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Biomedical subjects

T Shinzato

Publications and source records attributed to T Shinzato.

117 records · Page 7Linked to original sources
PubMedDate not supplied

Relationship between dialysis induced hypotension and adenosine released by ischemic tissue.

Two types of dialysis induced hypotension apparently exist. One type presents as gradually decreasing blood pressure with eventual symptoms (gradual hypotension), whereas the other presents as abruptly and sharply decreasing blood pressure, along with symptoms (abrupt hypotension). In the current study, the authors found that the plasma hypoxanthine concentration during abrupt hypotension was significantly higher than before the hypotension occurred (20 min after saline was administered or at the beginning of dialysis), whereas comparison of the plasma hypoxanthine concentration during gradual hypotension and that before the hypotension occurred (20 min after saline was administered or at the beginning of dialysis) revealed no significant difference. The current results indicate that abnormally increased adenosine triphosphate (ATP) degradation associated with tissue ischemia occurred during abrupt hypotension but not during gradual hypotension. It can be speculated that the increased release of adenosine due to abnormally increased ATP degradation caused the abrupt hypotension. This conclusion seems reasonable given that adenosine directly decreases small vessel tone and inhibits prejunctional release of norepinephrine.

Adenosine↗
PubMedDate not supplied

Late complications in traumatic coronary artery fistula: report of a case requiring surgical repair after 8 years.

We report the unusual case of a patient with traumatic coronary artery fistula who had been free of symptoms for more than 4 years, but who ultimately required surgical repair 8 years after the trauma due to late complications including angina pectoris, atrial flutter and fibrillation, congestive heart failure, and tricuspid regurgitation. Our findings suggest that early surgical repair should be undertaken in cases of traumatic coronary artery fistula, even if the shunt is minimal and early symptoms are mild. The persistence of, or a slow increase in, shunt flow over the years greatly increases the risk of the ultimate development of life-threatening complications.

Angina Pectoris↗
PubMedDate not supplied

Some new aryl-sydnones: effects on murine tumours.

The effects of new aryl-sydnones: 3-[4-X-3-nitrophenyl]-1,2,3-oxadiazolium-5-olates, where X = Cl (SYD-1); pyrrolidino (SYD-2); piperidino (SYD-3) and morpholino (SYD-4) on the survival of mice bearing Sarcoma 180, Ehrlich carcinoma, B10MCII (Fibrous histiocytoma) and L1210 leukemia ascitic tumours, on the proliferation of cultured tumour cells and on the synthesis of DNA in L1210 leukemia were determined. SYD-1 and SYD-2 in vivo significantly enhanced the survival of S180, Ehrilich and B10MCII tumour-bearing mice. Furthermore, SYD-2 showed significant activity against L1210. SYD-3 and SYD-4 did not show antitumour activity. SYD-1, in vitro was the most cytotoxic against all the above tumour cells. All of the drugs tested inhibited thymidine uptake by L1210 cells, SYD-4 being the least active.

Animals↗
PubMedDate not supplied

Continuous measurement of pressure in internal arteriovenous fistulae and prevention of symptomatic hypotension during hemodialysis.

To continuously monitor the blood pressure (BP) in an internal arteriovenous fistula, the blood tubing wall was punctured with a long, fine needle (25 gauge), and the needle tip was advanced into the fistula vein through the lumen of the outflow blood access puncture needle. It was found that the intrafistula BP thus measured varied in parallel with the systemic arterial BP during hemodialysis (HD). When the intrafistula BP fell to 60% of the level at the start of HD, 50 ml of saline was administered. As a result, hypotension was prevented completely in 60 HD in five patients who often showed symptomatic hypotension during HD.

Adult↗
PubMedDate not supplied

A new treatment strategy using both intermittent short dialysis and continuous ambulatory hemofiltration.

The authors devised a new treatment strategy using continuous ambulatory hemofiltration (CAHF) in between short hemodialyses (short HD). For CAHF, a small wearable hemofilter (0.1 m2) was developed using a membrane permeable to low molecular weight proteins. During short HD, no body water was removed, but saline, equivalent to 3% body weight, was administered at a constant rate. During CAHF, 1 L of replacement fluid was administered intravenously after every meal to increase the replacement volume. Switch from the conventional to new strategy resulted in far more stable blood pressure during short HD, a decrease in time averaged body weight, and a decrease in a decrease in time averaged blood urea nitrogen and plasma beta 2-m levels.

Ambulatory Care↗
PubMedDate not supplied

Change in sympathetic activity before, during, and after dialysis-induced hypotension.

During the hemodialyses of eight patients with end-stage renal failure, who often had sudden-onset dialysis-induced hypotension, catecholamine (CA) levels were measured in the ultrafiltrate obtained by a mini-filter placed in series upstream of the dialyzer. The water evaporation rate from the skin (reflecting the perspiration rate) was also monitored. Results showed a temporary elevation in CA levels in the ultrafiltrate before hypotension occurred. This rise did not continue for long, returning to baseline when hypotension actually occurred. The temporary elevation may reflect transient compensation by the sympathetic nervous system for the decrease in vascular wall tension. It was also found that there was considerable water evaporation from the skin during hypotension. Because sweat gland activity is reflexively modulated by the baroreceptor, perspiration after a drop in blood pressure may reflect the normal diminiution in baroreceptor activity.

Adult↗
PubMedDate not supplied

Relationship of protein catabolic rate or Kt/V with morbidity.

The authors investigated the influence of Kt/V and protein catabolic rate (PCR) on dialysis failure for 689 hemodialysis (HD) outpatients treated at the seven dialysis facilities in Aichi Prefecture, Japan. Dialysis failure was defined as death or hospitalization for reasons other than blood access, accident, wound, or mental disease. Patients were followed for 2 years. The rate of patients who developed dialysis failure during the observation period relative to the total patient population was defined as the dialysis failure rate. A total of 123 patients developed dialysis failure, which was fatal in 33 cases. In patients with Kt/V values of 1.6 or higher, the mean dialysis failure rate was significantly lower at 12.0% than that (19.2%) of patients with Kt/V values between 0.8 and 1.6 (p < 0.04). In patients that had PCR values under 0.8 g/kg/day, the dialysis failure rate was significantly higher at 32.5% than that (15.8%) of patients with PCR values between 0.8 and 1.4 g/kg/day (p < 0.0001).

Adult↗
PubMedDate not supplied

A new wearable system for continuous monitoring of arteriovenous fistulae.

A wearable system to constantly monitor the bruit generated by an AV fistula at times other than during dialysis was developed, and provided early detection of rapidly developing thrombi that cause occlusion of the fistular vessels. The system consists of a downsized microphone that continuously monitors the bruit generated, a warning device worn like a wristwatch, and a wire running down from the microphone to the emergency warning device. The microphone converts the bruit into an electrical signal and outputs it to the warning device. The emergency warning is then sounded whenever the input signal from the tiny microphone is weaker than a preset level. The warning device was set off in 4 of 21 long-term dialysis patients with arteriovenous fistulas, and within several hours all 4 developed an occlusion. One of the 14 patients with a graft had the device go off while sleeping, but it was a false alarm due to positioning that resulted in compression of the fistula arm.

Aged↗