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Biomedical subjects

A Hashimoto

Publications and source records attributed to A Hashimoto.

At least 271 records · Page 15Linked to original sources
PubMed1993

Cerebral death-like conditions after aortic aneurysm surgery using retrograde cerebral perfusion.

A patient with Stanford type A acute aortic dissection who developed severe cerebral dysfunction after surgery using retrograde cerebral perfusion through the superior vena cava was examined. The patient was able to regain normal brain function with no neurological deficit. Postoperative venography taken through the superior vena cava showed the presence of competent venous valves at the venous angles. This suggests that the valves interrupted cerebral perfusion, decreasing blood flow to less than that required. After consideration of the possible causes of brain damage incurred during surgery for aortic aneurysm using retrograde cerebral perfusion, it was concluded that this patient was able to recover normal brain function because the surgery was performed under profound hypothermia.

Adult↗
PubMed1993

[International normalized ratio (INR) for optimal anticoagulant therapy].

Optimal therapeutic ranges for an oral anticoagulant therapy has been discussed for many years. Prothrombin time, prothrombin time ratios (PTR) and thrombotest have been employed so far, but, recently, International Normalized Ratio of prothrombin time (PT-INR or INR) has been introduced. We investigated paying special interest to INR, the effectiveness of oral anticoagulant therapy in 170 prosthetic valve patients and in 157 patients with various cardiovascular diseases who received warfarin at two different centers. The thrombotest, prothrombin time and INR were measured at follow-up visits every month. Regarding the 170 patients with prosthetic valves with a mean follow-up period of 2.44 years, 9 thromboembolisms (TE) were reported. The average TT and INR values in TE-free patients among 101 in whom coagulability could be measured, were 21.1% and 1.73 respectively. The average TT and INR values in 5 patients with TE were 26.4% and 1.53 respectively and this was significantly (p < 0.01) higher (smaller) than in TE-free patients. 157 patients (mean age 55 +/- 12 y.o.) with various cardiovascular diseases (Table 2) were followed up for a mean of 4.9 +/- 3.2 years. As is seen in figure 4, mean INR values in TE patients were 1.28, in patients with bleeding complications 4.1, and in event free patients 2.07 respectively. In conclusion, with INR greater than 2.75, no thromboembolic complication occurred, but several hemorrhagic complications occurred at INR greater than 3. Therefore INR therapeutic ranges between 2.0-3.0 are recommendable both for the prevention of TE and bleeding complications.

Administration, Oral↗
PubMed1993

[Effect of retrograde cerebral perfusion in preserving cerebral function during circulatory arrest].

The efficacy of retrograde cerebral perfusion (RCP) method was evaluated in 26 patients who underwent aortic arch reconstruction. Surgical procedures were; ascending-proxymal arch replacement involving Bentall type procedures (17 cases), total arch replacement (4 cases), and distal arch replacement (5 cases). The RCP were performed through selective cannulation on the superior vena cava at 18.4 degrees C of the average rectal temperature. The perfusion pressure was 28.3 (+/- 5.9) cmH2O and flow was 360 (+/- 15.4) ml/min. RCP time was 74.1 (+/- 26.2) min. Twenty-four patients survived among 26 patients and 2 patients died after operation. Postoperative consciousness was confirmed in 25 patients. Postoperative neurological complications were 1) delayed arousal 5 cases, 2) delirium 3 cases, 3) respiratory disorders 5 cases, 4) double vision 2 cases, 5) cerebral infarction (CI) 1 case. These complications except-CI were resolved in early postoperative period. And regarding effective time period of RCP, incidence of neurological complications were significantly higher in cases which received RCP over 80 min. Therefore we consider that 80 min is a safety time period. In conclusion, RCP is a useful step for preserving the brain during the operation of graft replacement of aorta involving aortic arch.

Aortic Dissection↗
PubMed1993

Repeated canine herpesvirus (CHV) reactivation in dogs by an immunosuppressive drug.

To examine the possibility of repeated reactivation of canine herpesvirus (CHV), 2 serial treatments with the corticosteroid drug prednisolone (PD) were given at different periods following oral-nasal infection of pups and adult dogs. CHV was not recovered from infected, untreated dogs or from uninfected, treated controls. Viral reactivation of CHV, without clinical signs, was induced twice in 2/3 adults and in 2/3 pups treated at intervals that ranged from 1 to 3 months following the initial infections. Highest viral titers were obtained from nasal swab samples, with lower titers found in the oral pharynx, penis or vagina. In some, but not all dogs, the infectivity titers of the nasal secretion samples were higher after the initial prednisolone treatments than after the second treatments. The duration of viral shedding after the second series of steroid treatments also was shorter than the shedding period following the initial reactivations. The results presented here suggest that latent CHV occurs in both pups and adults dogs following infection and that active infections, with viral shedding, may occur repeatedly for prolonged, but undetermined, periods.

Age Factors↗
PubMed1993

[Effectiveness of continuous retrograde cerebral perfusion for surgical treatment of aneurysms of the aortic arch--comparison with antegrade cerebral perfusion].

Several methods have been used for an adjunct to perform operation of aortic arch aneurysms. However, their results were often not so reasonable. Recently retrograde cerebral perfusion was reported as a new adjunctive method. In our institute, for the past 6 and a half years from May 1985 to April 1992, 50 patients underwent reconstruction of the transverse aortic arch by using two methods of artificial cerebral perfusion. One method is continuous antegrade cerebral perfusion (ACP, for 32 patients), and the other is continuous retrograde cerebral perfusion (RCP, for 18 patients), each technique was combined with deep hypothermia (18-20 degrees C) and low flow perfusion (10-30 ml/kg/min) to lower half body performed from femoral artery. In our RCP circuit, an additional pump was used for cerebral perfusion to superior vena cava, but the circuit was much simpler than the circuit in ACP. We compared the two methods (ACP versus RCP) as regards to the following items and the results were showed in parentheses; hospital death (8/32, 25%: 2/18, 11%), respiratory complication (8.27, 30%: 3/18, 17%), neurological complication (7/29, 24%: 1/18, 5.5%), duration of extracorporeal circulation (306.8 +/- 74.5 min: 260.4 +/- 60.0 min), periods of pre-ECC in the operation (160.3 +/- 69.2 min: 117.7 +/- 35.3 min), duration of cerebral perfusion (113.6 +/- 45.4 min: 74.1 30.5 min) and amount of bleeding (3424 +/- 2881 ml: 1802 +/- 1291 ml). RCP has superior advantages in all of those in comparison with ACP. These results suggest that RCP is a useful adjunctive method for reconstruction of aortic arch with a low operative risk.

Adult↗
PubMed1993

[Efficacy of myocardial preservation using GIK solution for prolonged ischemic heart].

The efficacy of myocardial preservation using GIK solution combined with continuous cold blood perfusion was assessed in patients with prolonged ischemia. Fifteen patients receiving more than 4 hours' ischemia were divided into two groups. In Group A, seven patients were associated with severe aortic regurgitation and showed increased left ventricular volume of more than 60 mm in LVDd and 45 mm in LVDs. In Group B, eight patients had a normal left ventricular volume of less than 60 mm in LVDd and 45 mm in LVDs echocardiographically. There was no significant difference in ischemic time, or preoperative hemodynamic parameters between the two groups. The postoperative cardiac index was 2.93 +/- 0.87 in Group A and 4.3 +/- 0.8 in Group B (p < 0.01). The postoperative shortening fraction was 0.17 +/- 0.01 in Group A, 0.43 +/- 0.12 in Group B (p < 0.01). These parameters significantly deteriorated in Group A compared to Group B. Released enzymes (GOT, CK-MB) were significantly increased in Group A with prolonged ischemic time. In conclusion, postoperative cardiac function after 4 hours' ischemia using GIK solution deteriorated in the patients with a dilated heart due to aortic regurgitation.

Aortic Valve Insufficiency↗
PubMed1993

[Recent advances of surgical treatment of aortic arch aneurysm using retrograde cerebral perfusion].

Between March 1985 and September 1992, 68 patients underwent the replacement of the arch aorta. To protect the brain we had used selective cerebral perfusion (SCP) in 33 cases, but since October 1990 we have used retrograde cerebral perfusion (RCP) in 35 cases. Compared with SCP, RCP decreased the incidences of cerebral infarction and irreversible cerebral complications from 27% to 4% (p < 0.01), and hospital mortality rate from 27% to 14%. However RCP over 80 minutes made complication of transient consciousness disturbance in 4 of 7 cases (57%). We measured cerebral blood flow (CBF) by transcranial Doppler at middle cerebral arteries in 7 cases. After RCP, CBF decreased between 50% and 10% and could not be detected in 3 cases. Reactive hyperemia occurred in all cases after RCP ended. RCP will increased circulatory arrest time by about 30 minutes according to our clinical data.

Aortic Dissection↗
PubMed1993

[Sutureless aortic valve replacement for peri-annular pseudoaneurysm and perivalvular leakage due to prosthetic valve endocarditis].

A 49-year-old man who had undergone AVR entered our hospital with congestive heart failure and continuing slight fever. By cardiac imaging, he was diagnosed prosthetic valve endocarditis with periannular pseudoaneurysm and perivalvular leakage. He underwent a new translocation method using a composite valve (a prosthetic valve directly sutured a ring prosthesis, which was separated from an intraluminal ringed graft). Post operative course was uneventful. He recovered well after the operation.

Aneurysm, False↗
PubMed1993

[Functional evaluation of skeletal muscle ventricles for circulatory assist].

Skeletal muscle has a potential power for cardiac assist. Two approaches have been used to harvest this power: dynamic cardiomyoplasty, which involves the application of muscle directly to the heart to support cardiac contractile function; and the construction of skeletal muscle pouches or ventricles, which are used as separate pumps working either in parallel or in series with the heart. In this study, we evaluated the function of the skeletal muscle ventricles (SMVs) for circulatory assist. In six dogs (18.5 +/- 2.3 kg, mean +/- S.E.M.), SMVs were constructed from the right latissimus dorsi muscle, and placed in the right hemithorax. After a 3-week vascular delay period, the SMVs were preconditioned electrically by 2 Hz continuous stimulation for six weeks. Nine weeks later, SMVs were connected to a mock circulation device for functional evaluation. As right-sided pumps, at a preload of 10 mmHg, SMVs generated stroke work of 0.63 +/- 0.04 x 10(6) ergs with 25 Hz and 0.80 +/- 0.06 x 10(6) ergs with 85 Hz, which exceeded that of the native right ventricle. As left sided pumps, also at a preload of 10 mmHg, SMV stroke work was 0.49 +/- 0.13 x 10(6) with 25 Hz 0.90 +/- 0.09 x 10(6) ergs, which was roughly half that of the left ventricle. These results demonstrate that SMVs have the potential to function as left or right heart assist devices.

Animals↗
PubMed1993

Virus reactivation in bitches with a medical history of herpesvirus infection.

Virologic and pathologic investigations were done on prednisolone-treated bitches with a history of canine herpesvirus (CHV) infection. Reactivation of CHV was demonstrated in 5 Beagle bitches after daily administration of 600 mg of prednisolone for 5 days. The reactivation was confirmed in 4 of 5 bitches. Canine herpesvirus was recovered from nasal, oral, vaginal, and ocular secretions on the 5th to 21st days after initiation of treatment with prednisolone, and also from nasal mucosa and tonsil tissues. Results indicated that latent CHV infections develop and that the virus may be reactivated, without clinical signs, in dogs with a history of CHV infection.

Abortion, Veterinary↗
PubMed1993

Bubble formation and decompression sickness on direct ascent from shallow air saturation diving.

To find the minimum supersaturation pressure for detectable bubble formation and for contraction of decompression sickness (DCS), three shallow air saturation dives at the depth of 6 m, 7 m, and 8 m were performed. The ultrasonic M-mode method was used for detecting bubbles. The exposure period was 3 d for all dives. Ten subjects were compressed to both 6 m and 7 m, and nine subjects were compressed to 8 m. One bubble streak was shown in the 6-m dive group. A small number of bubbles were seen in four subjects in the 7-m dive. All subjects in the 8-m dive presented various amounts of bubbles. DCS was not observed in the 6-m and 7-m dives. On the other hand, in the 8-m dive, four subjects suffered from DCS and required recompression treatment. The minimum depth for detectable bubble formation was assessed at around 6 m and the direct ascent from saturation at 8 m seems to have a high risk of DCS.

Adult↗
PubMed1993

[An arch and ascending replacement for aortic arch dissection by "separate hypothermia" retrograde cerebral perfusion].

We have developed a new technique of cerebral perfusion during operations on the aortic arch. The concept of this technique is as follows. A retrograde cerebral perfusion provides a relative long time to perform the distal aortic repair, and simplifies the operation. To avoid the disadvantages by deep hypothermia, we perfused from SVC cannula with blood cooled at 10-15 degrees C, from femoral artery with blood cooled at 20-26 degrees C. A successful case using this method is as follows. A 68-year-old man was referred to our hospital for aortic arch dissection. He underwent an operation 4 weeks after onset. Graft replacement of ascending aorta and aortic arch was performed under this method. We perfused blood from SVC cannula at an internal jugular vein pressure of 30 cmH2O, and SVC perfusion flow was 600 cc/min. By this separate hypothermia perfusion, the nasopharyngeal temperature is maintained about 15 degrees C, the rectal temperature is maintained 22-24 degrees C. The duration of cerebral perfusion from SVC cannula was 125 min, but prolonged emergence from anesthesia and neurological deficit were not seen.

Aged↗
PubMed1993

[Assessment of myocardial perfusion abnormality and hibernating myocardium by gated blood pool and exercise-stress thallium tomographies after successful coronary angioplasty].

Cardiac function and myocardial perfusion were assessed by exercise-stress thallium SPECT and resting gated blood pool SPECT techniques before and after 47 successful coronary angioplasties. Thallium perfusion was analyzed visually and quantitatively in stress and resting studies. Left ventricular ejection fraction (LVEF) and peak filling rate (PFR) were calculated and regional wall motion was scored by amplitude and phase images in radionuclide planar and tomographic imagings. The thallium redistribution in delayed or resting SPECTs was more sensitive (87%) for detecting myocardial ischemia compared to symptoms (36%) and ECG changes (60%). An exercise capacity, LVEF, PFR, and the scores of perfusion and regional wall motion were improved significantly after coronary angioplasty. Stress thallium and gated blood pool SPECTs showed the improvements of myocardial perfusion in 159 (79%) of 201 segments and regional wall motion in 47 (51%) of 92 segments, respectively. These results suggest that the combined use of stress thallium SPECT, gated blood pool planar and SPECT techniques can contribute not only to the assessment of the efficacy of coronary angioplasty but also to detecting the mismatching of myocardial perfusion and contraction ("myocardial hibernation") in infarct-related myocardial lesions.

Angina Pectoris↗
PubMed1992

Determination of free amino acid enantiomers in rat brain and serum by high-performance liquid chromatography after derivatization with N-tert.-butyloxycarbonyl-L-cysteine and o-phthaldialdehyde.

The concurrent determination of free amino acid enantiomers and non-chiral amino acids in rat brain and serum was accomplished by high-performance liquid chromatography with fluorimetric detection after derivatization with N-tert.-butyloxycarbonyl-L-cysteine and o-phthaldialdehyde. The method revealed the presence of a large amount of free D-serine (0.22 mumol/g of tissue; D/D + L ratio = 0.25) in the brain whereas D-aspartate and D-alanine were established to be at trace levels. These results further support the presence of D-serine in adult brain tissues as demonstrated by recent work using gas chromatography.

Amino Acids↗
PubMed1992

Exocytosis upon osmotic swelling in human epithelial cells.

Upon osmotic swelling human epithelial cells exhibited significant increases in the membrane capacitance. Evidence for exocytosis includes its dependency on temperature, cytosolic Ca2+ and ATP as well as its sensitivity to guanosine 5'-O-(3-thio)triphosphate (GTP gamma S) and N-ethylmaleimide (NEM). A role of the osmotic exocytosis in the subsequent cell volume regulation is suggested.

Adenosine Triphosphate↗
PubMed1992

The presence of free D-serine in rat brain.

Free amino acid enantiomers in adult rat brain extracts were analyzed as their N,O-pentafluoropropionyl isopropyl derivatives by gas chromatography on a capillary column of Chirasil-L-Val. A peak X, which exhibited the same retention time as the N,O-pentafluoropropionyl isopropyl derivative of authentic D-serine, was detected in the brain extracts. Electron impact and positive chemical ionization mass spectra of the peak X of the brain extracts were identical to those of authentic D-serine. The concentration of free D-serine and the ratio of D-serine/total serine in the brain were estimated to be 0.27 and 0.23 mumol/g of wet weight, respectively. These data provide the first evidence that substantial quantities of free D-serine are present in mammalian brain tissues.

Animals↗
PubMed1992

Membrane capacitance increases induced by histamine and cyclic AMP in single gastric acid-secreting cells of the guinea pig.

During acid secretion, gastric parietal cells undergo profound morphological changes including formation of the apical secretory membrane. To examine the mechanism of histamine-induced increases in the apical membrane area at the single cell level, we monitored the membrane capacitance by applying a time-resolved phase-sensitive detection method to singly isolated parietal cells of guinea pig. A real-time increase in the membrane capacitance was detected within several min after stimulation with histamine. An H2-blocker (cimetidine), but not an H1-blocker (pyrilamine), inhibited the histamine response. Dibutyryl cyclic AMP mimicked the histamine effect. The capacitance response to histamine was sensitive to cytosolic Ca2+, temperature and N-ethylmaleimide. The histamine response was inhibited by intracellular application of a non-hydrolyzable ATP analog (AMP-PNP) and an isoquinolinesulfonamide derivative that works as an inhibitor of protein kinase A (H-8). These results indicate that in parietal cells, elevation of intracellular cyclic AMP induces exocytotic insertion of intracellular membranes into the plasma membrane, presumably by activating protein kinase A.

Animals↗