PubMed Health⌕ Search

Biomedical subjects

S Ohsawa

Publications and source records attributed to S Ohsawa.

At least 19 recordsLinked to original sources
PubMed2000

Postoperative renal function after an abdominal aortic aneurysm repair requiring a suprarenal aortic cross-clamp.

We describe herein the postoperative renal functions of patients who required a suprarenal aortic cross-clamp during abdominal aortic surgery. Seven patients required a unilateral suprarenal aortic cross-clamp (group A) and six patients required a bilateral suprarenal clamp (group B). Eighty-three patients who required an infrarenal aortic clamp were assigned to group C. Renal hypothermia with renal perfusion or topical cooling during suprarenal clamp was not performed. No hospital deaths were encountered. In group B, the postoperative creatinine and blood urea nitrogen (BUN) levels remained statistically significantly higher than that of group C until the seventh postoperative day. The postoperative renal dysfunction (serum creatinine level >2.0 mg/dl) was 28.6% in group A and 50% in group B, while it was only 8.4% in group C, although no patient required either temporary or permanent hemodialysis. The postoperative peak BUN over 30 min suprarenal clamp was significantly higher than that within 30 min. In summary, the postoperative renal function was impaired after an extended bilateral suprarenal clamp. These findings suggest that if prolonged renal ischemia is thus expected, then renal preservation should be considered.

Aged↗
PubMed2000

Midline retroperitoneal versus midline transperitoneal approach for abdominal aortic aneurysm repair.

PURPOSE: The purpose of this study was to compare the midline retroperitoneal approach with the midline transperitoneal approach for abdominal aortic aneurysm (AAA) repair with respect to operative details, gastrointestinal complications, and wound complications. METHODS: From January 1990 through January 1998, 128 patients underwent elective aortic reconstruction for infrarenal AAA. Of these, 64 patients (the transperitoneal group) underwent conventional transperitoneal midline aortic exposure, whereas the remaining 64 patients (the retroperitoneal group) underwent retroperitoneal midline exposure of the aneurysm. RESULTS: Preclamp time, that is, the time from skin incision to aortic clamping, was significantly shorter in the transperitoneal group than in the retroperitoneal group (P <.001). However, the midline retroperitoneal approach was associated with decreased incidence of ileus (P <.01), earlier resumption of oral intake (P <.01), and decreased wound pain (P <.01), in comparison with the transperitoneal approach. Furthermore, there was no incidence of wound complications such as abdominal bulge or wound pain in any of the patients in the postoperative period or over the long term. CONCLUSIONS: The midline retroperitoneal approach for AAA was associated with fewer postoperative gastrointestinal and wound complications than the midline transperitoneal approach. Over the long term, there was no wound complication such as abdominal bulge and wound pain in any of the patients.

Aged↗
PubMed2000

Factors influencing joint-preserving operations in the treatment of the late stages of osteoarthritis of the hip.

Between November 1983 and December 1992, 136 hips (119 patients) with coxarthritis were operated on using joint-preserving techniques based on the rationale of Pauwels' osteotomy. The criterion for selection was a patient in whom the height of the joint space in the weight-bearing area of the hip was less than 1 mm. The mean age at operation was 48 years and the mean follow-up 109 months (60 to 171). Hips were categorised using Bombelli's classification of osteoarthritis, into atrophic and non-atrophic types. The endpoint was defined as that at which the height of the joint space became less than 1 mm again. The Kaplan-Meier curve showed that the rate of survival of the non-atrophic group was significantly better than that of the atrophic group. Cox's proportional hazard model indicated that the factors influencing the results of joint-preserving operations included Bombelli's classification, postoperative incongruence of the joint and the height of the joint space.

Adult↗
PubMed1999

Dynamic MR imaging of the carotid wall.

The purpose of this study was to clarify temporal changes of carotid wall enhancement using dynamic magnetic resonance (MR) and to correlate its findings with pathological conditions. Cervical carotid arteries of 84 consecutive patients were studied with a 1.5 T MR imager using phased array coils. Axial spoiled gradient-echo (SPGR) images (30-58 second scan time) with fat saturation were repeated 4-8 times after the injection of contrast material. We evaluated the presence and thickness of hypointense inner rims and hyperintense outer rims of the carotid wall, temporal changes of outer rim enhancement, and their changes in relation to pathological conditions. Hypointense inner rims and enhanced outer rims were clearly visualized in 87% (73/84) of our subjects. Enhancement of the outer rim was minimal in early phases and gradually increased. Patient age had a significant correlation with outer rim thickness. In the portions with large atheromatous plaques, inner rims were disrupted or thickened. A marked thickening of the outer rim was observed in one patient with arteritis. The outer rims adjacent to malignant tumors were often obscured. Our study suggests that dynamic MR images of the cervical carotid artery can uniquely demonstrate angiogenesis of the wall itself. The outer rim of the artery shows relatively rapid enhancement, and its thickness correlates with age.

Adult↗
PubMed1999

High-Fat diet enhances accumulation of hexachlorobenzene in rat dams and delays its transfer from rat dams to suckling pups through milk.

Effect of diets on the distribution and transfer of hexachlorobenzene (HCB) from dams to fetuses and suckling pups was investigated. In pregnant rats, the amount of HCB accumulated in fat tissues of the high-fat diet group was higher than that of the control diet group (P < 0.05). The amounts of HCB in fetuses of the high-fat and control diet groups were estimated to be about 0.28 and 0.12% of the dam's total intake during pregnancy, respectively. In both groups, a large proportion of HCB in dams disappeared during lactation period and was transferred to their pups through the milk. In the pups of the high-fat diet group, the amount of HCB in stomach contents was lower immediately after birth and decreased slowly compared with that in the control diet group during lactation. These results showed that a high-fat diet reduced the speed of the transfer of HCB from the dams to their suckling pups through milk.

Adipose Tissue↗
PubMed1999

Evaluation of effect and distribution of heparin administered in vascular reconstructive surgery.

BACKGROUND: The aim of this study was to find out whether intravenously administered heparin is distributed equally not only proximal but also distal to the arterial occlusion level in vascular reconstructive surgery. METHODS: Ten consecutive patients (7 men and 3 women) with an average age of 69.9 years (range, 51 to 76 years) who underwent graft replacement for aortic abdominal aneurysm from April to December 1994 were studied. Mean aortic clamp time was 76 minutes. Heparin sodium (100 U/kg) was administered intravenously to keep activated clotting time (ACT) over 250 secs and was neutralized by protamine sulfate (1 mg/kg) just after reperfusion. ACT, blood lactate and CPK-MM in the brachial and dorsal pedis artery were measured before heparin administration (control), just after arterial occlusion, just before reperfusion and 10 minutes after protamine administration. RESULTS: ACT was significantly prolonged after arterial occlusion and recovered after protamine administration with no significant differences between proximal and distal values at each point. Lactate showed significant increase after arterial occlusion which was more remarkable distally. CPK-MM was all the way within the normal range. CONCLUSIONS: In vascular reconstructive surgery which requires temporary arterial occlusion for as long as 80 minutes, the effect of heparin is excellent and equal throughout the body by collateral vessels, and the metabolic influence due to blockade of the blood flow is not so critical as to lead to cellular damage although anaerobic glycolysis is promoted distally due to hypoxia.

Aged↗
PubMed1998

Cardiopulmonary bypass established via a sutured vascular graft in the presence of extraanatomic bypass.

Cardiopulmonary bypass (CPB) was established via a sutured collagen sealed knitted Dacron graft in two patients who had undergone extraanatomic bypasses for lower limb ischemia, whose ascending aorta was not suitable for cannulation. One patient, with a history of femorofemoral bypass, underwent surgery for a ruptured aortic arch aneurysm (AAA) and the other patient, with a history of axillobifemoral bypass for chronic dissection involving the aortic arch and descending aorta, had unstable angina and underwent coronary artery bypass grafting. This technique of perfusion was found to be safe and effective for patients with an impaired ascending aorta who have undergone an extraanatomic bypass for the lower limb.

Aged↗
PubMed1998

Middle-term results of anatomic medullary locking total hip arthroplasty.

We report the results of cementless, anatomic, medullary locking hip prosthesis application in our first consecutive series. We used the so-called Asian size of prosthesis with proportionally smaller stem sizes in both diameter and length. Forty-seven stems and sockets were analyzed with a mean follow-up of 69 months. The mean Merle d'Aubigné hip scores were 8 points preoperatively and 16 points at the final follow-up. Radiologically, the stems showed excellent stability without loosening. Stress shielding around the stems did occur in most cases but did not progress. Preoperative bone quality influenced the extent of stress shielding evaluated at the final follow-up: higher stress shielding was noted in poorer quality bones at the time of operation. There were problems with the sockets. The shallow socket and impingement at the protruded rim seemed to cause a high incidence of dislocation (13%). Massive polyethylene wear occurred in 5 sockets. These sockets were 48 and 46 mm in diameter with 26 mm heads. In conclusion, the stems of the anatomic medullary locking hip prostheses used in Japan showed satisfactory stability even in poor quality bones, but there were problems with the polyethylene liners. Our solution was to use larger sockets with 22 mm heads.

Aged↗
PubMed1998

Primary aortoenteric fistula with a chronic isolated abdominal aortic dissection: report of a case.

A 47-year-old woman on long-term hemodialysis due to a chronic isolated abdominal aortic dissection was admitted to our department with severe abdominal pain. She had not suffered any hematemesis or melena. An emergency laparotomy revealed an abdominal aortic aneurysm with a diameter of 60mm, densely adhered to the ileum. An aortoenteric fistula manifesting as intramural rupture into the ileum was found after infrarenal abdominal aortic and bilateral common iliac cross-clamping. The fistula on the ileac side was nontransmural, but that on the aortic side communicated with the pseudolumen of the abdominal aorta, and contained mural thrombus. The infrarenal abdominal aorta and bilateral common iliac arteries were replaced with a collagen-sealed woven Dacron bifurcated graft. Histological examination of the ileum in this portion showed intramural bleeding and xanthomatous granulation with foam cell infiltration in the thickened subserosa. While it is difficult to diagnose nonpenetrating aortoenteric fistula preoperatively, such a fistula must be considered in a patient with severe abdominal pain, for whom previous abdominal aortic surgery has been performed or when an abdominal aneurysm is observed. To our knowledge, no other case of an aortoenteric fistula presenting as an intramural rupture into the ileum in an isolated abdominal aortic dissection has ever been reported.

Adult↗
PubMed1998

Massive aortic regurgitation by spontaneous rupture of a fibrous strand in a fenestrated aortic valve.

A very rare case of Marfan syndrome associated with acute aortic regurgitation due to rupture of a fibrous strand of a fenestrated aortic valve is presented. Although an aortic valve fenestration usually has no pathologic significance, its association with aortic annular dilatation plays an important role. Rupture of a myxomatously degenerated fibrous strand loaded with high tension from annular dilatation reducing the coaptation area of each cusp during diastole was the suspected cause of acute massive regurgitation by complete retroversion of the right coronary cusp. Rupture of a fibrous strand of a fenestrated aortic valve with a dilated annulus could result in acute massive aortic regurgitation, for which prompt surgical repair is mandatory.

Adult↗
PubMed1998

[The perspective of a medical technologist].

Medical technologists must send reliable laboratory data to clinicians before consulting about the data. It is indispensable for medical technologists to acquire and maintain special technological knowledge. What technologists can do to support clinical work is derived basically from the information involved in analyzing samples. Such information could be sent along with the data to the clinical doctor and thus support clinical work. In large hospitals, such as university hospitals, in addition to the usual support for clinicians, we should attempt to develop new methods for analyzing pathological conditions in various diseases. Moreover, we could even support clinical research with our special technological knowledge and skilled application. However, in small hospitals, medical technologists may have to do work that doctors in the laboratory usually do. Curricula and textbooks must be prepared to educate technologists to assume those roles when necessary.

Clinical Laboratory Techniques↗
PubMed1997

The release of nitroglycerin absorbed into the central venous catheter.

This study was conducted to evaluate the release of nitroglycerin (NG) that has been absorbed into the central venous catheter. A 0.05% NG solution was infused through a central venous catheter and the flow rates were set at 1, 5, or 10 ml/h, given over 12, 24, or 48 h. The catheter was flushed with lactate Ringer solution after completion of the NG infusion. The elution of the lactate Ringer solution from the tip of the catheter was then collected and assayed for its NG concentration by high performance liquid chromatography (HPLC). A higher concentration of NG was released with a faster flow rate and a longer infusion. The high level of NG release continued during the first 20 min, and ranged from a minimum of 0.07 mg/ml to a maximum that exceeded 0.15 mg/ml. Subsequently, the NG concentration gradually declined, but low concentrations of 0.006-0.02 mg/ml were still maintained 360 min later. Thus, it is suggested that if a catheter such as the Swan-Ganz continues to be used after the completion of a NG infusion, certain pharmacological effects due to the absorption of NG into the catheter body should be expected for at least 60 min.

Absorption↗
PubMed1997

Hexachlorobenzene accumulated by dams during pregnancy is transferred to suckling rats during early lactation.

The distribution of ingested stable, lipophilic environmental pollutants in dams and their transfer to fetuses and sucklings were investigated in rats fed a diet containing a small amount (35.1 nmol/100 g diet) of hexachlorobenzene (HCB). In the first experiment, we examined the distribution of HCB in pregnant and nursing rats fed the HCB diet during pregnancy and lactation. Its transfer to their sucklings was also studied. On d 16 after parturition, HCB concentrations in the blood, and subcutaneous and perirenal fat of nursing rats fed the HCB diet during pregnancy and lactation were approximately 1/3.5, 1/15 and 1/2.8, respectively, those of pregnant rats fed the HCB diet only during pregnancy. On the other hand, the HCB concentrations in the blood, and subcutaneous and perirenal fat of sucklings were approximately 6, 29 and 15 times higher than those of their dams. Therefore, a large amount of HCB apparently was transferred from dams to suckling pups through the milk. In the second experiment, we fed dams the HCB diet only during pregnancy and determined the distribution of HCB in the pregnant rats and fetuses as well as in the nursing rats and suckling pups. The estimated amount of HCB transferred from a dam to her fetuses corresponded to about 0.39% of her total intake during pregnancy. The amount of HCB detected in nursing rats on d 16 after parturition was much smaller than that in the pregnant rats, suggesting that a large proportion of the HCB that accumulated during pregnancy disappeared from the organs and fat tissues during lactation. The HCB concentration in the stomach contents of suckling pups fed by the dams who had consumed HCB before parturition was highest on d 2 after birth and decreased gradually during the 16 d after birth. In the blood, liver and fat tissues of suckling rats, the HCB concentrations increased until 7 d after birth and then decreased gradually. We conclude that the HCB that accumulated in dams during pregnancy was transferred to their suckling pups through milk in the early days after birth.

Animals↗
PubMed1997

Heel lifting as a conservative therapy for osteoarthritis of the hip: based on the rationale of Pauwels' intertrochanteric osteotomy.

Patients with osteoarthritis of the hip were treated with a conservative therapy of heel lifting. Orthoses were applied on 35 hips in 33 subjects and the cases were followed for 23 months on average. Dramatic pain relief was reported, but the time required to reduce or completely relieve pain increased according to the stage of osteoarthritis. The radiological results were not satisfactory. During the follow-up, only two hips showed improvement, 22 showed no change, and 11 deteriorated. The mechanism of heel lifting in relation to the hip joint was analysed, showing that pelvic obliquity was achieved and the trunk stabilized. In conclusion this simple orthosis was effective as a palliative therapy for osteoarthritis of the hip.

Biomechanical Phenomena↗
PubMed1997

[The leaflet fracture of a 19 mm SJM (HP) valve during valve insertion to the calcified small aortic annulus].

Aortic valve replacement was undergone in a 70-year-old woman with calcified aortic stenosis. Calcified and fused tricuspid aortic valve was excised and a 21 mm sizer passed with some difficulty through the annulus. A 19 mm SJM HP serious was selected and the horizontal mattress suturing technique was used. The valve was held at the cuff near the hinge guard and seated into the annulus by the usual amount of pressure, however, one leaflet fracture was retrieved and the valve was removed. A 19 mm standard SJM valve was then successfully implanted. The potential factors of leaflet fracture suggested that the leaflet thickness of smaller sized SJM valves showed smaller values than other bileaflet valves in the same sized-valves. In addition, the SJM valve does not have an orifice stiffening ring like other bileaflet valves. So, needless to say direct pressure to the leaflet, indirect pressure might cause valve destruction during insertion. The abnormal pressure applied to the direction from one hinge guard to the other can introduce deforming of the orifice ring resulting in leaflet fracture like this case. The pressure directed to the perpendicular direction may introduce leaflet escape due to the deforming of the valve orifice.

Aged↗
PubMed1996

Geranylgeraniol causes a decrease in levels of calreticulin and tyrosine phosphorylation of a 36-kDa protein prior to the appearance of apoptotic features in HL-60 cells.

It was demonstrated recently that geranylgeraniol (GGO) has potent apoptosis-inducing activity in various lines of tumor cells, including HL-60 cells. In the present study, we found that GGO markedly inhibited the expression of a calcium-binding protein, calreticulin, prior to the induction of apoptosis in HL-60 cells. Furthermore, we also observed a significant decrease in the tyrosine phosphorylation of a 36-kDa protein that is a major tyrosine-phosphorylated protein in HL-60 cells. These findings suggest that decreases in levels of calreticulin and in the tyrosine phosphorylation of the 36-kDa protein might be associated with the induction of apoptosis by GGO in HL-60 cells.

Amino Acid Sequence↗
PubMed1996

Thrombotic obstruction of a reinforced ringed expanded polytetrafluoroethylene graft caused by formation of a pseudoaneurysm at a nonanastomotic site: report of a case.

We report herein the case of a 72-year-old man in whom a nonanastomotic pseudoaneurysm arose from a reinforced ringed expanded polytetrafluoroethylene (EPTFE) graft (Gore-Tex, Flagstaff, AZ, USA) following an axillobifemoral bypass. The pseudoaneurysm developed 2 years after graft insertion and induced graft thrombosis. The development of the pseudoaneurysm can be attributed to the fact that his axillobifemoral bypass graft was so short it deformed the proximal anastomosis, and the graft was subcutaneously tunneled onto the major pectoral muscle. These technical errors placed the graft under too much tension in the longitudinal direction, which resulted in graft disruption and pseudoaneurysmal formation, followed by thrombosis of the axillary artery. Moreover, the possibility of direct trauma at the time of insertion cannot be substantiated. Although the very poor compliance and design of the externally supported ring could not tolerate stretch deformity in the Gore-Tex graft, only one other case of a nonanastomotic pseudoaneurysm has ever been reported.

Aged↗