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Biomedical subjects

T Ohwada

Publications and source records attributed to T Ohwada.

At least 73 records · Page 4Linked to original sources
PubMed1995

Endoscopic ultrasonographic abnormalities and lower esophageal sphincter function in reflux esophagitis.

Endoscopic ultrasonography of the lower esophagus was performed in 25 patients with reflux esophagitis and 13 age-matched controls. Thickening of the esophageal wall and abnormalities of its architecture were detected. As these morphological changes became more extensive, the lower esophageal sphincter pressure and the decrease of sphincter pressure on relaxation were both progressively reduced. There was a significant correlation between morphological abnormalities and lower esophageal function. Our results suggest that inflammatory damage to the muscle layer of the lower esophagus may impair lower esophageal sphincter function further, especially in patients with advanced esophagitis.

Aged↗
PubMed1995

Large-volume intraoperative peritoneal lavage with an assistant device for treatment of peritonitis caused by blunt traumatic rupture of the small bowel.

The benefits of large-volume intraoperative peritoneal lavage (IOPL), with an assistant lavage device, were evaluated retrospectively in 114 patients with peritonitis caused by blunt traumatic rupture of the small bowel. Postoperative complications caused by infection were a major problem after rupture of the small bowel (46 of 114, 39.4%). Both prolongation of the interval between injury and laparotomy and rupture of the lower part of the small bowel were risk factors for postoperative complications caused by infection. Large-volume IOPL (25.2 +/- 2.1 L) with an assistant lavage device reduced the rate of complications caused by infection from 30 of 58 (51.8%) to 15 of 56 (26.8%). The volume used for IOPL was closely related to the occurrence of postoperative complications resulting from infection. No complications from infection occurred in patients who received lavage with of 28.3 +/- 2.7 L of saline, whereas complications occurred in those patients treated with a smaller volume of lavage fluid (18.0 +/- 2.5 L). Large-volume IOPL should be considered in patients with blunt rupture of the small bowel who are at risk for infection, and the assistant device for IOPL may be useful for such treatment.

Adolescent↗
PubMed1995

Basic fibroblast growth factor increases regional cerebral blood flow and reduces infarct size after experimental ischemia in a rat model.

BACKGROUND AND PURPOSE: The aim of this study was to ascertain whether basic fibroblast growth factors (bFGF) caused reduction in size of cerebral infarcts in Sprague-Dawley rats with experimental ischemia. METHODS: In the first experiment we induced permanent occlusion of the left middle cerebral artery (MCA). Within 5 minutes after MCA occlusion, we infused bFGF (100 ng in 0.1 mL of saline) in the bFGF-treated group (n = 14) and 0.1 mL of saline alone in the control group (n = 7) into the common carotid artery ipsilateral to MCA occlusion. We harvested the brains 24 hours after MCA occlusion and determined infarct size planimetrically as a percentage of hemisphere size. In the second experiment cerebral blood flow (CBF) was continuously measured for 120 minutes after MCA occlusion in the bFGF-treated group (n = 9) and in the control group (n = 8) with the use of laser-Doppler flowmetry. RESULTS: Infarct size in the bFGF-treated group decreased significantly in comparison with that in the control group (repeated-measures ANOVA, P < .0001). CBF in the transitional areas between the MCA and the anterior cerebral artery significantly increased in the bFGF-treated group in comparison with that in the control group (repeated-measures ANOVA, P < .005). An approximate 58% decrease in infarct size and a 40% increase in regional CBF were seen on bFGF treatment. CONCLUSIONS: The present study suggested that intracarotid administration of bFGF (100 ng) can reduce infarct size after MCA occlusion. It was speculated that the increased CBF in the penumbral areas of MCA may contribute to contraction of infarct size.

Animals↗
PubMed1995

Chronotoxicity of glufosinate ammonium in mice.

The effect of a circadian-stage dependent dosing schedule on the toxicity of glufosinate was studied in mice. Male ICR mice were housed in a standardized 12:12 light:dark cycle for 3 w. Each animal was given 1500 or 3000 mg glufosinate/kg po. A highly significant circadian rhythm occurred in the resulting mortality, with the highest mortality from doses given during the light phase and the lowest from doses administered during the dark phase. The circadian-stage dependent dosing schedule had a marked influence on the pattern of acute glufosinate toxicity in mice.

Aminobutyrates↗
PubMed1995

[Cooperative multicentric study on posttraumatic epilepsy].

A multicenter cooperative study was conducted to investigate factors influencing posttraumatic epilepsy (PTE) and to evaluate the prophylactic effect of anticonvulsants. A retrospective study of 102 PTE patients revealed the following typical clinical features: occurrence in young males, traffic accidents, contusion and/or cerebral hematoma. The latent period after the injury was longer in children. The percentage of EEG paroxysmal activity gradually increased as the generalized abnormality diminished. A retrospective-prospective study of 1998 patients who suffered a head injury between 1984 and 1988 was conducted till 1994. During the follow-up period, 62 patients (3.1%) developed PTE. The drop-out cases were excluded, and the 154 cases followed at least two years were analyzed. Statistical analysis of differences between patients with and without PTE suggested following factors: young, immediate early epilepsy (within 24 hours after injury; IMEE) and early epilepsy (within one week after injury). The risk with the highest relative risk rate was early epilepsy. Multiple regression analysis revealed that three factors, IMEE, early epilepsy and young age, contributed to the prediction of PTE. There was no significant difference in the percentage of patients having PTE in the group treated with anticonvulsants and the untreated group. Anticonvulsant treatment after head injury was unlikely to have a prophylactic effect on the development of PTE.

Adolescent↗
PubMed1994

Pharmacokinetic study of mannitol in subjects with increased ICP.

Six human subjects received mannitol as an intravenous dip (DIV) infusion. In each subject, the concentration of mannitol and serum osmolality were rapidly elevated during mannitol administration and reached the maximum at the end of mannitol administration. Then, it exponentially decreased. There was a strong positive correlation between mannitol concentration and extrinsic serum osmolality. The integrated values of mannitol concentration difference between the central (Cc) and the peripheral compartment (Pc) correlated with the changes of ICP reduction during mannitol administration. The results indicate that the changes of ICP reduction depend on the mannitol concentration difference between Cc and Pc.

Adult↗
PubMed1994

Pharmacokinetics and pharmacodynamics of serum glycerol in patients with brain edema: comparison of oral and intravenous administration.

To clarify the pharmacokinetics and effect of ICP reduction of glycerol administered orally, the serum concentration of glycerol was measured by the enzymatic method and ICP was measured by the subdural balloon method in severe head injured patients with brain edema and increased ICP. Sequential change of serum glycerol concentration and its relationship to the reduction of ICP were analyzed. The results showed that the pharmacokinetics of glycerol through oral administration were similar to that of intravenous glycerol administration and the changes of ICP were also similar to that of intravenous glycerol administration. We determined that glycerol can be administered either per oral or per venous to obtain the same results for treatment of brain edema with raised ICP.

Administration, Oral↗
PubMed1994

Rapid fall in blood myoglobin in massive rhabdomyolysis and acute renal failure.

OBJECTIVE: Myoglobin kinetics of removal from the circulation were studied in patients following massive rhabdomyolysis, to see if myoglobin remains for long in the circulation in the anuric state and if myoglobin elimination was affected by therapeutic manipulation such as haemofiltration or haemodialysis. DESIGN: Randomised and controlled study. SETTING: Intensive care unit of a tertiary care teaching hospital. PATIENTS: 26 patients of rhabdomyolysis whose serum myoglobin exceeded more than 500 nmol/l. Thirteen patients developed acute renal failure and underwent treatment with blood purification (Group HD). The remaining 13 patients did not require treatment with blood purification (control subjects, Group non-HD). INTERVENTIONS: In patients of group HD, twelve were treated with haemofiltration and/or haemodialysis. One was treated with peritoneal dialysis. The patient of group non-HD were treated with fluid infusion alone. MEASUREMENTS AND RESULTS: The serum concentrations of myoglobin were serially determined. The highest levels of myoglobin was 1641 +/- 484 nmol/l (mean +/- SEM) in the group non-HD and were 8957 +/- 2300 in the group HD. In the group non-HD, the blood myoglobin fell exponentially once myoglobin release into the circulation ceased. This was also noted in the group HD. The exponential decrease was observed even on the days when the patient passed little urine or treatment with blood purification was not performed. CONCLUSION: In patients with massive myoglobinaemia, the blood myoglobin rapidly fell independent of renal function or any therapeutic manipulation. The results indicate that extrarenal factors played a major role in disposing circulating myoglobin in such patients.

Acute Kidney Injury↗
PubMed1994

The role of angiography in the assessment of blunt liver injury.

Angiography and therapeutic embolism (TE) were studied retrospectively in cases of blunt liver injury with regard to their indications and usefulness. The management of patients fell into three groups distinguished by the clinical evidence of the severity of the liver injuries. The most severe 42 cases (39.6 per cent) were managed surgically and promptly, the least severe 38 cases were not subjected to angiography and the intermediate group (26 cases; 24.5 per cent) underwent angiography and 12/26 cases underwent TE. However, haemodynamic stability on admission was not significantly different between these groups. In addition, all patients who underwent angiography and TE had more severe parenchymal injury on imaging studies while their haemodynamic instability was not identified on admission. Angiography and TE for blunt liver injury were most strongly indicated in patients with good haemodynamic responses to intravenous fluid administration during the acute phase and/or in cases of severe parenchymal injury on imaging.

Algorithms↗
PubMed1994

The effects of a carotid-jugular fistula on cerebral blood flow in the cat: an experimental study in the acute period.

The purpose of the present study is to investigate the effects of feline carotid-jugular (CJ) fistula (Spetzler's model) on cerebral blood flow (CBF) in the acute period after creation of the fistula. Using laser-Doppler flowmetry, cortical CBF was measured on the fistula side of 11 cats. Temporary occlusion and opening of the fistula led to an immediate increase and decrease, respectively, in cortical CBF. However, CBF returned to baseline within 1 minute, on average. CO2 reactivity in the closed fistula was preserved. It is suggested that cerebral hemodynamic changes due to Spetzler's CJ fistula model are minimal in the acute period after fistulization.

Acute Disease↗
PubMed1994

Draining vein pressure increases and hemorrhage in patients with arteriovenous malformation.

BACKGROUND: Recent radiological studies have shown that arteriovenous malformations with impaired venous drainage may be susceptible to hemorrhage. To evaluate this hypothesis using a hemodynamic approach, we measured intravascular pressure during surgery in three patients with arteriovenous malformation. SUMMARY OF REPORT: In three patients we measured intravascular pressures in the draining venous system and the feeding arteries simultaneously before removal of arteriovenous malformations with marked segmental stenotic or occlusive draining veins and evidence of hemorrhage. The draining vein pressures at prestenotic (or preocclusive) sites in the three patients were 38, 25, and 40 mm Hg, respectively, all significantly above the normal cortical venous pressure, whereas pressure measurements in poststenotic sites and the sagittal sinus pressure in the venous drainage system approached normal values. The feeding artery pressures in the patients were lower than normal cortical artery pressure because of the arteriovenous shunt. CONCLUSIONS: Intraoperative vascular pressure measurements support the hypothesis that arteriovenous malformations with impaired venous drainage may be associated with a local increase in venous pressure and thus may be susceptible to hemorrhage.

Adolescent↗
PubMed1994

Haemo-dialysis/-filtration using sodium bicarbonate depresses cardiac function in critically ill patients with acute renal failure.

The effect of sodium bicarbonate haemodialysis or haemofiltration on cardiac function was prospectively studied in 8 patients with acute renal failure. All of the patients exhibited consciousness disturbance and seven patients were on mechanical ventilation. All but one of the patients demonstrated moderate hyperlactataemia and seven patients were receiving vasoactive amine support. Arterial and mixed venous gas analysis and haemodynamic measurements were performed before and after haemodialysis/-filtration treatment. The buffer was changed in a randomised order between bicarbonate and acetate and 11 crossover studies were completed. After treatment with bicarbonate, the cardiac index and stroke index decreased significantly (4.0 +/- 0.3 to 3.4 +/- 0.4 L/ min/m2, p < 0.05 and 39.6 +/- 2.5 to 32.9 +/- 1.8 L/m2, p < 0.05), whereas no significant changes were observed in cardiac index or stroke index after treatment with acetate. Therefore, the post-dialytic percent changes of cardiac index, stroke index and left ventricular stroke work index were significantly decreased after bicarbonate sessions, as compared to after acetate sessions. Haemo-dialysis/-filtration using sodium bicarbonate can depress cardiac function in critically ill patients on mechanical ventilation with disturbed consciousness, and in those who are receiving vasoactive amine support due to uncompromised haemodynamics associated with hyperlactataemia.

Acetates↗
PubMed1994

Massive rhabdomyolysis associated with influenza A infection.

A 20-year-old male with massive rhabdomyolysis associated with a high fever and acute renal failure is reported. Influenza A infection was confirmed serologically. Myoglobin kinetics was studied in this case. Blood myoglobin fell exponentially independent of renal function or therapeutic modality such as hemodialysis/filtration, once myoglobin release into the circulation ceased. The finding suggested that catabolic steps of myoglobin take place extrarenally in patients with massive rhabdomyolysis and acute renal failure.

Acute Kidney Injury↗
PubMed1994

Activated charcoal interrupts enteroenteric circulation of phenobarbital.

The possibility of activated charcoal interrupting the enteroenteric circulation of phenobarbital was conducted in rabbits prepared by colectomy biliary drainage to block enterohepatic circulation. Fifty minutes after the administration of phenobarbital IV over ten minutes, activated charcoal (N = 7) or non-adsorbent gel (N = 8) were placed into the intestine at a dose of 4 g/kg. Blood was taken hourly for 5 h from the femoral artery and portal vein for the determination of phenobarbital concentration by the homogeneous enzyme immunoassay. The arterio-portal differences of phenobarbital concentrations were significantly greater in the animals treated with the charcoal at 2, 3 and 4 h after the treatment. There were significantly shorter plasma half lives of phenobarbital in the animals given charcoal (3.8 +/- 0.3 h vs 6.9 +/- 0.9 h, p < .02). This study provided evidence of significant enteroenteric circulation of phenobarbital which can be interrupted by the activated charcoal and removed by the mechanism of intestinal dialysis.

Animals↗
PubMed1994

Mechanically assisted intraoperative peritoneal lavage for generalized peritonitis as a result of perforation of the upper part of the gastrointestinal tract.

BACKGROUND: The efficiency of intraoperative peritoneal lavage (IOPL) and peritoneal drainage in patients with generalized peritonitis remains controversial. The benefit of large volume IOPL, using a newly designed device, and of peritoneal drainage were evaluated in 101 patients with generalized peritonitis. STUDY DESIGN: Patients were divided into two groups, one treated by mechanically assisted IOPL (group 1), and the other treated by manual IOPL (group 2). They were further divided into two groups, one undergoing drainage (DR group) and the other undergoing no drainage (ND group). Based on data in the progress notes, patients in these groups were compared with each other with respect to disease process, volume of IOPL fluid, incidence of infectious complications, and other prognostic factors. RESULTS: In group 1, the incidence of infectious complications was significantly lower than in group 2 (10.8 versus 62.9 percent, p < 0.01). Patients who underwent operative treatment 12 hours or more after onset of peritonitis had a lower incidence of infection following high volume IOPL (greater than or equal to 30 L) compared with those patients who underwent low volume IOPL. The incidence of infectious complications was significantly higher in the DR group (32.8 versus 12.9 percent). CONCLUSIONS: A large volume of saline (greater than or equal to 30 L) was needed for IOPL. The new device for IOPL proved to be very successful and efficient. When IOPL was successful, it seemed that peritoneal drainage did not provide any additional benefits to the treatment of generalized peritonitis.

Adolescent↗
PubMed1994

[Differential effects of isoflurane, sevoflurane and halothane on autonomic function determined by spectral analysis of heart rate variability].

The effects of isoflurane, sevoflurane and halothane on heart rate variability were studied in 18 patients scheduled for minor otolaryngeal surgery. After the surgery, R-R intervals were determined at minimum alveolar concentrations of 2.0, 1.5, 1.0 and 0.5 under mechanical ventilation. The data were plotted on a one-dimensional map and analyzed further by autoregressive spectral analysis. All three anesthetics suppressed both the low frequency component (Mayer wave related sinus arrhythmia; MWSA) and the high frequency component (respiratory sinus arrhythmia; RSA). The MWSA reflecting sympathetic activity was less affected by sevoflurane while the RSA reflecting parasympathetic function was less influenced by halothane. The one-dimensional map was useful to visualize the depth of anesthesia.

Adolescent↗
PubMed1994

An unruptured arteriovenous malformation with edema.

We report a case of unruptured arteriovenous malformation in which an extensive zone of increased signal intensity in the brain parenchyma adjacent to the nidus is demonstrated on T2-weighted MR. This area of perilesional hyperintense signal exerts a compressive effect, suggesting that it represents perilesional edema.

Brain Edema↗