Disseminated gonorrhea: diagnosis through contact tracing.

Over a 1-year period four patients were seen at the Jewish General Hospital with presumed disseminated gonococcemia. The patients'' histories, clinical findings and responses to therapy strongly supported this diagnosis; however, cultures from various sites were negative for Neisseria gonorrhoeae in all four patients. Sexual contacts of these patients were traced and appropriate cultures were found to be positive, demonstrating the importance of tracing sexual contacts to help confirm the diagnosis in such patients.     

Time-dependent fluorescence depolarization and lifetime studies of myosin subfragment-one in the presence of nucleotide and actin

Time-dependent fluorescence depolarization and lifetime studies have been made on myosin subfragment 1 to obtain information about mobility changes and dye environment changes when different nucleotides are added. Data are reported for static and actively hydrolyzing systems containing G- and F-actin. Preliminary data indicate that myosin labeled with the fluorophore 1,5 IAEDANS¹-and treated with DTT preserves its actin-activated V_max. S1 prepared in this manner gives lifetime changes which are nearly identical for all systems studied. S1 labeling without DTT addition gives a pattern of lifetimes similar, though not identical to ESR work. Either type of labeling produces no observable change in the polarization decay, and we set an upper limit of 15% length change for the elongate S1. An unusually long fluorescence decay lifetime for the S1-Mg⁺⁺ ATP-G-actin system is found which may indicate a new acto-S1 state stabilized by G-actin. The method for obtaining the bound fraction of S1's in the presence of actin is presented and applied to the S1-F-actin-Mg⁺⁺ ATP system. Qualitative agreement is obtained with other methods.     

Cholinergic induction of seizures in the rat prefrontal cortex

Intracerebral microinjection of the cholinergic agonist, carbachol, into the medial prefrontal cortex of the rat, induced a profound behavioral syndrome consisting of repetitive, stereotyped forepaw treading in an upright posture. Electroencephalographic analysis revealed multiple bursts of sharp waves, 200-300 microV, accompanying the carbachol-elicited motor behavior. Pretreatment with intraperitoneal doses of three anticonvulsant drugs, clonazepam, diazepam, and pentobarbital, blocked the manifestation of the motor behavior. These observations suggest that activation of cholinergically innervated regions of the rat medial prefrontal cortex induces an atypical form of seizures.     

Cuprolinic Blue: a specific dye for single-stranded RNA in the presence of magnesium chloride. I. Fundamental aspects

Summary Qualitative and quantitative aspects of the cationic dye Cuprolinic Blue were investigated with model films of polyacrylamide gel in which RNA, DNA and other biological polyanionic compounds had been incorporated. In the presence of 1m MgCl₂, Curpolinic Blue was found to bind specifically to single-stranded RNA, leaving native DNA, proteins, (acid) polysaccharides and phospholipids completely unstained. Under these conditions, Cuprolinic Blue is complexed by non-electrostatic bonds with non-stacked purine bases, mainly adenine. Optimal conditions for dye binding and differentiation have been defined. Both the Cuprolinic Blue-MgCl₂ staining of single-stranded RNA and the Cuprolinic Blue staining of RNA and DNA in the absence of MgCl₂ were found to obey the Lambert-Beer law. The advantages and possible applications of Cuprolinic Blue are compared with well-known (indirect) histochemical RNA staining procedures.     

Soma position is correlated with time of development in three types of identified reticulospinal neurons

The relationship among neuronal type, position, and time course of development of identified neurons was examined in the zebrafish (Brachydanio rerio). The cells studied, the reticulospinal neurons Mauthner, MiM1, and MiV1, are located within the same small region in the hindbrain, differ stereotypically in their positions within this region and also in their axonal projections. All of the cell types were generated and had initiated axonal outgrowth by the second day after fertilization. The time that these events occurred was specific for each cell type, with axonal outgrowth occurring about 10 hr after the neuronal birthday. Furthermore, the time of the events varied systematically according to the dorsoventral location of the neuron within the set.