Effects of typical and atypical antipsychotics on prepulse inhibition in schizophrenia: a critical evaluation of current evidence and directions for future research

Prepulse inhibition (PPI) of the startle response refers to an attenuation in response to a strong stimulus (pulse) if this is preceded shortly by a weak non-startling stimulus (prepulse). PPI provides a simple operational measure of sensorimotor gating, serving to prevent the interruption of ongoing perceptual and early sensory analysis. In accord with postulated deficits in early stages of information processing, there is ample evidence that PPI is disrupted in individuals with schizophrenia. PPI in animals is thought to represent a well-validated model for evaluating potential new treatments for schizophrenia. Currently, available data on the differential effects of typical and atypical antipsychotics suggest that atypical antipsychotics, in particular clozapine and risperidone, may be more effective than typical antipsychotics in improving PPI deficits in schizophrenia. However, studies have so far used small samples and/or between-subjects designs, and not examined the effects of other concomitant medications that may also influence PPI. The directions are identified for further applications of this model using within-subjects longitudinal designs and reasonable sample sizes to establish superiority of particular atypical antipsychotics over typical antipsychotics in improving PPI in schizophrenic populations.     

Visceral Leishmaniasis: Clinical Features,Pathology, Diagnosis and Chemotherapeutic Developments

Visceral leishmaniasis, or kala-azar, is a chronic disease caused by Leishmania donovani, Leishmania chagasi or Leishmania infantum. The disease is transmitted through the bite of a species of sandfly of the genus Phlebotomus, releasing amastigote parasites that invade various organs of the body and eventually result in such conditions as anemia, splenomegaly and hepatomegaly. Although no vaccine exists for the disease, diagnostic techniques based not only on pathological tests, but more sophisticated detectors such as polymerase chain reaction, enzyme-linked immunosorbent assay, latex agglutination and immunochromatographic strip testing have been developed. Traditional treatment for the disease consists of two pentavalent antimonial drugs, sodium stibogluconate and meglumine antimoniate, but the growing resistance to these drugs has compelled scientists to search for new efficient compounds. (c) 2002 Prous Science. All rights reserved.     

Studies on LHRBI of sheep corpora lutea--a preliminary report on in vivo administration to rhesus monkeys

An LH-receptor binding inhibitor (LHRBI), previously isolated from sheep corpora lutea in a partially purified form was subjected to wheat germ lectin chromatography. The unadsorbed fraction (UM-2R-III A) thus obtained had maximum LHRBI activity. This preparation was utilized to develop polyclonal antibodies. The purified fraction could be radioiodinated, suggesting its peptide nature. Intravenous injections of UM-2R-IIIA at 200 microg protein per dose in two doses per day at 9.30 h and 16.30 h on days 1 and 2 of the menstrual cycle to regularly cycling monkeys resulted in a shortening of the length of the cycle by 2 to 3 days. In addition, serum levels of progesterone increased prior to ovulation and remained high through the cycle of all three treated monkeys. It is possible that LHRBI induced enhanced synthesis and/or secretion of progesterone by the ovarian follicles thus suggesting a role for LHRBI in ovarian function.     

Identification of ocular cicatricial pemphigoid antibody binding site(s) in human beta4 integrin

PURPOSE: To identify specific site(s) on human ss4 molecule to which sera from ocular cicatricial pemphigoid (OCP) patients bind and to determine its role in the process of blister formation. METHODS: Clone the fragments representing the extracellular and intracellular domain of ss4 molecule from normal human conjunctival mRNA into an expression vector; map the region to which sera from OCP patients bind by Western blot analysis. Determine the role of the immunodominant region in pathogenesis by demonstrating the ability of the rabbit antibody to the immunodominant region to produce separation of basement membrane zone (BMZ) from the basal epithelial layer when incubated with normal human conjunctiva in an in vitro organ culture model. RESULTS: Majority of the OCP sera tested bound to the C-terminal end of the intracellular domain (IC3.0) of the human ss4 integrin. Further subcloning of IC3.0 demonstrated that a smaller fragment extending from 1489 aa to 1572 aa (IC3.4) was responsible for this binding. This region may have multiple antibody binding sites. Antibody to human IC3.0 and IC3.4 produced in rabbit, resulted in BMZ separation, histologically identical with that observed when normal human conjunctiva was cultured with OCP sera in an human conjunctival organ culture model. CONCLUSIONS: These observations identify IC3.4 as the antibody binding site for sera of OCP patients and suggest a possible role for it in blister formation. Indirectly it highlights certain important aspects of the structural and functional dynamics of the biology of the hemidesmosomes and basement membranes.     

Exophthalmometric values in a normal Indian population

PURPOSE. The purpose of this study was to establish a set of exophthalmometric values in a normal Indian population and to compute a regression equation for calculating these values. METHODS. Twenty-five-hundred clinically normal Indians of both sexes in the age group of 3-80 years, who did not have local or systemic disease likely to affect orbital or ocular structures, were enrolled in this study. Hertel's exophthalmometer was used to measure the degree of protrusion of the eyes. Statistical methods were used to calculate the mean values in the right and left eye in either sex and to compute a regression equation for calculating the exophthalmometric values. RESULTS. The range of exophthalmometric values in a normal Indian population aged 3-80 years was 7-19 mm for males and 7-21 mm for females. The exophthalmometric values were higher in the first decade, decreased in the second decade, and increased again in the third decade. They then remained stable for the next three to four decades. The peak was reached in the seventh decade in males and in the sixth decade in females. The lowest values in both sexes were attained in the eighth decade. The regression equations for the calculation of the exophthalmometric values are: In males for the right eye: Exophthalmometric value = 12.43 + 0.25 x age; In males for the left eye: Exophthalmometric value = 12.30 + 0.029 x age; In females for the right eye: Exophthalmometric value = 13.30 - 0.003 x age; In females for the left eye: Exophthalmometric value = 13.17 - 0.0003 x age. CONCLUSIONS. The trend of the normal exophthalmometric values for Indian subjects, by and large, was found to be similar to that quoted for other races. A knowledge of the normal values for this population subgroup can help clinicians in the early diagnosis and follow-up of patients with endocrine diseases, orbital tumors, craniofacial trauma and deformities and severe myopia.