Ultrastructural circadian variation of mast cells in the pinna of the mouse

It has been found previously under the light microscope that there was a circadian variation in mast cell number in the pinna of mice. The mast cell number was increased at 18.00 h and decreased at 06.00 h. In the current study, 5 mice of each group were synchronized for 4 weeks with a standard lighting regimen (light: 06.00-20.00 h; dark: 20.00-06.00 h). Both pinnas of every mouse of each group were removed at 06.00, 12.00, 18.00 and 24.00 h, respectively. Under the electron microscope, it was observed that more degranulated mast cells were found at 06.00 h and more intact mast cells were visible at 18.00 h. It appeared that the mast cell numbers, decreased and increased under the light microscope, were due to mast cell degradation and regranulation. This finding suggests that a functional circadian variation exists in the mast cell under physiological conditions.

The host range of the pKD1-derived plasmids in yeast

pKD1 is a 2 mu-like circular plasmid found in the yeast Kluyveromyces drosophilarum that can also stably replicate in Kluyveromyces lactis. We have found a short intergenic region in this genome that appears to be functionally neutral; that is, the introduction of foreign sequences into the single EcoRI restriction site located near one of the inverted repeats did not affect the high stability of the natural plasmid. By introducing a G418 resistance gene at this site, we constructed an autonomous recombinant plasmid. Since this vector did not require cir+ hosts for its stable maintenance, it could be used to examine the transformation host range of pKD1 among all the species belonging to the genus Kluyveromyces. Both species closely related to K. drosophilarum as well as a few other species that are very different in chromosomal GC% could be transformed to yield highly stable transformant clones.

P-7521--a new irreversible opioid ligand

In the receptor binding assay, P-7521 was a potent opioid ligand which acted mainly on mu receptor. The relative affinity ratio at mu, delta and kappa sites was 66:8:1. The inhibitory effects of P-7521 were 1868 and 6060 times more potent than morphine on the electrically evoked contractions in guinea pig ileum and mouse vas deferens, respectively and were readily antagonized by naloxone and Mr2266. These results indicate that P-7521 acted on mu receptor in guinea pig ileum and mouse vas deferens. In rabbit vas deferens, the compound had no agonist activity, but could antagonize the inhibitory effect of U-50488 H, a kappa agonist, showing the antagonistic characterization was on kappa receptor. The dissociation of P-7521 binding to opioid receptor were very difficult in mu binding assay and bioassays.

Quantitative study of circadian variations in mast cell number in different regions of the mouse

The tongue, pinna and dorsal skin of adult male C-1 mice were removed at 03.00, 06.00, 09.00, 12.00, 15.00, 18.00, 21.00 and 24.00 h, fixed in basic lead acetate and stained with Alcian blue-safranin or 0.5% toluidine blue. The mast cell numbers of these regions were counted and analyzed statistically by analysis of variance. It was found that there were circadian variations in the mast cell number in the tongue, pinna and dorsal skin. The difference between the minimum and maximum of circadian variation in mast cell number in all three regions was highly significant (p less than 0.01). Furthermore, the time points of the maximum and minimum of mast cell number varied between the different regions. The time point of the minimum in the tongue and pinna was at 06.00 h, whereas it was at 09.00 h in the dorsal skin. The time point of the maximum in the tongue and dorsal skin was at 21.00 h, but in the pinna it was at 18.00 h.

Study and clinical application of a porcine biomembrane for the repair of dural defects

A biomembrane was developed from pig peritoneum treated with 0.65% glutaraldehyde. This was evaluated for use as a dural substitute in an animal model and in a patient population. After being treated with the glutaraldehyde solution, the biomembrane lost its antigenicity while its collagen underwent an irreversible cross-linking reaction, causing it to become a stable nonviable polymer resistant to absorption by the host. The biomembrane was used experimentally in 43 procedures on 20 dogs and was applied clinically in 614 patients. The results demonstrated that it is an acceptable material for the repair of dural defects, with the following advantages: 1) it is nontoxic to the body and brain tissues, with minimal tissue reaction; 2) its biophysical properties facilitate watertight closure with sutures; 3) its distensibility makes it suitable for decompressive surgical dural repair; and 4) its visceral surface is extremely smooth, causing virtually no adhesions with the brain tissue while the outer surface readily heals with the subcutaneous tissue.

A gene fusion system using the aminoglycoside 3'-phosphotransferase gene of the kanamycin-resistance transposon Tn903: use in the yeast Kluyveromyces lactis and Saccharomyces cerevisiae

The aminoglycoside 3'-phosphotransferase type I (APHI)-coding gene of the bacterial transposon Tn903 confers resistance to kanamycin on bacteria and resistance to geneticin (G418) on many eukaryotes. We developed an APHI fusion system that can be used in the study of gene expression in these organisms, particularly in yeasts. The first 19 codons of the KmR (APHI) gene can be deleted, and replaced by other genes in a continuous reading frame, without loss of APH activity. Examples of vector constructions are given which are adapted to the yeast Kluyveromyces lactis transformation system. Their derivatives containing the 2 mu origin of replication can also be used in Saccharomyces cerevisiae.

[Surgical treatment of the second primary lung cancer]

1168 patients with primary carcinoma of lung had been treated by surgery in our hospital from 1976 to 1985. Among these patients we found 7 patients with second primary lung cancer. The incidence is 0.6% in this series. The criteria of the second primary lung cancer are: different histological type; synchronous lesion located in the contralateral lung or in different lobes or segments of the ipsilateral lung which must all be stage I; or prolonged interval between the initial and second resection (metachronous lesions), but the initial lesion must be proved as stage I. Lobectomy was the most common procedure for the initial and second resections. The result of the treatment was satisfactory with one patients surviving 6 years and 6 months. There was no operative mortality or complications. We consider that careful diagnosis is important and continued follow-up is necessary for all bronchogenic carcinomas.

A gene-cloning system for Kluyveromyces lactis and isolation of a chromosomal gene required for killer toxin production

A transformation system derived from the circular plasmid pKD1 has been developed for Kluyveromyces lactis. The principle is essentially equivalent to that of the 2 microns/Saccharomyces cerevisiae transformation system. The main features of the system are presented. Using a pKD1-based DNA bank of K. lactis, the KEX1 gene involved in the killer system was isolated by complementation.

The choice of opioid receptor subtype in isolated preparations by ohmefentanyl

Ohmefentanyl has significant inhibitory actions on the electrically evoked contractions of guinea pig ileum and mouse vas deferens. Their IC50 values are 0.15 nM and 0.89 nM, respectively. In the guinea pig ileum and the mouse vas deferens, both mu-antagonist naloxone and (mu + kappa)-antagonist Mr. 2266 antagonize readily the agonist action of ohmefentanyl, indicating that ohmefentanyl acts on mu-receptors in the guinea pig ileum and the mouse vas deferens. Like other mu-agonists, ohmefentanyl has agonist activity but no antagonist action in the rat vas deferens. In the rabbit vas deferens, the activity of ohmefentanyl is very weak. The IC50 value is 149 nM. These results further indicate that ohmefentanyl is a potent and selective mu-agonist.

Sequence organization of the circular plasmid pKD1 from the yeast Kluyveromyces drosophilarum

pKD1 is the only circular plasmid known in the genus Kluyveromyces. Nucleotide sequence analysis has revealed that this 4757 base-pairs long plasmid contained three major open reading frames, A, B, and C, and a pair of inverted repeats of 346 base-pairs. The molecule exists in two isomeric forms generated by internal recombination at these repeats. The functional organization of pKD1 genome appears to be quite analogous to that of the 2u plasmid of Saccharomyces cerevisiae. There is however little homology of sequences between these plasmids, except that the gene A has a dispersed but significant homology with the FLP recombinase gene of the 2u plasmid. S.cerevisiae cells can be transformed by derivatives of pKD1 carrying URA3 gene as a selection marker.

Analysis of a 1.6-micron circular plasmid from the yeast Kluyveromyces drosophilarum: structure and molecular dimorphism

A new plasmid has been found in the yeast Kluyveromyces drosophilarum. It is a double-stranded circular DNA, 1.6 micron in length (4.8 kilobase pairs). As in the case of Saccharomyces 2 mu circles, this plasmid occurs in two isomeric forms corresponding to the inversion of a segment between two 346-bp-long inverted repeats within the molecule. Each form has been separately cloned into bacterial plasmids. The new yeast plasmid, called pKD1, contains sequences that allow its replication in Saccharomyces cerevisiae.

Treatment of asthmatic patients sensitive to mites (Dermatophagoides farinae); a four-year study of immunotherapy with an extract of Dermatophagoides farinae

Dermatophagoides farinae (D.F.) is considered by many to be one of the main allergens in house dust. The present report is a four-year study with an extract of D.F. in 518 patients with extrinsic asthma. The extract was clinically effective in 315 out of 474 patients (66.5%) after the first course of therapy (20 weeks). It was even better (P less than 0.001) after more than two courses (76.5%). About 10% of the patients become almost entirely asymptomatic. The individuals whose skin reactions decreased after treatment showed the best results (P less than 0.05). After therapy the skin reaction and degranulation of mast cells were inhibited. Side effects were mild and transient. The results suggest that immunotherapy with D. farinae might be an acceptable measure of treatment for many patients with extrinsic asthma.