The effect of contrast dose,imaging time,and lesion size in the MR detection of intracerebral metastasis.

PURPOSETo evaluate the effect of MR contrast dose versus delayed imaging time on the detection of metastatic brain lesions based on lesion size.METHODSContrast MR examinations with gadoteridol were obtained in 45 patients with brain metastases. The patients were divided into two groups: 16 received cumulative standard dose (0.1 mmol/kg) and 29 received cumulative triple dose (0.3 mmol/kg). Both groups were evaluated at two dose levels (lower dose and higher dose) with two separate injections. Each patient received an initial bolus injection of either 0.05 (cumulative standard dose) or 0.1 (cumulative triple dose) mmol/kg of gadoteridol to reach the lower-dose level and underwent imaging immediately and 10 and 20 minutes later. Thirty minutes after injection, an additional bolus injection of 0.05 (cumulative standard dose) or 0.2 (cumulative triple dose) mmol/kg was administered to reach the cumulative higher-dose level (cumulative standard dose, 0.1 mmol/kg; cumulative triple dose, 0.3 mmol). Images were acquired immediately.RESULTSThere was no difference in the detection rate for lesions larger than 10 mm among T2-weighted, lower-dose immediate and delayed, or immediate higher-dose images in both study groups. Lesions smaller than 10 mm had improved detection with delayed imaging in both study groups; however, the immediate higher-dose studies still had the highest detection rate.CONCLUSIONIn the evaluation of small central nervous system metastases, either delayed imaging after the injection of standard contrast dose or higher contrast dose may improve their detection, and therefore affect clinical management. Higher contrast dose (cumulative triple dose) studies appear to be more effective than delayed imaging with standard dose.     

Magnetic resonance imaging in young adults with cerebral infarction due to moyamoya

The number, size, and location of cerebral infarctions, and blood flow in the middle cerebral artery as seen on proton magnetic resonance imaging were assessed in six white adults with angiographically documented moyamoya. Findings were correlated with clinical presentation, computed tomography, and angiography. Large hemispheric infarctions were found in five hemispheres, predominantly in watershed regions. Subcortical infarctions (n = 56) were found in all hemispheres. They were predominantly located in the centrum semiovale, in the distal beds of supply of the penetrating branches of the anterior and middle cerebral arteries. Infarction of the putamen was found in three hemispheres, caudate nucleus in four, globus pallidus in two, and anterior limb of the internal capsule in two. There were none in the posterior limb of the internal capsule, thalamus, brain stem, or cerebellum. Middle cerebral artery flow was visualized as a signal-void flow sign in only three hemispheres. Cerebral infarctions due to moyamoya are bilateral, multiple, often small, and asymptomatic, affecting predominantly the carotid circulation in watershed regions. Subcortical infarctions in the centrum semiovale and large hemispheric infarctions in hemodynamically compromised areas are the predominant findings.     

Experience with high-dose gadolinium MR imaging in the evaluation of brain metastases.

PURPOSE: To assess the effectiveness and safety of higher doses of gadoteridol in the MR evaluation of patients with brain metastases. MATERIALS AND METHODS: Thirty-one patients with a clinical suspicion of brain metastases were studied prospectively with gadoteridol, a new, nonionic, low-osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg and an additional dose of 0.2 mmol/kg 30 minutes later. Images were obtained before, immediately after, and 10 and 20 minutes after the initial dose. Images also were acquired immediately after the additional dose of gadoteridol. RESULTS: No adverse effects were attributed to the injection of gadoteridol. Four patients' examinations were excluded from analysis because of machine malfunction (two patients) and excessive motion artifact (two patients). Four patients had no detectable metastases. After the additional dose of gadoteridol, there was a marked qualitative improvement in lesion conspicuity and detection. The conspicuity of 80 of 81 lesions was increased in the high-dose studies, and 46 new lesions were detected in 19 of 27 patients. Quantitative image analysis demonstrated a significant increase in normalized mean lesion contrast between the initial-dose and high-dose studies (35 lesions identified in 13 patients, P less than .0001). The additional information gained by high-dose examinations contributed to a potential modification of the treatment in 10 of 27 patients. High-dose examinations increased flow-related artifact in the posterior fossa in 12 of 27 patients. CONCLUSION: Based on our preliminary results, high-dose gadolinium-enhanced MR examinations may have advantages over 0.1 mmol/kg examinations in detecting early and/or small metastases. This may be significant in the management of patients with cerebral metastases.     

Chromosomal screening of mentally retarded school children in Taipei.

The major concern of the national population policy in Taiwan in recent years has been to lower the incidence of hereditary diseases and mental retardation in the general population. It has been estimated that there are around 10,000 mentally retarded school children in Taiwan. If effective chromosomal screening can be extended to these children, some of the family members who are carriers of balanced chromosomal rearrangements may benefit from follow-up studies and genetic counseling. The present report is the result of a pilot study conducted from 1988 to 1991 to explore the possibility of chromosomal screening of mentally retarded school children in Taipei. A total of 871 blood samples were collected from 1,147 children registered in 46 schools or residing in homes for the retarded. Chromosomal analysis was successfully accomplished on 674 out of 871 blood samples. The following chromosomal abnormalities were observed: 28 Down's syndrome, four Klinefelter syndrome, one XYY, one triple X, 11 translocations, seven inversions, four mosaics, three duplications, one deletion and one with an extra marker chromosome. After follow-up cytogenetic analyses of 13 families with probands with structural chromosomal anomalies, three of these families were shown to have one or two carriers of balanced translocated chromosomes. It seems that the present screening system would not be practical or cost-effective if it were applied island-wide in the future.     

Ultrastructural,histochemical, and freeze-fracture evaluation of multilamellated structures in human pulmonary alveolar proteinosis

Ultrastructural, histochemical, and freeze-fracture studies of material recovered by bron-choalveolar lavage from patients with pulmonary alveolar proteinosis revealed four types (A, B, C, and D) of multilamellated structures (MS). Type A, the major component, consisted of concentric, trilaminar structures which were composed of two electron-dense layers and a central lucent layer (5.7–7.5 nm in overall width) alternating with wider (25–30 nm) electron-lucent intervening layers. Type B MS were formed by concentric lamellae with a 5–5.3-nm periodicity. Type C MS were composed of wavy, electron-dense lamellae with a 4–4.5-nm periodicity. Type D MS were conglomerated masses of intricately arranged double or triple electron-dense layers (7.5–13.5 nm wide) alternating with wider (30–40-nm) electron-lucent layers. The electron-dense lamellae of type A, type C, and type D MS were stained with ruthenium red, the Thiéry method, and concanavalin A, indicating the presence of carbohydrate components. Freeze-fracture studies revealed smooth inner and outer surfaces in type A MS, with the fracture planes passing through the central parts of the trilaminar structures; the intervening layers contained 10-nm particles, which probably are proteins. Type B MS had smooth surfaces, and type C MS had slightly particulate surfaces; while type D MS showed tubular or polygonal structures, 350 nm wide, with rows of particles 7–8 nm in diameter. It is concluded that type A and type D MS contain proteins and carbohydrates, probably in the form of glycoproteins, as well as phos-pholipids, and are related to tubular myelin. Type B and type C MS are considered to contain mainly phos-pholipids; type C MS are also considered to contain carbohydrates and to be related to lamellar bodies of type II alveolar epithelial cells.     

Existence of a small population of IL-2Rβhi TCRint cells in SCG and MRL-lpr/lpr mice which produce normal Fas mRNA and Fas molecules from the lpr gene

Mice carrying the lpr gene, SCG and MRL-lpr/lpr mice, were used to characterize the phenotype and lpr gene of abnormally proliferating T cells in these mice. A major population which expanded in these mice were T cells expressing intermediate (int) levels of T cell receptor (TCR) (and CD3) and the phenotype of interleukin-2 receptor (IL-2R)β^lo α^? (possibly abnormal TCR^int cells). The levels of TCR^hi cells of thymic origin (generated through the mainstream of T cell differentiation in the thymus) profoundly decreased after the onset of disease. However, a small population of normal TCR^int cells (i.e. IL-2Rβ^hi α^?) were also found to exist in all tested organs. For example, the majority of abnormal IL-2Rβ^lo TCR^int cells were CD4^?8^? CD2^?, while normal IL-2Rβ^hi TCR^int cells were a mixture of single-positive cells (mainly CD8⁺), CD4^?8^? cells and CD2⁺ cells. Moreover, normal TCR^int cells preferentially produced normal Fas mRNA and Fas molecules from the lpr gene. This phenomenon explains the leaky appearance of normal Fas mRNA and Fas molecules in mice carrying the lpr gene. It is suggested that a small population of IL-2Rβ^hiTCR^int cells are resistant to the lpr genetic abnormality.     

Do we talk to different people in different ways?: types and sources of social support and support-gaining strategies

The present paper examined whether people employ different support-gaining strategies toward various sources of support. In Study 1, 231 Taiwanese undergraduates were asked the frequency of each strategy they used for three support types: tangible, psychological, and informational, from four support sources: parents, professors, same-sex close friends, and same-sex acquaintances. In Study 2, 363 undergraduates were asked to think of an opposite-sex friend: an acquaintance, a close friend, or romantic partner, and write the frequency of each strategy they used. Results of ANOVA indicated that main effects of source and strategy and a three-way interaction of source by strategy by gender were significant. In Study 1, the students used various strategies most frequently toward parents and same-sex close friends, and least frequently to professors, and in Study 2, more frequently to close friends and romantic partners than to acquaintances. The strategy most often used was reasoning, followed by entreaty, roundabout request, exploitation, promise of reward, exhortation, and threat, in the descending order. No effect was found for the support type factor.     

EXPERIMENTAL MESANGIOPROLIFERATIVE GLOMERULONEPHRITIS IN RATS INDUCED BY INTRAVENOUS ADMINISTRATION OF ANTI-THYMOCYTE SERUM

Focal glomerulonephritis was induced in rats, by a single intravenous injection of anti-Thy-1.1 antibody (ATS). One hour after the administration, the glomeruli of affected rats developed necrotic changes of the mesangial cells while after two hours, mesangiolytic changes appeared. From six days onwards, focal segmental mesangial proliferation which persisted until 30 days, occurred. This is thought to be the first report of experimental nephritis induced by pure anti-mesangial antibody.     

Characteristics affecting cervical sagittal alignment in patients with chronic low back pain

BackgroundSagittal spino-pelvic malalignment in patients with chronic low back pain (CLBP) have been reported in the past, which may also affect cervical spine lesions. The purpose of this study is to investigate the cervical alignment in patients with CLBP.MethodOf the patients who visited an orthopedic specialist due to low back pain lasting more than three months, 121 cases (average 71.5-years-old, 46 male and 75 female) with whole standing spinal screening radiographs were reviewed (CLBP group). Cervical parameters included cervical lordosis (CL), C2–C7 sagittal vertical axis (C2-7 SVA), and the T1 slope minus CL (T1S-CL). Cervical spine deformity was defined as C2-7 SVA >4 cm, CL <0°, or T1S-CL ≧20°. We compared the cervical alignment of these patients with 121 age and gender matched volunteers (control group).ResultsThe prevalence of cervical spine deformity was significantly higher in the CLBP group than in the control group (20.7% vs. 10.7%, P = 0.034). The mean CL was smaller in the CLBP group than in the control group (16.1° vs. 21.4°, P = 0.002). The mean C2-7 SVA was 17.6 mm vs. 18.7 mm in the CLBP group and in the control group, respectively (P = 0.817). The mean T1S-CL was larger in the CLBP group than in the control group (9.1° vs. 3.5°, P < 0.001). Multivariate analysis showed that people with CLBP were more likely to have cervical deformities than people without CLBP (odds ratio 2.16, 95% confidence interval 1.006 to 4.637).ConclusionsThis study results suggest that people with CLBP present with worse cervical sagittal alignment and higher prevalence of cervical spine deformities than age and gender matched volunteers with no CLBP. This means CLBP impacts cervical spine lesions negatively.Level of evidenceⅣ