Effects of calcitonin gene-related peptide on canine cerebral artery strips and the in-vivo vertebral blood flow in dogs

Summary The effects of calcitonin gene-related peptide (CGRP) on canine cerebral arteries and on vertebral blood flow were investigated in-vivo and in-vitro and the findings compared with the effects of vasoactive intestinal peptide (VIP) and substance P. Administration of CGRP into the vertebral artery caused a dose-dependent and long-lasting increase in blood flow. The in-vivo vasodilatory effects of substance P and VIP were short-lasting. CGRP (0.1 to 100 nmol/l) elicited a concentration-dependent relaxation of the isolated middle cerebral and basilar arteries when the tissues were precontracted by exposure to prostaglandin F₂ (PGF₂). This effect was not antagonized by propranolol, atropine, tetrodotoxin, (N-Ac-Tyr¹, D-Phe²)-growth hormone-releasing factor(1–29)-NH₂ or (D-Pro², D-Trp^7,9) substance P. CGRP also reduced concentration-dependently the contraction of cerebral arteries induced by KCl or 9,11-epithio-11,12-metano-thromboxane A₂ (STXA₂). Mechanical removal of the endothelium did not abolish the vasodilatory response to CGRP. In PGF₂-contracted canine cerebral arteries, VIP (0.1 to 100 nmol/l) was less potent a vasodilator than CGRP. At low concentrations (0.01 to 1 nmol/l) substance P elicited a rapid and short-lasting relaxation, and in the absence of endothelium this relaxation disappeared. These findings are clear evidence that CGRP modulates vascular tone.     

Optimum selection of an implantable secondary battery for an artificial heart by examination of the cycle life test

An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries. Each of the batteries was charge/discharge cycled at 37 degrees C to 39 degrees C using a charge current of 1 C ampere, and they were each fully discharged under either pulsatile discharge loads, which mimicked pulsatile operation, or a nonpulsatile load equivalent to the average of the pulsatile loads. The two Li-ion batteries made by different manufacturers both met the minimum requirement of cycle life of more than 1,500 cycles, considering safety coefficient regardless of the discharge pattern. In addition, the temperature increase of these Li-ion batteries (3 degrees C) was lower than that of Ni-Cd and Ni-MH batteries (15-25 degrees C). Out of these four batteries, the two Li-ion batteries are the most suitable for use in a totally implantable artificial heart system.     

DNA analysis of a patient with two different marker chromosomes using Y-specific DNA probes

A female patient with unilateral gonadal dysgenesis was a mosaic for three cell lines, 45,X/46,X, + marI/46,X, + marII, including two different marker chromosomes. DNA analysis using 17 Y-specific DNA probes revealed that each marker consists of different segments of the Y chromosome.     

ULTRASTRUCTURE OF AN ANAPLASTIC GIANT-CELL CARCINOMA FOUND 8 YEARS AFTER OPERATION ON A PAPILLARY CARCINOMA OF THE THYROID

Light and electron microscopic studies have been made on an anaplastic giant-cell tumor that developed in a woman 8 years after an operation on the thyroid for papillary carcinoma. Many giant cells were observed in the anaplastic tumor tissue, but no follicles. Numerous tightly-packed mitochondria and abundant ribosomes were present, but there were no desmosomes. The basement membrane was not distinct.     

Simple,rapid, and accurate determination of deletion mutations by automated dna sequencing of heteroduplex fragments of the adenomatous polyposis coli (APC) gene generated by PCR amplification

Germline mutations in patients with familial adenomatous polyposis were analyzed by polymerase chain reaction (PCR) amplification of the adenomatous polyposis coli gene. PCR products from heterozygous patients for deletions of this gene formed four distinct bands on polyacrylamide gel electrophoresis. The four fragments were subsequently purified and both strands of each fragment were directly sequenced, using an automated DNA sequencer and the same primers as those for PCR amplification. It was found that the two slower migrating fragments were “bulge” heteroduplexes, while the other two were homoduplexes made up of two wild-type strands and two deletion-mutant strands, respectively. The sites of deletions in the adenomatous polyposis coli gene could be exactly determined in four of the five patients. In an attempt to identify deletion-carriers of familial adenomatous polyposis at the presymptomatic stage, a family study was also carried out, and two children were found to have the same mutations as those of their affected parents. The direct sequencing of heteroduplex fragments generated during PCR amplification is a potentially useful method for detecting mutations of not only the adenomatous polyposis coli gene but also many other genes of genetic diseases. © 1993 Wiley-Liss, Inc.     

The UDP-galactose translocator gene is mapped to band Xp11.23-p11.22 containing the Wiskott-Aldrich syndrome locus

We have cloned a segment of the human gene encoding UDP-galactose translocator by genetic complementation of its defective mutant in mouse FM3A cells. Chromosome mapping using fluorescentin situ hybridization revealed that the cloned gene hybridized to the Xp11.23-11.23 region of the X chromosome. This region is shared by the locus of Wiskott-Aldrich syndrome, an X-linked recessive immunodeficiency disorder, characterized by defective sugar chains on cell surface components. Genetic and phenotypic similarities suggest a possible link between UDP-galactose translocator and the Wiskott-Aldrich syndrome (WAS).     

The ventilatory threshold gives maximal lactate steady state

Summary The purpose of this study was to examine whether the ventilatory threshold (Th _v) would give the maximal lactate steady state ([1a]_{ss, max}), which was defined as the highest work rate (W) attained by a subject without a progressive increase in blood lactate concentration [1a]_b at constant intensity exercise. Firstly, 8 healthy men repeated ramp-work tests (20 W·min^–1) on an electrically braked cycle ergometer on different days. During the tests, alveolar gas exchange was measured breath-by-breath, and theW atTh _v (W _{Th v}) was determined. The results of two-way ANOVA showed that the coefficient of variation of a singleW _{Th v} determination was 2.6%. Secondly, 13 men performed 30-min exercise atW _{Th v} (Th _v trial) and at 4.9% aboveW _{Th v} (Th _v + trial), which corresponded to the 95% confidence interval of the single determination. The [1a]_b was measured at 15 and 30 min from the onset of exercise. The [1a]_b at 15 min (3.15 mmol·1^–1, SEM 0.14) and at 30 min (2.95 mmol·1^–1, SEM 0.18) were not significantly different inTh _v trial. However, the [1a]_b ofTh _v+ trial significantly increased (P<0.05) from 15 min (3.62 mmol·1^–1, SEM 0.36) to 30 min (3.91 mmol·1^–1, SEM 0.40). These results indicate thatTh _v gives the [1a]_ss,max, at which one can perform sustained exercise without continuous [1a]_b accumulation.     

Effect of solvent evaporation rate on microphase-separated structure of segmented poly(urethane-urea) prepared by solution casting

A useful instrument for polymer film preparation by solution casting was employed in this study. It enabled us to control the solvent evaporation rate of the polymer solution. By using this instrument, the aggregation of hard segments in segmented poly(urethane-urea) (SPUU) was investigated. SPUU was prepared from poly(tetramethy1ene oxide), 4,4′-diphenylmethane diisocyanate and ethylenediamine. The effect of solvent evaporation rate on the microphase-separated structure of SPUU was elucidated by dynamic mechanical analysis, tensile test, differential scanning calorimetry analysis, small-angle X-ray scattering measurement, IR and IR dichroism analyses. The aggregation of hard segments in SPUU was observed to be affected considerably by the solvent evaporation rate of the cast film during the preparation. It was found that the slower the solvent evaporation rate, the higher the aggregation of hard segments to form rigid hard segment domains in SPUU. Nine months after casting, this casting effect still remained on the aggregation state of hard segments of SPUU films, although the interdomain spacing was not influenced by its rate.     

Evidence in patients with systemic lupus erythematosus of the presence of antibodies against RNA-dependent DNA polymerase of baboon endogenous virus.

Immunoglobulin G (IgG) in six out of 30 patients with systemic lupus erythematosus (SLE) strongly inhibited the activity of RNA-dependent DNA polymerase (RDPase) of baboon endogenous virus, M7, while IgG obtained from scleroderma patients, rheumatoid arthritis patients and normal subjects was less reactive. Experiments with anti-human IgG and with IgG F (ab')2-bound immunoaffinity columns indicated that the inhibition of RDPase was antibody-mediated. The RDPase inhibiting activity of SLE IgG was considered not to be due to cross-reactions of anti-nuclear antibodies including anti-DNA, anti-ribonucleoprotein, anti-Sm and anti-SS.B antibodies. SLE IgG preferably inhibited the RDPase activity of baboon endogenous virus and a feline endogenous virus, RD114. These findings support the hypothesis that retrovirus(es) might be involved in SLE.