and to provide continuing healthcare services where necessary. The number of clinic sites has more than doubled, while patient encounters have quadrupled.

The effect of para-aminobenzoic acid and taurocholic acid feeding on human bile composition

Seven patients were investigated after cholecystectomy and exploration of the common bile duct to determine bile composition and excretion rates. An initial depression of the major components of bile stabilized by the sixth postoperative day. Feeding of para-aminobenzoic acid and taurocholic acid to these patients demonstrated an increase in excretion of total bile acids, taurine and glycine conjugates, cholates and deoxycholates. Para-aminobenzoic acid in the doses used failed to block glycine conjugation. Preferential conjugation of bile acid with glycine is due to a deficient taurine pool and not a preferential metabolic pathway.