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F Yamazaki

Publications and source records attributed to F Yamazaki.

At least 73 records · Page 4Linked to original sources
PubMed1992

Omentopexy for revascularization of free tracheal grafts in rats.

In rats, we examined the effect of an omentum wrapping on the vascularization of the trachea and on regeneration of the mucosal epithelium in the very early stage after free tracheal grafting. Two pieces of trachea were obtained from each donor rat. One piece was transplanted into the peritoneal cavity of the recipient rat and wrapped with omentum. The other piece was transplanted subcutaneously into the abdominal wall, without omentopexy. Recipients were sacrificed at random on days 1, 2, 3, and 4 after operation (5 rats/day). The increase of blood vessels rose significantly earlier in the omentopexy tracheas than in those without omentopexy (p less than 0.01), with all the former showing a normal ciliated, columnar epithelium in the membranous region of the trachea on day 4, accompanied by excellent epithelial regeneration in the cartilaginous region. These results suggest that omentopexy causes revascularization to occur earlier and to be completed in a shorter time, and that it also promotes epithelial regeneration following free tracheal grafting.

Animals↗
PubMed1992

Neovascularization effect with He-Ne laser in the rat trachea.

The tracheal tissue of a rat was heterotopically transplanted beneath the abdominal skin of a syngenetic rat, and the transplanted graft was irradiated with a He-Ne laser (2.41 J/cm2). Four or seven days following transplantation, Chinese ink staining was used to ascertain the number of newly generated vessels. Rats sacrificed on day 4 were divided into 3 groups, according to the number of laser irradiation treatments: A0, A2, and A4. Similarly, rats sacrificed on day 7 were divided into groups B0, B2, and B4. Among the A groups, vascular counts were 49.5 +/- 31.1 in group A0 (n = 6), 108.9 +/- 34.7 in group A2 (n = 7), and 90.9 +/- 24.6 in group A4 (n = 4). Neovascularization was significantly more pronounced in the irradiated groups that in the non-irradiated group. In the B groups, vascular counts were 148 +/- 58 in group B0 (n = 6), 146 +/- 56 in group B2 (n = 5), and 147 +/- 49 in group B4 (n = 5). There was no significant difference between the irradiated and non-irradiated B groups. Laser irradiation was determined to stimulate neovascularization, and the possibility of a clinical application for this procedure was suggested.

Animals↗
PubMed1992

An improved method for measurement of sweat expulsions during profuse sweating.

We present an improved ventilated-capsule method of recording for clear sweat expulsion patterns using nitrogen gas as a carrier gas heated to promote sweat evaporation. With this method, sweat expulsion patterns were more clearly recorded than with the conventional ventilated-capsule method. Taking the derivatives of these recordings of sweating expulsions could eliminate slow fluctuation components in the patterns of sweating. The results indicate that this method is useful in providing more-accurate measurements of sweat expulsion frequencies during profuse sweating.

Adult↗
PubMed1992

The role of dextran 40 and potassium in extended hypothermic lung preservation for transplantation.

We have previously demonstrated that a low-potassium dextran solution provides superior and more reliable preservation of lungs for 12 hours than that provided by the commonly used Euro-Collins solution. This study was designed to examine the individual contributions of dextran 40 and a low (extracellular) potassium concentration to lung preservation. In a randomized, blinded study using an in vivo canine single-lung transplant model, lungs preserved with low-potassium dextran solution (K+, 4 mmol/L; dextran 40, 20 gm/L) were compared to lungs preserved with low-potassium, no-dextran solution (K+, 4 mmol/L) and high-potassium dextran solution (K+, 123 mmol/L; dextran 40, 20 gm/L). The lungs were assessed immediately and 3 days after transplantation. The low-potassium dextran solution provided excellent immediate pulmonary function with little variability (arterial oxygen tension, 519 +/- 12 mm Hg, measured on the transplanted lung alone, inspired oxygen fraction = 1.0, n = 6). Removing the dextran 40 from the flush solution (low-potassium group) led to a significant deterioration in pulmonary function (arterial oxygen tension, 243 +/- 78 mm Hg, n = 6, p less than 0.01). The high-potassium dextran solution provided extremely poor preservation (arterial oxygen tension, 176 +/- 79 mm Hg; n = 6; p less than 0.01). Two animals in this group died within 6 hours of operation. Viability of the transplanted bronchus was significantly improved with the two solutions containing dextran 40. These results indicate that dextran 40 and low potassium concentration both contribute significantly to the uniformly excellent 12-hour lung preservation seen with the low-potassium dextran solution.

Animals↗
PubMed1992

The immunosuppressive effect of FK 506 on canine lung transplantation.

The immunosuppressive potency of FK 506 was studied after left lung transplantation in adult mongrel dogs in comparison with cyclosporine. Fiberoptic bronchoscopy, bronchial mucosal blood flow measurement with laser Doppler velocimetry, and chest x-ray and pathologic examinations were performed. Group A had no immunosuppression (n = 5); group B received FK 506 (0.10 mg/kg/day intramuscularly (n = 5); group C received cyclosporine (20 mg/kg/day orally) (n = 5). In group A four dogs died of rejection on the seventh to the twenty-first postoperative days. Another one was killed on the fourteenth postoperative day because bronchial dehiscence occurred at the anastomosis. In group B one died of alveolar rejection on the seventh postoperative day. The remaining four survived 28 days and were put to death. In group C all five dogs survived 28 days and were put to death. In group A bronchial stenosis or dehiscence at the anastomosis was found in every one during the early postoperative period. In group B stenosis did not develop in any of the dogs, including the one that died on the seventh postoperative day. In group C slight stenosis was seen in one dog, severe narrowing in another, and good healing in the remaining three. The transplanted lungs were almost normal histologically in four animals of group B, and one showed alveolar phase rejection. In all animals of group A severe rejection was observed, and in group C two of five animals showed vascular phase rejection, two latent phase, and one fibrosis. Histologic examination of the bronchial anastomosis in group B showed almost normal bronchial epithelium and slight submucosal infiltration of mononuclear cells. In group A there was desquamation of epithelium and mild to moderate mononuclear cell infiltration. In group C hyperplasia of the epithelium was observed in two animals, an abscess at the site of anastomosis in one, and mild to moderate mononuclear cell infiltration in all five. With use of laser Doppler velocimetry, bronchial blood flow in group B was found to be the same as in group C. Laser Doppler velocimetry values reached preoperative levels by the twenty-eighth postoperative day in both groups. Although diarrhea developed in two dogs of group B, no other significant side effect of FK 506 was seen.

Animals↗
PubMed1991

Serum immunoglobulin M (IgM) during early development of masu salmon (Oncorhynchus masou).

1. The development of serum immunoglobulin M (IgM) was studied by measuring IgM concentration in early developmental stages of masu salmon (Oncorhynchus masou) using single radial immunodiffusion. 2. IgM concentration was measurable from 88 days after hatching (46.5 micrograms/ml) and was maintained at a relatively constant level (less than 100 micrograms/ml) until 235 days after hatching. 3. IgM concentration increased significantly to a level of 691 +/- 37 micrograms/ml (mean +/- SE, N = 59) during the period from 251 to 429 days after hatching. The highest level of serum IgM was maintained from 429 days to 489 days after hatching. 4. The increase of IgM concentration was not accompanied by parallel increases in total serum protein concentration.

Animals↗
PubMed1991

Anti-ischaemic and vasospasmolytic effects of a novel Ca2+ channel blocker, SD-3211, in vitro.

1. The present study was undertaken to determine the vasospasmolytic activity of a novel non-dihydropyridine type of Ca2+ channel blocker, SD-3211, in isolated canine coronary arteries and its ability to reduce myocardial ischaemic damage in isolated perfused rabbit hearts. 2. The vasospasmolytic effect of SD-3211 was investigated using 3,4-diaminopyridine-induced rhythmic contraction, in comparison with its enantiomer (SD-3212), nicardipine and diltiazem. SD-3211 was shown to reduce the peak tension and increase the contraction frequency. The order of potency for the relaxation of the peak tension was as follows: nicardipine greater than SD-3211 greater than diltiazem greater than SD-3212 and being compatible with that for the relaxant effects of these compounds on KCl-induced contraction in the same specimen. 3. Furthermore, the effect of SD-3211 on myocardial damage due to global ischaemia for 60 min followed by 60 min of reperfusion was examined. SD-3211 at a concentration of 2 X 10(-8) mol/L was given for 40 min before and again for 60 min after the ischaemia. SD-3211 attenuated the increase in leakage of creatine phosphokinase from the hearts and the decrease in pH of perfusate during reperfusion, while concomitantly providing a significant improvement in the post-ischaemic recovery of developed tension. 4. These results suggest that SD-3211 has properties to reduce coronary vasospasm and to provide protection against ischaemic damage, both of which may have beneficial actions in the treatment of ischaemic heart disease.

4-Aminopyridine↗
PubMed1991

[Mother Teresa].

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Catholicism↗
PubMed1991

A reevaluation of heparin requirements for cardiopulmonary bypass.

We wished to determine if reduction in the standard heparin administration for cardiopulmonary bypass could be accomplished safely with the use of membrane oxygenators. An experimental study was designed to evaluate two different heparin administration protocols for cardiopulmonary bypass with hollow-fiber membrane oxygenators. Two groups of six pigs were submitted to hypothermic cardiopulmonary bypass (28 degrees C) for 3 hours, then rewarmed, decannulated, and reassessed after 1 hour. In group I (control) heparin was administered to maintain the activated clotting time in excess of 450 seconds; in group II activated clotting time was maintained between 250 and 300 seconds. The mean total heparin administered was 41,000 units in group I and 25,000 units in group II. Concentration of coagulation factors II, V, and VIII, fibrinogen, and platelet count were determined before, during, and 1 hour after bypass. No significant difference in any of these coagulation parameters was observed between the groups. The performance of the oxygenators was similar in both groups, with no evidence of thrombosis. Thus reduced heparin administration, enough to keep activated clotting time between 250 and 300 seconds, was not related either to major coagulation factors and platelet consumption or to derangements in the oxygenator's performance.

Animals↗
PubMed1990

Synthesis of an appropriately protected core glycotetraoside, a key intermediate for the synthesis of "bisected" complex-type glycans of a glycoprotein.

A stereocontrolled synthetic route to a glycotetraoside, allyl O-(3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1--- -4)-O- (3,6-di-O-allyl-2-O-benzyl-beta-D-mannopyranosyl)-(1----4)-O-3, 6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1----4)-3-O- benzyl- 2-deoxy-6-O-p-methoxy-phenyl-2-phthalimido-beta-D-glucopyranoside, an important intermediate for the synthesis of "bisected" complex type glycans of glycoproteins has been established by employing two glycosyl donors, 3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl trichloroacetimidate and 4-O-acetyl-3,6-di-O-allyl-2-O-benzyl-alpha-D-mannopyranosyl bromide, and a glycosyl acceptor, allyl O-(3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1----4) -3-O- benzyl-2-deoxy-6-O-p-methoxyphenyl-2-phthalimido-beta-D-glucopyranoside.

Carbohydrate Conformation↗
PubMed1990

Synthesis of alpha-D-Manp-(1----3)-[beta-D-GlcpNAc-(1----4)]-[alpha-D-Manp+ ++-(1----6)] - beta-D-Manp-(1----4)-beta-D-GlcpNAc-(1----4)-[alpha-L-Fucp- (1----6)]-D- GlcpNAc, a core glycoheptaose of a "bisected" complex-type glycan of glycoproteins.

A synthesis of alpha-D-Manp-(1----3)-[beta-D-GlcpNAc-(1----4)]-[alpha-D-Manp++ +-(1----6)]- beta-D-Manp-(1----4)-beta-D-GlcpNAc-(1----4)-[alpha-L-Fucp-( 1----6)]-D- GlcpNAc was achieved by employing benzyl O-(3,4,6-tri-O-benzyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1--- -4)-O- (2-O-benzyl-beta-D-mannopyranosyl)-(1----4)-O-(3,6-di-O-benzyl-2-deoxy-2 - phthalimido-beta-D-glucopyranosyl)-(1----4)-3-O-benzyl-2-deoxy-6-O-p- methoxyphenyl-2-phthalimido-beta-D-glucopyranoside as a key glycosyl acceptor. Highly stereoselective mannosylation was performed by taking advantage of the 2-O-acetyl group in the mannosyl donors. The alpha-L-fucopyranosyl residue was also stereoselectively introduced by copper(II)-mediated activation of methyl 2,3,4-tri-O-benzyl-1-thio-beta-L-fucopyranoside.

Carbohydrate Conformation↗
PubMed1990

A regio- and stereo-controlled synthesis of beta-D-Glcp NAc6SO3-(1----3)-beta-D-Galp6SO3-(1----4)-beta-D-GlcpNAc 6SO3- (1----3)-D-Galp, a linear acidic glycan fragment of keratan sulfate I.

A stereocontrolled synthesis of beta-D-GlcpNAc6SO3-(1----3)-beta-D-Galp6SO3-(1----4)-beta-D- GlcpNAc6SO3- (1----3)-D-Galp, was achieved by use of benzyl O-(2-acetamido-3,4 di-O-benzyl-2-deoxy-6-O-p-methoxyphenyl-beta-D- glucopyranosyl)-(1----3)-O-(2,4-di-O-tert-butyldiphenylsilyl-beta- D- galactopyranosyl-(1----4)-O-(2-acetamido-3-O-benzyl-2-deoxy-6-O-p-methox yphenyl - beta-D-glucopyranosyl)-(1----3)-2,4,6-tri-O-benzyl-beta-D-galactopyranos ide as a key intermediate, which was in turn prepared by employing two glycosyl donors, 3,4-di-O-benzyl-2-deoxy-6-O-p-methoxyphenyl-2-phthalimido-beta-D- glucopyranosyl trichloroacetimidate and O-(3,6-di-O-acetyl-2,4-di-O-benzyl-beta-D-galactopyranosyl)-(1----4)-3-O - benzyl-2-deoxy-6-O-p-methoxyphenyl-2-phthalimido-beta-D-glucopyranosyl trichloroacetimidate, and a glycosyl acceptor, benzyl 2,4,6-tri-O-benzyl-beta-D-galactopyranoside.

Carbohydrate Conformation↗
PubMed1990

Radiologic correlation with early physiologic function of the transplanted canine lung.

There is no single reliable method for assessment of the transplanted lung. Multiple modes of assessment are therefore used. In a canine model designed to assess lung preservation, the reliability of information gained from chest radiographs performed in the early post-transplant period was examined. The function of 20 left lung allografts, stored for 12 hours after pulmonary artery flush preservation was studied. Radiographs graded according to disease severity were compared with physiologic function of the transplanted lung assessed immediately and at three days post-transplantation. This protocol enables study of acute preservation-related lung injury and the delayed manifestations of ischemic and reperfusion injury after a three day period of recovery, while avoiding confounding rejection and infectious episodes. The chest radiograph did not reliably reflect function of the flush-preserved transplanted lung. Thus, relying only on this modality may lead to erroneous conclusions. In this study, the progression of radiographic changes associated with the "reimplantation response" differed from previous descriptions, possibly reflecting differences in operative technique or improved lung preservation.

Animals↗
PubMed1990

The superiority of an extracellular fluid solution over Euro-Collins' solution for pulmonary preservation.

Limited donor supply is the major factor restricting the application of lung transplantation. A uniformly reliable method of lung preservation would improve donor organ availability. At present, Euro-Collins' solution, an intracellular fluid-type solution, is most widely used in organ preservation. However, we have previously shown that initial pulmonary flush with an extracellular-type solution (low-potassium dextran solution [LPD]) provided better pulmonary preservation than Euro-C. In the present study, we used an in vitro-ventilated, blood-perfused rabbit lung model to examine whether the mechanism for this improvement was related to the effect of LPD during pulmonary flush or its effect during storage. Rabbit lungs were harvested and stored after pulmonary flush with different solutions (group 1: 400 ml of LPD; group 2: 400 ml of Euro-C; group 4: 300 ml of Euro-C followed by 100 ml of LPD; n = 5 in each group). The lungs were then preserved at 10 degrees C for 18 hr and reperfused with fresh venous blood. After 10 min of reperfusion, lungs in group 1 showed the highest PO2 (group 1: 124.4 +/- 7.7 mmHg; group 2: 46.2 +/- 9.4 mmHg P less than 0.01). Lungs in both group 3 and group 4 showed better lung function and lower wet/dry weight ratio than those in group 2. We conclude that LPD provides better lung preservation by its effects both on pulmonary flush and on storage.

Animals↗
PubMed1990

The effect and optimal time of administration of verapamil on lung preservation.

Calcium channel blockers have recently been shown to improve pulmonary and myocardial preservation. The effect of verapamil on hypothermic lung preservation was investigated using an isolated ventilated rabbit lung perfusion model. In phase 1, preserved lungs were not flushed prior to extraction. Four groups of five animals were studied: group 1 (no verapamil), group 2 (verapamil administration prior to extraction), group 3 (verapamil at reperfusion only), group 4 (verapamil both prior to extraction and at reperfusion). In phase 2, two groups of five animals received pulmonary artery flush with low potassium (4 mmol/L), 2% low-potassium dextran (LPD) solution; group 1 (without verapamil), group 2 (flush and reperfusion with verapamil). As in phase 1, lungs were stored for 30 hr at 10 degrees C prior to reperfusion. In phase 3, the protocol was identical to phase 2, except that the storage time was extended to 48 hr. PO2 (mean +/- SE) of effluent blood in lungs treated with verapamil prior to extraction (122.8 +/- 5.0 mmHg) was significantly increased in comparison with lungs not receiving verapamil (69.0 +/- 3.3 mmHg) or only receiving verapamil at the time of reperfusion (87.1 +/- 11.9 mmHg). Gas exchange after 30 hr storage was equivalent in lungs flushed with LPD with or without verapamil. However verapamil did provide an advantage when preservation times were extended to 48 hr (62.3 +/- 8.5 mmHg, 46.9 +/- 2.3 mmHg). Verapamil administered prior to lung extraction provides better lung function following preservation, but has benefit over LPD flush only with extended periods of preservation (48 hr).

Animals↗
PubMed1990

Donor selection for single and double lung transplantation. Chest size matching and other factors influencing posttransplantation vital capacity.

In six single lung transplant (SLT) and six double lung transplant (DLT) recipients, the relationships of the recipient's posttransplantation vital capacity (posttx VCR) to the recipient's predicted normal vital capacity (pred VCR) and the donor's predicted normal vital capacity (pred VCD) were investigated. After left SLT the left posttx VCR was correlated with the left predicted VCD (r = 0.83; p less than 0.05); however, no correlation was found between these after DLT. In contrast, there was a tendency toward correlation between the posttx VCR and the predicted VCR after DLT (r = 0.75; p less than 0.1), but no such trend was apparent after SLT. These results suggest that posttx VCR depends primarily on predicted VCD after SLT and on pred VCR after DLT. Therefore, in donor-recipient size matching for lung transplantation a donor with a pred VCD greater than the pred VCR should be chosen for a left SLT recipient, whereas a donor with a pred VCD near the pred VCR would be suitable for a DLT recipient.

Adult↗