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Biomedical subjects

O Fukuda

Publications and source records attributed to O Fukuda.

At least 19 recordsLinked to original sources
PubMed1991

Modified thermal diffusion flow probe for the continuous monitoring of cortical blood flow.

A small thermal diffusion flow probe has been developed to monitor the dynamic changes in cerebral blood flow in small animals. Constantan wire was used as a heat source to make a miniature probe. The pair of thermocouples used to detect the heat gradient between two gold plates was elongated to avoid heat conduction between them, and this improvement allowed us to make quantitative measurements. After several basic experiments, local cerebral blood flow was measured simultaneously, using both the modified thermal probe and the hydrogen clearance method in four rabbits. A close relationship was obtained between the local cerebral blood flow values measured by hydrogen clearance (F, ml/100g/min) and the reciprocal of the thermocouple voltage (1/V;1/mV). The regression line was F = 29111(1/V - 1/226), (r = 0.92, P less than 0.001). We suggest that the modified thermal probe is a reliable and quantitative means of measuring flow. In addition, another probe modified for clinical use was evaluated. Continuous monitoring of local cerebral blood flow in postoperative patients was performed, and some illustrative cases are described.

Aged↗
PubMed1991

The correlation of skin blood flow with age, total cholesterol, hematocrit, blood pressure, and hemoglobin.

Normal skin blood flow at the deltoid region in 55 men whose ages ranged from 20 to 72 years was measured by the xenon-133 clearance method. In addition, the correlation of skin blood flow with age, systolic blood pressure, total cholesterol, hematocrit, hemoglobin, and total protein was analyzed by multiple regression analysis. The following results were obtained. Normal skin blood flow was found to decrease with increase in age, total cholesterol, and systolic blood pressure and showed a tendency to increase with elevation in hematocrit and hemoglobin values. Of the six parameters examined in the present study, the parameter that showed the strongest correlation with skin blood flow at the deltoid region was age, followed in decreasing order by total cholesterol, hematocrit, systolic blood pressure, and hemoglobin. It could therefore be concluded that age is the most reliable factor in clinically estimating skin blood flow. Furthermore, inasmuch as total cholesterol, hematocrit, systolic blood pressure and hemoglobin values also were correlated with skin blood flow, these values also should be taken in account in the synthetic evaluation of skin blood flow. It was skin blood flow at the deltoid region that was strongly correlated with age. This was followed by systolic blood pressure, hematocrit, and hemoglobin. Total cholesterol showed a weak correlation with age, but total protein did not demonstrate any correlation with skin blood flow and age. The results of the present study show that skin blood flow would be poor in the elderly and in patients with arteriosclerosis, hypertension, and anemia. Since it is suggested that the wound-healing process is delayed in such patients, utmost care should be exercised in treating their wounds.

Adult↗
PubMed1991

Differences in critical cerebral blood flow with age in swine.

Normal cerebral blood flow (CBF), critical CBF at a flat reading of the electroencephalogram (EEG), and reversibility of the flat EEG after reperfusion were investigated in a total of 59 pigs, including seven newborns (1 to 3 days of age), 38 juveniles (1 month old), and 14 adults (7 months old). The CBF was determined by the hydrogen clearance method; the EEG was recorded continuously and a power spectrum analysis was performed. Cerebral ischemia was produced by occlusion of both common carotid arteries and induction of hypotension (approximately 50 mm Hg). The flat EEG reversibility was investigated for 3 hours after reperfusion. As parameters of brain development, the neuronal density and the time at which the S-100 protein appeared in the brain were examined. Normal CBF was highest in neonatal pigs and decreased with age. The critical CBF at a flat EEG was lowest in newborn pigs and was elevated with development of the brain. Tolerance against cerebral ischemia was greatest in newborn pigs.

Aging↗
PubMed1989

A case of septic cavernous sinus thrombosis with sequential dynamic angiographic changes. A case report.

A case of intracavernous aneurysm secondary to septic cavernous sinus thrombosis demonstrating sequential dynamic angiographic changes is reported. Serial angiograms of a 32-year-old man with septic cavernous sinus infection revealed a normal study, stenosis, recovery of stenosis, and aneurysmal formation. Superficial temporal-middle cerebral artery anastomosis and internal carotid artery ligation were performed because of progressive ophthalmoplegia. Neurological deficit rapidly disappeared. Anigiographic changes and surgical treatment of septic cavernous sinus thrombosis are discussed.

Adult↗
PubMed1989

Experimental studies on complete global brain ischemia using the isohistogenic infantile head transplant model in Lewis rats.

A new experimental model is presented, using isohistogenic Lewis rats and microsurgical techniques. Transplantation of the head and forelimbs of the infantile rat was done to the groin of an adult rat. The goal was to study the effects of ischemia on brain tissue. This model also proved useful for other experiments in studies of facial and cranial bone growth. The model presented proved efficient for the study goals, and long-term experiments were possible. The maximum ischemia time tolerated by brain tissue was found to be somewhere between 60 min and 120 min.

Animals↗
PubMed1989

[A new thermal diffusion flow probe for continuous monitoring of cerebral blood flow in small animals].

The Peltier stack, which allows quantitative measurement of cerebral blood flow (CBF) by means of thermal diffusion, has a probe too large for use in small animals. However, it is difficult to measure CBF by a thermal diffusion method involving the use of a constantan heating wire, because of heat conduction between the two gold plates. The authors developed a new thermal diffusion flow probe, using a constantan wire as a heat source rather than the Peltier stack. With the new probe, separation of the gold plates and attachment of a pair of long thermocouples minimize heat conduction between the two plates. Moreover, the probe itself is considerably smaller than that of the Peltier stack. The new probe was inserted to the subdural space of rabbits and the voltage (V; mV) was measured with an amplifier by the circuit of constant current method. CBF (F; ml/100 g/min) was measured simultaneously by the hydrogen clearance method in the adjacent cortex. A regression equation of F = 29, 111 (1/V-1/226) was obtained between 35 pairs of F and V (r = 0.92, p less than 0.001), which verified that CBF can be accurately measured with the new probe.

Animals↗
PubMed1989

[MRI of acute cerebral infarction].

Sequential changes of magnetic resonance imaging (MRI) in sixteen patients with acute cerebral infarction are studied in comparison with the findings of computed tomography (CT). The sixteen patients were examined within 36 hours from the onset of symptoms on resistive type MRI (0.15T) using T1 weighted image (IR2000/500) and T2 weighted image (SE2000/80), and on CT. In general, large infarcted lesions of the cortex-subcortex seemed to be visualized earlier than small lesions of the basal ganglia and brainstem. In 8 patients, the infarcted lesions were detected on MRI earlier than on CT. For example, early detecting time within 12 hours were 2, 6, 7, and 10 hours after onset. In two patients of this group, lesions were detected on T2-weighted image earlier than on T1-weighted image. In two cases, small lesions of the brainstem were detected only on MRI. The size of abnormal findings gradually developed and reached a maximum on days 5 to 7 sequentially. The difference between infarction and perifocal edema was not clear even on MRI. The changes gradually subsided and assumed a stable size after about 2 months. Contrast enhancement effect was observed in four patients. In two of these cases, the signal intensity of T2-weighted imaging was decreased just at the region which was enhanced with contrast medium. MRI is useful for early diagnosis of ischemic cerebral infarction, and may elucidate some aspects of the pathophysiology of ischemic stroke.

Acute Disease↗
PubMed1988

Acute glomerulonephritis during the third trimester of pregnancy.

We report a very rare case of acute poststreptococcal glomerulonephritis (PSGN) occurring in the eighth gestational month. The pregnancy succeeded despite initially severe nephrotic syndrome, and after delivery there was a complete recovery to normal renal function. Fetal prognosis was also good. The diagnosis of PSGN was made based on serological examinations and postpartum renal biopsy. Light and electron microscopic findings showed that the glomerular lesions were different from those of typical pre-eclampsia.

Acute Disease↗
PubMed1988

Hereditary occurrence of lateral cervical fistulas.

Three cases of hereditary lateral cervical fistulas are reported. The patients had lateral cervical fistulas bilaterally and different types of auricular malformations. The mothers of the patients also had lateral cervical fistulas. Moreover, one mother had bilateral microtias and the other mothers bilateral preauricular fistulas. The literature is reviewed and discussed.

Ear↗
PubMed1988

An experimental study of craniofacial growth in a heterotopic rat head transplant.

In order to examine whether or not facial bones are themselves able to regulate their own growth, we devised a new experimental model in which we transplanted the whole head of an infant rat to the body of an isohistogeneic adult rat by means of microvascular anastomoses. The advantage of this model is that the transplanted head has neither scars nor any moving soft tissues that could modify growth around facial bones. Using this model, we conducted a study of the nasomaxillary region that has led us to conclude that facial bones do in fact regulate their own growth. The results also suggested that facial bone sutures play a more active role in the growth process than presently suspected.

Animals↗
PubMed1988

[A case of isolated cerebral angiitis with sequential angiographic changes].

The pathogenesis of migraine has not been completely understood. However, it is generally accepted that the prodromal symptoms encountered in classic migraine usually result from vasoconstriction of intracranial vessels, while the headache itself results from dilation of other cranial vessels, often branches of the external carotid artery. Despite of increasing refinement in angiographic technique, many authors demonstrate the difficulty of interpreting abnormal radiographic findings in patients of migraine. We experienced recently a rare case who complained of migraine with neurological disorder manifesting for dynamic changes of cerebral arteries on sequential angiography. This 39-year-old man was admitted to our hospital with complaint of classic migraine accompanied with transient hemiparesis of the left side. Curious dynamic changes were noted sequentially on the repeated angiograms sequentially during his hospitalization. The carotid angiogram on admission showed narrowing at the right M1 portion. The second angiogram obtained at the fourth hospital day showed reduction of the narrowing, and occlusion of the right angular artery. The patient was treated with Ergotamine. The third angiogram taken after admission for the period of 1 month showed increased stenosis at the right M1 portion. Isolated angiitis of central nervous system was suspected because of such sequential dynamic angiographic changes, and steroid therapy was started. However he began to suffer from hemiparesis of left side one week after the treatment. Therefore, EC-IC bypass was performed, and his symptoms were improved gradually. Migraine is one of the common neurologic disorders countered in clinical practice. This report suggests that careful observation is needed in patients of migraine.

Adult↗
PubMed1987

Neurilemoma of the ansa cervicalis.

A case of neurilemoma originating from the ansa cervicalis is presented. Available literature is reviewed, and the rarity of the tumor is discussed. It is believed that some cases of neurilemoma in which the nerve of origin was not identified may in reality have originated from the ansa cervicalis.

Child↗
PubMed1987

Scanning electron microscopic study on the angioarchitecture of glomeruli in experimental toxemia of pregnancy in the rabbit.

Experimental toxemia of pregnancy in late gestation in rabbits was induced by constricting the aorta below the renal arteries on day 21 of gestation. Light and transmission electron microscopic examination of glomeruli on day 29 revealed only a slight swelling of endothelial cells. The angioarchitecture was also investigated using scanning electron microscopic examination of methyl methacry corrosion casts of the glomeruli. The kidney in experimental toxemia was characterized by a reduction of glomerular vessel diameter compared to that of normal pregnant rabbits. This probably resulted from enlargement of the endothelial cells, suggesting a reduced blood supply to the glomerulus. These findings suggest that interference with the blood supply to the pregnant uterus is an important factor in the development of the renal lesion of experimental toxemia of pregnancy in the rabbit.

Animals↗