Search PubMed⌕ Search

Biomedical subjects

T Yoshioka

Publications and source records attributed to T Yoshioka.

At least 289 records · Page 16Linked to original sources
PubMed1997

Transurethral visual laser ablation of the prostate for benign prostatic hyperplasia using a KTP/YAG laser.

BACKGROUND: Transurethral visual laser ablation of the prostate (VLAP) has been established as an alternative method for the treatment of benign prostatic hyperplasia (BPH). However, most VLAP procedures utilize only a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. Since a potassium-titenyl-phosphate (KTP) laser offers limited tissue penetration, KTP can be safely utilized to excise part of the obstructing prostatic tissue. This study assessed the interaction between KTP vaporization and YAG coagulative ablation to determine the safety and efficacy of VLAP utilizing a combined KTP/YAG treatment. METHODS: Forty patients with bladder outlet obstruction secondary to BPH were treated with VLAP using a KTP/YAG laser. The laser light was delivered by an angle delivery device. RESULTS: Most cases demonstrated a significant improvement in routine subjective and objective parameters (AUA symptom score, peak flow rate, average flow rate, and amount of residual urine). No significant complications relating to this procedure were reported, however, 4 patients experienced postoperative acute urinary retention. CONCLUSION: KTP/YAG laser ablation of the prostate is safe and effective for the treatment of BPH.

Aged↗
PubMed1997

Immunohistochemical studies on matrix metalloproteinase-9 (MMP-9) and type-IV collagen in endometrial carcinoma.

Immunohistochemical staining of MMP-9 and the type-IV collagen was performed on paraffin sections of endometrial carcinoma. Immunostaining in 129 cases of endometrial cancer detected MMP-9 in 19.0% of the cases. MMP-9 positive was shown in 30% of the cases with vessel invasion, and in 12.7% of the cases without vessel invasion (p < 0.05). MMP-9 showed positive in many cases with poor differentiation and lymph node metastasis, but still failed to achieve statistical significance. MMP-9 staining did not correlate with disease outcomes. We can not clarify that MMP-9 is associated with tumor-cell invasion and metastasis. Type-IV collagen deposition at the tumor-stromal border was studied in 58 cases of endometrial carcinoma in which disruptions were seen in varying degrees. The type-IV collagen in the primary lesion decreased as the differentiation decreased. Even in the lymph node metastasis lesions, the type-IV collagen was stained and was almost in agreement with the primary lesions. In the primary lesions, there was no relationship between MMP-9 staining and the type-IV collagen. It was suggested that the type-IV collagen observed in endometrial carcinoma was more concerned with the differentiation of the tumor than with the degradation by MMP-9.

Adenocarcinoma↗
PubMed1997

Sapecin B, a novel fly toxin, blocks macroscopic K+ currents in the GH3 rat pituitary cell line.

Sapecin B is structurally homologous to charybdotoxin (CTX), which is found in scorpion venom. This study investigated the effects of sapecin B on the Ca(2+)-activated K+ currents [IK(Ca)] and the rapidly inactivating K+ currents in clonal rat GH3 pituitary cells with whole cell voltage-clamp methods. Sapecin B (20 nM) reversibly blocked the CTX-sensitive Ix(Ca) (the BK current) in a dose-dependent manner, with a half-maximal inhibitory concentration of approximately 0.9 nM, comparable to that of 0.08-0.4 nM for CTX. The Ca2+ currents in GH3 cells, however, were not affected by sapecin B (40 nM), indicating that the blockade of IK(Ca) by sapecin B is not a secondary effect of Ca2+ current inhibition. The effect of sapecin B on IK(Ca) resembled that of CTX, as expected from the structural similarities shared by CTX and sapecin B. We also found that sapecin B largely inhibited the 4-aminopyridine-sensitive, rapidly inactivating K+ currents in a dose-dependent manner, with a half-maximal inhibitory concentration of approximately 40 nM, whereas CTX had little effect on this current in GH3 cells. Sapecin B may thus provide a useful tool, complementary to CTX, for probing the functional role of molecular domains in the BK channels and the structural similarities common to the BK and the rapidly inactivating A-type K+ channels.

4-Aminopyridine↗
PubMed1997

A sublethal dose of LPS to pregnant rats induces TNF-alpha tolerance in their 0-day-old offspring.

The newborn has high mortality in septic shock. Induction of endotoxin tolerance may prevent endotoxic shock in the newborn. The present study showed that a small dose of Salmonella enteritidis lipopolysaccharide (S. ent. LPS), Rc mutant Escherichia coli lipopolysaccharide (J5 LPS), or tumor necrosis factor-alpha (TNF-alpha) given to pregnant rats on the 19th day of gestation induced endotoxin tolerance in their 0-day-old offspring. S. ent. LPS or J5 LPS injected into pregnant rats increased plasma endotoxin-like activity in dams, although not in their fetuses, and increased plasma TNF-alpha concentration in both dams and their fetuses. The endotoxin-tolerant newborn rats were also resistant to TNF-alpha. In those newborn rats, an LPS injection increased plasma TNF-alpha concentration and liver TNF-alpha mRNA abundance. These experiments showed that the endotoxin tolerance could be due to TNF-alpha tolerance. In conclusion, prenatal treatment of dams with a small dose of S. ent. LPS, J5 LPS, or TNF-alpha was beneficial in preventing endotoxic shock in the newborn.

Abortion, Veterinary↗
PubMed1997

cDNA cloning, characterization, and chromosome mapping of UBE2E2 encoding a human ubiquitin-conjugating E2 enzyme.

A cDNA encoding a human ubiquitin-conjugating enzyme (E2) with N-terminal extension (UBE2E2/UbcH8) was isolated. Amino acid sequence within the UBC domain of UBE2E2 shares over 90% identity with human UbcH6, mouse UbcM2, and Drosophila UbcD2, whereas the N-terminal region shows little amino acid sequence similarity with known proteins. The UBE2E2 gene is transcribed in various tissues as a 1.9-kb transcript. The UBE2E2 protein formed a thioester bond with ubiquitin in an E1-dependent manner, indicating that the gene product is a functional E2 enzyme. The UBE2E2 gene was assigned to human chromosome 3p24.2 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed1997

Assignment of STK6 to human chromosome 20q13.2-->q13.3 and a pseudogene STK6P to 1q41-->q42.

Fluorescence in situ hybridization analysis of human STK6 encoding a mitotic centrosomal protein kinase, Aik, revealed two signals in chromosome bands 20q13.2-->q13.3 and 1q41-->q42. Somatic cell hybrid panel analyses showed the existence of an identical sequence to STK6 cDNA on chromosome 20, and a processed pseudogene on chromosome 1. These results suggest that STK6 is localized at 20q 13.2-->q13.3 and a pseudogene STK6P at 1q41-->q42.

Aurora Kinase A↗
PubMed1997

Staphylococcal scalded skin syndrome in an adult. Identification of exfoliative toxin A and B genes by polymerase chain reaction.

A 68-year-old man developed areas of erythema with flaccid bullae and wrinkling on his face, upper extremities, chest, right buttock, and shins. Histological examination revealed an intraepidermal cleavage with a sparse cellular infiltration in the dermis, consistent with a diagnosis of staphylococcal scalded skin syndrome. Cultures from an abscess of his right knee joint and his blood were both positive for Staphylococcus aureus. Both S. aureus isolates were confirmed to be double-producers of ETA and ETB using the polymerase chain reaction. The use of nonsteroidal anti-inflammatory drug seemed to be one of the predisposing factors in this patient.

Aged↗
PubMed1997

Endotoxemia following enteral refeeding in children.

Plasma endotoxin-like activity, tumor necrosis factor alpha (TNFalpha) concentrations, core body temperature, and liver functions were measured before and after enteral feeding in children who had been deprived of enteral feeding for 5 days because of their illness. Transient endotoxemia and elevations in plasma TNFalpha concentrations occurred. Core body temperature, aspartate aminotransferase, alamine aminotransferase, and bilirubin concentrations were normal in patients who had elevated plasma endotoxin-like activity. Transient endotoxemia following enteral feeding may be due to the translocation from the gastrointestinal (GI) tract as a result of increased mesenteric circulation and peristalsis. No clinical consequences were noted despite transient endotoxemia. The transient endotoxemia is not due to the immature GI tract; instead, it results from enteral feeding following the deprivation of enteral feeds.

Asthma↗
PubMed1997

Patterns of inspiratory muscle shortening during hypoxia and hypercapnia in dogs.

The shortening of parasternal intercostal muscles (Para) and crural (Cru) and costal diaphragms (Cos) are not precisely understood. We therefore examined shortening patterns of these inspiratory muscles by using chronically implanted sonomicrometers in dogs. To avoid acute effects of surgery, measurements were performed 3 weeks after implanting the sonomicrometers. Patterns of length changes of Para, Cru, and Cos were measured during hypoxia and hypercapnia under two levels of anaesthesia. Respiratory length change (delta L) was assessed as a percentage change relative to the resting length at functional residual capacity (LFRC). Peak tidal shortening was defined as the maximal change from LFRC (delta L/LFRC). Under light anesthesia, the delta L/LFRC was the same among the three muscle groups at all tidal volumes (VT). Under deep anaesthesia, the delta L/LFRC both of Cru and Cos exceeded that of Para. Under light anaesthesia, the maximal shortening velocity ((delta L/LFRC)/delta t) of Cru was greater than that of Para. Under deep anaesthesia, the (delta L/LFRC)/delta t of Para was exceeded by that both of Cru and Cos. Furthermore, the (delta L/LFRC)/delta t of each inspiratory muscle was greater during hypoxia than during hypercapnia at equal volume. We conclude that: 1) the contribution of the diaphragm to ventilation increases during deep anaesthesia; 2) the muscle shortening velocity during hypoxia or hypercapnia is lower in parasternal intercostal muscles than in the diaphragm; and 3) there is no difference in the shortening pattern between crural and costal diaphragms.

Anesthesia↗
PubMed1997

Therapeutic effect of cytomedicine on mesangio-proliferative glomerulonephritis in human interleukin-6 transgenic mice.

We previously demonstrated that IgG1 plasmacytosis in human interleukin-6 transgenic mice (hIL-6 Tgm) was suppressed by the implantation of SK2 hybridoma cells (SK2 cells, which secrete anti-hIL-6 monoclonal antibodies) microencapsulated in a semipermeable and biocompatible device. In this study, we demonstrated that the mesangio-proliferative glomerulonephritis in hIL-6 Tgm was also improved by the same treatment. These results strongly support the concept of cytomedicine, which is a novel drug delivery system (DDS) using living cells. However, an electron microscopy study showed that cytomedicine has a limited duration of effectiveness because of the disappearance of space for cell proliferation in the microcapsule. Thus, the control of cell proliferation in a device must be developed to prolong the function and effectiveness of cytomedicine.

Animals↗
PubMed1997

[Studies on compounds with antioxidant activity--development of hypoglycemic agents, troglitazone (CS-045)].

An interest in compounds having both the quenching activity of the active oxygen species (antioxidant activity) and hypoglycemic and/or hypolipidemic activities significantly increases in the field of angiopathic disease, especially in the elderly. We studied hindered phenols in order to find biologically active compounds having the above activities. As a result, several compounds, such as 1,3-benzoxathioles, phenoxypentanoic acids, phenoxypentanols, 2-chloro-3-phenylpropionic acids, and thiazolidines, were found. Among these compounds, a thiazolidine, troglitazone, (CS-045), 1, showed desired biological properties both in vitro and in vivo without causing any increase in liver weight, and so was developed as a new type of antidiabetic agent. In this review, the structural design and the biological activities including antioxidant activities are described.

Animals↗
PubMed1997

Quenching of nitric oxide by an oral carbonaceous adsorbent.

The ability of carbonaceous particles (AST-120), originally developed as an enteral adsorbent of uremic toxins, to quench nitric oxide (NO) was tested. NO in solutions prepared by two methods [NO gas bubbling and NO generating system, i.e., decomposition of 1-hydroxy-2-oxo-3-(aminopropyl)-3-isopropyl-1-triazene] were determined by a NO-specific reduction of carboxy-2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide using an electron paramagnetic resonance spectrometry. NO concentrations were less in samples containing increasing concentrations of AST-120. In a separate study, nitrite concentrations in lipopolysaccharide-treated RAW264 cells were significantly less in incubation medium containing AST-120. Thus, AST-120 may be applicable as an enteral anti-NO agent.

Adsorption↗
PubMed1997

Effects of spaceflight on enzyme activities and ultrastructure of fast-type skeletal muscles of rats.

The activity of succinate dehydrogenase in the medial gastrocnemius muscles of rats was significantly increased following a 2-week spaceflight (p < 0.05). That of phosphofructokinase in plantaris muscles was lowered after the flight (p < 0.05). The overall activities of both enzymes were effectively maintained during the flight. No structural alterations in the mitochondria or other organelles were observed in response to spaceflight. However, disordering of myofilament and central nucleus were often seen in the fast muscle during recovery after landing, but not immediately after landing. These observations indicate that spaceflight increases susceptibility to sarcomere damage and metabolic activity in a specific muscle during reloading.

Animals↗
PubMed1997

Does local or global orientation determine the McCollough effect?

In this research, the McCollough effect was observed by using an ambiguous test pattern of coarse gratings made out of fine gratings. Coarse gratings meet at right angles to fine gratings. The global features (coarse gratings) in the test pattern became more salient if the test pattern was blurred, and the frequency of the McCollough effect, corresponding to the global orientation of the test pattern, increased with the increase of the extent of blur. The McCollough effects corresponding to the local orientation of the test pattern occurred frequently if the subjects adapted to fine gratings before viewing the test pattern, whereas the McCollough effects corresponding to the global orientation of the test pattern occurred frequently if the subjects adapted to coarse gratings. Our results indicate that the perceptual organization is an important determinant in the McCollough effect.

Adult↗
PubMed1997

Molecular mechanisms of apoptosis in HL-60 cells induced by a nitric oxide-releasing compound.

Nitric oxide (NO) generated from 1-hydroxy-2-oxo-3, 3-bis(2-aminoethyl)-1-triazene (NOC 18), an NO-releasing compound, induced monocytic differentiation of human promyelocytic leukemia HL-60 cells as assessed by expression of nonspecific esterases and morphologic maturation. Simultaneously, DNA fragmentation and morphological alterations typical of apoptosis were also induced. To investigate the mechanisms of apoptosis during differentiation of HL-60 cells induced by NO, the endogenous levels of Bcl-2 and Bax were assessed by immunoblotting. Treatment of cells with NOC 18 slightly reduced the level of Bcl-2 followed by Bax. These changes might be involved in the induction of apoptosis. The involvement of the activation of the interleukin-1 beta converting enzyme (ICE) family of proteases (caspases), such as ICE and CPP32, in the pathways was also investigated. CPP32, but not ICE, was strongly activated in response to NOC 18 stimulation, thereby implicating CPP32-like activity in the induction of apoptosis. Moreover, the possible involvement of tyrosine phosphorylation in apoptosis was investigated. Pretreatment of cells with herbimycin A, an inhibitor of tyrosine kinases, suppressed DNA fragmentation and CPP32-like activity, whereas pretreatment with vanadate, an inhibitor of tyrosine phosphatases, enhanced both parameters, suggesting that tyrosine phosphorylation might be involved in the pathways of apoptosis in HL-60 cells induced by NO.

Apoptosis↗
PubMed1997

Oxygen-dependent fragmentation of cellular DNA by nitric oxide.

Although active oxygen species and related metabolites, such as nitric oxide (NO), have been postulated to play important roles in the apoptosis of various cells, a precise mechanism leading to cell death remains to be elucidated. Recently we found that the lifetime of NO depends greatly on the concentration of environmental oxygen and that NO reversibly inhibits mitochondrial respiration and ATP synthesis; the inhibitory effect is stronger at physiologically low oxygen tension than under atmospheric conditions (Arch. Biochem. Biophys. 323, 27-32, 1995). The present work describes the effects of the NO-generating agent, 1-hydroxy-2-oxo-3,3-bis(2-aminoethyl)-1-triazene (NOC 18) and oxygen tension on the respiration, ATP synthesis and apoptosis of HL-60 cells. When respiration was inhibited by NOC 18, cellular ATP levels decreased significantly and DNA fragmentation was elicited. Both events were enhanced by decreasing oxygen tension and suppressed by adding NO-trapping agents, such as 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) and oxyhemoglobin. The fragmentation of cellular DNA was inhibited in a dose dependent manner by herbimycin A, a tyrosine kinase inhibitor. Fragmentation of the DNA of HL-60 cells was also induced either by peroxynitrite, superoxide or hydroxyl radical by some mechanism which was diminished by lowering the oxygen tension. These results indicated that the decrease in cellular ATP and activation of tyrosine kinase might play important roles in NO-induced apoptosis particularly under physiologically low oxygen tensions.

Adenosine Triphosphate↗
PubMed1997

Epoxyquinomicins A, B, C and D, new antibiotics from Amycolatopsis. II. Effect on type II collagen-induced arthritis in mice.

The anti-arthritic effects of epoxyquinomicins on type II collagen-induced arthritis in DBA/1J mice were examined. Prophylactic treatment with epoxyquinomicins A, B, C and D (1-4 mg/kg) had potent inhibitory effects on type II collagen-induced arthritis. In contrast to nonsteroidal anti-inflammatory drugs (NSAIDs), epoxyquinomicin C (1-30 mg/kg) had neither an anti-inflammatory effect on carrageenan-induced paw edema in rats nor an analgesic effect on acetic acid-induced writhing in mice. These results suggest that the mode of action of epoxyquinomicins is different from that of NSAIDs and that epoxyquinomicins may become useful drugs for the treatment of rheumatoid arthritis.

Actinobacteria↗