Fine structural localization of arylsulfatase in the rabbit blood platelets has been investigated in this study. Among many cell organellae, reaction products were exclusively observed in the alpha granules of the platelets. Within the alpha granules, arylsulfatase activity appeared to localize in variable patterns, i.e. reaction products confined mainly at the peripheral region in many granules, while they deposited heavily throughout the granule matrices in some others. In a blood platelets, each alpha granule showed the different staining pattern which indicated more variable functional heterogeneity in the granules.

Animals↗

PubMed1975

DNA degradation in an amber mutant of Escherichia coli K12 affecting DNA ligase and viability.

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Alleles↗

PubMed1975

Behavioral effects of L-dopa and thyrotropin-releasing hormone in schizophrenic patients: a preliminary report.

L-Dopa (in a dose of 300-400 mg daily) was used concomitantly with conventional antipsychotic drugs in four patients with long-standing schizophrenia (of more than 10 years' duration). In two of these four patients marked symptomatic improvement was observed, while in the other two symptoms remained unchanged. Symptoms that were found most responsive included disturbance of contact with others and emotional poverty.

Adult↗

PubMed1975

Indirect selection for plasmid mutants: isolation of ColVBtrp mutants defective in self-maintenance in Escherichia coli.

An efficient method for isolation of a large number of plasmid mutants is described. It is based on the fact that N-methyl-N'-nitro-N-nitrosoguanidine induces a number of closely linked mutations within a short segment of the bacterial chromosome. Thus, selection for reversions of an auxotrophic marker located on the ColVBtrp plasmid yielded a large fraction (more than 50 percent) of mutants defective in some plasmid functions, including its own maintenance in the host bacteria. The results of preliminary characterization of strains carrying these mutated plasmids are presented.

Colicins↗

PubMed1975

Genetic analyses of an amber mutation in Escherichia coli K-12, affecting deoxyribonucleic acid ligase and viability.

Genetic analyses of an Escherichia coli K-12 mutant possessing the amber mutation lig-321 were carried out. This mutant is defective in deoxyribonucleic acid (DNA) ligase and conditionally lethal. We constructed strains harboring an F'lig+ or F'lig-321 plasmid. Genetic complementation analyses were done by using these plasmids and by constructing a lig-4/F'lig-321 merodiploid. It was shown that lig-321 does not complement lig-4, unless the former is suppressed by an amber suppressor. The same was found to be the case between lig-321 and lig-ts7. Transductional mapping of lig-321, by a four-factor cross, revealed that lig-321 is very closely linked to lig-4. The frequency of recombinants between the two alleles was not unreasonable for assuming that they arose by intragenic recombination. The lig-4 and lig-ts7 alleles are known to reside in the structural gene for DNA ligase, in which lig-321 may also be located.

Alleles↗

PubMed1975

Effects of eye movements upon excitability of the superior colliculus in cats.

Influences of saccadic eye movements upon excitability of cat superior colliculus (SC) were examined in chronic cats carrying implanted electrodes and in encephale isole cats. Excitability of SC was assessed by recording orthodromic responses of SC (SC ortho-response) to electrical stimulation of the optic chiasm. The SC ortho-response consisted of four components; i.e. presynaptic T1 and postsynaptic C1, C2 and C3. Eye movements suppressed the first two components (T1 and C1) and enhanced the latter two (C2 and C3). Retinal impulses caused by movements of images were found responsible for suppression of T1 and C1: 1) This was seen when cats moved eyes seeing external objects in light. In dark, neither T1 nor C1 received any influence from eye movements. 2) By moving visual stimuli rapidly before eyes of paralysed cats the same suppression of T1 and C1 was obtained. Suppression of C1 was deemed as a postsynaptic sign of SC for saccadic suppression. In contrast to suppression of T1 and C1, enhancement of C2 and C3 was dependent upon a central factor: 1) Enhancement of C2 and C3 followed eye movements, independent of the ambient illumination. 2) Saccade-like movements of a slit of light in front of immobilized eyes never induced enhancement of C2 and C3. 3) PRF stimulation, effective to cause saccade-like eye movements, always elicited enhancement of C2 and C3, independent of the ambient condition and even after eyes had been immobilized. This phenomenon was interpreted as indicating that corollary discharges are sent to SC.

Animals↗

PubMed1975