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Biomedical subjects

Y Kitazawa

Publications and source records attributed to Y Kitazawa.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Chronic myelocytic leukemia induced into remission by interferon-alpha associated with early esophageal cancer].

A fifty-one-year-old male patient visited the Department of Dermatology of Toho University Ohashi Hospital with a complaint of generalized exanthema, which was diagnosed assyringoma; at that time his leukocytosis was recognized. He was admitted to our department on August 8, 1988. Physical examination on admission revealed slight hepatosplenomegaly. WBC count was elevated (50,700/microliters). He was diagnosed as having Ph1-positive CML in the chronic phase and was treated with IFN-alpha (HLBI, Sumitomo, 3 x 10(6) units/day, daily, I. M.) from August 12, but an elevated lesion was detected at the lower part of his esophagus by endoscopy, and it was diagnosed by biopsy as squamous cell carcinoma. Radical operation for esophageal cancer was performed on September 26; at that time his WBC count was 17,400/microliters. After discharge, his WBC level was maintained within normal range by IFN-alpha. On August 2, 1989, he was readmitted to our hospital because of lymphoblastic crisis. Although he attained transient complete remission, he died of pneumonia after the relapse on January 10, 1990. IFN-alpha therapy is suggested to be useful for the treatment of CML associated with gastrointestinal cancer because of its possible parenteral administration and mild toxicity.

Carcinoma, Squamous Cell↗
PubMed1990

Biphasic intraocular pressure response to Q-switched Nd:YAG laser irradiation of the iris and the apparent mediatory role of prostaglandins.

In rabbits, laser irradiation of the iris causes an immediate rise in intraocular pressure (IOP), with a concomitant increase of prostaglandins (PGs) in the aqueous humor. We studied IOP responses to Q-switched Nd:YAG laser application to the iris in unanesthetized rabbits, and found that a prolonged IOP reduction lasting for 6-24 hr invariably followed the transient IOP rise of 0.5-2 hr duration. The magnitude of both the IOP rise and reduction was dependent on the level of laser energy. A masked, randomized study revealed that the intraperitoneal administration of indomethacin (50 mg kg-1) prior to laser application significantly reduced the ocular hypertensive and hypotensive responses to laser irradiation (energy: 24 mJ). The maximum IOP rise from baseline was 5.4 +/- 3.0 mmHg (n = 10) with the intraperitoneal vehicle and 1.5 +/- 4.2 mmHg (n = 10) with intraperitoneal indomethacin administration. Thus, the difference was statistically significant (P less than 0.025, Student's t-test). The maximum IOP reduction from baseline was -8.5 +/- 2.6 mmHg (n = 10) with the intraperitoneal vehicle and -4.0 +/- 2.4 mmHg (n = 10) with intraperitoneal indomethacin (P less than 0.001, Student's t-test). The concentration of PGE2 in the aqueous humor, as determined by radioimmunoassay on samples obtained at 2 and 4 hr after laser application, was found to be significantly increased in rabbits that received the vehicle solution but not in animals that were pretreated with intraperitoneal injection of indomethacin. This suggests that this PG or other cyclooxygenase products are involved with mediation of the initial IOP increase and the prolonged decrease in IOP that follows laser irradiation of the iris.

Animals↗
PubMed1990

Platelet size and function in septic rats: changes in the adenylate pool.

Cecal ligation and puncture (CLP) were performed in rats. After 4 hr (early sepsis) and 16 hr (late sepsis), platelet morphology and function were studied. At 16 hr, platelet counts for the CLP group were significantly lower than for the sham-operated control group. Low maximum aggregation rates (MAR) and decreased platelet counts were elicited in platelet-rich plasma with 4 M ADP and 2 micrograms/ml collagen. However, with platelet counts equalized, MAR for the CLP group increased significantly, especially after 16 hr. The platelet-large cell rate and platelet distribution width decreased temporarily at 4 hr, then rose significantly at 16 hr. No significant changes were observed in the mean platelet volume after 4 hr, but there were significant increases after 16 hr. Total adenine nucleotide (TAN) levels within the platelets rose significantly in the CLP group, suggesting the appearance during the late sepsis of large, heavy platelets or adenine nucleotide-rich platelets. The platelet adenylate pool was divided into granular and cytoplasmic fractions, respectively characterized by ADP and ATP increases. However, no septicemia-related differences were noted in the degree of binding between goat antirat fibrinogen and platelet surface glycoprotein IIb/IIIa complex. Internal environment changes in the platelets indicated that during septicemia hyperfunctional or hypersensitive platelets with a latent capacity for active aggregation and release appeared in the circulation. Hypercoagulability in septicemia involves activation of coagulation factors, stimulation of the coagulation cascade, volume changes accompanying increased platelet TAN content, and changes in AN distribution in the two pools. These findings significantly increase our understanding of the transition from the prethrombotic state to thrombosis in septicemia.

Adenine Nucleotides↗
PubMed1990

Altered hepatic mitochondrial fatty acid oxidation and ketogenesis in endotoxic rats.

Rat hepatic mitochondrial function, including oxidative phosphorylation, fatty acid oxidative capacity, kinetic parameters of carnitine palmitoyltransferase I (CPT I), and sensitivity of CPT I to malonyl-CoA inhibition were studied in vitro in isolated mitochondria following Escherichia coli lipopolysaccharide (LPS). The hepatic mitochondrial CPT I in LPS-treated rats showed a lower apparent maximum velocity (Vmax) for palmitoyl-CoA and Ki for malonyl-CoA without changes in apparent Km for palmitoyl-CoA. The rate of oxygen consumption or end-product formation of palmitoyl-L-carnitine and octanoate was not altered, but the rate of CPT I-dependent palmitoyl-CoA (plus L-carnitine) oxidation was reduced by LPS, when acetyl-CoA produced via beta-oxidation was directed toward citrate. When acetyl-CoA was directed to acetoacetate, the oxygen consumption rates of palmitoyl-L-carnitine and palmitoyl-CoA (plus L-carnitine) were decreased by LPS, although mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase activity was not altered. These results indicate that hepatic mitochondria isolated from LPS-treated rats show lower ketogenic and long-chain acyl-CoA oxidative capacity than those of fasted controls, and inhibition of ketogenesis is elicited at a site distal to CPT I in addition to reduction in CPT I activity.

Animals↗
PubMed1990

Apraclonidine effects on ocular responses to YAG laser irradiation to the rabbit iris.

Apraclonidine (p-aminoclonidine) ophthalmic solution effectively reduces the rise in intraocular pressure (IOP) following anterior segment laser surgery. We tested the effect of topical 0.5% apraclonidine on intraocular pressure and on protein and prostaglandin (PG) E2 concentrations in aqueous humor following Q-switched Nd:YAG laser irradiation to the iris of albino rabbits, at an energy level of 2 to 200 mJ. IOP was measured prior to and for 24 hr after irradiation. Aqueous humor was withdrawn before and 1 hr after laser irradiation for determining protein (Lowry method) and PGE2 (radioimmunoassay). Four to seven rabbits were used for each experiment. The increase in IOP and protein concentration following laser irradiation was demonstrated to be dependent on the amount of laser energy. Apraclonidine completely abolished the IOP rise, and significantly reduced the elevation of protein content. Apraclonidine failed to affect the increase in PGE2.

Animals↗
PubMed1990

Trabecular pigmentation following extracapsular cataract extraction and posterior chamber intraocular lens implantation.

We prospectively evaluated the change in trabecular pigmentation following extracapsular cataract extraction and posterior-chamber intraocular lens implantation in 70 patients (94 eyes) with senile cataracts. Using the Boys-Smith pigment gradation lens to measure semiquantitatively the amount of pigment visible in the angle, we estimated the mean trabecular pigmentation preoperatively and at 3-month intervals postoperatively. Both the mean pigmentation and the number of eyes with heavy pigmentation rose after the operation and then gradually returned to preoperative levels. There was no correlation between the amount of trabecular pigmentation and intraocular pressure.

Adult↗
PubMed1990

[Effects of the administration of urinary trypsin inhibitor on the morphology and function of platelets in the rat septic models].

Effects of urinary trypsin inhibitor (UTI) on the number, morphology and function of platelets under septic state were studied in rat models of cecal ligation and puncture (CLP). At formation of CLP, 5,000 U/kg/h of UTI was serially administered intraperitoneally and blood was sampled after 16 hours. Comparative study among sham-operation group, CLP group, and CLP + UTI group revealed: 1) inhibition of the platelets of platelet counts and appearance of large-sized, active platelets by UTI in the CLP + UTI group, 2) increase of platelet maximum aggregation rate (MAR) by ADP and increase of collagen in the CLP group, while inhibition in the CLP + UTI group and 3) by HPLC evaluation of adenine nucleotide in the platelet, increased levels of total ATP and ADP in the CLP group, particularly, increases of ATP in the metabolic pool and ADP in the granular pool. CLP + UTI group did not show these changes in the adenylate pool. UTI was thus considered to stabilize the platelet cycle in sepsis. Platelets under septic state might be hyperactive, and thrombosis is easy to occur. UTI administration might work for maintaining constancy of the platelet internal environment and improve septic state because adenine nucleotide level in the platelet did not change in the CLP + UTI group through changed in the CLP group.

Adenine Nucleotides↗
PubMed1990

[Measurements of reversibility of optic disc cupping in glaucoma using a computerized videographic image analyzer].

Optic disc changes were studied in young and elderly glaucoma patients who underwent reduction of intraocular pressure (IOP) by filtrating surgery. A computerized videographic image analysis system (Optic Nerve Head Analyzer, Rodenstock) was used to measure the cup/disc-ratio, the ratio of the rim area over the disc area (rim area/disc area-ratio), and the ratio of the cup volume over the disc area (cup volume/disc area-ratio) before and after filtrating surgery. Each parameter was assessed as total and quadrantal values. Materials consisted of 19 eyes of 15 patients (8 eyes of 5 patients with primary open angle glaucoma, 2 eyes of 2 patients with secondary glaucoma, and 9 eyes of 7 patients with developmental glaucoma). Sixteen eyes (84%) of 12 patients showed a decrease of the total cup/disc-ratio after operation. In this group, the patients had a decrease in IOP of 18.9 +/- 10. 6mmHg (mean +/- SD) after the operation. Among 16 eyes that had a decreased total cup/disc-ratio, statistically significant decrease of the cup/disc-ratio (p less than 0.01) and statistically significant increase of the rim area/disc area-ratio (p less than 0.01) were noted in total and for all quadrants except for the temporal. The greatest improvement of cupping was seen in the nasal quadrant. With regard to cup volume/disc area-ratio, a statistically significant decrease was observed in total and in all quadrants (p less than 0.01). The IOP change correlated linearly with that of the total cup volume/disc area-ratio (R = 0.51, p less than 0.05). No statistically significant linear correlation was noted between age and the change in any disc parameter.

Adolescent↗
PubMed1989

Ocular hypotensive effect of 8-hydroxycarteolol, a metabolite of carteolol.

8-hydroxycarteolol hydrochloride (8-OH carteolol) is a main metabolite of carteolol hydrochloride (carteolol). We conducted a randomized double-masked single-drop study in an attempt to compare the effects of the ophthalmic solution of 8-OH carteolol and carteolol on intraocular pressure (IOP) in rabbits with water-load and monkeys. Both 8-OH carteolol (0.01 and 0.1%) and carteolol (1 and 2%) suppressed the water-load induced IOP rise in rabbits. 8-OH carteolol was more effective in suppressing the water-load induced IOP rise in rabbits compared with carteolol on equimolar basis. Both 8-OH carteolol (0.1%) and carteolol (2%) caused a statistically significant decrease in IOP in monkeys. 8-OH carteolol was estimated to be more potent than carteolol in lowering IOP on equimolar basis in monkeys.

Administration, Topical↗
PubMed1989

Long-term results of 5-fluorouracil trabeculectomy for primary open-angle glaucoma.

The effect of 5-fluorouracil (5-FU) subconjunctival injection on the bleb formation and intraocular pressure (IOP) following trabeculectomy was studied in 27 primary open-angle glaucoma patients (33 eyes) who had never been operated upon (25 eyes) or had undergone single trabeculectomy that failed to reduce IOP (8 eyes). The results were analyzed by means of life table analysis and compared with those of 65 primary open-angle glaucoma eyes that had undergone trabeculectomy without postoperative administration of 5-FU as the first or the second filtering surgery. The surgical techniques and postoperative care were virtually identical between the eyes treated with 5-FU and the eyes that had undergone trabeculectomy without 5-FU. At the end of 28-month follow-up, the success probability was 74.8% without any postoperative antiglaucoma medication, and 100% with antiglaucoma medication. Whereas, the success probability with postoperative antiglaucoma medication was as low as 60.8% for the first, and 51.5% for the second trabeculectomy without 5-FU at the 24-month follow-up. Postoperative, subconjunctival injection of 5-FU appears to improve the prognosis following trabeculectomy in primary open-angle glaucoma patients.

Adult↗
PubMed1989

The prevention of an acute rise in intraocular pressure following Q-switched Nd:YAG laser iridotomy with clonidine.

We evaluated the ability of topical clonidine to suppress an acute rise in postoperative intraocular pressure (IOP) following Nd:YAG laser iridotomy. A total of 36 eyes (29 patients) with chronic primary angle-closure glaucoma underwent Q-switched Nd:YAG laser iridotomy: 18 eyes were treated topically with 0.5% clonidine ophthalmic solution prior to and immediately following the procedure, and a control group of 18 eyes underwent Nd:YAG laser iridotomy without topical clonidine. The control group was selected to match the clonidine-treated group in terms of preoperative IOP, the extent of peripheral anterior synechia, and the total amount of laser energy delivered. None of the clonidine-treated eyes experienced an IOP rise greater than 4 mm Hg over baseline, whereas 4 of the nontreated eyes (22.2%) developed an IOP rise greater than 10 mm Hg. The mean IOPs were significantly lower during the first 4 h postsurgery in the clonidine-treated eyes.

Administration, Topical↗
PubMed1989

The effect of Ca2(+) -antagonist on visual field in low-tension glaucoma.

A prospective study was conducted to evaluate the effects of Ca2(+)-antagonist on the visual field in low-tension glaucoma (LTG). Twenty-five consecutive patients (50 eyes) with LTG received nifedipine at 30 mg/day per os for 6 months. Visual field was tested with an Octopus 201 (program G1) prior to and each month during the period of nifedipine administration. In addition to tonometry and the measurements of systemic blood pressure and pulse rate, the reactivity of peripheral vessels was estimated by determining the response of skin temperature of a finger to cold water (4 degrees C). Twelve eyes (six patients) showed a constant improvement of visual field as expressed by an increase in mean sensitivity (MS). Canonical discriminant analysis demonstrated that the visual field is likely to improve with systemic nifedipine in patients who are young, have a higher initial MS and lower intraocular pressure, and have less decrease in diastolic blood pressure with the nifedipine administration and better cold recovery of skin temperature after their hand is soaked in cold water.

Administration, Oral↗
PubMed1989

"Spontaneous" pneumocephalus associated with aerobic bacteremia.

Three cases of "spontaneous" pneumocephalus suspected to have resulted from aerobic bacteremia caused by Enterobacter cloacae, Escherichia coli, and Klebsiella aerogenes are reported. In two cases, the E. cloacae and K. aerogenes were isolated from the cerebrospinal fluid. These cases were characterized by a rapid accumulation of air, without niveau, in the subarachnoid space and ventricles.

Adult↗
PubMed1989

Altered hepatic fatty acid metabolism in endotoxicosis: effect of L-carnitine on survival.

The activities of palmitoyl-coenzyme A (CoA) synthetase, carnitine acetyltransferase (CAT), and carnitine palmitoyltransferase (CPT) and the levels of ketone bodies, reduced coenzyme A (CoASH), carnitine, and their esters, which are involved in fatty acid metabolism, in rat liver and plasma were measured after the administration of Escherichia coli lipopolysaccharide (LPS). We also studied the effect of L-carnitine treatment before LPS administration on survival and on hepatic fatty acid metabolism. The activities of CAT and CPT and the concentrations of ketone bodies, CoA, and carnitine derivatives (except for malonyl-CoA) declined in the liver after LPS administration. The activity of palmitoyl-CoA synthetase was changed little after LPS administration, and the level of hepatic malonyl-CoA increased significantly, suggesting that LPS causes activated fatty acids to undergo esterification and lipogenesis rather than oxidation. Treatment of rats with L-carnitine before LPS greatly increased the survival rate, but did not affect enzymes that metabolize fatty acids, CoA, or carnitine derivatives in the liver. Further studies are necessary to elucidate the mechanism of the effect of carnitine on post-LPS survival.

Animals↗
PubMed1989

[Computerized digital image analysis of optic nerve heads with a three-dimensional image analyzer, IMAGEnet and a comparison with the Optic Nerve Head Analyzer].

Computerized digital image analysis of the optic nerve heads of 17 eyes with various sizes of optic disc cupping was performed using two kinds of three dimensional image analyzers, the IMAGEnet and the Optic Nerve Head Analyzer (ONHA). Intraphotographic error variances of measurements with both instruments were evaluated by measuring each image of the optic discs twice. The mean coefficient of variation (CV) with the IMAGEnet for the vertical cup/disc ratio, the horizontal cup/disc ratio, the cup volume, the rim area, and the rim area/disc area ratio were 3.75%, 3.03%, 7.89%, 2.55% and 1.36%, respectively. With the ONHA, the mean CV for the total cup/disc ratio, the cup volume, the rim area, and the rim area/disc area ratio were 0.82%, 0.21%, 2.39%, and 1.56%, respectively. The value of the cup/disc ratio and the cup volume obtained by the IMAGEnet was smaller than those by the ONHA (p greater than 0.1). Conversely, the rim area and rim area/disc area ratio measured by the IMAGEnet were statistically significantly larger than those by the ONHA (p = 0.01). Statistically significantly positive correlation was demonstrated for measurements made by both instruments in all disc parameters (p less than 0.01). These results seem to indicate the high reliability of the two instruments, however, further investigation is needed for the evaluation of the accuracy of measurements.

Glaucoma↗
PubMed1989

Use of apraclonidine to reduce acute intraocular pressure rise following Q-switched Nd:YAG laser iridotomy.

We evaluated the effectiveness of topical apraclonidine (ALO 2145, p-amino clonidine hydrochloride) in suppressing an acute postoperative intraocular pressure (IOP) rise following Nd:YAG laser iridotomy. Fifty-eight eyes (45 patients) with chronic primary angle-closure glaucoma underwent Q-switched Nd:YAG laser iridotomy. Twenty-nine eyes followed prospectively underwent Nd:YAG laser iridotomy following the topical administration of 0.5% apraclonidine prior to and immediately following the procedure. A retrospective control group of 29 eyes underwent Nd:YAG laser iridotomy without topical apraclonidine. Only one eye (3.4%) treated with apraclonidine experienced an IOP rise greater than 10 mm Hg over baseline, while five among 29 untreated eyes (17.2%) developed an IOP rise greater than 10 mm Hg.

Aged↗