High-resolution computed tomography in pulmonary lymphangio(leio)myomatosis and pulmonary tuberous sclerosis

We report two cases where high-resolution computed tomography (HRCT) assisted in the diagnosis of a patient with lymphangioleiomyomatosis and a patient with pulmonary tuberous sclerosis. HRCT was used in both cases where the chest radiographs and conventional computed tomographic scans appeared relatively normal but the conditions were strongly suspected.

Evaluation of intracranial and extracranial carotid steno-occlusive diseases in Taiwan Chinese patients with MR angiography: preliminary experience

BACKGROUND AND PURPOSE

We attempted to evaluate the location of vascular lesions in cases of cerebrovascular steno-occlusive diseases in Chinese persons living in Taiwan.

METHODS

With three-dimensional time-of-flight magnetic resonance angiography (MRA) as a screening tool, 108 symptomatic patients with cerebrovascular steno-occlusive diseases were examined. Cardioembolic disease and cerebral hemorrhage cases were excluded. The degrees of stenosis of bilateral cervical carotid arteries and their major intracranial tributaries were recorded. They were categorized as nonsignificant stenosis (0% to 49%), significant stenosis (50% to 99%), and total occlusion.

RESULTS

Our data revealed that 32.4% of the cases were normal in either cervical carotid arteries or their intracranial tributaries. In 24.1% of the cases, significant extracranial carotid stenosis or occlusion was the only finding on MRA. In 25.9% of the cases, only significant intracranial-tributary stenosis was found. In 17.6% of them, significant lesions were found in both extracranial and intracranial carotid artery tributaries.

CONCLUSIONS

A racial difference between Chinese and white patients in location of lesion in cerebrovascular steno-occlusive diseases was confirmed. About one third of symptomatic Chinese patients living in Taiwan showed small-vessel disease. Approximately 24% of patients had only extracranial carotid disease, and about 26% had only intracranial carotid tributary disease. We need a larger series of patients to confirm these findings. However, MRA might be a good screening tool for steno-occlusive cerebrovascular disease, especially in persons of a race with more intracranial carotid disease, such as the Chinese.

Magnetic resonance imaging of vertebral compression fractures

In this study, magnetic resonance imaging (MRI) was used to analyze the signal intensity and vascularity of compression fractures of vertebrae in 74 patients. The possibility of nonunion was assessed according to the specific image findings and clinical presentation. All patients had chronic back pain for more than 3 months and compression fractures of the vertebrae initially demonstrated by plain radiography. Pre-enhanced T1 and T2*-weighted images (*multiplaner gradient recall sequence) and postenhanced MRI were obtained. Images were divided into three categories according to the signal intensity of the fractured vertebrae such as hyperintensity (n = 35), hypointensity (n = 24) on T1-weighted image and necrotic type compression fractures of the vertebrae (n = 15). Of the 15 necrotic-type cases, 13 disclosed "fluid"-containing space at the collapsed vertebrae and two showed "air"-containing space at the vertebral body. We believe that these findings are pathognomonic signs of nonunion of the collapsed vertebrae. Surgical specimens were obtained from the four patients whose vertebrae showed necrosis and granulation tissue. After posterior spinal instrumentation, the collapsed vertebral body regained the height and presence of the open end-plate of the vertebra on postoperative lateral radiography. The superior capabilities of MRI offers useful criteria that make the diagnosis of nonunion in compression fractures of the spine possible. Thus, a space with "fluid" or "air" collection at the anterior aspect of a collapsed vertebra as well as strong enhancement with Gd-DTPA at the posterior aspect of the collapsed vertebra may be considered to be pathognomonic signs of nonunion of the fractured vertebra.

Correlation between quantitative severity of stress thallium-201 myocardial perfusion defect and severity of coronary stenosis

The correlation between the quantitative myocardial perfusion defect severity of stress 201Tl single-photon emission computed tomography and the severity of coronary stenosis was investigated in 28 patients with angina pectoris. Among the 28 patients, four had normal or nearly normal coronary angiograms, seven had one-vessel disease, six had two-vessel disease and 11 had three-vessel disease. Seven patients had prior myocardial infarctions and two had collateral flows to the diseased vessels. The quantitative 201Tl defect severity score was obtained by summing the standard deviations of each pixel in which the counts fell > 2.5 SD below the mean normal counts. The severity of coronary stenosis was expressed as the Gensini score. The quantitative 201Tl defect severity score correlated significantly with the Gensini score. In patients without prior myocardial infarction or collateral flow, a more significant correlation between the quantitative 201Tl defect severity score and the Gensini score was found. Quantitative analysis of stress 201Tl defect severity provides a useful, noninvasive assessment of the functional severity of coronary stenosis compared with coronary angiography.

MRI of meniscus and cruciate ligament tears correlated with arthroscopy

Findings from magnetic resonance imaging (MRI) studies of 50 knees were retrospectively interpreted. The results were correlated with arthroscopic findings. Multiple pulse sequences were performed including sagittal double-echo, coronal T1-weighted and gradient echo, axial gradient echo or fat suppression imaging. Three-dimensional MRI was performed if there was a high suspicion of a tear of the anterior cruciate ligament. The individual positive predictive value, sensitivity, specificity and accuracy were calculated from the comparison between MRI and arthroscopic findings of the menisci, anterior cruciate ligament and posterior cruciate ligament. The following results were obtained: 1) Tears of the medial meniscus-positive predictive value, 72%; sensitivity, 87%; specificity, 86%; and accuracy, 86%. 2) Tears of the lateral meniscus-positive predictive value, 85%; sensitivity, 85%; specificity, 90%; and accuracy, 88%. 3) Tears of the anterior cruciate ligament-positive predictive value, 88%; sensitivity, 95%; specificity, 89%; and accuracy, 92%. 4) Tears of the posterior cruciate ligament-positive predictive value, 100%; sensitivity, 100%; specificity, 100%; and accuracy, 100%. It is concluded that MRI is a noninvasive and accurate method for detecting the internal derangement of the knee.

Dynamic enhancement MRI of anterior lobe in pituitary dwarfism

We examined 23 patients with pituitary dwarfism by dynamic MRI; with a repetition time of 150 or 50 ms. The time-enhancement difference curves of selected regions in the anterior lobes were plotted. Another 48 patients with no definite clinical pituitary disfunction were examined with the same technique. We found that the intensity of maximum enhancement in both groups was similar, but the time to achieve maximum enhancement was delayed in pituitary dwarfism with or without stalk transection; the time seemed longest with stalk transection. There was little difference in enhancement between patients with multiple hormone deficiency or isolated growth hormone deficiency. Dynamic MRI of the anterior lobes may be an important functional imaging study, and our results imply that poor perfusion is a useful finding in pituitary dwarfism, especially in patients without stalk transection and normal pituitary height.

The depolarization response element in acetylcholine receptor genes is a dual-function E box

All acetylcholine receptor subunit genes contain E boxes and are blocked by membrane depolarization. We have used transfected C2C12 myogenic cells to investigate the response, to electrical stimulation and KCl, of wildtype and mutant regulatory regions of the chick acetylcholine receptor alpha, gamma and delta subunit, and the mouse MLC genes. Point mutations revealed that E boxes function as activating elements targeted by the depolarization signal. These experiments suggest, and insertion of a depolarization response element into an unrelated promoter confirms, that plasma membrane depolarization switches the depolarization response element from an activating to a repressive mode.

Dobutamine stress echocardiography compared with dipyridamole thallium-201 single-photon emission computed tomography in detecting coronary artery disease

To compare the diagnostic value of dobutamine stress echocardiography with dipyridamole thallium-201 single-photon emission computed tomography (SPECT) in detecting coronary artery disease (CAD), we performed both tests on 54 patients who also underwent coronary arteriography. Dobutamine was infused at an incremental regimen of 5, 10, 20, 30 and 40 micrograms.kg-1.min-1. Dipyridamole was infused at a rate of 0.14 mg.kg-1.min-1 over 4 min. Dobutamine stress echocardiography detected 40 (93%) and SPECT 42 (98%, P = ns) of the 43 patients with significant CAD, defined as > or = 50% diameter stenosis. The specificity was 73% (8 of 11) for both tests. The sensitivity for detecting individual coronary artery stenosis with dobutamine stress echocardiography was 81% (30 of 37) for the left anterior descending artery, 75% (24 of 32) for the right coronary artery, and 61% (17 of 28) for the left circumflex artery. For SPECT it was 89%, 97% (P < 0.05 vs dobutamine stress echocardiography) and 75%, respectively. Among the 97 stenotic coronary arteries, 17 had mild to moderate stenosis (50%-69% diameter stenosis) and 80 had severe stenosis (> or = 70% diameter stenosis). With dobutamine stress echocardiography, 53% of the arteries with mild to moderate stenosis were identified vs 78% of those with severe stenosis (P < 0.05). With SPECT, the sensitivity was 82% (14 of 17) in mild to moderate stenosis and 89% (71 of 80) in severe stenosis (P = ns). No major side effects occurred during either test. Thus, both dobutamine stress and SPECT are highly sensitive for detection and localization of CAD.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes of brainstem and perimesencephalic cistern: dynamic predictor of outcome in severe head injury

OBJECTIVES

Based on the findings in computed tomography scans, we defined a grading system that is well correlated to the changes of the brainstem and its perimesencephalic cistern during intracranial hypertension.

MATERIALS AND METHODS

The grades are defined as follows: Grade 0 is normal, grade 1 represents widening of the perimesencephalic cistern without brainstem change, grade 2 represents obliteration of the cistern without brainstem change, grade 3 represents a deformed brainstem; grade 4 represents brainstem density change, and grade 5 represents any combination of grades 3 and 4. As a comparison to the Glasgow Coma Scale (GCS) system, we examined this new system in 334 cases, in which 138 cases were classified as severe head injuries.

RESULTS

In cases of mild head injury (GCS score > 8), this new system was correlated to the GCS system well in grades 0 to 2. In cases of severe head injury, the prediction of outcome is better in our system because it is well correlated to dynamic change of intracranial hypertension, especially in cases with nonsurgical masses of grades 3 and 5.

CONCLUSIONS

Our grading system is easy to use, and is well correlated to give an accurate prediction of outcome in cases with severe head injury based primarily on the results of an initial computed tomography scan, even without clinical information, and it should play a role in the classification of head injury.

Diagnosis of coronary artery disease using dipyridamole thallium-201 imaging

Dipyridamole thallium-201 imaging, using single-photon emission computed tomography, was evaluated for its safety and diagnostic efficacy in 109 patients with angiographically documented coronary artery disease and 35 normal subjects. The most common side effects after the intravenous administration of dipyridamole thallium-201 (0.56 mg/kg) included chest pain in 41 patients, dizziness in 20 patients, headache in 16 patients, and ST segment depression > or = 1 mm in 15 patients. Aminophylline was required to reverse the side-effects in 46 patients, and 45 of the 46 patients experienced complete relief of symptoms. Of the 109 patients with coronary artery disease, 104 had abnormal dipyridamole thallium images. The per patient sensitivity was 95%. Of the 35 normal subjects, 27 had normal thallium images. The per patient specificity was 77%. The sensitivity and specificity for the individual vessels were 84% and 87% for the left anterior descending artery, 67% and 97% for the left circumflex artery, and 89% and 85% for the right coronary artery, respectively. Dipyridamole thallium-201 imaging is a relatively safe noninvasive method and is an effective alternative to exercise thallium-201 scintigraphy for the diagnosis of coronary artery disease.

Findings of anomalous pulmonary venous return using MRI

This study represents a preliminary retrospective assessment of the value of spin-echo magnetic resonance imaging (MRI) in detecting and describing total or partial anomalous pulmonary venous return (APVR). MRI was performed in 21 cases of APVR; orthogonal planes were used in all. Of the 21 cases, 19 were classified as total APVR (TAPVR) and two were partial APVR (PAPVR). Of the 19 cases of TAPVR, seven supracardiac, nine cardiac, one infracardiac and two mixed type were noted. The detection rate of each pulmonary vein combined in all three planes was 57% in the right superior pulmonary vein (RSPV), 62% in the left superior pulmonary vein (LSPV), 76% in the right inferior pulmonary vein (RIPV), and 86% in the left inferior pulmonary vein (LIPV). The axial plane was most effective (RSPV: 38%; LSPV: 52%; RIPV: 71%; LIPV: 81%). The coronal plane offered a better detection rate than the axial plane in RSPV (43%) and additional information of bronchial and visceral situs. Imaging of the combined axial and coronal planes was sufficient to evaluate each individual pulmonary vein. The sagittal plane gave no additional information in this respect. Accurate identification of pulmonary venous confluence and anomalous pulmonary venous channel was 95% (20/21). Limitation of echocardiography and and angiocardiography makes cardiac MRI important in assessing pulmonary vein and pulmonary venous confluence. It obviates the need for invasive angiocardiography and is an important supplement to an inadequate echo.

Magnetic resonance imaging of rotator cuff lesions

The purpose of this study was to evaluate the diagnostic performance of magnetic resonance imaging (MRI) in rotator cuff diseases. Forty consecutive patients studied by MRI from September 1990 to September 1992 were included in the study. MRI was performed on a 1.5 tesla MR scanner. Each MRI study was reviewed by two radiologists experienced in rotator cuff tendons. The MRI finding was compared with the surgical result. MRI sensitivity for all tears (partial and complete) was 1.0 (22/22), specificity 0.89 (16/18), accuracy rate 0.95 (38/40), and the predictive value 0.92 (22/24). Signal changes of the rotator cuff tendon (primary signs) were the most reliable criteria in diagnosis of the tear. Changes of subacromial and subdeltoid fat planes and bursa (secondary signs) were complimentary when primary signs were indeterminant. The direction of the long axis of abnormal signal intensity in the rotator cuff tendon may be a good indicator when differentiating tears from tendinitis. We conclude that MRI shows excellent performance in the determination of the presence or absence of a rotator cuff tear.

Differential diagnosis of extrahepatic biliary atresia from neonatal hepatitis: a prospective study

The clinical presentations of cholestasis in infancy caused by neonatal hepatitis and biliary atresia are very similar. Diagnosis may be difficult on many occasions, but the surgical treatment of biliary atresia should be performed as early as possible. We established a 3-day workup protocol for the differential diagnosis of biliary atresia and neonatal hepatitis and compared the diagnostic accuracy, sensitivity, specificity, and predictive values of various methods. One hundred and twenty-six infants, including 84 with neonatal hepatitis (age, 65.1 +/- 24.1 days) and 42 with biliary atresia (age, 60.3 +/- 31.1 days), were studied prospectively from July 1982 to December 1990. The diagnostic accuracy of various methods was as follows: liver histology, 96.8%; color of duodenal juice, 91.6%; peak radioisotope count in duodenal juice, 84.2%; ultrasonographic examination of the hepatobiliary system, 80.2%; and persistence of clay-colored stool, 80.2%. After stepwise logistic regression, the diagnostic methods of significance were liver biopsy, color of duodenal juice, abdominal ultrasonography, and stool color. However, stool color and the onset of jaundice could not differentiate severe neonatal hepatitis from biliary atresia. The diagnostic methods of significance then were liver biopsy and duodenal juice color. With this 3-day protocol, no biliary atresia was missed although four cases of neonatal hepatitis were misdiagnosed, resulting in unnecessary laparotomy; we found an overall diagnostic accuracy of 96.8%. We conclude that this 3-day diagnostic protocol is very helpful in the differential diagnosis of neonatal hepatitis and biliary atresia. Liver histologic examination is the most reliable single test for the differential diagnosis.

[Computed tomography of gastric carcinoma using water as a contrast agent]

To overcome the problem of poor mixing of gastrointestinal tract contents with a diluted iodinated contrast agent in abdominal computed tomography, pure water was adopted as an oral contrast agent. In 25 cases of clinically suspected gastric carcinoma, a subsequent pathological examination revealed six cases of early gastric cancer and 19 cases of advanced gastric cancer. We performed CT of the stomach using the following revised procedure: patients were given 600-1000 mL of water by mouth after an intramuscular dose of Buscopan to distend and immobilize the stomach. Gastric mucosal enhancement and the poorer enhanced submucosal layer were demonstrated by a bolus intravenous injection of iodine-containing contrast medium using an automatic injector synchronized with the CT machine. Based on abnormal gastric wall thickening and the abnormal mural enhancement patterns, an accuracy of 96% was attained in differentiating early gastric cancer from advanced gastric cancer, but the detection rates for extragastric invasion, gastric ulcers and lymphadenopathy were 67%, 43% and 63%, respectively. CT staging of gastric cancer was 72%, and was especially accurate for stages I and IV. Water as oral contrast agent for CT of the GI tract was readily accepted by patients and caused no side effects. Using water as an oral contrast for gastric CT is of great help in staging gastric cancer.

Evaluation of hip disorders by radiography, radionuclide scanning and magnetic resonance imaging

Thirty-six hips were studied because of significant hip pain. Radiography of the hip and bone scintigraphy showed subtle changes. Magnetic resonance imaging (MRI) was performed using a 1.5 Tesla superconductive unit. All MRI findings were confirmed by surgical or pathologic results. Twenty-nine hips had a single lesion, including: infection (one), fracture (eight), avascular necrosis of the femur(two), or contralateral hip (four), transient osteoporosis (six), osteoporosis (one), post-irradiation myositis (one), metastasis (four), and synovitis (two). Twenty-six lesions (89.6%) appeared normal on the radiographs of the hip, while three lesions (10.4%) showed only osteoporotic change. Another seven hips had more than one lesion, including: avascular necrosis and fracture (four), fracture foci (two), and metastasis and fracture (two). Radiography of the hip showed either a negative finding or detected only a single lesion, missing other important pathologic foci. MRI is extremely sensitive to alterations in the bone marrow that may represent pathology occult to plain radiography and bone scintigraphy of the hips. For diagnosis and treatment planning, MRI of the hips should be performed early in patients with persistent pain and negative radiography findings.

MR patterns of rotator cuff and labral lesions: comparison between low-field and high-field images

Eighteen people (10 men, 8 women) were examined on a 0.3-T (low-field) imager with T1-weighted axial and coronal images and either axial or coronal T2-weighted images. Thirty-two people (22 men, 10 women) were examined on a 1.5-T (high-field) imager with axial T1-weighted images and coronal, sagittal dual-echo images. Rotator cuff lesions were diagnosed by the following findings: abnormal signal in the tendon, irregularity or discontinuity at the musculo-tendinous junction, or muscle abnormality. Glenoid labrum tears were considered if one or more of the following criteria were present: labral deformity of unusual size, focal defect, amputation or displacement with fluid, or capsular stripping. Comparison between the high-field and low-field MR images in the evaluation of rotator cuff lesions suggests that the high-field imager is better than the low-field imager in the differentiation of tendinitis from tears, in the confirmation of bursitis and in detection of subscapularis lesions. A higher contrast-to-noise ratio (CNR), less time consumption, and more section planes (especially, sagittal sections) appear to be the main reasons for this. As far as labral lesions are concerned, the performances of the high-field imagers and low-field imagers were almost equal. The artifact of greater chemical shift with a high-field imager would more or less, we assume, degrade the better CNR achievable in the diagnosis of labral lesions.

Exercise thallium-201 tomographic scintigraphy in the diagnosis of coronary artery disease: emphasis on the effect of exercise level

Exercise thallium-201 imaging using single-photon emission computed tomography (SPECT) was evaluated in 154 patients with angiographically documented coronary artery disease (CAD) and in 25 normal subjects. Of the 154 patients with CAD, 134 (87%) had abnormal thallium images. By contrast, only 77 (50%) patients had ischemic ST-segment depression (p < 0.001). Among 25 normal subjects, 20 had normal exercise SPECT images. The specificity of exercise SPECT imaging (80% or 20/25) in excluding patients with CAD was not significantly higher than that of exercise electrocardiography (76% or 19/25). For the detection of individual vessel involvement by analysis of territories of perfusion abnormalities, the sensitivity and specificity of exercise SPECT were 72% and 96% for the left anterior descending, 78% and 85% for the right coronary, and 47% and 98% for the left circumflex artery. Ninety (group 1) of the 154 patients with CAD achieved adequate exercise end points (ischemic ST-segment depression or > 85% of maximal predicted heart rate) and 64 (group 2) did not. Exercise SPECT showed significantly more perfusion abnormalities in group 1 than in group 2 (96% vs 75%, p < 0.001). We conclude that: (1) exercise SPECT thallium imaging is more sensitive than exercise electrocardiography for detecting patients with CAD; (2) the sensitivity of the test is affected by the level of exercise; and (3) it is valuable in the identification of individual vessel involvement.

Multiplanar gradient recalled images of the knee: comparison of different flip angles and echo times

To determine the most appropriate combination of echo time (TE) and flip angle in gradient echo images of the knee, the authors used different TEs (10, 20 and 30 msec) and flip angles (10, 30, 50, 70, 90, 120 and 150 degrees) to perform a systematic study of MRI on 10 volunteer knees. Contrast-to-noise ratios of cartilage-fat, fluid-cartilage, fluid-fat and fluid-ligament were calculated and compared. Images with a 30-degree flip angle combined with 20 msec of TE were found to have the best contrast-to-noise ratios in both objective data analysis and subjective observation. Hyaline cartilage of the knee was hyperintense and was well delineated on this pulse sequence, appearing distinct in contrast to the intra-articular fluid. It is concluded that this T2-weighted gradient echo pulse sequence is an alternative to conventional spin echo T2-weighted imaging of the knee.

Predictive value of total body bone mineral density for vertebral fractures in elderly women. Geriatric Study Group

In a general population-based geriatric disease survey in Taipei City, the bone mineral density (BMD) of 58 women over 65 years of age was measured for the whole body, lumbar spine (L2-L4), and proximal femurs using a 153Gd based dual photon absorptiometer. These women were found to have at least one vertebral fracture. The results showed that the BMD readings of both the lumbar spine (L2-L4) (mean Z score +/- SEM = 0.05 +/- 0.12) and the femoral neck (mean Z score +/- SEM = -0.20 +/- 0.10) were not statistically different from those of age-matched controls. However, the total body BMD in these 58 patients was significantly lower than in the normal controls (mean Z score +/- SEM = -1.07 +/- 0.10, p < 0.0001). In the normal control group (N = 69, age 50-85), there was a significant linear correlation between the total body and lumbar BMD (r = 0.81, p < 0.0001). This correlation was not found in the 58 women with vertebral fractures (r = 0.14, NS). Our results suggest that geriatric women with vertebral fractures are more osteoporotic than normal aged women, even though they have a relatively mild degree of spinal osteoporosis. But, because of age-associated degenerative changes or other factors, conventional anteroposterior lumbar BMD measurements cannot detect the difference. The total body BMD readings, but not the lumbar or femoral neck BMD readings, seem to be less affected by these local changes and may provide a better discriminative or predictive value for vertebral fracture in this particular age group.

Correlation between left ventricular systolic function and dipyridamole thallium SPECT redistribution patterns in coronary artery disease

The dipyridamole thallium-201 single photon emission computed tomography (SPECT) and resting gated blood pool ventriculography were sequentially conducted in 31 consecutive patients with angiographically proven coronary artery disease. The functional significance of various thallium redistribution patterns was assessed. The patients with an entirely complete (CR) or partial (PR) redistribution pattern had a higher global left ventricular ejection fraction than those with combined PR and no redistribution (NR), while patients with an entirely CR pattern did not have a statistically better ejection fraction than those with PR. Furthermore, myocardial segments with normal perfusion (N) and those with CR or PR had a higher regional ejection fraction than those with NR in the infero-apical area and the septal area. The regional ejection fraction was statistically higher in patients with CR than in those with PR in the septal area and higher, though not statistically significant, in the infero-apical area. The functional difference between groups with N and CR was not significant. Thus, we conclude that the redistribution patterns of dipyridamole thallium SPECT are closely correlated with systole function. Myocardium, in the presence of redistribution, will have a better functional performance in coronary artery disease.

Solid and papillary neoplasm of the pancreas: report of three cases

We report 3 cases of solid and papillary neoplasm of the pancreas, which is a rare pancreatic tumor with distinct clinicopathologic characteristics. Sonographic, computed tomographic (CT) and gross pathologic findings of these 3 patients were obtained and compared. The tumors had a smooth, enhanced capsule and variable internal architecture. Two of the tumors appeared to be of the heterogeneous soft tissue density type, while one of the tumors was of the mixed solid and cystic type. Because the CT appearance of this tumor is subject to variation, it should be differentiated from other pancreatic lesions with variable CT appearances. Several CT features such as soft tissue density of the mass in a precontrast study, a well-enhanced capsule and the absence of pancreatic or biliary duct dilatation, as well as the characteristic young-female predilection, may aid in a correct diagnosis before surgery.

Age-related changes in vitamin D metabolites, osteocalcin, alkaline phosphatase and parathyrin in normal Chinese women in Taipei

To evaluate the age-related changes in the bone remodeling rate, the vitamin D status, and parathyroid function of healthy Chinese women, we selected two serum markers of bone turnover, osteocalcin and alkaline phosphatase (ALP). These markers as well as vitamin D metabolites and parathyrin (parathyroid hormone, PTH) were tested in healthy Chinese female volunteers aged 18 to 80 years residing in the Taipei urban area. The results showed no significant change with aging in the 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)2D) and immunoreactive c-terminal PTH (i-cPTH) serum levels. However, there was a trend towards lower 25(OH)D levels at the two extremes of age. The serum levels of 1,25(OH)2D and i-cPTH were comparable with reports of other countries. The serum 25(OH)D levels of our subjects were in general lower than those reported in U.S. white women, but similar to those of European women. The serum osteocalcin levels showed a triphasic change: high in early adulthood, decreasing during the 4th decade of life and then increasing continuously until age 70. After age 70, a decreasing trend was again seen. The serum ALP levels showed a continuous increase from the 3rd to the 8th decade of life. All of the subjects had their bone mineral density (BMD) measured. Linear or polynominal regression analysis as well as multiple regression analysis failed to show a significant correlation between the serum parameters and the BMD measurements at various sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Refined crystal structures of "aged" and "non-aged" organophosphoryl conjugates of gamma-chymotrypsin

"Aged" organophosphoryl conjugates of serine hydrolases differ from the corresponding "non-aged" conjugates in their striking resistance to nucleophilic reactivation. The refined X-ray structures of "aged" and "non-aged" organophosphoryl conjugates of gamma-chymotrypsin were compared in order to understand the molecular basis for this resistance of "aged" conjugates. "Aged" and "non-aged" crystalline organophosphoryl-gamma-chymotrypsin conjugates were obtained by prolonged soaking of native gamma-chymotrypsin crystals with appropriate organophosphates. Thus, a representative "non-aged" conjugate, diethylphosphoryl-gamma-chymotrypsin, was obtained by soaking native crystals with paraoxon (diethyl-p-nitrophenyl phosphate), and a closely related "aged" conjugate, monoisopropyl-gamma-chymotrypsin, was obtained by soaking with diisopropylphosphorofluoridate. In both crystalline conjugates, the refined structures clearly reveal a high occupancy of the active site by the appropriate organophosphoryl moiety within covalent bonding distance of Ser195 O gamma. Whereas in the "non-aged" conjugate both ethyl groups can be visualized clearly, in the putative "aged" conjugate, as expected, only one isopropyl group is present. There is virtually no difference between the "aged" and "non-aged" conjugates either with respect to the conformation of the polypeptide backbone as a whole or with respect to the positioning of the side-chains within the active site. In the "aged" conjugate, however, close proximity (2.6 A) of the negatively charged phosphate oxygen atom of the dealkylated organophosphoryl group to His57 N epsilon 2 indicates the presence of a salt bridge between these two moieties. In contrast, in the "non-aged" conjugate the DEP moiety retains its two alkyl groups; thus, lacking a negative oxygen atom, it does not enter into such a charge-charge interaction and its nearest oxygen atom is 3.6 A away from His57 N epsilon 2. It is suggested that steric constraints imposed by the salt bridge in the "aged" conjugate lie at the basis of its resistance to reactivation.

Gamma-chymotrypsin is a complex of alpha-chymotrypsin with its own autolysis products

The determination of three separate gamma-chymotrypsin structures at different temperatures and resolutions confirmed the presence of electron density in the active site, which could be interpreted as an oligopeptide as had previously been suggested by Dixon and Matthews [(1989) Biochemistry 28, 7033-7038]. HPLC analyses of the enzyme before and after crystallization demonstrated the presence of a wide variety of oligopeptides in the redissolved crystal, most with COOH-terminal aromatic residues, as expected of the products of chymotrypsin cleavage, which appeared to arise from extensive autolysis of the enzyme under the crystallization conditions. The refined structures agree well with the conformation of both gamma-chymotrypsin and alpha-chymotrypsin. The electron density in the active site is thus interpreted as arising from a repertoire of autolysed oligopeptides produced concomitantly with crystallization. The COOH-terminal carbons of the polypeptide(s) display short contact distances (1.97, 2.47, and 2.13 A, respectively) to Ser195 O gamma in all three refined structures, but the electron density is not continuous between these two atoms in any of them. This suggests that some sequences are covalently bound as enzyme intermediates while others are noncovalently bound as enzyme-product complexes.

Decreased bone mineral density in patients with prolonged thyrotoxicosis before and after treatment

To investigate the effects of prolonged thyrotoxicosis, we measured the bone mineral densities (BMD) of 24 untreated patients who had suffered from symptoms of thyrotoxicosis for at least 1 year. We also recruited 116 healthy Chinese women residing in the Taipei area as normal controls. The BMDs of these 24 patients for the whole body skeleton, lumbar spine, femoral neck, greater trochanter and Ward's triangle were all significantly lower than those of normal controls (one sample t-test, two-tailed alternative). Older patients had lower absolute values and a trend towards more severe bone loss, which was most significant at the femoral trochanter and Ward's triangle (p less than or equal to 0.05). The decrease in BMD was more pronounced in the vertebral bodies than in the proximal femur for all patients, implying predominantly trabecular bone loss in this disease. The BMDs of 10 patients were reevaluated 1 year after successful medical treatment. These 10 patients had remained euthyroid for 1 year with antithyroid drugs and showed a small, but significant, improvement in their BMDs at the lumbar spine and the proximal femur on reevaluation. However, the recovery was far from complete. Our findings suggest that thyrotoxicosis causes a remarkable loss of bone mineral, which cannot be compensated for after 1 year of successful treatment. Thus, early diagnosis and therapeutic intervention are important for preventing osteoporotic fractures, especially in elderly patients.

Reduced hypothalamic blood flow after radiation treatment of nasopharyngeal cancer: SPECT studies in 34 patients

To determine the effect of cranial irradiation on hypothalamic blood flow, we performed 44 regional cerebral blood flow studies with 99mTc hexamethyl propyleneamine oxime (HMPAO) single-photon emission CT (SPECT) on four normal volunteers and 34 patients with pathologically proved nasopharyngeal cancer. Twenty-three men and 15 women, 30-65 years old, were divided into four study groups: group 1 served as a control and consisted of four normal volunteers and six patients studied prior to cranial irradiation; group 2 patients had cranial irradiation half a year before the SPECT study (n = 12, one from group 1); group 3 patients were irradiated 1 year before the study (n = 13, three from group 1 and two from group 2); and group 4 patients were irradiated at least 5 years before SPECT imaging (n = 9). Six patients were studied twice. Quantification of the 99mTc-HMPAO brain SPECT studies was done separately by three radiologists to obtain the hypothalamus/occipital (H/O) and hypothalamus/parasagittal (H/P) ratios. Endocrinologic studies were performed in all cases and the hypothalamus-thyrotroph-thyroid, hypothalamus-gonadotroph-testis (ovary), hypothalamus-lactotroph, hypothalamus-somatotroph, and hypothalamus-corticotroph-adrenal axes were evaluated separately. We determined that regional hypothalamic blood flow was reduced after cranial irradiation in patients with nasopharyngeal cancer. The H/O ratio of groups 3 and 4 did not differ from that of group 2 (one-half year after cranial irradiation). The H/O ratio was significantly reduced 6 months and 1 year after cranial irradiation; mean +/- SD = 0.5801 +/- 0.0829 (p less than .025), 0.5725 +/- 0.0791 (p less than .01) versus 0.6477 +/- 0.0458 before cranial irradiation, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of atretic prolonged obstructive jaundice; technetium 99m hepatolite excretion study

Since 1982 we have developed a diagnostic method for differentiation between atretic prolonged obstructive jaundice (biliary atresia) and nonatretic prolonged obstructive jaundice in a neonate. The first report was presented at the Fukuoka Meeting in 1983. Analysis of duodenal juice (excretion test of intravenous injected hepatolite into the duodenum) has proved to be extremely reliable to differentiate biliary atresia from nonatretic prolonged obstructive jaundice. The major diagnostic features of the study are (1) biliary tract to bowel transit of radiotracer, and (2) observation on color of duodenal juice. Diagnostic accuracy was 98.4%. It is time-saving, requiring only 6 hours, noninvasive, and simple.

Combined femoral pseudoaneurysm and arteriovenous fistula: diagnosis by Doppler color flow mapping

This case report is the first to describe a combined femoral pseudoaneurysm and arteriovenous fistula resulting from a cardiac catheterization, diagnosed by color Doppler.

Medical dissolution of gallstones by ursodeoxycholic acid: a clinical trial on 14 patients

Fourteen patients with radiolucent gallstones proved by oral cholecystography (OC) and ultrasonography were treated with daily doses of 600 mg of ursodeoxycholic acid (UDCA) for one year. Among them, 2 patients had complete dissolution of gallstones and another one had partial dissolution. The success rate was 21.4% (3/14). Of the remaining 11 patients who failed to respond to UDCA treatment, calcifications of varied degrees were demonstrated in every gallstone by computed tomography (CT). None of these 14 patients had statistically significant changes in serum lipids, liver function tests and hemograms during the course of treatment and only one (7.1%) patient had transient diarrhea. It was concluded that UDCA was effective and safe for medical dissolution of non-calcified gallstones. However, the underestimation of the calcification of gallstones by OC precluded successful medical dissolution by UDCA. Therefore, meticulous selection of non-calcified gallstones by CT rather than OC as candidates for dissolution may improve the success rate.

Imaging of experimental arterial thrombi with iodine-131-labeled fibrin-specific monoclonal antibody

The applicability of anti-fibrin monoclonal antibody in detecting intra-circulatory blood clots was studied in 17 dogs in two groups: 13 dogs in the study group and 4 dogs in the control group. In the study group, dogs were punctured at the femoral artery and a thrombogenic coil was injected percutaneously to the iliac artery to induce blood clot. After 30 minutes, a dose of I-131 labeled anti-fibrin monoclonal antibody-3E6 (84-280 microCi) was injected intravenously. The dogs were imaged with a scinticamera at 6, 24 and 48 hours after antibody injection. In the control group, 3 dogs were studied with the same procedure but the I-131 labeled anti-fibrin monoclonal antibody was replaced with an I-131 labeled irrelevant monoclonal antibody. The remaining 1 dog for control was punctured and was injected with I-131 labeled anti-fibrin monoclonal antibody but no coil injection was performed. In the study group, 11 out of 13 dogs (85%) showed clot visualization at either 6 hours (4 dogs) or 24 hours (7 dogs) after anti-fibrin monoclonal antibody injection. There was no false positive results for the 4 dogs in the control group. Our studies showed that radiolabeled anti-fibrin monoclonal antibody may be a potential tool for noninvasive detection of intravascular blood clots.

Intratumor injection of absolute ethanol under ultrasound guidance for the treatment of small hepatocellular carcinoma

For the treatment of small hepatocellular carcinoma, intratumor injection of absolute ethanol under ultrasound guidance was performed in 27 tumors in 23 patients, with a tumor diameter of between 1.0 and 3.3 cm. The initially elevated serum alpha-fetoprotein levels in 15 patients decreased during treatment, with 13 returning to normal after this regimen. In the 6 patients who finally received surgical resection, 4 had complete necrosis of the tumor, while the other 2 had a small peripheral residual cancer nest. In the remaining non-resected 17 cases, follow-up CT, multiple biopsies and angiography revealed evidence of viable tumor in only 3 cases. After additional ethanol injections, these 3 cases were successfully treated. Inhomogeneous distribution of the injected ethanol and difficulty in identifying the tumor after previous injections accounted for the incomplete necrosis of the tumor. To cope with these problems, a steel coil was implanted in the tumor before treatment, and a needle with multiple side holes was used in the last 3 cases, with satisfactory results. Ethanol injection is promising and may even be curative in the treatment of small hepatocellular carcinoma.

Small hepatocellular carcinoma: intratumor ethanol treatment using new needle and guidance systems

Intratumor injection of absolute ethanol to treat small hepatocellular carcinoma sometimes results in incomplete necrosis of the tumor. Causes of this include inhomogeneous distribution of the ethanol and difficulty in identifying the tumor after previous ethanol injections. To solve these problems, the authors designed a multiple-side-hole needle for ethanol injection and implanted one or more small steel coils into the tumor before treatment to serve as a landmark. Six patients thus treated all showed adequate necrosis on follow-up computed tomography, biopsy, and angiography studies; initially elevated serum alpha-fetoprotein levels present in five patients were decreased. A resected surgical specimen obtained in one patient showed extensive necrosis of the tumor as well as of the surrounding healthy liver; only a small locus of equivocally viable cancer cells remained in the tumor margin.

Kinetic studies and structure-activity relationships of bispyridinium oximes as reactivators of acetylcholinesterase inhibited by organophosphorus compounds

The kinetics of the reactivation of acetylcholinesterase inhibited by isopropyl methylphosphonofluoridate was studied. The reactivators used include nine bispyridinium monooximes and three bispyridinium dioximes. The dissociation constant (Kd) and the rate constant (k2) of dephosphorylation of the complex formed from the organophosphorus acetylcholinesterase (OP-AChE) and the oxime were measured. The reactivation parameters obtained from the in vitro kinetic studies were used to elucidate the structure-activity relationships. The hydrophobic property of a nonoxime substituent at the 3-position on the pyridinium ring can exert a positive effect on their binding affinity to OP-AChE. However, the rate constants (k2) of the nucleophilic displacement of OP-AChE by oximes depend negatively on these physical and structural factors of the oximes. The correlations of the in vivo antidotal efficacy (ED50) of these bispyridinium oximes have been analyzed with their pharmacological properties, e.g., reactivation potency, antimuscarinic activities, and antinicotinic activities. However, no satisfactory correlations were observed. It may be concluded that the detoxication mechanism of poisoning by isopropyl methylphosphonofluoridate is different from those of pinacolyl methylphosphonofluoridate and paraoxon.

Mechanisms of global support and posttraumatic enophthalmos: I. The anatomy of the ligament sling and its relation to intramuscular cone orbital fat

The mechanisms of posttraumatic enophthalmos were evaluated to determine the interrelation between fat and ligaments in globe support. Anatomic studies demonstrate that the ligaments form an essential "sling" framework for the globe but are alone insufficient to maintain the globe's full forward position. Removal of extramuscular fat in cadavers and in patients undergoing blepharoplasty did not significantly change globe position. Loss of intramuscular cone fat (atrophy or displacement) in cadavers and patients produced enophthalmos. Fat atrophy is not a prominent feature in most patients with posttraumatic enophthalmos. Some loss of intramuscular cone fat from displacement outside the muscle cone is frequently present. The principal mechanism, however, of posttraumatic enophthalmos involves a displacement and change in the shape of orbital soft tissue. Loss of bone and ligament support permits posterior displacement and a reshaping of orbital soft tissue under the influence of gravity and the remodeling forces of fibrous scar contracture. The shape of the retrobulbar orbital contents changes from a modified cone to a sphere, and the globe sinks backward and downward. Given that the volume of orbital soft tissue is constant following trauma, procedures to restore the shape and position of the orbital soft tissue by mobilization and bone reconstruction will correct or significantly improve enophthalmos.

Right ventricular ejection fraction. Validation of first-pass radionuclide studies by contrast angiography

The accuracy of first-pass radionuclide angiocardiography (FPRNA) in the assessment of right ventricular ejection fraction (RVEF) using a multicrystal scintillation camera in the right anterior oblique view has not been reported. To test the validity of this technique, RVEFs derived from first-pass time-activity curves with and without background correction were compared with those obtained from contrast ventriculography in 36 patients. Background regions-of-interest tested included tricuspid valve, free wall, and horseshoe-shaped approaches. The tricuspid valve approach yielded a mean RVEF of 0.485 +/- 0.100 (SD) which slightly underestimated the contrast mean value (0.553 +/- 0.099, p less than 0.05) but correlated well (r = 0.88). The horseshoe approach yielded a mean value of 0.548 +/- 0.100 which approximated the contrast mean value and also correlated well (r = 0.81). The free wall approach yielded a mean of 0.502 +/- 0.095 which did not differ from contrast data (p greater than 0.05) but correlated less well (r = 0.77). With the method without background correction, a much lower mean value (0.387 +/- 0.081, p less than 0.01) and less correlation (r = 0.77) were obtained. Thus, FPRNA using a multicrystal camera in the right anterior oblique view is a reliable technique for measuring RVEF when a tricuspid valve or horseshoe-shaped background approach is employed, but is less accurate if the time-activity curve without background correction is applied.

Ultrasonography of small hepatic tumors using high-resolution linear-array real-time instruments

Abdominal ultrasonography using a high-resolution linear-array real-time scanner was compared to computed tomography, celiac arteriography, and radionuclide imaging in 24 patients with a total of 33 hepatocellular carcinomas (HCC), 10 patients with cavernous hemangioma (12 tumors), and 2 patients with metastatic carcinoma of the liver (3 tumors), all smaller than 3 cm. Ultrasound proved to be the most sensitive method of detecting such small tumors. Most small HCCs were hypoechoic and most small hemangiomas hyperechoic. Aspiration cytology and/or biopsy under ultrasound guidance detected 92.3% of HCCs and 100% of hemangiomas. Intraoperative ultrasound was employed in 19 cases of small HCC and aided resection in 8. Real-time ultrasound may play a prominent role in early detection and diagnosis of small HCCs.

Sagittal fractures of the maxilla and palate

Sagittal fractures of the maxilla and palate are infrequent and can demonstrate significant instability with conventional methods of treatment. They require that rigid, horizontal stability of the dentition be obtained, as well as restoration of midface projection and height. The most effective and precise management has utilized a combination of open reduction and internal fixation at the piriform aperture and zygomatic buttress and posterior palate, use of a maxillary arch bar as a tension band, and utilization of a palatal splint.