Detection of Streptococcus pneumoniae in clinical specimens, its antimicrobial susceptibility and serotypes

The purpose of our investigation was the detection of S. pneumoniae and the isolation frequency of PRSP/PISP from the patients of the area. 457 strains of S. pneumoniae were isolated from the clinical specimens which had been requested for cultivation from the individual general practitioners in the city. Screening of the PRSP/PISP in 457 strains was carried out with the oxacillin (MPIPC) disk method. The MIC (benezylpenicillin: PCG) was measured at the same time in 73 strains, and compared with the disk method. The results were as follows: 1) Regarding the detection rate of S. pneumoniae, nose discharge was the highest (11.4%) in all the specimens. 2) There was a greater number of isolation of S. pneumoniae in one year from November to March. Then it was scarce in August and September. This change in seasons was noted. 3) There were many 9-year olds and over-60 year olds in the age group of the patients in whom the S. pneumoniae was isolated. 4) All 30 strains where a 6 mm diameter was found when a MIC was compared with the MPIPC disk method were resistant (PRSP/PISP). All 20 strains with a > or = 20 mm diameter were sensitive (PSSP). But in the 23 strains which had a 7 mm -19 mm, 7 strains (30%) were PSSP, and 16 strains (70%) in the intermediate (PISP). 5) A diameter of 6 mm was found in 194 strains (42.5%) with the MPIPC disk method, among the 457 strains isolated from the clinical specimens. 141 strains (30.9%) were found with a diameter of 7 mm -19 mm and 122 strains (26.7%) with a diameter of > or = 20 mm. 6) More than 70% in PRSP/PISP were multiple antimicrobiotics resistant strains to PCG, EM and MINO. 7) The distribution of the serotype in PRSP/PISP was in the order of 19 type (41.3%), 23 type (21.7%), 6 type (13.0%). Moreover, it was in the order of 3 type (18.5%), 6 type (11.1%), 19 type (11.1%), and there were few 23 type (3.7%) for PSSP. The distribution of the serotype was different for PRSP/PISP and PSSP.     

A new tectal afferent nucleus of the infrared sensory system in the medulla oblongata of Crotaline snakes

The existence of an infrared sensory neuron group with ascending fibers which directly reach the optic tectum in Crotaline snakes was confirmed with three methods. (1) With the retrograde horseradish peroxidase (HRP) method, labeled neurons were not found within the nucleus descendens lateralis nervi trigemini (DLV), but in an unnamed cell group located immediately ventral to the DLV of the contralateral side at the transitional portion between the nucleus oralis (DVo) and the nucleus interpolaris (DVi). This unnamed cell group, which was seen only in the Crotalinae, was provisionally called the 'new nucleus'. (2) Normal brain series of 15 species were stained by the methods of Bodian-Otsuka, Klüver-Barrera and Nissl staining to compare the cytoarchitecture of the medulla oblongata. The 'new nucleus' was found only in species belonging to the Crotalinae. This nucleus was situated in fiber tracts which appeared to correspond to the lemniscus spinalis and tractus spino-cerebellaris of the reptilian medulla oblongata, and contained medium-sized multipolar or fusiform neurons. (3) In an electrophysiological study 16 single units responding unimodally to an infrared stimulus were recorded. Three of these recording sites were determined with Pontamine sky blue marking to be near or within the 'new nucleus'.     

A simulation study of high-speed silicon heteroemitter bipolartransistors

Using a two-dimensional numerical simulator, the upper limit of Si homotransistor cutoff frequency is estimated within the assumed conditions of punchthrough voltage. The potential speed advantages of silicon heteroemitter bipolar transistors (Si HBTs) (such as low emitter storage time, low emitter-base junction capacity, and possibility for large base width reduction) are shown by comparing Si HBTs with a Si homotransistor. It is confirmed that the cutoff frequency is enhanced from 48 to 127 GHz by the Si HBT structure. The optimum values of heteromaterial properties for high-speed HBT operation including energy gap, band discontinuity, and heterointerface recombination are discussed     

Influence of natural, electrically neutral lipids on the potentiometric responses of cation-selective polymeric membrane electrodes

Ionophore-free ion exchanger electrodes were found to exhibit quite a high selectivity for the creatininium ion; however, measurements in diluted urine samples revealed large emf drifts. Potentiometric, chromatographic, NMR, and mass spectrometric evidence did not reveal any major cationic interfering agents, and anionic interfering agents cannot trivially explain the consistently positive emf drifts. Ultrafiltration of urine samples showed that the interfering agents have molecular weights below 1000 u. The drifts are apparently caused by electrically neutral lipophilic compounds of low molecular weight that are easily extracted into organic phases. Follow-up experiments showed that p-cresol and cholesterol cause no significant emf responses but that coproporphyrin, phosphatidylserine, taurocholic acid, cholic acid, phosphatidylethanolamine, and octanoic acid cause positive emf drifts of the type that was observed with the urine samples. The extent of the responses and the response time depend not only on the specific compound but also on the cation in the sample solution. These results suggest that the emf drifts are due to extraction of such natural lipids into the organic membrane phase where they interact in an ionophore-like fashion with the analyte and interfering ions. Changes in the potentiometric selectivities after contact with natural lipids support this interpretation. The same effect of natural lipids is also expected for ionophore-based electrodes. Indeed, exposure of a valinomycin-based electrode to a methylene chloride extract of urine resulted in a significant reduction of the Na+ discrimination, increasing log Kpot(K,Na) from -3.9 to -3.1.