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Biomedical subjects

K Ando

Publications and source records attributed to K Ando.

At least 181 records · Page 10Linked to original sources
PubMed1998

Telomerase activity in lung cancer cells obtained from bronchial washings.

BACKGROUND: Telomerase, a ribonucleoprotein enzyme that functions in the maintenance of telomeres (specialized structures at the ends of chromosomes), has been reported to be a novel diagnostic marker for malignant diseases. We sought to determine whether measurement of telomerase activity in bronchial washings is of value in the diagnosis of lung cancer. METHODS: Extracts of cells in bronchial washings were analyzed for telomerase activity by use of a telomeric repeat amplification protocol (TRAP) assay. Telomerase activity inside cells was evaluated by use of an in situ TRAP assay. The results of both TRAP assays were compared with those obtained from cytologic examination, which employed standard Papanicolaou staining. RESULTS: When results from the two TRAP assays were combined, telomerase activity was detected in bronchial washings from 18 (82%; 95% confidence interval [CI] = 60%-95%) of 22 patients with lung cancer. In contrast, cancer cells were detected by cytologic examination in the bronchial washings of nine (41%; 95% CI = 21%-64%) of the same 22 patients, a statistically significant difference (two-sided P = .0061). In patients with lung cancer, telomerase-positive cells could be detected in bronchial washings irrespective of tumor location--11 of 14 (79%; 95% CI = 49%-95%) peripheral cancerous lesions and seven of eight (88%; 95% CI = 47%-100%) central cancerous lesions were detected by use of TRAP assays (for comparison, two-sided P = .5349). CONCLUSIONS: A high percentage of patients with lung cancers had detectable telomerase activity in bronchial washings. Thus, the use of a cell extract-based or an in situ TRAP assay in addition to cytologic examination may make the diagnosis of lung cancer more reliable.

Adult↗
PubMed1998

Absolute calibration of a soft X-ray spectrograph for X-ray laser research using white beam.

Absolute calibration of a soft X-ray spectrograph has been performed using a white beam of synchrotron radiation. The calibrated spectrograph was a flat-field grazing-incidence spectrograph with an X-ray CCD detector for X-ray laser research. Absolute sensitivity of the spectrograph system can be obtained from transmitted spectra using filters made of several different materials, each providing an absorption-edge wavelength standard. The absolute sensitivity determined in this work shows nearly the same behaviour with wavelength as that in another calibration experiment using a laser-produced plasma as an X-ray source.

Journal Article↗
PubMed1998

Overexpression of a minor component of myelin basic protein isoform (17.2 kDa) can restore myelinogenesis in transgenic shiverer mice.

Shiverer (shi) mice, which are neurologically mutant, lack a large portion of the gene for the myelin basic proteins (MBPs), have virtually no myelin in their central nervous system (CNS), and shiver, undergo seizures, and die early. At least five types of MBPs (21.5, 18.5, 17.3, 17.2 and 14.0 kDa) are known to be generated through alternative splicing from a single MBP gene. We have produced transgenic shi mice carrying a cDNA encoding mouse 14-kDa MBP isoform, the most abundant form of MBPs, under control of a mouse MBP gene promoter, and showed that expression of the 14-kDa MBP can restore CNS myelination. To test whether the 17.2-kDa MBP isoform, one of the minor components of MBPs, can also elicit myelination in homozygous shi mutants, we produced seven independent transgenic shi mice carrying cDNA encoding the mouse 17.2-kDa MBP isoform, and the transcription of which was driven by a mouse MBP gene promoter. The axons in the cerebellum of one transgenic line, which exhibited the highest expression of transgene-derived mRNA ( approximately 50% of the level of total MBP mRNA in the normal mouse brain), were myelinated. This mouse exhibited nearly normal behavior. These findings indicate that the 17.2-kDa MBP isoform, even when the only 17.2-kDa MBP isoform is present, has the ability to elicit CNS myelination in transgenic shi mice. This transgenic strategy will be useful for elucidating the role of each type of MBP isoform in CNS myelinogenesis.

Alternative Splicing↗
PubMed1998

Nitrergic innervation of the cerebral arterial tree in the bent-winged bat (mammalia: Microchiroptera).

The distribution and origin of cerebrovascular nitrergic nerves were studied immunohistochemically and histochemically in the bent-winged bat. The supply of nitric oxide synthase (NOS)-immunoreactive (IR) and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-positive nerves to the bat major cerebral arteries differs from the general mammalian pattern in that it is preferential for the vertebrobasilar system (VBS) as opposed to the internal carotid system. Interestingly, a few nerve cells with bright NOS immunofluorescence and intense NADPHd activity were localized in the walls of the vertebral artery (VA) and basilar artery (BA) from many individual bats. Cerebral perivascular NOS-IR nerves were generally immunoreactive for vasoactive intestinal polypeptide (VIP). NOS-IR neurons intrinsic to the BA and VA expressed variable degrees of VIP immunoreactivity and showed no acetylcholinesterase (AChE) activity. Most cell bodies of the microganglia (MG) in the carotid canal and tympanic cavity, and those of the cranial and cervical facial ganglia, showed both NOS and VIP immunoreactivities and were stained intensely for NADPHd. From these and other findings, it is suggested that, in the bent-winged bat at least, the BA and VA of the cerebral arterial tree are frequently dually innervated by two neurochemically defined nitrergic neurons, the cranial parasympathetic VIP-IR and AChE-positive neurons, which are derived mainly from the MG via the internal carotid artery, and the intrinsic neurons, either IR or immunonegative for VIP but negative for AChE, which form an outflow tract from some caudally located ganglia projecting to the VBS via the VA.

Acetylcholine↗
PubMed1998

Adenovirus-mediated gene transfer to the ocular surface epithelium.

Gene transfer to the ocular surface epithelium is of potential therapeutic value. It was determined whether a reporter gene can be introduced into the ocular surface epithelium in vitro (human cell lines), ex vivo (human tissues), and in vivo (rats) by treating with a recombinant, replication-deficient, adenovirus type 5. Human and conjunctival cell lines were cultured with various multiplicities of infection (MOI; 3.2x10(-5)-5x10(-1)) of adenovirus vector (Ad5:Adex1CAlacZ) containing the reporter gene lacZ (1.3-2.0x10(4) PFU ml-1). The ex vivo study used human corneal and conjunctival tissues obtained from an eye bank and during surgery. Non-specific upregulation of inflammatory cytokines of conjunctival epithelium infected by Ad5 was assayed and its suppression by steroids. For the in vivo study, Ad5 (5x10(5) PFU, 5-10 microliter) was applied to the eyes of 8-12-week-old cotton rats, which were enucleated 24 and 48 hr later. The maximum lacZ expression in vitro was demonstrated in the corneal epithelial cell line at 7 days (1x10(-1) MOI) and conjunctival epithelial cell line at 2 days (4x10(-4) MOI). Furthermore, lacZ was also expressed in the superficial corneal and conjunctival epithelium in the ex vivo study. IL-6, IL-8, and ICAM-1 expression from conjunctival epithelium by Ad5 was significantly inhibited by treatment with betamethasone (BM). For the in vivo study, only the conjunctival epithelium demonstrated beta-Gal activity at 24 and 48 hr after application. These data indicate that adenovirus vector is capable of directly delivering gene to the corneal and conjunctival epithelium, suggesting a variety of possible gene therapy uses. The concomitant application of steroid eye drops may avoid inflammation.

Adenoviridae↗
PubMed1998

Cell death induced by high-linear-energy transfer carbon beams in human glioblastoma cell lines.

The cytotoxic effect of high-linear-energy transfer (LET) carbon beams on two human glioblastoma cell lines (A172 and TK1) was analyzed, especially concerning cell death, including apoptosis. Gamma-ray radiation was used for comparison. The results of standard colony formation assay showed that the survival fraction of each cell line decreased in an LET-dependent manner. The results of other direct cytotoxic assays, dye exclusion test, and lactate dehydrogenase (LDH) release assay, also displayed a similar relationship between the cytotoxic effect of carbon beams and LET. The maximum values of the cell death index (CDI) were 50.2% in A172 and 37.5% in TK1, both obtained on day 7 after exposure to carbon beams of 80 keV/microm. Apoptosis was observed only on days 4 and 7 after carbon beam irradiation, with maximum values of 7% in A172 and 4.5% in TK1, and the induction of apoptosis after high-LET radiation could be p53-independent. This indicated that a combination of multiple assays to detect cell death was important in evaluating the radiosensitivity of tumor cells, because this approach could more precisely reflect the clinical effectiveness of radiotherapy.

Apoptosis↗
PubMed1998

Management of vesicoureteral reflux secondary to neurogenic bladder.

The authors encountered 108 cases of vesicoureteral reflex (VUR) in 231 cases of neurogenic bladder complicating spina bifida. Bladder compliance and percent volume (% vol.) were measured pre- and postoperatively and the patients were divided into four groups retrospectively according to the treatment. Ninety-five percent of low-grade VUR (grades I and II) disappeared spontaneously with conservative therapy or after augmentation cystoplasty without antireflux surgery; 92% of high-grade VUR (grade III or more) required ureteral reimplantation with or without bladder augmentation. Reflux did not recur in any case of ureteral reimplantation with bladder augmentation, however, it did recur in 20.4% of the cases of simple ureteral reimplantation without bladder augmentation. Percent volume and bladder compliance in cases of recurrence following simple ureteral reimplantation were significantly lower than in the successful cases. This study suggests that low-grade VUR can resolve spontaneously with conservative therapy or with a suitable maneuver to improve bladder compliance. High-grade reflux in cases of preserved bladder volume (% vol.>75%) and compliance (>7 ml/cmH2O) can be treated successfully with simple ureteral reimplantation, however, in cases of low volume (% vol.<60%) and low compliance (<4 ml/cmH2O), reimplantation with bladder augmentation is recommended.

Adolescent↗
PubMed1998

Telomeric length and telomerase activity vary with age in peripheral blood cells obtained from normal individuals.

The telomerase activity and length of telomeres of peripheral blood mononuclear cells obtained from 124 healthy individuals aged 4-95 years was measured. Telomerase activity level was semiquantitatively assessed by a fluorescent-telomeric repeat amplification protocol (fluorescent-TRAP) using an internal telomerase assay standard, fluorescent primers and an automated laser fluorescent DNA sequencer. Telomeric length, measured by assay of terminal restriction fragments (TRFs), was determined in HinfI-digested DNA by Southern blot analysis using a (TTAGGG)4 probe. TRF length was determined in 80 individuals and age-related progressive reduction of size was observed. TRF length in peripheral blood mononuclear cells obtained from normal individuals (aged 4-39 years) decreased by approximately 84 bp per year, while in individuals aged > or = 40 years it decreased by 41 bp per year. In contrast, telomerase activity showed an apparent biphasic pattern with aging. Individuals aged 4-39 years showed a progressive decrease in telomerase activity, whereas 65% of those aged > or = 40 years showed relatively stable but very low telomerase activity, and the remaining individuals aged > or = 40 years had no detectable telomerase activity. These data obtained from normal individuals might in the future be of value to help risk stratify and manage the care of patients with leukemia.

Adolescent↗
PubMed1998

Y-shaped tracheobronchial stent for carinal and distal tracheal stenosis.

A Y-shaped tracheo-bronchial tube was designed and used for two patients with carinal stenosis following a lower tracheal resection in one case and a malignant tracheal fistula in the other. The tube consisted of three parts including a Y-shaped, thin-walled, soft silicone stent; a spiral-wire-reinforced main tube; and a curved tracheostomy tube. The stent was inserted easily and comfortably through the tracheostomy under fiberoptic bronchoscopic guidance with minimal local anesthesia. The positioning stability of the tube was excellent because of the carina-shaped structure of the tube end. Resistance to compression was satisfactory due to the embedded spiral wire. The insertion procedure through the tracheostomy was smooth, even in patients whose respiratory condition was severe or critical. Satisfactory phonational activity was also provided by breathing through the hole on the tube back up to the vocal cord. Bronchoscopic inspection was uncomplicated, and the patients themselves could easily clean the stent. Since palliation of the airway obstruction is the main purpose of such a stent for patients with either severe lower tracheal or carinal stenosis, and because of the difficulty of ordinary stent insertion in this part of the airway, this device appears to offer excellent stability and easy insertion of the stent. In addition, the ease of maintenance and suctioning through the tracheostomal end allows for an excellent quality of life in which the patients are able to return to their homes.

Adult↗
PubMed1998

Effect of n-3 fatty acid supplementation on lipid peroxidation and protein aggregation in rat erythrocyte membranes.

Human erythrocytes in the circulation undergo dynamic oxidative damage involving membrane lipid peroxidation and protein aggregation during aging. The present study was undertaken to determine the effect of n-3 fatty acid supplementation on lipid peroxidation and protein aggregation in the circulation and also the in vitro susceptibility of rat erythrocyte membranes to oxidative damage. Wistar male rats were fed a diet containing n-6 fatty acid-rich safflower oil or n-3 fatty acid-rich fish oil with an equal amount of vitamin E for 6 wk. n-3 Fatty acid content in erythrocyte membranes of rats fed fish oil was significantly higher than that of rats fed safflower oil. The degree of membrane lipid peroxidation and protein aggregation of rats fed fish oil was not significantly higher than that of rats fed safflower oil when the amounts of phospholipid hydroperoxides, thiobarbituric acid-reactive substances, and detergent-insoluble protein aggregates were measured. When isolated erythrocytes were oxidized under aerobic conditions in the presence of Fe(III), the degree of membrane lipid peroxidation of erythrocytes from rats fed fish oil was increased to a greater extent than that of rats fed safflower oil, whereas the degree of membrane protein aggregation of both groups was increased in a similar extent. Hence, n-3 fatty acid supplementation did not affect lipid peroxidation and protein aggregation in membranes of circulating rat erythrocytes, and the supplementation increased the susceptibility of isolated erythrocytes to lipid peroxidation, but not to protein aggregation, under the aerobic conditions. If a sufficient amount of vitamin E is supplied, n-3 fatty acid supplementation may give no undesirable oxidative effects on rat erythrocytes in the circulation.

Animals↗
PubMed1998

Pedicled external spermatic fascia flap for urethroplasty in hypospadias and closure of urethrocutaneous fistula.

PURPOSE: To prevent the development of urethrocutaneous fistula after urethroplasty for hypospadias or recurrence after closure of a urethrocutaneous fistula, the authors developed a new simple technique wherein the readily available external spermatic fascia (ESF) surrounding the testis and cord is used as a pedicled blanket flap to cover the neourethra or the site of closure of a urethrocutaneous fistula. RESULTS: In three patients who had urethroplasty for hypospadias incorporating our ESF flap procedure, no urethrocutaneous fistula developed. It was also effective for closure of urethrocutaneous fistula in five patients, some of whom had had recurrent fistula formation.

Adult↗
PubMed1998

Reconstitution of immune systems in RAG2-/- mice by transfer with interleukin-12-induced splenic hematopoietic progenitor cells.

The administration of a high dose of IL-12 into the mice resulted in the induction of splenomegaly. From the flow cytometry analysis of cellularity in an enlarged spleen, it was demonstrated that Thyl.2-CD45RB-c-Kit + Sca-1 + Lin- hematopoietic progenitor cells markedly increased in IL-12-administered mouse spleen compared with untreated mouse spleen. The IL-12-induced hematopoietic progenitor cells showed a greatly enhanced colony-forming activity in CFU-granulocyte/macrophage (CFU-GM), blast-forming units-erythroid (BFU-E) and CFU-spleen (CFU-S) assay. Moreover, it was initially demonstrated that the transfer of IL-12-induced splenic hematopoietic progenitor cells into immunodeficient RAG2-/- mice caused a complete reconstitution of their immune functions including T- and B-cell-mediated immunity. Thus, the evidence that IL-12 has a capability of inducing hematopoietic progenitor cells possessing stem cell-like activity in vivo, indicated another important immunomodulating activity of IL-12 in immunotherapy.

Animals↗
PubMed1998

Correlation between cell death and induction of non-rejoining PCC breaks by carbon-ion beams.

We have shown a correlation between cell death and induction of non-rejoining chromatin breaks in two normal human cells and three human tumor cell lines irradiated by carbon-ion beams and X rays. Non-rejoining chromatin breaks were measured by counting the number of remaining chromatin fragments detected by the premature chromosome condensation (PCC) technique. Carbon-ion beams were accelerated by the Heavy Ion Medical Accelerator in Chiba (HIMAC). The cells were irradiated by two different mono-LET beams (LET = 13 keV/micrometer and 77 keV/micrometer ) and 200 kV X rays. The RBE values of cell death for carbon-ion beams relative to X rays were 1.1 to 1.4 for 13 keV/micrometer beams and 2.5 to 2.9 for 77 keV/micrometer beams. The induction rate of non-rejoining PCC breaks per cell per Gy was found to be highest for the 77 keV/micrometer beams for all of the cell lines. The results found in this study show that there is a good correlation between cell death and induction of non-rejoining PCC breaks for these human cell lines.

Astrocytoma↗
PubMed1998

Residual chromatin breaks as biodosimetry for cell killing by carbon ions.

We have studied the relationship between cell killing and the induction of residual chromatin breaks on various human cell lines and primary cultured cells obtained by biopsy from patients irradiated with either X-rays or heavy-ion beams to identify potential bio-marker of radiosensitivity for radiation-induced cell killing. The carbon-ion beams were accelerated with the Heavy Ion Medical Accelerator in Chiba (HIMAC). Six primary cultures obtained by biopsy from 6 patients with carcinoma of the cervix were irradiated with two different mono-LET beams (LET = 13 keV/micrometer, 76 keV/micrometer) and 200kV X rays. Residual chromatin breaks were measured by counting the number of non-rejoining chromatin fragments detected by the premature chromosome condensation (PCC) technique after a 24 hour post-irradiation incubation period. The induction rate of residual chromatin breaks per cell per Gy was the highest for 76 keV/micrometer beams on all of the cells. Our results indicated that cell which was more sensitive to the cell killing was similarly more susceptible to induction of residual chromatin breaks. Furthermore there is a good correlation between these two end points in various cell lines and primary cultured cells. This suggests that the detection of residual chromatin breaks by the PCC technique may be useful as a predictive assay of tumor response to cancer radiotherapy.

Biomarkers↗
PubMed1998

Microsatellite instability in human mammary epithelial cells transformed by heavy ions.

We analyzed DNA and proteins obtained from normal and transformed human mammary epithelial cells for studying the neoplastic transformation by high-LET irradiation in vitro. We also examined microsatellite instability in human mammary cells transformed to various stages of carcinogenesis, such as normal, growth variant and tumorigenic, using microsatellite marker D5S177 on the chromosome 5 and CYl7 on the Chromosome 10. Microsatellite instabilities were detected in the tumorigenic stage. These results suggest that microsatellite instability may play a role in the progression of tumorigenecity. The cause of the genomic instability has been suggested as abnormalities of DNA-repair systems which may be due to one of the three reasons: 1) alterations of cell cycle regulating genes. 2) mutations in any of the DNA mismatch repair genes, 3) mutation in any of the DNA strand breaks repair genes. No abnormality of these genes and encoded proteins, however was found in the present studies. These studies thus suggest that the microsatellite instability is induced by an alternative mechanism.

Breast↗
PubMed1998

Spontaneous perforation of choledochal cyst: a study of 13 cases.

Of the 187 cases of infantile choledochal cyst treated at our hospitals, we encountered 13 with spontaneous perforation. All cases were under 4 years old. Eight cases were found to have biliary peritonitis and 5 had a sealed perforation. The shape of the extrahepatic bile duct was cystic in 8 and fusiform in 5. The cyst wall around the perforation was filmy and bile was found to be oozing through the thinned wall. Nine perforations were single while 4 cases had multiple perforations. Four of 17 perforations occurred in the posterior part of the cyst wall. Only 1 case of perforation was associated with protein plugs in a common channel, while 7 of the 10 cases of choledochal cyst requiring percutaneous biliary drainage due to signs of raised intrabiliary pressure were found to have protein plugs. We consider that spontaneous perforation of a choledochal cyst is not rare in infancy. The etiology of a perforation must be epithelial irritation of the biliary tract due to refluxed pancreatic juice caused by pancreatico-biliary malunion associated with mural immaturity due to infancy, rather than an abnormal rise in ductal pressure or congenital mural weakness at a certain point.

Abdominal Pain↗