Up-regulation of human telomerase catalytic subunit during gastric carcinogenesis

BACKGROUND

Telomerase activation is thought to be essential for the stabilization of telomere length, through which immortalization and oncogenesis are achieved, but little is known about the regulation of telomerase in human gastric carcinoma cells.

METHODS

A total of 27 primary gastric tumors, 29 cases of intestinal metaplasia, and 30 cases of normal mucosa, as well as 8 gastric carcinoma cell lines, were examined for the relation between telomerase activation and gastric carcinogenesis. Telomerase activity was detected by telomeric repeat amplification protocol, and the expression of each telomerase subunit was evaluated by Northern blot analysis or reverse transcriptase--polymerase chain reaction.

RESULTS

Telomerase activity was found in all 8 gastric carcinoma cell lines and in 25 of 27 gastric carcinoma tissue samples (93%), and weakly observed in 11 of 29 gastric intestinal metaplasia samples (38%). None of 30 normal gastric tissue samples displayed telomerase activity. The mRNA expression of human telomerase catalytic subunit (hTERT) was up-regulated in 26 of 26 tumor tissue samples (100%) and in 19 of 24 intestinal metaplasia (79%) in which telomerase activity was weak or negative. Normal gastric mucosa expressed the telomerase gene, albeit at low levels. In contrast to hTERT, human telomerase RNA component and human telomerase-associated protein expression did not parallel telomerase activity, which was independent of tumor stage and histology.

CONCLUSIONS

hTERT expression is up-regulated during an early stage in the carcinogenic process, and telomerase activation may be a critical step in gastric carcinogenesis.

The nuclei innervating digastric muscle do not project to the hypoglossal nucleus in the rat

We employed the retrograde neural tracing method using the pseudorabies virus bartha strain (PRV-Ba) to investigate the projection from accessory trigeminal nucleus (Acc5) or accessary facial nucleus (Acc7) to hypoglossal nucleus (HP). After injection of PRV-Ba into the bellies of the digastric muscle, the PRV-Ba containing neurones were observed in Acc5 of the cranial belly injected rats and Acc7 of caudal belly injected rats ipsilaterally, but not in HP. These results suggest that Acc5 and Acc7 may not project to HP and that movements of the digastric muscle are not related to cooperation with tongue movements during mastication.

The coexistence of calcitonin gene-related peptide and substance P in pericellular arborization and satellite cell of goat trigeminal and nodose ganglia

Pericellular arborization is reported to be the self-regulating structure in sensory ganglia. Although the calcitonin gene-related peptide (CGRP) or substance P (SP) immunoreactive pericellular arborization appeared in the sensory ganglia, there was no available information that CGRP and SP colocalize in this structure. As the attempts to resolve the question described above, the present study was undertaken to identify the coexistence of CGRP and SP in pericellular arborizations of the goat nodose and trigeminal ganglia by double immunohistochemistry. As the results show, CGRP immunoreactivity was present in every pericellular arborization containing SP immunoreactivity in trigeminal ganglia, however, pericellular network containing CGRP or SP immunoreactivity was not present in nodose ganglia. Unexpectedly, a few small satellite elements were observed to contain intense CGRP and SP immunoreactivity at the periphery of CGRP and SP immunoreactive neurones in nodose ganglia. Therefore, these results suggest that CGRP and SP coexist in pericellular arborizations, and that satellite cell as well as pericellular arborization may be involved in intraganglionic regulation of goat sensory ganglia.

Evidence that a beta-1,4-endoglucanase secreted by Acetobacter xylinum plays an essential role for the formation of cellulose fiber

Cellulose-producing Acetobacter xylinum has been known to secrete a cellulose-hydrolyzing beta-1,4-endoglucanase (CMCax). When antibodies to recombinant CMCax were added to the culture medium, the formation of cellulose fiber was severely inhibited. Western blot analysis using the antibody showed that this enzyme was secreted into the medium even by a cellulose non-producing strain (Cel-). These results indicate that beta-1,4-endoglucanase in the medium plays a critical role in the formation of cellulose fiber by the microorganism.

Hypoplastic anaemia complicating myxoedema coma

The case of a 68 year old women presenting in myxoedema coma is described. She was found to be anaemic with a haemoglobin of 8.2 g/dl. Further investigations showed a pancytopenia and a hypoplastic anaemia confirmed by bone marrow. The patient recovered and became euthyroid following initial treatment with intravenous tri-iodothyronine (T3) and later oral thyroxine (T4) replacement with resolution of pancytopenia and return of bone marrow to normal.

Surface features of human aortic atherosclerosis as seen with scanning electron microscopy

Using SEM, we have observed surface structures of atherosclerotic lesions of human aortas obtained from autopsies ranging from 59 to 84 years of age (5 males and 4 females). We have found four major interesting features on the lumenal surface of the aortas: 1) blood cells including leukocytes adhering to the endothelial surface, 2) a de-endothelialized surface showing both elastogenesis and elastolysis, 3) abundant cholesterol-ester crystals in extracellular spaces, and 4) cave-like structures possibly suggesting new capillarization in the thrombotic atherosclerotic plaques. We concluded that SEM has a great value in revealing more interesting surface structures if morphological studies are previously done in detail so that the characteristic shapes can be identified, and perhaps then meaningful interpretations can be made on the mechanism of human atherogenesis.

Gradient-index planar optics for optical interconnections

Use of a gradient-index (GRIN) substrate is proposed as a novel signal-propagation medium for planar optics. The GRIN substrate provides planar optics designers not only a three-dimensional light propagation space but also smart optical diffraction-limited imaging. Experimental results on the imaging of an input signal to multiple destinations by the GRIN planar optics are presented.

Vestibular schwannoma with repeated intratumoral hemorrhage

A symptomatic hemorrhage from a vestibular schwannoma is extremely rare, despite its relatively high incidence in the cerebellopontine angle. Much more unusual are repeated intratumoral hemorrhages. The authors report on such a rare case of repeated intratumoral hemorrhage from a vestibular schwannoma, presenting with sudden exacerbation of headache, nausea and vomiting. This second hemorrhage was confirmed by CT scan on the day of the onset of symptomatic exacerbation, which was 9 days after the initial CT scan, showing an enlarged amount of blood within the tumor. The MRI scan confirmed this CT finding. After removal, the tumor proved to be a typical vestibular schwannoma of mixed Antoni types A and B. Thin-dilated vessels with hemorrhage and hemosiderin-laden macrophages were observed. The patient's postoperative course was uneventful. A total of 28 reported cases of a single intratumoral hemorrhage in vestibular schwannomas, and one reported case of repeated hemorrhage are reviewed.

Beam-array combination with planar integrated optics for three-dimensional multistage interconnection networks

We propose a configuration of planar integrated optics for three-dimensional multistage interconnection networks. To show the feasibility of cascading operations in the planar integrated optics, we present experimental results on the beam combination of signal- and power-beam arrays at a node stage. The beam-combination efficiency measured in the experiment is ~42% of the theoretical limit.

Xanthine dehydrogenase/xanthine oxidase and oxidative stress

Xanthine dehydrogenase (XDH) and xanthine oxidase (XOD) are single-gene products that exist in separate but interconvertible forms. XOD utilizes hypoxanthine or xanthine as a substrate and O2 as a cofactor to produce superoxide (·O2 (-)) and uric acid. XDH acts on these same substrates but utilizes NAD as a cofactor to produce NADH instead of ·O2 (-) and uric acid. XOD has been proposed as a source of oxygen radicals in polymorphonuclear, endothelial, epithelial, and connective tissue cells. However, several questions remain about the physiological significance and functions of XOD on aging and oxidative stress. XOD is reported to play an important role in cellular oxidative status, detoxification of aldehydes, oxidative injury in ischemia-reperfusion, and neutrophil mediation. For example, XOD may serve as a messenger or mediator in the activation of neutrophil, T cell, cytokines, or transcription in defense mechanisms rather than as a free radical generator of tissue damage. Emerging evidence on the synergistic interactions of ·O2 (-), a toxic product of XOD and nitric oxide, may be another illustration of XOD involvement in tissue injury and cytotoxicity in an emergent condition such as ischemia or inflammation.

Prevalence of childhood asthma based on questionnaires and methacholine bronchial provocation test in Korea

BACKGROUND

In most epidemiological survey studies, only subjective symptoms and past medical history of asthma have been used as diagnostic criteria. Even though a questionnaire survey can be performed in a large population study at low cost, limitations such as lack of objectivity and poor predictability in non-specific bronchial hyperresponsiveness cannot be avoided.

OBJECTIVES

The purpose of this study was to elucidate the prevalence of current asthma based on questionnaires and methacholine bronchial provocation test, and the prevalence of atopy in Korea.

METHODS

We performed modified ATS respiratory questionnaires and allergen skin-prick test with 10 common inhalant allergens among 3219 subjects aged 7-19 years in Seoul and a rural part of a small city, Chungju in Korea. Methacholine bronchial provocation tests were also performed among those who had asthma symptoms according to the questionnaire. The criteria of asthma was presence of both asthma symptoms and non-specific bronchial hyperresponsiveness. Atopy was defined as when an allergen induced weal size is same or larger than that caused by histamine.

RESULTS

The prevalence of asthma based on questionnaires and methacholine bronchial provocation tests was 4.6%, while the prevalence of wheeze was 8.2% and 19.3% of total population complained of one or more respiratory symptoms related to asthma on the questionnaires. There was no significant difference according to age, sex and living area. The mean prevalence of atopy was 35.0% and the most common allergens were Dermatophagoides farinae (30.9%), Dermatophagoides pteronyssinus (27.5%), cat fur (20.4%) and cockroach (11.8%). The atopy prevalence in Chungju area was higher than that in Seoul and males showed a higher prevalence than females. The asthma prevalence was higher among atopics (6.8%) than among non-atopics (2.7%). None of questionnaire items were enough to predict the presence of bronchial hyperresponsiveness in terms of sensitivity, specificity and positive predictive value.

CONCLUSION

The prevalence rate of current asthma in Korea was 4.6% and the prevalence rate of atopy in Korea was 35.0%. Questionnaire-based surveys are not enough to predict the actual prevalence of asthma.

Outcome of pediatric patients with severe brain injury in Korea: a comparison with reports in the west

There have been relatively wide variations in the results of studies examining the outcomes of severe brain injury in children. Among the reasons for these variations in outcome, prehospital care can be considered as one of the factors. In Korea, major hospitals use an aggressive and sophisticated management policy very similar to that practiced in the West. However, effective prehospital management, such as emergency care at the scene of injury and during transport by paramedics, have not yet been established. In order to evaluate the influence of prehospital care on the outcome in severely brain-injured children, we report the outcome recorded in 73 pediatric patients treated in our hospital following severe brain injury and compare these results with those reported from centers in the western community, where well-trained paramedic care and an excellent transfer system are in operation. The overall mortality rate in our patients was 23%; 41% had a good recovery, 22% moderate disability, and 12% severe disability, and 1% remained in a vegetative state. In conclusion, we would like to suggest that prehospital care does not remarkably influence mortality rates in severely brain-injured children.

Focusing-grating-coupler arrays for uniform and efficient signal distribution in a backboard optical interconnect

Several one-dimensional arrays of focusing grating couplers are designed for uniform distribution of incident optical powers to several processing boards in a backboard interconnection scheme. As main design parameters, both the length and the duty cycle of each focusing grating coupler are determined on the bases of ray-optic propagation-mode analysis in a slab waveguide and of rigorous coupled-wave diffraction analysis for out-coupled radiation modes. The backboard interconnection scheme incorporating the one-dimensional focusing-grating-coupler arrays, when used to distribute a guided optical power of TE(0) mode to several converging waves radiated only toward a glass substrate, displayed a power uniformity of 5% and a total coupling efficiency of 99.1%, which can be highly acceptable in practical use.

Sulfonated polystyrene as a new gradient-index medium for light-focusing elements

We have discovered that the sulfonation of polystyrene can form a gradient-index medium useful for lightfocusing purposes. We found that the refractive index of sulfonated polystyrene varies with the degree of sulfonation and that the refractive index of the fully sulfonated polystyrene decreased by approximately 0.06 at 0.633 microm from that of pure polystyrene.

Planar optical configurations for crossover interconnects

Two planar optics configurations for crossover interconnects are described, and the interconnection capacity of each configuration is derived on the basis of Gaussian beams' being relayed by microlens arrays. To reduce the optical path differences between bypass- and exchange-connection routes in the crossover configurations, we propose the use of two different substrates.

Three dimensional structures of pulmonary elastin; airway vs vascular elastin

Elastin is known to occur in the lung parenchyma and pleura as well as in the pulmonary vessels, but no detailed studies of this elastin's linkage between them have been done in three dimensions. For many years we have known that there is abundant elastin in the mammalian lungs, which may be associated with etiology of causing emphysema. We have developed selective casting methods to allow us to determine the location where elastin is found morphologically. The method involves casting either the vasculature via the right ventricle, or the airways via the trachea in the air sacs. Studies of the vasculature were done with the lung inflated to 80% of the vital capacity. The casted lungs were then put in 0.1 N NaOH at 75 degrees C for 48 hours, turning them frequently. THis method removed all non-elastin tissues. The scanning electron microscopy (SEM) was used to reveal the three dimensional pictures of elastin structures from both lung parenchyma and pulmonary vessels. Elastin was seen as fenestrated sheets and some fibers in both the vessels and the airways. Elastin in the two different locations was often interconnected. Studies on 6 dogs, 8 rabbits, and 2 pigs showed no significant species difference at the level of resolution of the SEM, which was used to study the specimens after they had been freeze-dried.

Variations in strength of the porcine aorta as a function of location

Dissecting aneurysms split the wall of the aorta and other large arteries to create a false lumen in parallel with the true lumen. Experiments were designed to determine the pressure required to tear the media and the work required per unit area to propagate the dissection once it started. India ink was injected into the media of 17 opened porcine aortas through a needle inserted parallel to the lumen of opened aortas placed in a saline bath. The ink was infused at 0.9 ml/min with a constant infusion pump as the pressure was monitored with a pressure transducer. The size of the bleb formed by the ink in the media was recorded with a video camera mounted perpendicular to the lumenal surface. All data were recorded on a computer. The pressure-volume curve was used to obtain the distensibility of the media (the upslope), the peak pressure, the tearing pressure, and the work of dissection (the area under the P-V curve once tearing occurred). The projected area of the bleb was calculated from the video images, and the work/area was calculated. The peak pressures were always extremely high, and ranged from 634 +/- 204 (SD) mmHg for the lower abdominal aorta to 816 +/- 145 mmHg for the lower thoracic aorta. The work/area ranged from 1.88 +/- 0.89 mJ/cm2 for the upper abdominal aorta to 11.34 +/- 4.05 mJ/cm2 for the lower abdominal aorta. An ANOVA showed that the lower abdominal aorta tore at lower pressures initially, but required much more energy to propagate the dissection. We believe that this is because of structural differences in the elastin pattern in the abdominal aorta.

Optical perfect-shuffle interconnection using a computer-generated hologram

We propose the use of a computer-generated hologram that combines a fanout and focusing element that can be used to perform an optical perfect-shuffle interconnection. The hologram is designed by calculation of the interference fringes between diverging waves from four point sources and a reference plane wave. With this element we show experimentally the resulting perfect-shuffle pattern. The use of the computer-generated hologram makes it easy to implement a planar optical perfect-shuffle interconnect, which is compact, has low aberration, and is easy to align. The planar optics configuration for a perfect-shuffle interconnection network is also discussed.

Development of elastin layers in the aortic wall of human fetuses

The presence of elastin layers in the aortic walls of twelve human fetuses was confirmed with scanning electron microscope pictures after hot alkali treatment and histochemical examination. In addition, the number of elastin layers in aortic walls of 5 different segments were compared in fetuses of varying ages. Aldehyde fuchsin stained slides of elastin ascending aortas showed a range between 27 and 55 layers of elastin in fetuses of 8 weeks to 32 weeks. However, in the lower abdominal aortas, elastin layers decreased from 28 to only 3 layers for fetuses of the same age. Furthermore, as elastin layers decreased from ascending aorta to abdominal aorta with the progression of fetal life, similar changes in the elastin lamellae were observed. These results suggest that while aortas grow rapidly in length, the medial elastin thickens slowly, perhaps due to slow development of hydrodynamic forces and pressures. Also the adventitial elastin appears to lose out gradually along the length from ascending aorta to abdominal aorta.

Compartmental analysis of RBC circulation through the rabbit kidney

This experiment involved 12 rabbits of both sexes, weighing 2.1 kg. After anesthesia, the kidneys were exposed, isolated and cannulated in the renal artery, ureter and sometimes in the vein as well. The kidney were perfused through the renal artery with Krebs-Henseleit solution, which were then filtered to be free of particles, gased with 95% O2-5% CO2, and kept at 37 degrees C. We measured RBCs concentrations by means of Coulter Counter in the venous outflow collected, and plotted them against the volume perfused. Using 2 different flow rates, 9 ml/min (group I) and 19 ml/min (group II), we found that the RBCs decreased in a multiexponential decay fashion and a biophysical model for each flow rate was constructed. These models indicated that there were more cell stores (2.20 x 10(10)) in the fast compartment of group II than in group I (1.72 x 10(10)). This difference is not statistically significant, but certainly coincides with urine flow collected from ureter cannula during perfusion. Our present data clearly suggest that in order to clear 99% blood cells out of 10-12 gm rabbit kidneys, at least 3-6 ml of cell free perfusate is required while clearing the whole blood cells out of human kidneys (200-240 gm) may need 600 ml or more. Thus, we recommend that at least 600 ml of perfusate should be used to clear most of the blood cells in the renal vasculature before renal transplantation is performed.

Morphological evidence of pulmonary vascular leakage through gaps observed with casting methods and S.E.M

We have used selective casting methods to separate pulmonary elastin from vascular elastin in the lungs of rabbits, dogs and pigs. The lungs are digested with 0.1 N NaOH at 75 degrees C for 24 approximately 48 hours with frequent turning as the lungs are filled with air to about 80% of the vital capacity prior to the casting which is done at pressure of 20 approximately 50 mmHg. After vascular injections, we saw many small globular bits of casting material well separated from cast vessels and lying in the pulmonary elastin. Surface forces should make the casting material creep along the vessels even if they are not completely filled, so that the spherical shape is the one expected if the case is extruded into the parenchymal space and the air space. We conclude that this suggests that the pulmonary circulation is partially and temporarily 'open' as seen in the spleen and some other organs, rather than a completely 'closed' one as is generally accepted. At least some of these extravasations may be associated with lymphatics, although we have not proved this.

Planar optical implementation of crossover interconnects

We propose a planar optical configuration for implementation of crossover interconnects. The planar overlay allows two-dimensional pixel arrays located on a wafer-scale integrated circuit to be interconnected in a compact and vibrationally robust configuration. By using an acute-angle microprism array with apex angles of 70.52 deg fabricated on a silicon substrate, we show the experimental result of the crossover interconnections. Some practical limits of the planar optical crossover interconnections are also discussed.