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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 145 records · Page 8Linked to original sources
PubMed1989

The platysma myocutaneous flap for oral reconstruction. Experience with MacFee's cervical incision.

The present study was performed to demonstrate and evaluate the effectiveness of the Platysma Myocutaneous Flap in conjunction with MacFee's cervical incision (MacFee, 1960) for reconstruction after oral cancer excision. Ten squamous cell carcinoma cases were provided for postoperative evaluation of tongue movement and aesthetic problems of the cervical skin. It was found that the thickness of the skin island was adequate for covering the oral defects and was not a hindrance to proper postoperative function. MacFee's incision improved the condition of the scar caused by flap elevation. The procedure for preparing the muscle pedicle beneath the cervical skin tunnel was carried out without much difficulty by carefully preparing the surgical field.

Adult↗
PubMed1989

Role of the medullary vasomotor centre in the development of plateau waves.

Plateau waves can sometimes be found in various neurosurgical patients with increased intracranial pressure (ICP). In spite of the clinical importance of the waves, the precise mechanism producing them is still obscure. It has been reported that the waves are often accompanied by a reduction of arterial blood pressure (ABP) and suppression of respiration, suggesting a role of the brain stem in their development. In this study, we induced intracranial hypertension in dogs by occluding the neck veins, then stimulated the pressor and depressor areas of the brain stem, observing changes of ICP, ABP, cerebral blood flow (CBF), respiration and heart rate. Stimulation of the brain stem usually caused an increase in the ICP accompanied by variations of the ABP, CBF, respiration and heart rate. These variations were divided into two types: Type I and Type II. Type I which was induced by the stimulation of the pressor area of the brain stem comprised an arterial pressor response, an increase of CBF, hyperventilation and bradycardia. Type II which was caused by stimulation of the depressor area, included declines of the ABP and CBF, respiratory suppression and bradycardia. Of these, variations observed in Type II were similar in many respects to the plateau waves observed in clinical practice. We suggest that the depressor area of the medullary vasomotor centre may play an important role in eliciting the cerebral vasomotor reaction in the development of plateau waves in intracranial hypertension.

Animals↗
PubMed1989

Development of percutaneous intramuscular electrode for multichannel FES system.

A percutaneous intramuscular electrode was developed for controlling paralyzed extremities by FES. The electrode was made of a Teflon-coated 19 strand rope wound from ultrafine SUS 316L stainless steel wires and was helically coiled for giving high flexibility. Because of low percentages of electrode failure in the body, stable and reliable FES was achieved for a long time.

Electric Stimulation Therapy↗
PubMed1989

A multichannel FES system for the restoration of motor functions in high spinal cord injury patients: a respiration-controlled system for multijoint upper extremity.

A multichannel functional electrical stimulation (FES) system for the restoration of quadriplegic upper extremity function is described. The system is composed of a personal computer NEC PC-8801mkII, peripheral electronic circuits, CRT display and respiratory sensors for volitional control by the patient, and percutaneous electrodes. A C4 quadriplegic patient could drink canned tea by herself by using this FES system. Distinct features of the system are as follows: 1) Versatile volitional control was realized by controlling the memory allocation of the stored stimulation data by voluntary respiratory signals. 2) Sophisticated fine control of the fingers, wrists, and elbow was realized by creating the multichannel stimulation data from recorded myoelectric activities of normal subjects during movements of the upper limb.

Arm↗
PubMed1989

The effects of elevated potassium on sympathetic ganglion cells in culture.

Effects of a high potassium (40 mM) medium on the survival and differentiation of sympathetic ganglion cells from chick embryos were studied in dissociated cell culture. In the high potassium medium, survival of the sympathetic ganglion neurons was improved and catecholamine fluorescence of the nerve fibers increased with several days in culture, while acetylcholinesterase activity was slightly positive. In contrast, in the control medium, catecholamine fluorescence was only faintly observed, while acetylcholinesterase became strongly positive. Catecholamine fluorescence was intensified by increasing the potassium concentration in a medium, while it was diminished by reversing the potassium level back to the normal one. The effect of the high potassium medium on catecholamine fluorescence was reduced by Ca++ influx inhibitors, diltiazem or Mg++. It is suggested that the high potassium medium increased the survival rate and prevented the sympathetic neurons from becoming cholinergic and allowed them to develop their adrenergic properties presumably through an increased level of the intracellular Ca++ due to Ca++ entry.

Animals↗
PubMed1989

Effect of flunarizine on arterial thrombosis after endarterectomy in rats.

Unilateral carotid endarterectomy was performed microsurgically in 60 rats. The effects of perioperative administration of aspirin and flunarizine, a Ca2+ entry blocker, on thrombus formation were examined 24 hours after endarterectomy. An untreated group of endarterectomized rats served as controls. Platelet adhesion, blood cells, and fibrin cords were observed at the cut edge of the intima as well as in the endarterectomized area in all three groups. However, these findings were significantly more extensive in the control group than in the drug-treated groups. Flunarizine was as effective as aspirin in inhibiting platelet adhesion and fibrin cord formation. Both drugs significantly increased the patency rate after carotid endarterectomy.

Animals↗
PubMed1989

The effects of intraventricular administration of norepinephrine on vasogenic edema.

The effects of intraventricular application of norepinephrine (NE) on the development of vasogenic edema was studied in mongrel dogs randomly divided into a control and an experimental group (NE group). Vasogenic edema was produced by infusion of a 2.0 M NaCl solution (hypertonic saline) unilaterally into the carotid artery. NE (40 micrograms/kg) was injected into the lateral ventricle 30 minutes before the infusion of hypertonic saline, after which intracranial pressure (ICP) and systemic blood pressure were continuously recorded. The animals were sacrificed 2 hours after the infusion of hypertonic saline and brain tissues were sampled from both hemispheres for measurement of the water content. Infusion of hypertonic saline produced a marked increase in ICP in the control group and a lesser increase in the NE group. The mean ICP in the control group was significantly higher (p less than 0.01) than that of the NE group from 30 to 120 minutes after saline infusion. The water content of the saline-infused hemisphere was significantly higher than that of the contralateral hemisphere in the control group, whereas the difference was not significant in the NE group. These results suggest that intraventricular administration of NE may protect against the development of intracranial hypertension due to vasogenic edema.

Animals↗
PubMed1989

Prognosis of intraventricular hemorrhage due to rupture of intracranial aneurysm.

The prognosis of intraventricular hemorrhage (IVH) from rupture of intracranial aneurysms was studied in 43 patients admitted to our institution and to Kaga Central Hospital between April 1984 and December 1987. The total number of aneurysmal subarachnoid hemorrhage (SAH) patients admitted during this period was 156, so that 28% of SAH patients had IVH. In this study, the patients were analyzed with respect to IVH grading, volumes of intraventricular and intracerebral hematoma, consciousness level, intracranial pressure (ICP), ventricular dilatation and age. The IVH resulted from aneurysmal rupture of the anterior communicating artery (48%), anterior cerebral artery (distal portion of the anterior communicating artery) (11%), internal carotid artery (21%), middle cerebral artery (25%), and vertebro-basilar artery (14%). The mortality rate in patients with IVH was 33%, a poorer rate than that in patients without IVH (25%). As for morbidity, 44% of the patients with IVH had no or moderate disability, whereas the other 23% had severe disability or were in a persistent vegetative state. On the other hand, there was no or only moderate disability in 63%, and severe disability or a persistent vegetative state in 12% of the patients without IVH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Lipoma of the cerebral peduncle. Case report.

A rare case of intracranial lipoma of the cerebral peduncle was reported. Computerized tomography (CT) and magnetic resonance imaging (MRI) of this unusual tumor are described. The unique capability of direct sagittal imaging makes MRI the best procedure for evaluating the midline abnormalities. She did not have operation because she was asymptomatic. She will be checked periodically in the outpatient clinic.

Adult↗
PubMed1989

Choroid plexus papilloma in early infants.

Four infants with choroid plexus papillomas which were successfully treated with surgery are described. All patients showed the clinical signs of increased intracranial pressure and hydrocephalus within 8 weeks after birth. The tumors were in the lateral ventricles and histologically three of them were benign papillomas and other one was a malignant papilloma. Computerized tomography scan was useful for the diagnosis of both of the tumor and the hydrocephalus that was caused by the overproduction of cerebrospinal fluid and/or the obstruction of it's pathway. The tumor stain on the angiograms was noticed in two patients. Three patients have grown normally in both physical and mental functions after the surgical treatment, whereas one showed psychomotor retardation because of poorly controlled hydrocephalus.

Angiography, Digital Subtraction↗
PubMed1988

Dural arteriovenous malformations in the anterior cranial fossa.

Two elderly patients with dural arteriovenous malformations in the anterior cranial fossa are reported. These patients experienced rupture of the malformations at the age of 73 and 87 years. Surgical excision of the malformation was carried out on the younger patient. In the other case megavoltage x-ray therapy was applied because radical operation was not prudent. A search of the literature provided 26 other cases of this malformation involving the anterior cranial fossa. These are the first cases of rupture of arteriovenous malformation in the anterior fossa in patients over the age of 70.

Aged↗
PubMed1988

Treatment of systemic hypertension and intracranial hypertension in cases of brain hemorrhage.

We studied the effects of nifedipine, chlorpromazine, reserpine, furosemide, and thiopental on the mean arterial blood pressure, mean intracranial pressure, and cerebral perfusion pressure in 38 patients with increased intracranial pressure resulting from either hemorrhagic cerebrovascular disease or systemic hypertension. These agents are widely used in neurosurgical practice for the treatment of systemic hypertension. Patients were assigned to two groups on the basis of their mean intracranial pressure. Group I comprised 20 patients with a mean intracranial pressure of 20-40 mm Hg (moderately increased ICP group), and Group II consisted of 18 patients with a mean intracranial pressure of greater than 40 mm Hg (severely increased ICP group). Nifedipine, chlorpromazine, and reserpine reduced mean arterial blood pressure by 18-20% in both groups (p less than 0.05 in each). In Group I these agents raised mean intracranial pressure by 10-35% and decreased cerebral perfusion pressure by 20-32% (p less than 0.05 for both), but in Group II these changes were more marked: mean intracranial pressure increased 38-64% and cerebral perfusion pressure decreased 40-54% (p less than 0.01 for both). Furosemide did not significantly reduce mean arterial blood pressure but slightly reduced mean intracranial pressure in each group. Thiopental reduced both mean arterial blood pressure and intracranial pressure in both groups. The effect on intracranial pressure was pronounced in Group II, in which mean arterial blood pressure fell by 18% (p less than 0.05) and mean intracranial pressure decreased 50% (p less than 0.01), whereas in Group I mean arterial blood pressure was reduced by 16% and mean intracranial pressure dropped 23% (p less than 0.05 in each).(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypertensive Agents↗
PubMed1988

Management of intraventricular haemorrhage in patients with haemorrhagic cerebrovascular diseases.

The authors propose a four-grade classification for intraventricular haemorrhage (IVH) caused by haemorrhagic cerebrovascular diseases. Grading is based on the distribution and volume of the haematoma in the ventricular system as revealed by computed tomography (CT). In Grade I IVH, CT shows no haematoma in the ventricular system, but the cerebrospinal fluid contains some fresh blood; Grade II IVH fills a circumscribed portion of one or both lateral ventricles. This grade is divided into two: Grade IIa having a haematoma volume of, or less than 20 ml in the ventricular system and Grade IIb of more than 21 ml; Grade III IVH fills the entire length of one lateral ventricle and none, or circumscribed portion, of the other lateral ventricle; and Grade IV IVH entirely fills both lateral ventricles. This grading scale correlated with the mortality and morbidity of the IVH patients. Its application will assist in the selection of continuous ventricular drainage or direct evacuation of intraventricular haematoma as the management method.

Adolescent↗
PubMed1988

Prognosis of intraventricular hemorrhage due to hypertensive hemorrhagic cerebrovascular disease.

The prognosis of intraventricular hemorrhage (IVH) due to hemorrhagic cerebrovascular disease has been regarded as unfavorable. The authors studied factors affecting the prognosis in 55 patients with IVH due to hypertensive thalamic and putaminal hemorrhages. The mortality rate in this study was 38%, a poorer rate than that in patients without IVH (18%). As for morbidity, 50% of the survivors (31% of all patients) with IVH had nor or moderate disability, but the other 50% had severe disability or were in a persistent vegetative state. On the other hand, there was no or moderate disability in 55%, and severe disability or a persistent vegetative state in 27% of the patients without IVH. Patients with intracerebral or intraventricular hematoma volumes greater than 25 ml, Glasgow Coma Scales of less than nine, intracranial pressures above 30 mm Hg, and ventriculocranial ratios over 0.22 had poor prognoses. These results suggest that greater volumes of intracerebral or intraventricular hematoma and the presence of acute hydrocephalus are of great significance when considering the outcomes of IVH cases.

Adult↗