Further technical considerations of the sleeve microanastomosis

In sleeve anastomoses, stenoses at the suture site have been the main concern. Mechanical dilatation is one way to prevent the stenosis, as suggested by Lauritzen. In the present study, 50 vessels (femoral and carotid) and 10 veins were used for sleeve anastomoses and the same numbers of vessels were used for conventional anastomoses (as control) to evaluate the effect of mechanical dilatation using resin corrosion cast (Mercox) because the Mercox cast facilitates three-dimensional stereoscopic views. Gradual dilatations around the suture sites were observed in seven carotid arteries, and three of seven resulted into aneurysm formation due to weakening of the inner vascular wall in the sleeve anastomosis. No dilatation or aneurysm was observed in the femoral arteries. Newly proliferating capillaries formed on the endothelial surfaces of the inner vascular walls around the suture sites after 4 weeks in the sleeve anastomoses. Operative time and endothelial trauma were markedly reduced with sleeve anastomoses. The gradual dilatation and aneurysm formation in the carotid arteries show that sleeve anastomoses should be used carefully for high-pressure arteries in clinical practice if mechanical dilatation is performed.     

Molecular analysis of five independent Japanese mutant genes responsible for hypoxanthine guanine phosphoribosyltransferase (HPRT) deficiency

Five independent mutations in the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene were identified in a partially HPRT deficient patient with gout and in four Lesch-Nyhan patients. Using the polymerase chain reaction (PCR) technique coupled with direct sequencing, the nucleotide sequences of the entire HPRT coding region amplified from the cDNA and also of each exon amplified form the genomic DNA were analyzed. Three independent point mutations in the coding region were detected in the partially HPRT deficient patient (Case 1) and in two Lesch-Nyhan patients (Case 2 and 3), resulting in single amino acid substitutions. The family study of Case 3, utilizing a PvuII restriction site created in the mutant gene, indicated that the mother was a heterozygote, and a sister and a fetal brother had inherited the normal HPRT gene from the mother. In two other mutants causing Lesch-Nyhan syndrome, a portion of the HPRT gene was deleted, and RNA splicing was missing in both mutants. A 4-bp deletion at the 5 end of exon 4 resulted in formation of three different types of abnormal mRNA (Case 4). The other mutant (Case 5) produced abnormal mRNA including 26bp of intron 8 instead of the deleted 58bp at the 5 end of exon 9, because of a 74-bp deletion from intron 8 to exon 9.     

Increase in nucleoside diphosphatase in rat brain striatum lesioned with kainic acid

The activity of ammoniagenesis from guanine nucleotides was found to increase significantly in rat brain after infusion of kainic acid into the striatum. Among the enzymes involved in degrading guanine nucleotides, nucleoside diphosphatase was markedly increased in the lesioned striatum. The enzyme activity began to increase 2 days after the infusion, and reached the maximum on the 13th day, the level being 4 times as high as that of the intact contralateral region. The increased activity was due to Type L enzyme, judging from its substrate specificity. Puromycin and cycloheximide inhibited this increase, indicating that the increased activity resulted from an increase in the net synthesis of the enzyme. These findings suggest that Type L NDPase might play some important roles in gliosis after neuronal lesion.     

Maternal care in the red-headed spruce web-spinning sawfly,Cephalcia isshikii (Hymenoptera: Pamphiliidae)

We describe oviposition and maternal behavior in the sawfly Cephalcia isshikiiand examine the adaptive significance of this behavior. Females deposited eggs in a single but loose cluster on needles of terminal twigs of spruces, Piceaspp., and remained with the eggs usually on the underside of the twig facing toward the tip. The female attended her eggs until death without taking food but did not follow the first-instar larvae that moved from natal needles even if she survived until then. When the female was disturbed, she usually moved toward the source and attempted to bite it. Though at much lower frequencies, this aggressive behavior was also observed in gravid females and even in males. Field observations and female removal experiments indicated that the female enhanced the survival of the eggs through the reduction of arthropod prédation.     

Antitumor effect of RBS (rice bran saccharide) on ENNG-induced carcinogenesis

We examined whether orally administered RBS (rice bran saccharide), prepared from rice bran by hot water extraction, increases immunocompetence, inhibits gastrointestinal carcinogenesis with N-ethyl-N-nitro-N-nitrosoguanidine (ENNG) or shows an antitumor effect. After the administration of RBS, phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated blastogenesis of lymphocytes derived from the mesenteric lymph nodes and peripheral blood was enhanced, and the helper/ suppressor T-cell ratio was elevated, and migration activity of peritoneal macrophages was also increased in rats treated continuously with ENNG. ENNG-induced gastrointestinal carcinomas were observed in 43% of those administered RBS (ENNG-RBS) as compared with 88% in the control (ENNG) and 94% in the prednisolone (PRD) group (ENNG-PRD). The 12-month survival rate of rats bearing gastrointestinal cancer was 58% in the ENNG-RBS group as compared with 25% in the ENNG group and 15% in the ENNG-PRD group. RBS prevented the reduction in immunocompetence in the course of carcinogenesis, suppressed carcinogenesis, and prolonged the survival of rats with gastrointestinal cancer. Antitumor activities of RBS are thought to be a kind of host mediated action. The growth inhibition ratio of transplantable ENNG-induced cancer in Wistar rats was 42.1% in the RBS and 51.8% in the 5-FU group. Since little is known about the potent antitumor activity of -glucan, it would be interesting to consider the relationship between the structure and the biological activities of polysaccharides.     

Neural coding of speech sound in the telencephalic auditory area of the mynah bird

Summary The responses of neurons in field L in the auditory neostriatum of the mynah bird, Gracula religiosa, were recorded during presentation of intact or manipulated mimic voices. A typical mimic voice konnichiwa elicited responses in most of the neurons. Neurons in the input layer (L2) of field L showed many peaks on peristimulus time histograms while those in other layers (L1 and L3) exhibited only one or two peaks. Several neurons in L1 and L3 responded only to the affricative consonant /t/ in the intact mimic voices. They did not respond to the affricative consonant in the isolated segment or to the one in the playbacked voice in reverse. Forty-five percent of the neurons (33/ 73) decreased in firing rates at the affricative consonant in the isolated segment compared with in the intact voice. Some of these neurons, in which neither the affricative consonant in the isolated segment nor bursts of noise alone elicited responses, exhibited clear phasic responses to /t/ in the case when bursts of noise with particular central frequencies preceded the affricative consonant. The responsiveness of these neurons appears to receive temporal facilitation. These results suggest that these neurons code the temporal relationship of speech sound.Abbreviations HVc hyperstriatum ventrale, pars caudale - TFN temporally facilitated neuron - TSN temporally suppressed neuron     

Association of Lps gene with natural resistance of mouse macrophages against Legionella pneumophila

We have cloned a 1.6-kb region of chromosomal DNA from Thermoplasma acidophilum into Escherichia coli using as a probe part of the Methanococcus vannielii fus-gene. The sequence of the clone was highly homologous to part of the corresponding Methanococcus vannielii gene. By chromosome walking, a 4.7-kb EcoRI fragment containing the complete gene was isolated. Nucleotide sequencing revealed an open reading frame of 2196 nucleotides. The deduced amino acid sequence contains the known peptide sequence around the ADP-ribosylation site of T. acidophilum elongation factor 2, which unequivocally confirms that the fus-gene has been cloned. The amino acid sequence was compared to that of hamster and E. coli, as well as to known archaebacterial EF-2 sequences.     

Target size for a fibronectin-cell adhesion system determined by the X-ray inactivation method

In order to elucidate the mechanism of cell adhesion, the size of the functional site, both in the fibronectin molecule and in the mouse fibroblast cell, responsible for cell adhesion activity, was determined. The size was assumed to be equivalent to the target size, that can be determined from the X-ray inactivation dose. The target size of the cell-binding site in the fibronectin molecule was 32 kdalton. The molecular weight was much larger than that of the tripeptide, which has been reported to be the minimum peptides having a cell-binding activity. This suggests that submolecular regions in fibronectin other than the tripeptide are necessary for cell adhesion. The target size in the cell responsible for the adhesion to the fibronectin-coated surface was 4300 kdalton. The large molecular weight of the target could be explained by assuming that a complex protein system is involved in the cell-adhesion process in the cell.     

Dynamic light scattering from polydisperse suspensions of large spheres. Characterization of isolated secretory granules.

Dynamic light scattering is useful in determining the diameter of submicrometer particles in suspension. When both static scattering intensity P(K) and apparent diffusion coefficient D can be measured in a wide range of the length of the scattering vector K, it is possible to determine the number-average diameter dn and sharpness in size distribution of spheres. We derived approximate, but very simple, expressions for mean value of P(K) and mean value of D/D(dn) applicable to very large spheres for which the so-called Rayleigh-Debye condition is perturbed, where mean value of ... stands for the size average. These approximate expressions were compared with the numerical results based on the Mie scattering theory. Experimental results for isolated secretory granules, zymogen (dn approximately 800 nm) and chromaffin (dn approximately 400 nm) granules, were analyzed by use of the present formulation, and the dispersion in size distribution, sigma/dn = [(the mean of d2)/d2n - 1]1/2, was found to be about 0.2 for both types of granules.