Schizophrenia research: a biennium of progress. Proceedings from the Sixth International Congress on Schizophrenia Research. Colorado Springs, CO, April 12-16, 1997

The Sixth International Congress on Schizophrenia Research (ICOSR) took place in Colorado Springs, Colorado, April 12-16, 1997, where over 1,000 scientists presented and listened to the latest developments in the search for the cause and treatment of schizophrenia. The ICOSR is sponsored by Maryland Psychiatric Research Center, Case Western Reserve University, and the William K. Warren Foundation. The National Institute of Mental Health and several pharmaceutical companies contributed generously to the meeting. The ICOSR is co-organized by Dr. Carol A. Tamminga, Maryland Psychiatric Research Center, University of Maryland at Baltimore, and Dr. S. Charles Schulz, Case Western Reserve University, Cleveland, Ohio. The William K. Warren Research Award is given to a senior investigator, who has made outstanding contributions to our understanding of schizophrenia. The fifth William K. Warren Research Award was presented to Dr. Philip S. Holzman in recognition of his contributions to the identification of eye-tracking abnormalities as a potential phenotypic marker of the illness and also in recognition of his work as a lifelong mentor for schizophrenia researchers. The ICOSR Young Investigator Awards are presented to junior investigators who have demonstrated the potential to make significant contributions to research on schizophrenia. These awards promote scientific development by enabling these young researchers to attend the meeting. There were 30 Young Investigator Award winners. The ICOSR meeting is organized into four sessions: (1) a morning plenary session; (2) a plenary lecture; (3) a poster session; and (4) concurrent afternoon oral sessions. The morning plenary sessions are comprised of a set of 30-minute lectures, which provide an overview of a particular topic area relevant to schizophrenia research. The plenary lecture is an invited lecture on a basic topic related to current research efforts in schizophrenia. The poster sessions provide a forum for the presentation of prepublication reports of basic and clinical science projects. The afternoon sessions are a collection of approximately 10 focused presentations on current research projects related to a specific topic area. The purpose of this report is to provide an account of the proceedings from the plenary and afternoon oral sessions.     

Successful innominate thromboembolectomy of a paradoxic embolus

A 54 year-old man had symptoms of acute right hemispheric cerebral ischemia. He was initially considered for participation in a trial of early thrombolysis in stroke, but an innominate artery embolus was found with no apparent arterial source. The embolus was removed by means of a combined brachial and carotid bifurcation approach to protect the cerebral vasculature from embolic fragmentation during extraction. Further investigation revealed deep venous thrombosis, evidence of pulmonary emboli, and a patent foramen ovale, supporting a diagnosis of paradoxic embolus. Additional treatment included anticoagulation and placement of an inferior vena caval filter. The unusual condition of paradoxic embolus is reviewed, and the management of this patient is discussed.     

Separation of bacterial capsular and lipopolysaccharides by preparative electrophoresis

Preparative gel electrophoresis was used to separate and purify extracellular, capsular and lipopolysaccharides (EPSs, CPSs, and LPSs, respectively) from crude bacterial extracts. The procedure effectively separates CPS from LPSs. In addition discreet size ranges of these various polysaccharides can be isolated. The 'rough' (R-type), 'smooth' (S-type), and 'semi-smooth' LPSs were separated from one another. In addition different size classes of 'semi-smooth', or S-type LPS, can be separated. This procedure was demonstrated for diverse bacterial species, including the soil bacteria Rhizobium fredii, and the enteric bacterial species, Salmonella enteritidis and Proteus mirabilis. In the latter case, it was also possible to separate capsular polysaccharide from its lipid-bound form.     

Lamotrigine may limit pathological excitation in the hippocampus by modulating a transient potassium outward current

Actions of the new antiepileptic drug lamotrigine were characterised using whole cell patch clamp recordings from rat CA1 pyramidal cells in vitro. The results suggest that lamotrigine, besides its previously described effect on the fast sodium inward current and calcium currents, modulates the transient potassium outward current ID. This may be an effective mechanism to inhibit pathological excitation.     

Mode of action of lufenuron on larval cat fleas (Siphonaptera: Pulicidae)

Adult cat fleas, Ctenocephalides felis (Bouché), were fed suboptimal in vitro concentrations of lufenuron in blood to allow hatching of flea larvae for cytological study. At concentrations of 0.125, 0.25, and 0.5 ppm, larval hatch was 64, 15, and 4%, respectively. Larvae hatching from eggs laid by adults fed lufenuron at concentrations of 0.025, 0.08, or 0.125 ppm did not differ significantly from the control. However, many larvae from the 0.08-ppm group and higher concentrations died during the 1st instar. Examination of these larvae revealed that they were dying from desiccation caused by bleeding from microscopic lesions in the cuticle or the inability to complete the molt to the next instar. Electron micrographs showed that lufenuron often disrupted formation of the endocuticle resulting in the deposition of an amorphous mass of randomly oriented chitin microfibrils. Other larvae formed normal endocuticle but were unable to digest the old endocuticle or produce new procuticle after apolysis. Failure of larvae to digest old cuticle or form new cuticle was caused by degeneration of the epidermal cells needed for the synthesis of molting fluid and chitin.