Biomedical subjects

S J Hong

Publications and source records attributed to S J Hong.

At least 91 records · Page 5Linked to original sources

PubMed1998

Evaluation of intrinsic modulation of synaptic transmission by ATP in mouse fast twitch muscle.

This study aims to evaluate whether endogenous ATP or adenosine modulates the neurotransmission and contractile function of mouse phrenic nerve-diaphragm. Bath application of ATP (1 mM) and alpha, beta-methylene ATP (m-ATP, 0.1 mM) elevated muscle tones, depressed contractions (approximately 12%), and depolarized muscle membranes (approximately 20 mV). Adenosine (1 mM) or low concentrations of ATP (0.1 mM) had no effect. In a low Ca2+ media, ATP caused prolonged inhibitions of endplate potentials (EPPs), whereas m-ATP augmented EPPs while both agents produced slight effects in normal Tyrode solution. When applied by puff ejection, ATP and m-ATP additionally elicited fast transient suppressions of EPPs in association with inhibitions of high K+-evoked releases of miniature EPPs. Blockades of P2 purinoceptors with suramin antagonized all the effects of ATP and m-ATP except the prolonged inhibitions of EPPs induced by ATP, which were antagonized instead by 8-cyclopentyl-1,3-dipropylxanthine (CPDPX), an A1 adenosine receptor antagonist. Suramin and CPDPX did not change contractions nor alter EPPs evoked by a low- or high-frequency nerve stimulation. The results indicate that exogenously applied ATP and m-ATP, via activations of distinct pre- and postsynaptic purinoceptors, exert inhibitory and facilitatory pharmacological modulations on the mature neuromuscular junction. However, because of intrinsic high efficiency of the synaptic transmission under physiological conditions, endogenously released ATP and its degradation product-adenosine-do not build up to concentrations high enough to alter motor functions.

Acetylcholine↗

PubMed1998

Telomerase: a potential marker of bladder transitional cell carcinoma in bladder washes.

Telomerase is an enzyme that immortalizes cells by maintaining a constant telomere length. Here, telomerase activity in bladder washes was analyzed and compared with the final pathological diagnosis in 23 patients with bladder transitional cell carcinoma (TCC). Bladder washes and normal tissues were obtained from each patient prior to transurethral resection of bladder tumor. Telomerase activity was detected using telomeric repeat amplification protocol assay based on PCR. Cytological diagnosis of centrifuged cells from bladder washes was made using Papanicolau's stain. Results demonstrated that telomerase activity was detected in 95.7% of both cancer tissues and bladder washes. In normal tissues, telomerase activity was not detected in 22 of 23 samples. Regarding cytological diagnosis, only 69.6% of bladder wash samples had positive cytology. Moreover, in five cases of grade 1 TCC, only 20% of the cytological specimens were positive for malignancy, whereas 80% showed positive telomerase activity. These results demonstrate that telomerase activity is detectable in a majority of human bladder cancer tissues and bladder washes obtained from patients with TCC. In addition, results of this study suggest that the presence of telomerase in bladder washes may be a specific marker of bladder cancer, especially in low-grade tumors.

Aged↗

PubMed1998

Inhibition of protein synthesis by nitric oxide correlates with cytostatic activity: nitric oxide induces phosphorylation of initiation factor eIF-2 alpha.

BACKGROUND: Nitric oxide (NO) is cytostatic for proliferating cells, inhibits microbial growth, and down-regulates the synthesis of specific proteins. Studies were undertaken to determine the mechanism by which NO inhibits total protein synthesis and whether the inhibition correlates with established cytostatic activities of NO. MATERIALS AND METHODS: In in vitro experiments, various cell types were exposed to NO using either donors or expression of inducible NO synthase (iNOS). The capacity of NO to suppress total protein synthesis, measured by incorporation of 35S-methionine into protein, was correlated with the capacity of NO to suppress cell proliferation, viral replication, or iNOS expression. Phosphorylation of eIF-2 alpha was examined as a possible mechanism for the suppressed protein synthesis by NO. RESULTS: Both NO donors and expression of the iNOS suppressed total protein synthesis in L929 cells and A2008 human ovarian tumor cells in parallel with decreased cell proliferation. Suppressed protein synthesis was also shown to correlate with decreased vaccinia virus proliferation in murine peritoneal macrophages in an iNOS-dependent manner. Furthermore, iNOS expression in pancreatic islets or RAW264.7 cells almost completely inhibited total protein synthesis, suggesting that nonspecific inhibition of protein synthesis may be the mechanism by which NO inhibited the synthesis of specific proteins such as insulin or iNOS itself. This possibility was confirmed in RAW264.7 cells where the inhibition of total protein synthesis correlated with the decreased iNOS protein. The decrease in protein levels occurred without changes in iNOS mRNA levels, implicating an inhibition of translation. Mechanistic studies revealed that iNOS expression in RAW264.7 cells resulted in the phosphorylation of eIF-2 alpha and inhibition of the 80S ribosomal complex formation. CONCLUSIONS: These results suggest that NO suppresses protein synthesis by stimulating the phosphorylation of eIF-2 alpha. Furthermore, our observations indicate that nonspecific inhibition of protein synthesis may be a generalized response of cells exposed to high levels of NO and that inhibition of protein synthesis may contribute to many of the described cytostatic actions of NO.

Animals↗

PubMed1998

Ocular hypotensive and vasodilative effects of two beta-adrenergic blockers with intrinsic sympathomimetic activity.

PURPOSE: The ocular hypotensive and vasodilative effects of vaninolol and eugenolol, two beta-adrenergic blockers with intrinsic sympathomimetic activity, were tested in rabbits and their pharmacologic mechanisms were also studied in vitro. METHODS: Intraocular pressure was measured in ocular hypertonic rabbits which were induced by infusing 20% NaCl or 5% glucose solution. The rabbit's ocular blood flow was determined using the colored microsphere technique. The concentrations of cAMP were evaluated in porcine ciliary body and cultured A7r5 smooth muscle cells by radioimmunoassay. Ca+2 concentration was measured in A7r5 cells by spectrofluorometry after loading cells with Fura-2-AM. RESULTS: It was found that 0.5% eugenolol and vaninolol could suppress the intraocular pressure in glucose-induced ocular hypertensive rabbits and delay the intraocular pressure recovery in NaCl-induced ocular hypertensive rabbits. In addition, both agents improved the ocular blood flow in the iris, ciliary body, retina and choroid. Vaninolol and eugenolol of 10 microM inhibited the basal cAMP accumulation from 23.9 +/- 2.0 of control to 8.7 +/- 0.4 and 2.4 +/- 0.1 respectively and inhibited the isoproterenol-induced cAMP accumulation from 154.3 +/- 13.6 to 120.6 +/- 8.3 and 74.2 +/- 6.1 respectively in the porcine ciliary body. The cellular cAMP concentration was significantly increased from 10 +/- 1 of control to 96 +/- 5 (vaninolol) and 38 +/- 3 (eugenolol) in cultured A7r5 smooth muscle cells. Both agents also increased the intracellular calcium concentration in A7r5 cells. CONCLUSIONS: These results indicate that the lowering of intraocular pressure by vaninolol and eugenolol may be due to cAMP suppression in the ciliary body by beta-antagonist and/or alpha2-agonist activities. Both agents cause vasodilation via beta2-agonist action that increase the smooth muscle cellular cAMP level more than vasoconstriction via alpha-agonist activity by increasing an influx of extracellular Ca+2.

Adrenergic beta-Antagonists↗

PubMed1998

Calcium-induced changes on crystallins in organ-cultured porcine lens.

In this study, intact porcine lenses were cultured in vitro for 7 days supplemented with commercial balanced salt solution (BSS) which is usually used as an irrigation solution during intraocular surgery, and the lenses were maintained under various culture conditions, e.g. temperature and CO2 concentration. The intact porcine lenses after 7 days culture were analyzed with optical density scanner, gel permeation chromatography on TSK HM-55 column and SDS-PAGE (polyacrylamide gel electrophoresis). It was found that lenses exhibited the least opacity when lenses were cultured with Ca(+2)-free BSS buffer, CO2-free incubator and maintained at a temperature of 25 degrees C. After the lenses were cultured with Ca(+2)-free BSS or BSS medium, the composition of crystallins in lenses was separated with TSK HM-55 column. It was indicated that the percentage of high molecular weight (HMW) protein and (alpha-crystallin increased, and gamma-crystallin decreased in lenses incubated with BSS medium compared with lenses incubated with Ca(+2)-free BSS medium. Following an increase in the concentration of calcium in the medium from 4.3 mM, 20 mM, 50 mM, 100 mM to 200 mM, the opacity of the lens was measured with a densitometer. The changed percentage of various crystallins was similar to lenses with BSS media that increased in HMW protein and alpha-crystallin, decreasing in gamma-crystallin. In the case of lens protein pattern, the crystallin washed from TSK HM-55 gel was separated with SDS-PAGE (polyacrylamide gel electrophoresis). It was indicated that some of proteins disappeared when lenses were incubated with various concentrations of calcium. The vanished pH proteins were 20.5 kDa at 50 mM calcium, 20.5 kDa and 21 kDa at 100 mM, 20.5 kDa, 21 kDa, 22 kDa and 23 kDa at 200 mM which were compared with the protein bands in the presence of 20 mM calcium in BSS medium. This study indicates that the commercial balanced salt solution (BSS) which is usually used as an irrigating solution during intraocular operations may increase the risk for lens opacity because of the calcium contained in the solution.

Animals↗

PubMed1998

Dexon and nylon-sutured wound reaction in conjunctival flap after trabeculectomy combined with or without topical application of mitomycin-C.

In this study, rabbits were used to evaluate the sutured wound reaction with Dexon or nylon in the conjunctival flap 1, 4, 7, 14 and 28 days after trabeculectomy surgery with or without the use of mitomycin-C. Four major treated groups were used to compare their wound healing reaction; group 1--nylon-suture and non-mitomycin treatment; group 2--nylon-suture and mitomycin treatment; group 3--Dexon-suture and non-mitomycin treatment; group 4--Dexon-suture and mitomycin treatment. One day after surgery, the number of polymorphs was the greatest most in the nylon-sutured and non-mitomycin treated tissues (86 +/- 2). Four days after surgery, the number of polymorphs was the greatest most in Dexon-sutured and non-mitomycin treated tissues (109 +/- 87). The number of fibroblasts was the greatest most in nylon-sutured and non-mitomycin treated tissues (111 +/- 23). Seven days after surgery, the number of polymorphs was the greatest most in Dexon-sutured and mitomycin treated tissues (32 +/- 12). The number of fibroblasts was the greatest most in nylon-sutured and non-mitomycin treated tissues (126 +/- 15). Fourteen days after surgery, the number of fibroblasts was the greatest most in Dexon-sutured and non-mitomycin tissues (43 +/- 10). The number of goblet cells was the greatest most in nylon-sutured and non-mitomycin treated tissues (4 +/- 2). Twenty-eight days after surgery, the number of fibroblasts was the greatest most in Dexon-sutured and mitomycin treated tissues (40 +/- 15). The number of goblet cells was the greatest most in nylon-sutured and non-mitomycin treated tissues (4 +/- 2). Our conclusions are as follows: 1). The concentration of mitomycin in conjunctival wound edge should be maintained at as low a level as possible because the mitomycin will delay the wound healing process; 2). Nylon material is better than Dexon for conjunctival wound suture because nylon could induce a great quantity of fibroblasts before Dexon did.

Administration, Topical↗

PubMed1997

Effects of pilocarpine and other antiglaucoma drugs on cultured human Tenon's fibroblast cells.

It has been found that long-term therapy with topical antiglaucoma drugs may decrease the success of glaucoma filtering surgery. In this study, various antiglaucoma drugs, including carteolol, betaxolol, levobunolol, pilocarpine, and timolol, were investigated for their proliferative effect on cultured human Tenon's fibroblast cells. It was found that the 3H-thymidine uptake of cultured fibroblast cells was inhibited by commercial antiglaucoma drugs, including carteolol of 0.1% concentration (13%), 0.01% (50%) and 0.001% (53%), betaxolol of 0.05% concentration (14%), 0.005% (42%) and 0.0005% (62%), levobunolol of 0.05% concentration (2%), 0.005% (32%) and 0.0005% (55%), and timolol of 0.025% concentration (4%), 0.0025% (47%) and 0.00025% (55%), whereas the 3H-thymidine uptake was increased by commercial pilocarpine eyedrop from 103% (0.2% of concentration), 170% (0.02% of concentration) to 171% (0.002% of concentration), when cells were treated with commercial drugs for 100 min. Meanwhile, the proliferations of cultured fibroblast cells were stimulated by simultaneously combining 0.2%, 0.02% and 0.002% concentrations of pilocarpine eyedrops with other antiglaucoma drugs, such as carteolol of 0.1% concentration (50%), 0.01% (113%) and 0.001% (138%), betaxolol of 0.05% concentration (24%), 0.005% (128%) and 0.0005% (142%), levobunolol of 0.05% concentration (32%), 0.005% (87%) and 0.0005% (119%), and timolol of 0.025% concentration (15%), 0.0025% (94%) and 0.00025% (118%). Following incubation with pure pilocarpine, the proliferation of Tenon's fibroblast cells was inhibited for 84% (0.2% concentration), 84% (0.02% concentration) and 90% (0.002% concentration). When fibroblast cells were treated with commercial pilocarpine eyedrops for 24 hours, the 3H-thymidine uptake was increased to 160% (0.02% concentration) and 172% (0.002% concentration). This result shows that the commercial pilocarpine may play a crucial role for the proliferation of cultured human Tenon's fibroblast cells.

Adrenergic beta-Antagonists↗

PubMed1997

Spontaneous activity of guinea pig ileum longitudinal muscle regulated by Ca(2+)-activated K+ channel.

Isolated guinea pig ileum displayed spontaneous contraction and fluctuation of membrane potential originating from the longitudinal muscle. Transmural stimulation of the enteric nerve plexus evoked contractions that were followed by lowered muscle tone and decreased spontaneous activity. The Na+ channel blocker tetrodotoxin, N-type Ca2+ channel blockers omega-conotoxins GVIA and MVIIA, the muscarinic receptor antagonist atropine, and inhibitory mediators alpha, beta-methylene-ATP and sodium nitroprusside all inhibited stimulation-evoked contraction while restoring spontaneous motility. L-type Ca2+ channel blockers nifedipine and calciseptine completely suppressed evoked and spontaneous contractions. Blockade of the large-conductance Ca(2+)-activated K+ (Kca) channel with charybdotoxin (but not of small-conductance Kca channel by apamin or of ATP-regulated K+ channel by glybenclamide) induced spikelike depolarization, inhibited nerve stimulation-evoked membrane hyperpolarization, and increased spontaneous activity. The results suggest that the large-conductance Kca channel is constitutively activated for modulations of spontaneous activity, and that muscle excitation, through elevation of Ca2+ levels, stimulates the large-conductance Kca channel to suppress spontaneous activity.

Adenosine Triphosphate↗

PubMed1997

Trauma-induced changes of skeletal muscle membrane: decreased K+ and increased Na+ permeability.

Trauma of skeletal muscle causes membrane depolarization and reduces membrane resistance. The underlying mechanisms were studied in isolated mouse phrenic nerve diaphragms subject to sharp transections of muscle. Depolarization was most marked at the vicinity ( approximately 1 mm) of trauma, where the membrane potential dropped rapidly from about -80 mV to zero and repolarized to about -25 mV. At the end-plate region (located approximately 3 mm away from the cut end), the membrane gradually attained a plateau potential around -45 mV. The magnitude of depolarization was not reduced by inhibition of Na+, Ca2+, or Cl- channel, whereas the progress of depolarization was delayed in low-Na+ medium. Activation of the K+ channel with lemakalim induced some hyperpolarization at damaged site but produced a glybenclamide-sensitive outward current and hyperpolarization of end-plate region to the levels before trauma, as if there was no diminution of transmembrane K+ gradient in this area. Appropriate elevation of extracellular K+ to stimulate K+ conductance also hyperpolarized the end-plate region. The results suggest that depolarization at regions remote from trauma is related to decreased K+ and increased Na+ permeability. The cytoplasma compartmentalization and permeability changes may protect muscle fiber from trauma.

Animals↗

PubMed1997

Characterization of a P-type calcium current in a crayfish motoneuron and its selective modulation by impulse activity.

Previous studies have demonstrated that the voltage-dependent Ca2+ current recorded from the cell body of the crayfish abdominal motoneuron, F3, undergoes a long-term reduction as a result of increased impulse activity. The properties of the Ca2+ channels undergoing this long-term change were examined with the use of two-electrode voltage-clamp techniques. The Ca2+ current was activated at -50 to -40 mV and its amplitude was maximal at 0 mV (-135.0 +/- 25.8 nA, mean +/- SE, n = 14). The current-voltage relationship and the greater sensitivity of the Ca2+ channel to Cd2+ than Ni2+ indicated that Ca2+ influx occurs through high-voltage-activated (HVA) Ca2+ channels. Loose-patch recordings demonstrated that the Ca2+ current was generated by the membrane of the cell body. When Ba2+ was substituted for extracellular Ca2+, there was a 40% increase in the amplitude of the inward current and a negative shift of approximately 10 mV in the I-V relationship. Application of the P-type Ca2+ channel antagonist omega-agatoxin IVA (omega-AgTX IVA) produced a significant 33% (n = 6) reduction in the peak amplitude of the Ba2+ current, whereas neither the L-type Ca2+ channel antagonist nifedipine nor the N-type channel antagonist omega-conotoxin GVIA produced a reduction in the Ba2+ current. The voltage-dependent activation of this P-type (omega-AgTX-IVA-sensitive) Ca2+ channel was similar to previously identified P-type channels, but different from that of the non-P-type (omega-AgTX-IVA-resistant) Ca2+ channels. When Ca2+ currents were measured 6-7 h after an increase in impulse activity (5-Hz stimulation for 45-60 min), there was a 43% reduction in the amplitude of the P-type current, but no significant changes in the non-P-type current amplitude. These results demonstrate that at least two subtypes of HVA Ca2+ channels contribute to the macroscopic Ca2+ current observed in the cell body of this crayfish phasic motoneuron: one belongs to the previously described P-type Ca2+ channel and the other(s) does not belong to the N-, L-, or P-type Ca2+ channel. The long-term, Ca(2+)-dependent reduction in Ca2+ current previously demonstrated in motoneuron F3 is produced by the selective reduction of this P-type Ca2+ current. This activity-dependent reduction in the P-type Ca2+ current is likely involved in the long-term depression of transmitter release observed at the neuromuscular synapses of this motoneuron.

Animals↗

PubMed1997

Vanidilol: a vanilloid-type vasorelaxant and ocular hypotensive beta-adrenoceptor blocker with partial beta-2-agonist activity.

Vanidilol, [4'-(2-hydroxy-3-(tert-butylamino)propoxy)-3'-methoxyphenyl] -benzaldehyde, newly synthesized from vanillin, is a vanilloid-type beta-adrenoceptor blocker. The beta-adrenoceptor-blocking properties of vanidilol were studied both in vivo and in vitro. Intravenous injection of vanidilol (1.0, 3.0, 5.0 mg/kg) in anesthetized Wistar rats produced a decrease in blood pressure and a dose-dependent bradycardia response. Vanidilol inhibited the tachycardia effects induced by (-)isoproterenol, but had no blocking effect on the arterial pressor responses induced by phenylephrine. In isolated guinea-pig tissues, vanidilol attenuated the (-)isoproterenol-induced positive chronotropic and inotropic effects of the atria and trachea relaxation responses in a concentration-dependent manner. The parallel shift to the right of the concentration-response curve of (-)isoproterenol suggested that the agent was a beta-adrenoceptor competitive antagonist. The apparent pA2 values for vanidilol on the right atria, left atria and trachea were 7.67 +/- 0.03, 7.89 +/- 1.02 and 7.66 +/- 0.15, respectively, denoting that vanidilol was a nonselective beta-blocker. The intrinsic sympathomimetic activity of vanidilol and propranolol was determined on isolated atria and trachea from reserpinized guinea pigs. Propranolol caused significantly negative inotropic and chronotropic effects at 10(-6) mol/l or above, whereas vanidilol possessed less cardiodepressant activities than propranolol. In reserpinized tracheal strips, vanidilol produced dose-dependent relaxant responses, but propranolol was ineffective. Preincubating the preparations with ICI 118,551 (0.1-10 nmol/l), a beta 2-adrenoceptor antagonist, significantly shifted the concentration-relaxation curves of vanidilol to a region of higher concentrations. In isolated guinea-pig thoracic aorta, vanidilol (0.1-10 mumol/l) inhibited the phenylephrine (10(-5) mol/l)-induced tonic contraction in vascular smooth muscle which was related to the block of calcium influx. In 20% saline-perfused rabbits, vanidilol showed a marked delay in intraocular pressure recovery, demonstrating an ocular hypotensive action. Binding characteristics of vanidilol and propranolol were evaluated in [3H]dihydroalprenolol binding to porcine ventricular membranes. Vanidilol was less potent than propranolol in competing for the beta-adrenoceptor-binding sites. On the other hand, vanidilol had a high hydrophilicity in comparison with propranolol. In conclusion, vanidilol exhibited nonselective beta-adrenoceptor blocking, vasorelaxant and ocular hypotensive activities, but was devoid of alpha-adrenoceptor blocking and beta 1-agonist activity. Partial beta 2-adrenoceptor agonist activity and inhibitory activity on calcium influx may share in the vasorelaxant activity.

Adrenergic beta-2 Receptor Agonists↗

PubMed1997

Phenylephrine-induced Ca2+ oscillations in canine pulmonary artery smooth muscle cells.

Modulation of [Ca2+]i in response to receptor activation is a critical determinant of vascular smooth muscle tone. In this study, we examined the effect of continuous stimulation of alpha 1-adrenoceptors with phenylephrine (PE) on [Ca2+]i in single pulmonary artery smooth muscle cells (PASMCs) cultured from explants of canine intrapulmonary artery. Fura 2-loaded PASMCs pretreated with propranolol (5 mumol/L) were continuously superfused with PE at 37 degrees C on the stage of an inverted fluorescence microscope, and [Ca2+]i was measured using a dual-wavelength spectrofluorometer. Resting values of [Ca2+]i were 96 +/- 4 nmol/L. PE (10 mumol/L) stimulated oscillations in [Ca2+]i at a frequency of 1.35 +/- 0.07/min, which reached a peak [Ca2+]i of 650 +/- 26 nmol/L (n = 69 cells). The oscillations lasted for > 30 minutes and were constant in amplitude and frequency. Both the amplitude and frequency of PE-induced [Ca2+]i oscillations increased in a dose-dependent (3 x 10(-8) to 10(-4) mol/L) manner. Pretreatment with the alpha 1-adrenoceptor antagonist prazosin (50 nmol/L) or removal of extracellular Ca2+ abolished the repetitive [Ca2+]i oscillations induced by PE. The voltage-operated Ca2+ channel blockers nifedipine (1 mumol/L) and verapamil (1 mumol/L) had no effect on the [Ca2+]i oscillations. In contrast, inhibition of phospholipase C with U73122 (10(-7) to 10(-5) mol/L) attenuated the oscillations in a dose-dependent fashion. The nonselective protein kinase inhibitor staurosporine (10(-9) to 10(-7) mol/L) had a minimal inhibitory effect on the oscillations. Caffeine (30 mmol/L) and thapsigargin (1 mumol/L) abolished the oscillations, whereas pretreatment with ryanodine (1 to 100 mumol/L) had no effect. In freshly dispersed PASMCs, PE (10 mumol/L) induced oscillations in [Ca2+]i similar to those observed in cultured cells, and patch-clamp experiments revealed oscillations in membrane potential. These results indicate that PE induces [Ca2+]i oscillations in PASMCs via stimulation of alpha 1-adrenoceptors coupled to phospholipase C activation. Voltage-operated Ca2+ channels and protein kinases are not required for the oscillations. The requirement for extracellular Ca2+ and intracellular Ca2+ stores indicates that both Ca2+ influx and intracellular Ca2+ release play a role in the maintenance of the oscillations.

Animals↗

PubMed1997

Cardiac tamponade during transesophageal echocardiography in the patient of circumferential aortic dissection.

A 43-year-old woman, whose physical findings were consistent with Marfan's syndrome, presented with acute chest pain. Transthoracic two-dimensional echocardiography demonstrated dilated ascending aorta with a circular shape intimal flap at the root level. Subsequently, the patient required transesophageal echocardiography (TEE), but during esophageal intubation, the patient developed acute pericardial tamponade which resulted in death in spite of cardiopulmonary resuscitation. Although, some investigators recommend TEE as the first choice of diagnostic method of aortic dissection, hemodynamic stability is very important during TEE study. Therefore, aggressive sedation may be required in the case of circumferential dissection of the ascending aorta to prevent the increases of the blood pressure and the heart rate which suggested an extensive tear of the aortic intima during TEE procedure.

Adult↗

PubMed1997

Intestinal pathologic findings at early stage infection by Centrocestus armatus in albino rats.

This study was performed to observe intestinal pathology in early infection by Centrocestus armatus. The flukes were in the lowermost part of the intervillous space of the duodenum and jejunum from 1 day to 7 days postinfection (PI). The stroma of villi around the young fluke was edematous and infiltrated by inflammatory cells such as lymphocytes, plasma cells and eosinophils. The crypt became mildly hyperplastic and villi were moderately atrophied at 4 days PI. The intestinal lesion produced was confined to the areas around the fluke. The pathologic findings were not significantly different between 1,000 and 5,000 metacercariae infection groups. It is suggested that the lesion should be produced by mechanical destruction of the fluke on the enteroepithelial cells.

Animals↗

PubMed1997

Telomerase activity: a potential marker of bladder transitional cell carcinoma in bladder washes.

The enzyme telomerase maintains a constant telomere length in immortalized cells, allowing unlimited cell proliferation. Almost all cancer cells express telomerase activity. However, little data is available regarding the role of telomerase activity in the detection of bladder cancer with a bladder wash specimen. We detected telomerase activity in a bladder wash specimen of bladder cancer and normal tissues, and compared them with final pathologic diagnosis. Twenty-three patients with transitional cell carcinoma (TCC) of the bladder were enrolled in our study. A bladder wash specimen was obtained before transurethral resection of the bladder (TURB) and normal and cancer tissues from the same patients during TURB. Telomerase activity was analyzed in each specimen a using telomeric repeat amplification protocol (TRAP) assay based on polymerase chain reaction (PCR) technique. Cytologic diagnosis was performed using Papanicolaou's stain with cytocentrifuged cytology preparation. We observed telomerase activity in 95.7% (22/23) of bath cancer tissues and bladder wash specimens; only one case did not express telomerase activity. Telomerase activity was undetected in all normal tissues except one, which was obtained from a patient with carcinoma in situ. A total of 69.6% (16/23) of wash specimens were positive in cytopathologic diagnosis. The accuracy of cytopathologic diagnosis in pathologic grade 2 or 3 was relatively high (83.3%, 15/18). However, in five cases of grade 1 TCC only 20% (1/5) of cytologic diagnosis was positive whereas the telomerase activity of wash specimens was detected in 80% (4/5). Our data demonstrates that not only the majority of human bladder cancer tissues, but also the bladder wash specimens obtained from patients with TCC, expressed telomerase activity. It indicates that telomerase activity may be a reliable marker in detecting bladder cancer especially in cases with a low grade that bladder wash cytology can miss.

Aged↗

PubMed1997

A case of lymphomatoid papulosis occurred simultaneously with Ki-1-positive anaplastic large cell lymphoma.

Lymphomatoid papulosis (LyP) is a chronic self-healing skin eruption that is clinically benign but histologically mimics a malignant lymphoma. However, lymphomatoid papulosis with anaplastic large cell lymphoma responds poorly to medical treatments, including chemotherapies. We experienced a 60-year-old male patient with lymphomatoid papulosis occurred simultaneously with relapsed Ki-1-positive anaplastic large cell lymphoma who was treated with salvage chemotherapy but, unfortunately, failed to be rescued. We report it with a review of the literature.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

Magnetic resonance imaging in hemospermia.

PURPOSE: We evaluated the prostate and seminal tract with magnetic resonance imaging (MRI) in patients with hemospermia. MATERIALS AND METHODS: To evaluate the prostate and seminal tract in 17 patients 20 to 59 years old (mean age 44) with hemospermia we performed transrectal ultrasound and MRI using an endorectal surface coil with a 1.5 tesla unit. Mean duration of hemospermia was 32 months (1 week to 16 years). RESULTS: Abnormalities were noted on transrectal ultrasound in 15 of the 17 patients (88%) and on MRI in all. Of the 12 cases of hemorrhage 10 involved the seminal vesicle and 2 involved the ejaculatory duct. There were 12 cystic lesions, including 7 in the müllerian and 5 in the ejaculatory ducts. Of 19 cases calculi were detected in the prostate in 5, seminal vesicle in 8, and ejaculatory and müllerian duct cysts in 4 and 2, respectively. There was 1 case of prostatic atrophy and 1 wolffian duct anomaly associated with an ejaculatory duct cyst, ectopic ureterocele and absence of the left kidney. CONCLUSIONS: MRI with an endorectal surface coil is a powerful modality for evaluating the seminal tracts of patients with hemospermia. It can be performed clinically when transrectal ultrasonography is not satisfactory.

Adult↗

PubMed1997

Effects of antiglaucoma drugs and corticosteroids on the cellular glucose uptake in cultured porcine corneal endothelial cells.

In this study, various commercially used antiglaucoma drugs and corticosteroids were investigated in their effects on porcine corneal endothelial cells especially in cellular glucose uptake. Cellular glucose uptake directly affects the pumping efficiency in corneal endothelial cells. Following the cells' treatment with various antiglaucoma eyedrops for 100 min, the 3H-2-deoxyglucose uptake in cultured porcine corneal endothelial cells was affected by betaxolol from 3.1% (1.6 mM), 181% (0.16 mM) to 158% (0.016 mM), by timolol from 93% (0.79 mM), 227% (0.079 mM) to 151% (0.0079 mM), by carteolol from 141% (3.4 mM), 180% (0.34 mM) to 97% (0.034 mM), by levobunolol from 80% (1.5 mM), 98% (0.15 mM) to 90% (0.015 mM), by dipivefrin from 116% (0.2 mM), 176% (0.02 mM) to 108% (0.002 mM) and by pilocarpine from 115% (9.6 mM), 210% (0.96 mM) to 210% (0.096 mM) when the cells were compared with a control medium. In the presence of various corticosteroids, the glucose uptake in corneal endothelial cells was affected by fluorometholone from 160% (0.26 mM), 139% (0.026 mM) to 107% (0.0026 mM), by dexamethasone from 85% (0.25 mM), 117% (0.025 mM) to 109% (0.0025 mM) and by betamethasone from 95% (0.25 mM), 96% (0.025 mM) to 99% (0.0025 mM). These results show that the commercial eyedrops of antiglaucoma drugs and corticosteroids will not decrease the cellular glucose uptake in cultured porcine corneal endothelial cells except when incubated with high concentrations of betaxolol, levobunolol and dexamethasone.

Adrenal Cortex Hormones↗