Search PubMed⌕ Search

Biomedical subjects

Y K Tu

Publications and source records attributed to Y K Tu.

53 records · Page 3Linked to original sources
PubMed1995

The quantitative measurements of hip isometric muscle torques in Chinese young adults--a preliminary report.

A standard procedure for measurement of hip muscle strength (maximal isometric torque) with the Cybex 340 isokinetic dynamometer is presented. Twenty-two healthy males aged 30-40 years (average 34.3 years) were tested on hip flexors, extensors and abductors; in which the factors as sex, age, dominant side and testing session were all eliminated. The test was redone two weeks later on the same 10 males to evaluate its reproducibility. The results disclosed the maximal isometric torque of the hip flexors was stronger than that of extensors and abductors in both sides hips. The comparison between two sides hips showed only the abductors of right side hip significantly stronger than that of left side (P = 0.0259). The tests between the two different periods were quite compatible. The results have clinical implications for objective assessment of preoperative and postoperative hip strengths in patients with hip arthropathy and thus giving a reasonable guidance for physiotherapeutic management.

Adult↗
PubMed1993

Therapy for supratentorial malignant astrocytomas: survival and possible prognostic factors.

Maximum feasible resection of the tumor followed by 50 Gy whole brain irradiation was the routine management for patients with malignant glioma in this series. To determine treatment results and possible prognostic factors, a retrospective analysis was done of 116 patients with pathologically proven supratentorial malignant astrocytomas (71 glioblastoma multiforme and 45 anaplastic astrocytoma) from January 1981 to December 1990. The mean age of the patients at the time of diagnosis was 46 years for glioblastoma multiforme and 37 years for anaplastic astrocytoma. In 86% of the patients, their condition improved or was constant after surgery; in 14% of the patients, the conditions worsened. The median survival time was 10 months for patients with glioblastoma multiforme and 22 months for those with anaplastic astrocytoma. Cox regression analysis showed that the duration of symptoms, extent of resection, irradiation and tumor histology were significantly related to the survival time. However, gross total resection did not improve the survival time relative to a subtotal resection, although both were shown to be better than a partial resection or biopsy.

Adult↗
PubMed1993

Prognostic factors of intraspinal neurilemmoma and meningioma with severe preoperative motor deficits.

A total of 20 cases of intraspinal benign tumors (13 neurilemmomas and seven meningiomas) with severe motor deficits operated on from 1978 to 1991 were reviewed. Motor deficits were graded according to the classification of Cooper and Ebstein. Grade IV represented slight movement of the lower extremities, but no ability to walk or stand; grade V was complete paralysis. There were 16 patients classified as grade IV and four classified as grade V. All patients underwent total excision of the tumor and postoperative physical therapy. After various periods of follow-up, 13 patients could walk independently, five could walk with assistance, one could stand, and one was still restricted to a wheelchair. For the 13 patients who could walk independently, 11 were able to stand within one month after surgery. In contrast, of the seven patients who could not walk independently, only two managed to stand within one month of surgery. Statistically, age, duration of paraplegia and tumor location all had a significant influence on the recovery of motor function. Being able to stand within one month of surgery was predictive of a good recovery.

Adult↗
PubMed1992

Solitary cerebellar metastases: analysis of 11 cases.

Solitary cerebellar metastatic tumors are rarely reported in the literature. We reviewed 240 posterior fossa tumors treated in the past eight years. There were 11 cases of solitary metastases in the cerebellum. The primary tumor was lung cancer in five cases and breast carcinoma in two cases; the remaining three cases had colon cancer, nasopharyngeal carcinoma (NPC) and Ewing's sarcoma, respectively. All patients underwent craniectomy and gross total excision of the tumor. Seven patients survived less than one year, two cases died in the second year, and one case of NPC survived for more than two years. The only survival is a case of Ewing's sarcoma who underwent surgery 14 months ago. The symptoms and signs of all patients improved satisfactorily after surgery. Four patients received postoperative irradiation to the posterior fossa and two cases of lung cancer had a thoracotomy for the primary lung lesion; however, the survival period was not prolonged. We suggest that a cancer patient or a patient in the fifth to seventh decades of life presenting headache, gait disturbance and vomiting should promptly undergo a computed tomography (CT) scan of the head. In selected cases, surgical intervention for solitary metastatic tumors in the tiny posterior fossa may be the best initial treatment. Adjuvant therapies should then be added according to the type of tumor.

Adolescent↗
PubMed1990

Comparison of crystalloids and colloids for hemodilution in a model of focal cerebral ischemia.

Forty dogs were subjected to 6 hours of occlusion of the left internal carotid and middle cerebral arteries. They were divided into two "hemodilution groups" of 13 dogs each and a control "nonhemodiluted group" of 14 dogs. Thirty minutes after arterial occlusion, isovolemic hemodilution was performed by phlebotomy and infusions of low-molecular weight (MW) dextran in one group and of lactated Ringer's solution in the other group. The animals were sacrificed 1 week after temporary arterial occlusion. Hemodilution reduced the hematocrit to a level of 33% to 34%, which lasted throughout the week in both groups. After hemodilution there was a very significant reduction in blood viscosity, plasma total protein content, and fibrinogen levels in both groups in the acute stage; these levels gradually returned to baseline by the end of the week. In the group with lactated Ringer's solution hemodilution, both osmotic and oncotic pressures were decreased by hemodilution in the acute stage. In the control and low-MW dextran groups, osmotic and oncotic pressure remained unaltered throughout the week. Hemodilution resulted in a slight decrease in mean arterial blood pressure in all groups in the acute stage, but there were no significant changes in central venous, pulmonary arterial, or pulmonary wedge pressures. During the week of study, there were no differences in the cardiac index and total blood volume between the groups, and no significant changes in hematological parameters with the exception of a slight increase in bleeding time immediately after hemodilution with low-MW dextran. Daily neurological assessment showed consistently poorer condition during the first 5 days in the group with lactated Ringer's solution compared to either the control group or the group receiving low-MW dextran. Based on Mann-Whitney U-testing, the infarct volume of the lactated Ringer's solution recipients, expressed as a percentage of the total volume of that hemisphere (median 15.7%, range 6.6% to 25.2%) was significantly larger than that of the group receiving low-MW dextran (median 2.2%, range 0% to 15.8%) and that of the control group (median 11.9%, range 0% to 39.9%). The results indicate that, in this model, hemodilution with colloids was beneficial, whereas hemodilution with crystalloids was deleterious. It is likely that the decrease in oncotic pressure observed after hemodilution with lactated Ringer's solution is one of the most important reasons for its detrimental effect.

Animals↗
PubMed1990

Thoracic spondylosis: experience of 4 cases.

Thoracic spondylosis is relatively uncommon compared to cervical or lumbar spondylosis. It may cause spinal canal stenosis and result in radiculopathy, neurogenic claudication, and most commonly, myelopathy. We present our experience in the management of 4 cases with symptomatic thoracic spondylosis. The lower thoracic spine was involved in all 4 cases. The pathological changes are almost the same as in cervical or lumbar spondylosis except that ossification of ligamenta flava is more common in thoracic spondylosis. The ossified ligamenta flava may adhere tightly to the dura mater, and therefore increase the difficulty of operation. The results of decompressive laminectomy for thoracic spondylosis were acceptable.

Adult↗
PubMed1989

Acute effects of isovolemic hemodilution with crystalloids in a canine model of focal cerebral ischemia.

We used 44 splenectomized dogs to study the effects of isovolemic hemodilution with a crystalloid solution. The dogs were randomly divided into a hemodilution and a control group. In each group, 17 dogs were subjected to 6 hours of internal carotid and middle cerebral artery occlusion, and five dogs received sham operations. Isovolemic hemodilution by phlebotomy and Ringer's lactate infusion was performed 30 minutes after arterial occlusion and resulted in an average hematocrit of 32-33%. Hemodilution significantly reduced viscosity, fibrinogen and total protein concentrations, and plasma oncotic pressure. Systemic arterial blood pressure and pulmonary wedge pressure decreased slightly with hemodilution, but central venous pressure and pulmonary arterial pressure did not change significantly. There was a similar decrease in cardiac index in both hemodiluted and control dogs, which may have been due to the effects of barbiturate anesthesia. Intracranial pressure increased significantly with time in all dogs subjected to arterial occlusion, but this increase was significantly more severe in the hemodiluted dogs. Specific gravity, measured just after the dogs were killed, 6 hours after hemodilution, was significantly lower in the white matter and basal ganglia of the left (ischemic) hemisphere in hemodiluted dogs than in controls. Regional cerebral blood flow decreased significantly in the left hemisphere after arterial occlusion. This decrease was almost completely reversed by hemodilution except in the basal ganglia, where the increase in edema caused by hemodilution was the greatest.

Animals↗
PubMed1988

Isovolemic hemodilution in experimental focal cerebral ischemia. Part 1: Effects on hemodynamics, hemorheology, and intracranial pressure.

A total of 76 splenectomized dogs were entered in a study of the value and effects of isovolemic hemodilution. Of these, seven were not included in the analysis because of technical errors. Of the remaining 69 dogs, 35 were treated with hemodilution; 28 were subjected to a 6-hour period of temporary occlusion of the distal internal carotid artery and the proximal middle cerebral artery, and seven underwent a sham operation only, with arterial manipulation but no occlusion. The other 34 dogs were not subjected to hemodilution; 26 of these underwent temporary arterial occlusion and eight had a sham operation only. In each group the animals were about equally divided into 1) an acute protocol with regional cerebral blood flow measurements by a radioactive microsphere technique and sacrifice at the end of the acute experiment, and 2) a chronic protocol with survival for 1 week to permit daily neurological assessment and final histopathological examination but without blood flow measurements. Isovolemic hemodilution was performed about 1 hour after the arterial occlusion or sham operation and was accomplished by phlebotomy and infusions of low molecular weight dextran to bring the hematocrit to a level of 30% to 32%. This treatment resulted in a very significant reduction in viscosity and fibrinogen levels. The decrease in hematocrit lasted throughout the week in the animals in the chronic protocol. The decrease in viscosity correlated almost linearly with the decrease in hematocrit. There was a slight decrease in systemic arterial pressure with hemodilution but there were no significant changes in central venous pressure or in pulmonary arterial or wedge pressure. There was a slight decrease in cardiac index in both the hemodilution and control groups, which may have been due to the effects of barbiturate anesthesia. There was a slight increase in the measured blood volume in both groups, which was probably artifactual and related to the method of calculation. Intracranial pressure increased significantly with time in all animals subjected to arterial occlusion, but this increase was less severe in the hemodilution group. There was no significant change in intracranial pressure in sham-operated animals, whether hemodiluted or not. The results of cerebral blood flow measurements, assessment of neurological conditions, and measurement of infarct size are given in Part 2 of this report.

Animals↗
PubMed1988

Isovolemic hemodilution in experimental focal cerebral ischemia. Part 2: Effects on regional cerebral blood flow and size of infarction.

Seventy-six splenectomized dogs were entered in a study of the value and effects of isovolemic hemodilution. Of these, seven were not included in the analysis because of technical errors. Of the remaining 69 dogs, 35 were treated with hemodilution; 28 were subjected to a 6-hour period of temporary occlusion of the distal internal carotid artery and the proximal middle cerebral artery, and seven underwent a sham operation only, with arterial manipulation but no occlusion. The other 34 dogs were not subjected to hemodilution; 26 of these underwent temporary arterial occlusion and eight had a sham operation only. In each group the animals were about equally divided into 1) an acute protocol with regional cerebral blood flow measurements by a radioactive microsphere technique and sacrifice at the end of the acute experiment, and 2) a chronic protocol with survival for 1 week to permit daily neurological assessment and final histopathological examination but without blood flow measurements. The general experimental protocol, the hemodynamic and rheological measurements, and the changes in intracranial pressure are described in Part 1 of this report. In the animals with arterial occlusion, blood flow decreased significantly in the territory of the ischemic middle cerebral artery. This decrease was partially reversed by hemodilution in the animals so treated. When the changes in blood flow before and after hemodilution in treated animals are compared with the changes at equivalent times in animals without hemodilution, the increases in flow in the gray matter of the ischemic hemisphere brought about by hemodilution are statistically significant. The neurological condition of the animals in the chronic protocol (sacrificed 1 week after occlusion) with hemodilution, as evaluated by daily neurological assessment, was significantly better than that of the control animals. In the animals sacrificed acutely (8 hours after arterial occlusion), the volume of infarction as estimated by the tetrazolium chloride histochemical method was 7.36% of the total hemispheric volume in the control animals and 1.09% in the hemodiluted animals, showing a statistically significant difference (p less than 0.005). In the chronic animals these values were 9.84% and 1.26%, respectively (p less than 0.005), as calculated by fluorescein staining. By histopathological examination the volume of infarction in the chronic animals was calculated as 10.92% in the control animals and 1.20% in the hemodiluted animals (p less than 0.005).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Is surgical therapy needed for unruptured arteriovenous malformations?

A conservative attitude toward unruptured arteriovenous malformations (AVMs) has been based on the belief that surgical resection is too risky and that their natural history is benign. We have operated on 103 patients with a cerebral AVM. In the 49 patients with unruptured AVMs, there was no mortality, and the morbidity was 14.2%. Similarly, low surgical morbidity has been reported from several centers during the last few years. The chance of hemorrhage for both ruptured and unruptured AVMs is about 3% per year, and the combined morbidity and mortality of each hemorrhage is at least 40%. All patients with an AVM should be individually considered for possible surgical resection, whether or not they have bled.

Adolescent↗
PubMedDate not supplied

Hemimegalencephaly treated by hemispherectomy: report of two cases.

Hemimegalencephaly is a rare congenital anomaly of the brain characterized by unilateral hypertrophy, usually with an abnormal gyri pattern and derangement of the cortical architecture. We report 2 patients with hemimegalencephaly who presented with early-onset seizures, hemiparesis and developmental delay. An electroencephalogram showed hemispheric continuous spikes and spike-and-waves in one patient and repetitive spike-and-waves in the other. Magnetic resonance imaging showed left hemimegalencephaly in both cases and in case 1 pachygyria and heterotopia. A functional hemispherectomy was done on case 1 at the age of 33 months and on case 2 at 7 months due to difficulty in seizure control with antiepileptic drugs. The frequency of seizure dramatically decreased and there was an obvious improvement in neurologic development after surgical intervention. Pathology revealed disorganized lamination of the cortical layers with increased neuron size and bizarre-shaped neurons in both cases. Heterotopia of neurons and glia in the subarachnoid space was noted in case 1. Hemispherectomy should be performed as soon as possible when medical treatment fails to control seizures.

Brain↗
PubMedDate not supplied

Growth retardation as the initial manifestation of intracranial tumors: report of two cases.

Two boys (9 years and 14 years old) were brought to visit our pediatric endocrine clinic with the chief complaint of short stature. Because of growth retardation, they were admitted for further evaluation. Physical examinations, including neurological examinations, were unremarkable but the laboratory examination confirmed the diagnosis of hypopituitarism in both patients. Skull radiography examinations showed some calcifications at suprasellar regions in the case 1 but negative findings in case 2. Furthermore, computed tomography (CT) of the head of case 2 performed at an outside hospital half a year before was reported to be normal, so case 2 fits the conventional diagnosis of idiopathic hypopituitarism. However, magnetic resonance image (MRI) study of the head disclosed that both of them are victims of an intracranial tumor, craniopharyngioma and germ cell tumors respectively. After surgical intervention, followed by radiotherapy, both patients were stable without any neurological deficit. Our experience confirmed that an MRI study of sellar region is warranted in search of the etiology of hypopituitarism.

Adolescent↗
PubMedDate not supplied

Intradural extramedullary epidermoid cyst of the spinal canal: report of one case.

A 9-year-old girl developed a progressive unsteady gait for one month. Hyperactive reflexes of the four extremities and a spasticity of the lower extremities were found. Bilateral Babinski responses were elicited. An intradural extramedullary mass of upper thoracic spinal cord was demonstrated using magnetic resonance imaging and was confirmed as an intradural extramedullary epidermoid cyst at surgery. This epidermoid cyst was from congenital origin. No congenital anomalies such as spina bifida or dermal sinus were associated. The epidemiology, clinical features, radiology, surgical treatment and pathology of this benign tumor are discussed.

Child↗