PubMed Health⌕ Search

Biomedical subjects

N Suwanwela

Publications and source records attributed to N Suwanwela.

At least 19 recordsLinked to original sources
PubMed1998

Takayasu arteritis: ultrasonographic evaluation of the cervico-cerebral arteries.

PURPOSE: To present the ultrasonographic findings of the cervico-cerebral arteries in patients with Takayasu arteritis. MATERIALS AND METHODS: We used duplex ultrasound to study the arteries in the neck including the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA) and the vertebral arteries. For the intracranial arteries, transcranial Doppler ultrasound was used to study the blood flow velocities and directions in the middle cerebral artery (MCA), anterior cerebral artery (ACA), posterior cerebral artery (PCA), ophthalmic artery, basilar and vertebral arteries. The ultrasonographic findings were compared with magnetic resonance angiography (MRA) and standard angiography. RESULTS: Four patients with the diagnosis of Takayasu arteritis were studied. One patient presented with ischemic optic neuropathy and was found to have absent radial pulse. Two patients presented with severe hypertension in young age. The other patient had accidental findings of unmeasurable blood pressure in both arms. One patient had abnormal carotid duplex ultrasound. He was found to have an occlusion of the right ICA. Thickening of the wall of the left ICA was also noted. Reduction of flow velocity in the MCA was demonstrated on TCD. There was evidence of collateral circulation from the contralateral carotid artery demonstrated by reversal of flow in the ipsilateral A1 segment of the ACA. MRA and angiography confirmed the ultrasound findings. Three patients had normal carotid duplex ultrasound but one of them was found to have a severe stenosis at the origin of the common carotid artery by MRA and angiogram. Absence of one vertebral artery was noted in three patients. MRA and angiogram confirmed the occlusion of the same vertebral arteries at their origins. In one patient, reversal of flow in the intracranial part (V4 segment) of the affected vertebral artery indicating collateral flow from contralateral vertebral and basilar arteries was demonstrated. CONCLUSION: Ultrasonography could be used as an additional noninvasive procedure apart from CT angiography, MRI and MRA in patients with Takayasu arteritis. Occlusion and wall thickening of the neck artery could be detected by color coded B-mode and Doppler ultrasound. Transcranial Doppler was useful in evaluation of flow velocity and flow direction of the arteries around the circle of Willis.

Adolescent↗
PubMed1998

Myelodysplastic syndromes in Thailand: a retrospective pathologic and clinical analysis of 117 cases.

To gain more insight into the understanding of myelodysplastic syndromes (MDS) as they occur in Thailand, a retrospective clinicopathologic analysis was conducted in patients (age > 15 years) diagnosed as MDS from January 1992 to December 1996 at the five major medical centers in various geographic regions of the country. The central reviewers independently examined the bone marrow and peripheral blood smears of all the patients and classify the disease according to the French-British-American (FAB) classification. There were a total of 117 eligible patients. The median age of the patients was 56 years (range 16-86). The male:female ratio was 1:1. Thirty-two percent of the patients were younger than 40 years. The frequency of the FAB subtypes was RA/RARS, 54.7; RAEB, 23.1; CMML, 9.4; and RAEB-T, 12.8%. Anemia was the most common symptom presenting in 84.6% of the patients. In the 34 patients in whom the cytogenetics in the bone marrow were analysed, 44.1% revealed abnormalities. Of these, monosomy 7 and trisomy 8 were the most common aberration, each being detected in 26.7% of the patients. Transfusions were the main therapeutic modality in 80% of the patients. Kaplan-Meier analysis revealed a 5 year survival rate of 29% for the whole group with a median survival of 24 months. Twenty-five percent of the patients had progressed to acute myelogenous leukemia (AML) with a median time to disease-progression of 23 months. The median survival for RA/RARS, RAEB, CMML and RAEB-T were 58.4, 19.9, 10.7 and 8.7 months, respectively (P < 0.001). The stepwise Cox regression analysis revealed the percentage of blasts in the bone marrow as the only parameter significantly associated with survival and disease progression. On comparison with data from other countries, the age of Thai patients with MDS is considerably lower than the western population but is comparable to other asian countries. The distribution of the FAB subtypes and the survival of the patients are similar. The major prognostic features, however, lie in the percentage of blasts in the bone marrow rather than the degree of the observed cytopenia.

Adolescent↗
PubMed1997

Transcranial Doppler ultrasound criteria for hemodynamically significant internal carotid artery stenosis based on residual lumen diameter calculated from en bloc endarterectomy specimens.

BACKGROUND AND PURPOSE: Transcranial Doppler (TCD) is often used in conjunction with carotid duplex ultrasonography (CDUS) to evaluate the hemodynamic significance of internal carotid artery (ICA) stenosis. We examined the sensitivity and specificity of TCD criteria for detection of a hemodynamically significant stenosis (residual lumen diameter < 1.5 mm) at the origin of the ICA. METHODS: We selected patients who underwent carotid end-arterectomy (CEA) and had preoperative TCD data available. Eighty-one patients underwent transorbital evaluation, 49 of whom also had transtemporal TCD performed. The endarterectomy specimens were removed en bloc and sectioned, and the minimal residual lumen diameter calculated by computer analysis. RESULTS: For the transorbital approach, the strongest indicators of a residual lumen diameter < 1.5 mm were reversed flow in the ipsilateral ophthalmic artery and a > 50% peak systolic velocity difference between the carotid siphons (distal ICAs) in patients with unilateral ICA origin stenosis. They were 100% specific and 31% and 26% sensitive, respectively. For the transtemporal approach in patients with a unilateral stenosis, a > 35% difference in ipsilateral middle cerebral artery (MCA) peak systolic velocity relative to the contralateral MCA or a > 50% difference in contralateral anterior cerebral artery (ACA) peak systolic velocity relative to the ipsilateral ACA were 100% specific for identifying a residual lumen diameter of < 1.5 mm. Sensitivities were 32% and 43%, respectively. Irrespective of contralateral stenosis, a > 35% difference in ipsilateral MCA peak systolic velocity relative to the ipsilateral posterior cerebral artery had a 100% specificity and a 23% sensitivity for detecting a < 1.5 mm minimal residual lumen diameter. CONCLUSIONS: Although the TCD sensitivity for detecting a hemodynamically significant stenosis is relatively low, it can be highly specific (up to 100%). We conclude that TCD enhances the specificity of highly sensitive CDUS criteria for detecting a hemodynamically significant ICA stenosis.

Aged↗
PubMed1996

Non-Hodgkin's lymphomas in Thailand. A retrospective pathologic and clinical analysis of 1391 cases.

BACKGROUND: Geographic variations in the histopathologic pattern of non-Hodgkin's lymphoma (NHL) are well documented. Insight into this epidemiologic data might shed light on the underlying etiology. Currently, there is a paucity of information regarding the pattern of NHL occurring in Thailand and Southeast Asia. The current nationwide study was undertaken to obtain a clearer definition of the disease among Thais and to compare this information with data from other Asian and Western countries. METHODS: A retrospective analysis of histopathologic subtypes and clinical features was conducted in 1391 patients (age > or = 15 years) with NHL, who were treated at 6 major medical centers in 4 representative areas of Thailand. One hundred and thirty unselected cases were immunohistochemically studied. The reports from other countries used for comparison were identified through a computerized search on MEDLINE. RESULTS: Of the total cases studied, follicular lymphomas constituted 3.8% and diffuse lymphomas 91.4%. The frequency of low and intermediate grade (including large cell immunoblastic, using the Working Formulation) were 12.8% and 72.9%, respectively. The most common histologic subtype was the diffuse large cell and large cell immunoblastic entity, which constituted 39.9% of the cases studied. The rate of small lymphocytic and diffuse small cleaved subtypes were higher than in the United States. Of the 130 cases studied, T-cell lymphoma comprised 16.1%, which was much less than in Japan, China, or Taiwan. CONCLUSIONS: The histopathologic pattern of NHL in Thailand was characterized by the features noted for Asia, i.e., a low rate of the follicular entity and a preponderance of the diffuse aggressive subtypes. In addition, the frequency of the small lymphocytic and diffuse small cleaved subtypes were increased compared with the Western population and the rate of T-cell lymphoma appeared to be less than in Far East Asia.

Adult↗
PubMed1996

Takayasu arteritis in Thailand: clinical and imaging features.

PURPOSE: To present and evaluate the clinical and imaging features of patients with Takyasu arteritis in Thailand. MATERIALS AND METHODS: Clinical and angiographic findings were studied in 63 patients with Takayasu arteritis collected at Chulalongkorn Hospital Medical School, Bangkok. Imaging features including CT scan in 15 patients, magnetic resonance imaging in 14 patients and magnetic resonance angiography in ten patients were evaluated and compared to angiography. RESULTS: Among 63 patients there were 43 females and 20 males with the ratio female to male 2.15:1. The most common age groups were in the third and fourth decades of life. The most common clinical findings were hypertension and absence or weakness of pulses. Elevated erythrocyte sedimentation rate was found in 50%. For angiography, the most common vessel affected was the abdominal aorta (20%). The second and third most common sites were renal arteries (18.7%) and the subclavian arteries (14.3%). Coronary artery involvement was found in two out of eight patients. No pulmonary involvement was found in eight cases studied by pulmonary angiography. For classification of angiogram, the most common type of involvement (66.7%) was extensive involvement of the aorta and branches (type V of new classification established from International Conferences on Takayasu arteritis in Tokyo 1994). No patient was found to have only involvement of brachiocephalic branches or ascending aorta and brachiocephalic branches. CT scan showed calcification in the vessel walls (8/15 cases) which helped in diagnosis of the disease. Wall thickness, surrounding tissue, appearance of the vessel and intraluminal thrombus could be well seen. Magnetic resonance imaging added more detail in multiple planes and could demonstrate vascular flow. High detection rate of the lesions (94.8%) was found for the aorta. The study was less sensitive for smaller vessels. Magnetic resonance angiography showed better correlation of the findings of brachiocephalic arteries compared to angiography. Subclavian steal syndrome could be diagnosed. For renal arteries, MR angiography could correctly demonstrate occlusion of renal artery in six out of eight cases. In the other two cases only stenoses of the vessels were found on angiograms. One renal arterial stenosis on MR angiography was confirmed by angiography. CONCLUSION: Takayasu arteritis could be found in Thailand. Clinical features were almost the same as in reports from other countries. Various forms of arterial involvement were demonstrated by imaging modalities. Angiography remained the best method for detection and diagnosis of Takayasu arteritis in correlation with clinical and laboratory findings. Although CT scan, magnetic resonance imaging and magnetic resonance angiography were limited and less sensitive for detection of the lesions, they were useful as noninvasive modalities showing more details of intraluminal clot, vascular wall and surrounding tissue which could be correlated with pathological findings and pathogenesis of the disease. Our study suggests that MR imaging and MR angiography can be screening and diagnostic techniques for patients with suspected Takayasu arteritis.

Adolescent↗
PubMed1996

Hyperacute stroke: evaluation with combined multisection diffusion-weighted and hemodynamically weighted echo-planar MR imaging.

PURPOSE: To evaluate acute stroke with conventional, multisection diffusion-weighted (DW), and hemodynamically weighted (HW) magnetic resonance (MR) imaging. MATERIALS AND METHODS: The three MR imaging techniques were performed in 11 patients within 10 hours of the onset of acute hemiparesis. The volume of DW and HW abnormalities were compared with infarct volumes depicted at initial and/or follow-up MR or computed tomography (CT). RESULTS: Findings at DW and HW imaging were abnormal in nine of the 11 patients, despite normal findings at initial CT and/or MR. In all nine patients, infarcts were depicted at follow-up CT or MR. The DW abnormality was generally smaller and the HW abnormality was generally larger than the infarct volume determined at subsequent imaging. In the two patients with normal findings at DW and HW imaging, symptoms resolved completely within 1-48 hours. CONCLUSION: Different aspects of hyperacute cerebral ischemia are depicted at DW and HW imaging before infarction is depicted at conventional MR or CT. These techniques may improve stroke diagnosis and may contribute to advances in treatment.

Acute Disease↗
PubMed1996

Carotid Doppler ultrasound criteria for internal carotid artery stenosis based on residual lumen diameter calculated from en bloc carotid endarterectomy specimens.

BACKGROUND AND PURPOSE: Carotid duplex ultrasound is widely used to screen patients for carotid endarterectomy and if combined with MR angiography and transcranial Doppler may be an alternative to conventional angiography in the preoperative assessment. We have examined the correlation between Doppler velocities and the residual lumen diameters of internal carotid arteries from surgical pathological specimens to establish Doppler criteria for residual lumen diameter independent of percent stenosis. METHODS: Ninety-one patients who underwent 99 carotid endarterectomies for internal carotid artery stenosis within 6 months of their carotid duplex ultrasound evaluation were studied. The endarterectomy specimens were removed en bloc, and the minimal residual lumen diameter was calculated by computer analysis. The sensitivity and specificity of the Doppler criteria for determining high-grade stenosis were calculated and receiver-operator curves generated. RESULTS: Peak systolic velocity (PSV), end-diastolic velocity (EDV),and carotid index (peak internal carotid artery velocity/ common carotid artery velocity) correlated with the residual lumen diameter. PSV > 440 cm/s, EDV > 155 cm/s, or carotid index > 10 indicated a residual lumen diameter of < or = 1.5 mm (specificity of 100% and sensitivity of 58%, 63%, and 30%, respectively). When these criteria were combined, the sensitivity increased to 72%. A PSV > 200 cm/s combined with either an EDV > 140 cm/s or a carotid index > 4.5 has a sensitivity of 96% and a specificity of 61%. CONCLUSIONS: Doppler criteria can be both specific and sensitive for detecting a significant stenosis, defined as a < or = 1.5 mm residual lumen diameter. By adjustment of the velocity criteria, it can be 100% specific or a highly sensitive test (96%).

Blood Flow Velocity↗
PubMed1994

Primary meningioma intimately related to skull: case report and review of the literature.

A report is made of a primary meningioma intimately associated with the left sphenoid ridge and temporal bone of a 41-year-old woman. The lesion produced hyperostosis of the involved bones, ipsilateral proptosis, and reduced vision for 4.5 years. The radiotherapy yielded little improvement of the exophthalmos and vision. Review of 125 reported meningiomas intimately related to the skull and presenting primarily with hyperostosis and minimal soft tissue component, including the current case, disclosed that all but one affected the cranium proper, particularly the middle ear, temporal bone, frontal bone, and parietal bone. The exceptional one was in the mandible. They tended to occur between the fifth and seventh decades of life with the peak occurrence between the fifth and sixth decades. The average age was 46 years for overall. The female-to-male ratio was 2:1. Six of 125 primary meningiomas closely associated with the skull were malignant and two of these spread to the lungs. The pulmonary metastasis was spontaneous in one case.

Adult↗
PubMed1992

Takayasu arteritis in Thailand.

Takayasu arteritis is a disease of world-wide distribution. Geographic difference in sex incidence, anatomical distribution, and the type of lesion is observed. Hypertension is very common in the present series, as well as in combination with absent or deficit of peripheral pulses. These symptoms correlate well with arteriographic findings of brachiocephalic and renal artery obstructive lesion. While aneurysm and stenotic lesions have a predilection in the abdominal aorta, stenotic lesion of the thoracic aorta occurs more commonly than aneurysm. However, aneurysm of the aorta as well as of the brachiocephalic arteries is seen more frequently than in the reports, of others. The presence of "funnel-shape" resulting from renal artery obstructive lesion and dilatation or aneurysm of contiguous aorta was characteristic of Takayasu arteritis in our series. The material presented in this report reflects not only geographic variation but also the severe form of this disease. Total aortography, coronary arteriography and pulmonary arteriography, are of value not only for the diagnosis of Takayasu arteritis but also for demonstration of anatomical distribution, severity and type of lesion.

Adolescent↗
PubMed1992

Case report: chronic spinal cord compression from extramedullary haematopoiesis in thalassaemia--MRI findings.

A 27-year-old-man with beta-thalassaemia/HbE presented with signs and symptoms of spinal cord compression due to epidural extramedullary haematopoiesis. Magnetic resonance images demonstrated spinal cord constriction and atrophy suggesting that the disease process was long-standing. On transverse T2-weighted images, high signal intensity was observed within the spinal cord suggestive of post-compressive spinal cord myelomalacia or gliosis.

Adult↗
PubMed1992

CT findings in tuberculous spondylitis.

The computed tomographic (CT) features of ten documented cases of spinal tuberculosis were analyzed. All cases showed evidence of vertebral body destruction, with paravertebral soft tissue masses. Four cases revealed extension of involvement into the neural arches. Calcification within the paraspinal soft tissue was found in only two cases. Two of four cases who received intravenous contrast medium demonstrated evidence of rim enhancement around multilocuated fluid collections. Compared to conventional roentgenography, CT better delineated the extent of bony destruction, involvement of the spinal canal and existence of paraspinal soft tissue masses.

Adolescent↗
PubMed1992

Cerebral abscesses due to Pseudomonas pseudomallei.

Two cases of cerebral abscesses caused by Pseudomonas pseudomallei are reported. The first case, a 51-year-old women had a sudden onset of progressive right hemiparesis and right facial palsy and died within 7 days. Postmortem examination disclosed brain abscess in association with disseminated infection outside the central nervous system. The second case, a 9-year-old boy displayed cerebral abscesses as an isolated manifestation. Recovery occurred after treatment with ceftazidime. Review of the ten case reports of cerebral melioidosis revealed that the lesion occurred in patients of all ages and was more common in men than in women. The frontoparietal lobe was the most common location. Fever, headache, and hemiparesis were frequent clinical manifestations while seizures, ataxia were uncommon. CT scanning, serum antibody titer along with hemoculture were useful investigate tools. The importance of early diagnosis and prompt treatment is emphasized for this fatal but treatable disease.

Anti-Bacterial Agents↗
PubMed1991

Magnetic resonance images of brain stem infarct in periarteritis nodosa.

A 35-year-old woman displayed unusual symptoms of progressive bulbar dysfunction. At necropsy, systemic necrotizing vasculitis and small pontine infarcts were demonstrated. The angiographic and magnetic resonance imaging findings are described. The latter investigation is a sensitive method for detecting such pontine lesions. To our knowledge, this case is the first report of magnetic resonance imaging findings of brain stem infarct in a patient with periarteritis nodosa.

Adult↗
PubMed1988

Unilateral proptosis as a clinical presentation in primary angiosarcoma of skull.

A case is reported of unilateral proptosis of the left eyeball as a unique clinical presentation of primary angiosarcoma of the skull involving the sphenoid and frontal bones and roof of the orbit on the left side of a 32-year-old man. The intraosseous, extradural non-encapsulated, and friable tumour contained cytoplasmic factor VIII-related antigen. After complete removal of the tumour the patient has been well for 10 months of the follow-up period. This case brings the total number of reported primary angiosarcomas of the cranium to nine. All patients were male and most of them were young. The average age was 24 years. The frontal bone seems to be the site of predilection for cranial angiosarcomas. Surgical extirpation, radiation, or combined surgical removal and radiation have been used for treating angiosarcoma of the skull with variable results. It is suggested that angiosarcoma of the skull has a worse prognosis than angiosarcoma of bones other than the cranium because the patient may die of secondary neoplastic involvement of the brain.

Adult↗
PubMed1987

Spontaneous penetration of dura mater and bone by glioblastoma multiforme.

Three patients are reported whose cranial dura mater and bones were penetrated by intracranial glioblastomas in the absence of previous craniotomy or radiotherapy. The gliomatous nature of the tumors was confirmed by localization of cytoplasmic glial fibrillary acidic protein (GFAP) of the neoplastic cells. Review of the literature disclosed only 15 glioblastomas, including the three cases, spontaneously penetrating the cranial dura mater and bones. These patients ranged in age from 3.5 to 70 years with an average age of 40 years. The male/female ratio was 5/8. Five glioblastomas were in the temporal lobes, three were in the frontal lobes, three were in the frontotemporal regions, two were in the occipital lobes, one was in the frontoparietal region, and one was in the temporoparietooccipital region. Six glioblastomas also had spontaneous distant metastases. In the absence of previous craniotomy and radiotherapy, rapid growth of the glioblastomas may promote such spontaneous penetration into the cranial dura mater and bones.

Adult↗
PubMed1986

Primary intraorbital extraocular primitive neuroectodermal (neuroepithelial) tumour.

A case is reported of primary primitive neuroectodermal (neuroepithelial) tumour occurring in the right orbit of a 52-year-old man. The intraorbital extraocular location is unique for this kind of neoplasm. The malignant tumour was differentiated into primitive neuroepithelial, ependymal, and oligodendroglial cells. The neuroglia was identified by localisation of cytoplasmic glial fibrillary acidic protein. It is suggested that this primary intraorbital, extraocular, primitive neuroectodermal tumour with neuroglial differentiation is akin to the primitive neuroectodermal tumours of the neuraxis, including the cerebellar medulloblastomas, and to some peripheral nerve tumours known as malignant neuroepitheliomas, malignant ependymomas, and neuroblastomas. The ectomesenchymal remnant of the neural crest or ectopic neuroepithelium or both may have been the origin of the present tumour. Differentiation of the neuroectodermal component of the neural crest or heterotopic neuroepithelium or both would create a primitive neuroectodermal tumour with diverse neuroglial elements.

Humans↗