Biomedical subjects
Publications and source records attributed to T Harada.
The rectus abdominis muscle flap, combined with the external oblique fascia, were utilized in cranial-base reconstruction. In a wide defect caused by resection of a giant meningioma, the dura was reconstructed with the external oblique fascia and anterior sheath, and the cranial-base defect was reconstructed with the rectus abdominis muscle flap.
It has already been reported that anaphylatoxin (AT) is closely related to inner ear lesions. In this study the pathology of inner ear damage caused by AT was investigated in Hartley strain and C4 deficient guinea pigs (C4D-GP). Although the biological activity of C3a and C5a is strong, it is of short duration, and the resulting ear damage is considered to be reversible. Because of the cellular degeneration caused by this slight damage, the damage owing to continuously activated C4a is thought to be irreversible, that is, atrophy in the stria vascularis, degeneration and sloughing of the cochlear neurons, and stretching of Reissner's membrane, and C4a is therefore considered to be requisite for the manifestation of inner ear damage.
We followed up 92 patients who underwent curative hepatic resection for hepatocellular carcinoma between 1982 and 1991. The long-term survival rates for these 92 patients for 1, 3, and 5 years were 98.8, 81.6, and 57.3%, respectively. As of May 1991, the carcinoma had recurred in 52 patients (56.5%). Recurrent tumors usually occurred in the residual liver within 3 years after surgery but were not always located near the primary lesion. The biologic characteristics of the primary tumors, such as serum alpha-fetoprotein, tumor size, number of tumors, and portal involvement, were closely related to recurrence and long-term survival. However, the type of hepatectomy performed on the primary tumor had little influence on recurrence or long-term survival. We conclude that recurrence cannot be avoided by hepatic resection alone, much less with limited resection; postoperative positive adjuvant therapy is required to prevent recurrence for patients with satellite nodule and/or portal involvement.
To justify lumbar fusion or stabilization, a quantitative assessment and definition of spinal instability are essential. To quantify spinal instability, the tensile stiffness of a motion segment (vertebra-disc-vertebra) was measured with a spinal distractor during spinal decompression surgery. Stiffness was indicated by the relationship between load and displacement between the two adjacent spinous processes where a vertebral spreader was suspended. A load-displacement curve was recorded at each step of surgical decompression and fixation while the motion segment was being distracted at a constant speed. The device used for measuring stiffness of a spinal motion segment is a lumbar spinal spreader with a load strain gauge and a displacement transducer. The stiffness of a spinal motion segment was reduced as disc degeneration developed. Degenerative spondylolisthetic discs showed the least stiffness (lowest, 3.9 N/mm; average, 5.4 N/mm). The stiffness of herniated discs, however, was relatively greater (average, 11.8 N/mm). The stiffness of normal motion segments was greater than affected segments. If the stiffness of a motion segment before decompression was graded as 100, it was reduced to 82% after partial laminectomy and facetectomy and to 65% after discectomy on average. After interbody fusion by iliac bone graft, it increased to 133% and to 184%, after Luque fixation.
The clinical records of 1,372 cases of otitis media with effusion (OME) treated during the past 10 years were reviewed in search of associations with sensorineural hearing loss (SNHL). In 14 cases (1.0%), the development of SNHL was considered to be etiologically related to OME. These 14 cases were classified into two groups. In group A, which consisted of 5 cases, the clinical feature was acute onset of SNHL and gradual improvement. In group B of 9 cases, SNHL progressed gradually or insidiously and did not improve. Different pathophysiology may be assumed to underlie these two groups. The results of this study demonstrate that we have to pay attention to a possible development of SNHL during the course of OME.
The H2-receptor is considered to mediate the stabilization of the membrane of mast cells by enhancing cAMP synthesis. In the present study, we investigated the effect of H2-receptor antagonists, i.e. H2-blockers, on nasal hypersensitivity using a histamine nasal provocative test. A 7-day administration of cimetidine tended to lower the histamine threshold. Famotidine administered in the same way caused no significant decrease in the histamine threshold. Based on the above results, we postulate that famotidine should be preferred to cimetidine as an H2-blocker in patients with gastric and/or duodenal ulcers.
Three cases of labyrinthine anomaly confirmed by polytomography and CT scan are reported. They showed similar dysplasia of the bony labyrinth: dilation and fusion of the lateral semicircular canal (SCC) and of the vestibule with a normally shaped cochlea and other SCCs. One side was involved in 2 cases and both sides in 1 case. The 1st case showed normal hearing levels with markedly reduced response to caloric stimulation in the affected ear. The 2nd case showed conductive hearing loss due to cholesteatoma with normal bone conduction hearing levels and normal caloric response. The 3rd case showed bilateral conductive hearing loss of unknown cause. The classification of labyrinthine anomalies and labyrinthine functions is discussed. Labyrinthine anomaly detected by CT scan and polytomography can be present in patients with normal cochlear and/or vestibular function.
The circumstances facilitating hydrostatic pressure communication between the bladder and renal pelvis were evaluated. In particular, we compared active detrusor contractions occurring spontaneously during voiding and evoked contractions produced during electrical pelvic nerve stimulation with passive abdominal compression. These variables were evaluated with respect to urine flow rate and bladder capacity. Waveform analysis of the pacemaker characteristics of the renal pelvis shows that the rat pelvis has a narrow frequency band of spontaneous contraction at 0.5 +/- 0.06 Hz. The baseline waveform and pressure of the pelvis is effected by urine flow and bladder capacity. Significant elevations in pelvic pressure of 25.8 +/- 7.9 and 28.7 +/- 5.8 cm H2O were observed for bladder pressures of 30 cm H2O (n = 8) at flow rates in the range of 2.5-5.0 and over 5.0 ml/kg/h respectively (p less than 0.05). At flow rates between 2.5 and 5.0 ml/kg/h, spontaneous contractions produced an increase in pelvic pressure in all rats, while electrical stimulation produced an increase in pelvic pressure in 63%. At flow rates above 5 ml/kg/h, abdominal compression produced sharp elevations in pelvic pressure in 75%. At the same flow rate, electrical stimulation produced a slow increase in 75% and spontaneous contraction produced a slow increase in 86%. These results suggest that the exposure of the upper urinary tract to vesical pressures occurring during active and passive contractions is facilitated by flow.
In order to evaluate the effectiveness of microwave coagulation therapy on urinary bladder carcinoma, we conducted a series of experiments using carcinoma VX-2 cells designed for the application on animal hosts. Three days after implantation of VX-2 cells into the bladder of the rabbits, microwave coagulation therapy was performed. The antitumor effect, i.e. the survival rate, the histological study and the immunological response of the microwave therapy was examined in comparison with the control group (no treatment), the partially cystectomized group and the sham-operated group (no tumor cell implantation). The results were obtained as follows. (1) The survival rate in the microwave group was greater than that in the control group. (2) The stimulation index value (SI), which represents humoral immunity, decreased postoperatively in all groups. In the microwave group, SI increased gradually beginning 21 days after the transient decrease. (3) Histological findings revealed severe degeneration, necrosis and complete eradication of the cancer cells of the bladder wall in the microwave group, however, perforation of the urinary bladder could not be detected. The results indicate that microwave coagulation therapy is an effective procedure for urinary bladder tumors. Furthermore, microwave therapy may also accelerate the inactivation of immunological suppressors in the carcinoma host, an additional benefit of the microwave procedure.
In 250 eyes with retinal detachment due to macular hole, the visual prognosis of each surgical technique was evaluated. (1) Macular diathermy adversely affected the visual prognosis. (2) Macular buckling+macular diathermy produced a poorer visual prognosis than macular buckling alone. (3) The visual prognosis resulting from gas tamponade alone or vitrectomy+gas tamponade was better than that resulting from macular diathermy. It is not clear whether there is a significant difference in visual prognosis between gas tamponade alone and vitrectomy+gas tamponade. (4) Macular laser photocoagulation does not adversely affect the visual prognosis. Judging from these results, gas tamponade, which has the possibility of better visual prognosis and less operation stress, should be selected as the initial technique.
By the use of computer-assisted morphometric analysis of the organ of Corti and/or measurements of action potential threshold changes, inner ear changes in chinchillas were evaluated 4 weeks after application on the round window membrane of a Pseudomonas aeruginosa exotoxin A solution. Severe inner ear damage was detected after application of 50 ng (5 microL at a concentration of 10 micrograms/mL) exotoxin A, whereas application of 5 ng exotoxin did not cause measurable inner ear damage. Perilymph concentrations of exotoxin A were measured with an enzyme-linked immunosorbent assay 1.5 to 19 hours after 50 ng, 0.5 micrograms, or 5 micrograms of exotoxin A was applied on the round window membrane. Only the highest concentration produced measurable levels of exotoxin in the inner ear fluids. It is concluded that exotoxin A present on the round window membrane of the chinchilla has the ability to penetrate into the inner ear and cause irreversible inner ear changes.
To prevent the development of metabolic disturbances caused by overeating, we performed vertical banded gastroplasty in an adult woman with Prader-Willi syndrome. Her fasting blood sugar (FBS) and urinary sugar excretion (US) decreased during 6 months after the surgery under strict dietary control in the hospital. The insulin response to oral glucose at 6 months after surgery was as good as in the normal controls. A barium meal study in the 11th postoperative month revealed that the staple line was partially ruptured. After this, FBS and US increased, and the glucose tolerance and insulin response worsened. At 24 months, US was still less than preoperative US, and the oral glucose tolerance test showed a better result than before operation. At 29 months, her condition was brought under control with use of Glibenclamide. At 60 months, her FBS and US were at the same level as before operation. She was doing a part-time job. In conclusion, the effect of gastroplasty in preventing worsening of glucose metabolism in a case of Prader-Willi syndrome lasted satisfactorily for 24 months in spite of the partial breakdown of the staple line.
A new technique for simultaneously recording urethral closure pressure and cross sectional area profile is described. The cross sectional area of the urethra could be measured using the field gradient principle. The procedure was performed readily in male patients and the recordings can be graphically presented during measurement. A high degree of reproducibility using this method was obtained. Typical recordings of control subjects was well as patients with pathology were obtained using this technique. The results of this study show that the maximum urethral closure pressure obtained was 60.8 + 3.4 mmHg and functional profile length, 4.8 + 0.4 cm. Internal meatus cross sectional area was 0.67 + 0.04 cm2 and the minimum urethral cross sectional area was 0.12 + 0.02 cm2. This method has been shown to be readily applicable in measuring urethral closure pressure in males and can potentially be used as a tool of comparing the functional parameters of pressure with the anatomical value of diameter.
We examined the effect of the selective alpha-2 agonist dexmedetomidine and antagonist atipamizole on the upper urinary tract, renal pelvic pressure and ureteral peristalsis. Experiments were performed on twelve Sprague-Dawley female rats weighing 275-323 grams, with administration of urethane (1.2 micrograms/kg). Ventilatory support was provided through a tracheotomy. A continuous normal saline infusion was maintained through the left iliac vein at a rate of 2.5 ml/hr. Arterial pressure was measured at the left iliac artery, which was cannulated with a PE-100 tube connected to a pressure transducer. A mid-line incision was then made from the xyphoid to the symphysis to expose the left kidney, both ureters, and the bladder. The bladder was intubated and drained to avoid bladder pressure increase. Measurements of urine output rate were made from the right ureter and renal pelvic or ureteral pressure was measured using a nephrostomy placed into the pelvis. A ureterostomy was produced by introducing another catheter, into the upper segment of the left ureter for ureteral pressure measurements. The rats were divided into two groups as follows: 1) dexmedetomidine group (n = 6); injected intravenously with 2 micrograms/kg of dexmedetomidine dissolved in 0.5 ml saline. 2) atipamizole group (n = 6); injected intravenously with 2 micrograms/kg of atipamizole dissolved in 0.5 ml saline. Ureteral peristaltic frequency, baseline pressure, and contraction amplitude were compared before, after, and between the bolus injections of 2 micrograms/kg dexmedetomidine (n = 6) or 2 micrograms/kg atipamizole (n = 6) in 0.5 ml saline. The results showed that dexmedetomidine at 2 micrograms/kg produced a significant decrease in arterial pressure and an increase in urine output from 1.2 + 0.8 to 3.6 + 1.2 ml/min. There was no effect on the baseline pelvic pressure of 6.8 + 1.2 cmH2O or amplitude of the renal pelvic contractions: 3.5 + 0.6 cmH2O. The frequency of pelvic contractions was reduced from 0.37 + 0.03 to 0.27 + 0.02 Hz. Atipamizole at 2 micrograms/kg produced a significant reduction in urine flow rate of 1.1 + 0.8 to 0.6 + 0.2 ml/min. Atipamizole also showed no significant effects on baseline pelvic pressure or frequency, but increased the amplitude of pelvic contractions from control values of 3.0 + 0.9 to 3.4 + 0.9 cmH2O. Dexmedetomidine reduced both the baseline ureteral pressure of 8.5 + 2.4 and peristaltic contraction pressure of 11.5 + 2.3 cmH2O in 4/6 rats. Atipamizole reduced base-line ureteral pressure and increased peristaltic rate.(ABSTRACT TRUNCATED AT 400 WORDS)
The effect of terazosin on the lower urinary tract function was studied by combined recording of bladder and urethral pressures and external sphincter electromyogram in 8 male decerebrate dogs. Reflex micturitions were induced by bladder filling before and after terazosin. The statistical analysis was carried out on the urodynamic parameters. During the collecting phase, terazosin at doses of 10, 30 and 100 micrograms/kg produced a significant decrease in maximum urethral pressure in the dose dependent manner. Threshold pressure was significantly shown to decrease at doses of 30 and 100 micrograms/kg. In the urodynamic parameters of the emptying phase there was a significant decrease in maximum contraction pressure at 10 and 30 micrograms/kg, and in voided volume at 100 micrograms/kg. Terazosin seems to facilitate an initiation of the bladder contraction with a decrease in threshold pressure. In concludes that alpha 1 adrenergic activity seems to take an important role for the maintenance of the urethral pressure and to control the initiation of bladder contraction in modulation with threshold pressure.
Twenty semen samples were collected and two aliquots of 1.5 ml were prepared from each sample. One sample of each pair (fraction-one) was used for evaluation of semen parameters and total acrosin activity of spermatozoa. The other sample of each pair (fraction-two) was mixed with an equal volume of Ham's F-10 medium and filtered through the Sperm Prep II. At the end of the filtration, the filtrate was pooled, sperm parameters were evaluated and total acrosin activity was assessed. Percentage of normal spermatozoa, sperm motility, and total acrosin activity of spermatozoa were significantly higher in the postfiltered fraction-two than in the fresh fraction-one. Considering the great importance of acrosin for fertilization, it is suggested that Sperm Prep II filtration method may be beneficial in preparing spermatozoa from infertile men with low acrosin profiles for assisted reproduction programs. Further studies will be necessary, however, in order to confirm this, since the present study concerned men with known fertility.
The bladder and urethral activities during the rhythmic bladder contractions were evaluated before and after the intraarterial administration of methylene blue, which prevents the activation of soluble guanylate cyclase. The methylene blue produced an increase in the bladder activity and a decrease in the urethral smooth muscle relaxant response induced with bladder contraction. The L-arginine/nitric oxide pathway seems to modulate the vesicourethral function.
A 63-year-old male complained of right upper abdominal pain and jaundice. Laboratory data on admission showed hyperbilirubinemia, elevation of biliary enzymes and an extraordinarily high value of serum CA19-9 (60,000 U/ml). Diagnostic imaging modalities including abdominal ultrasonogram, abdominal CT and PTC suggested a stone impaction of the common bile duct. Jaundice subsided after PTC-drainage in association with decreasing serum CA19-9 value, which returned to the normal level six weeks later. Spontaneous delivery of the stone via the fistula was confirmed by cholangiography through the drainage tube. Though there are few reports of such a high serum CA19-9 level, the possibility of benign biliary tract disease should be considered in patients showing an extraordinarily high serum CA19-9 value.