Diffusion-weighted imaging in Wallerian degeneration

We report two patients displaying hyperintensities on diffusion-weighted imaging (DWI) in the area of Wallerian degeneration (WD) at 12 days after stroke. High signal intensities were more conspicuous on DWI than on T2-weighted images. Both patients showed decreased diffusion anisotropy resulting in elevated apparent diffusion coefficient in the area of WD. These patients illustrate that DWI may be useful in the detection of the early stage of WD.

Distribution of HLA-A, -B and -DRB1 alleles in patients with sudden sensorineural hearing loss

This study was performed to investigate the association between human leukocyte antigen (HLA) and susceptibility to sudden sensorineural hearing loss in the Korean population. HLA-A and HLA-B typing using a standard microlymphocytotoxicity technique and HLA-DRB1 genotyping were performed in 35 patients with sudden sensorineural hearing loss and in 206 healthy controls. Prednisone (usual dose 60 mg/day) was administered for 6 days and tapered for an additional 4-6 days. Both initial hearing levels at the onset of deafness and final hearing levels after treatment were examined and evaluated for association with HLA alleles. The frequency of HLA-DRB1*14 was increased in patients with sudden sensorineural hearing loss compared with controls (relative risk [RR] = 2.7, p = 0.016). The frequencies of HLA-A2, -A31, -B52, -B61, -DRB1*04, -DRB1*11 and -DRB1*12 were slightly higher than in the controls, but did not reach statistical significance. When an association between the treatment results and HLA alleles was also evaluated, the frequency of HLA-DRB1*04 was found to be increased in the patients who did not respond to steroid treatment compared with both patients who responded well to steroid (50%, vs 16%, p = 0.034) and controls (RR = 3.0, p = 0.046). These results suggest that there is an association between HLA-DRB1*14 and disease susceptibility and that the presence of HLA-DRB1*04 may be an useful marker for predicting a poor prognosis in Korean patients with sudden sensorineural hearing loss.

Neuronal metabolic changes in the cortical region after subcortical infarction: a proton MR spectroscopy study

OBJECTIVES

To investigate whether proton magnetic resonance spectroscopy ((1)H MRS) can detect neuronal metabolic changes in the cortical region in patients with cortical dysfunction after subcortical infarction.

METHODS

Fifteen patients with subcortical large (diameter>/=20 mm) infarcts were studied; nine patients with cortical dysfunction (group A), and six without (group B). Seven patients with lacunar infarction served as controls. Infarct volume was measured on T2 weighted images with an image analyser. (1)H MRS data were obtained in three regions; high signal intensity area on T2 weighted image, overlying cortex with a normal T2 MRI appearance, and contralateral homologous cortical region.

RESULTS

Infarct volume was not different between groups A and B. N-acetylaspartate (NAA)/creatine+phosphocreatine (Cr) ratios in the cortical region overlying subcortical infarcts in group A were significantly lower than those in group B and the control group (p=0.002). The NAA/Cr ratios in the overlying cortex were significantly lower than those in the contralateral normal cortex in group A on the initial (p=0. 015) and follow up (p=0.028) (1)H MRS, but these differences were not found in group B and the control group.

CONCLUSIONS

The results support the idea that the cerebral cortex is a responsible location for cortical dysfunction after subcortical infarctions. (1)H MRS can be used as a sensitive method for the detection of a neuronal metabolic damage, which is not demonstrated by conventional MRI.

Anti-aging effects of the traditional Chinese medicine bu-zhong-yi-qi-tang in mice

Among the "alternative medicines," which may ably supplement modern Western medicine in the treatment of certain diseases, the holistic approach and mild nature of the majority of Traditional Chinese Medicine (TCM) may make it particularly suitable for the treatment of diseases associated with old age, as the general health of elderly patients is already compromised. The TCM formulation of bu-zhong-yi-qi-tang (B.Z.Y.Q.T.), prescribed mainly for the improvement of circulation and in particular that to the gastroenteric regions, may have anti-aging effects. In the present study, possible anti-aging effects of B.Z.Y.Q.T. were studied using normal (ICR) mice and the Dull, P/8 and R/1 strains of the Senescence Accelerated Mouse (S.A.M.). Following repeated oral administrations of B.Z.Y.Q.T. at 250 and 500 mg/kg the test mice were assessed for (1) endurance (2) learning and memory (3) neuromuscular coordination and (4) changes in the levels of monoamines in the brain. The results indicated that B.Z.Y.Q.T. improved endurance in all strains in a dose-dependent manner. At the higher dose of 500 mg/kg, it improved memory in the R/1 and P/8 S.A.M. mice. In prolonged rota-rod tests, which assessed both motor coordination and endurance, B.Z.Y.Q.T. significantly improved performance in the P/8 S.A.M. mice. Elevated dopamine and noradrenaline were observed in cortical tissues of the S.A.M./Dull and ICR mice respectively with the high dose of 500 mg/Kg, B.Z.Y.Q.T. Taken together, the results indicated that B.Z.Y.Q.T. appeared to exert anti-aging effects in mice and elevation in certain monoamines in brain cortical tissues. How and whether the monoamines changes after B.Z.Y.Q.T. treatment might be related to the behavioral effects await further investigation.

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Dynamic contrast-enhanced MR imaging of bacterial abscess and VX2 carcinoma in rabbits: comparison of gadopentetate dimeglumine and a macromolecular contrast agent

OBJECTIVE

The objective of this study was to compare enhancement patterns of a blood-pool contrast agent, Gadomer-17, with those of gadopentetate dimeglumine in bacterial abscesses and VX2 carcinoma in rabbits.

MATERIALS AND METHODS

Fourteen rabbits with experimentally induced bacterial abscesses and VX2 carcinoma in both thighs underwent dynamic contrast-enhanced MR imaging with Gadomer-17 and gadopentetate dimeglumine at a 24-hr interval. The enhancement ratios (postcontrast to precontrast signal intensities) of lesions in the same animal were assessed and correlated with microvessel density.

RESULTS

For Gadomer-17, the enhancement ratio of the abscesses (1.66 +/- 0.39) peaked 15 min after the injection, while that of the carcinoma (2.05 +/- 0.16) peaked at 10 min. The enhancement ratios of the carcinoma were consistently higher than those of the abscesses up to 30 min. For gadopentetate dimeglumine, peak enhancement ratio of the abscesses (2.30 +/- 0.75) was seen 5 min after the injection, while that of the carcinoma (2.32 +/- 0.51) was seen at 3 min. The enhancement ratios of the carcinomas were significantly higher at 1 min, but significantly lower at 20-30 min, compared with those of the abscesses, as a result of rapid decrease of enhancement ratios in the carcinomas. The microvessel density was 9.8 +/- 5.2 vessels per field of view for the abscesses and 36.3 +/- 9.5 vessels per field of view for the carcinoma (p < 0.001).

CONCLUSION

Delayed peak enhancement and slow decay were found in both bacterial abscess and VX2 carcinoma with Gadomer-17, whereas early peak enhancement and rapid decay were found especially in VX2 carcinoma with gadopentetate dimeglumine. Enhancement ratios on MR imaging with a blood-pool contrast agent correlated well with the microvessel density in bacterial abscess and VX2 carcinoma.

Neck infection associated with pyriform sinus fistula: imaging findings

BACKGROUND AND PURPOSE

Acute suppurative neck infections associated with branchial fistulas are frequently recurrent. In this study, we describe the imaging findings of acute suppurative infection of the neck caused by a third or fourth branchial fistula (pyriform sinus fistula).

METHODS

Imaging findings were reviewed in 17 patients (11 female and six male patients, 2 to 49 years old) with neck infection associated with pyriform sinus fistula. Surgery or laryngoscopic examination confirmed the diagnoses. Fourteen patients had a history of recurrent neck infection and seven had cutaneous openings on the anterior portion of the neck (all lesions were on the left side). Imaging studies included barium esophagography (n = 16), CT (n = 14), MR imaging (n = 2), and sonography (n = 3).

RESULTS

A sinus or fistulous tract was identified in eight of 16 patients on barium esophagograms. In 14 patients, CT studies showed the inflammatory infiltration and/or abscess formation along the course of the sinus or fistulous tract from the pyriform fossa to the thyroid gland. In nine patients, CT scans showed the entire course or a part of the sinus or fistulous tract as a tiny spot containing air. MR images showed a sinus or fistulous tract in two patients, whereas sonograms could not depict a sinus or fistulous tract in three patients. All 17 patients were treated with antibiotics. In one patient, the sinus tract was surgically excised, while 15 patients underwent chemocauterization of the sinus or fistulous tract with good outcome. Follow-up was possible for 16 of the 17 patients.

CONCLUSION

When an inflammatory infiltration or abscess is present between the pyriform fossa and the thyroid bed in the lower left part of the neck, an infected third or fourth branchial fistula should be strongly suspected.

Development of DNA delivery system using Pseudomonas exotoxin A and a DNA binding region of human DNA topoisomerase I

Gene therapy is defined as the delivery of a functional gene for expression in somatic tissues with the intent to cure a disease. Thus, highly efficient gene transfer is essential for gene therapy. Receptor-mediated gene delivery can offer high efficiency in gene transfer, but several technical difficulties need to be solved. In this study, we first examined the DNA binding regions of the human DNA topoisomerase I (Topo I), using agarose gel mobility shift assay, in order to identify sites of noncovalent binding of human DNA Topo I to plasmid DNA. We identified four DNA binding regions in human DNA Topo I. They resided in aa 51-200, 271-375, 422-596, and 651-696 of the human DNA Topo I. We then used one of the four regions as a DNA binding protein fragment in the construction of a DNA delivery vehicle. Based on the known functional property of each Pseudomonas exotoxin A (PE) domain and human DNA Topo I, we fused the receptor binding and membrane translocation domains of PE with a highly positively charged DNA binding region of the N-terminal 198 amino acid residues of human DNA Topo I. The resulting recombinant protein was examined for DNA binding in vitro and transfer efficiency in cultured cells. The results show that this DNA delivery protein is a general DNA delivery vehicle without DNA sequence, topology, and cell-type specificity. The DNA delivery protein could be used to target genes of interest into cells for genetic and biochemical studies. Therefore, this technique can potentially be applied to cancer gene therapy.

Therapeutic dilemmas in the management of thyroid cancer with laryngotracheal involvement

Invasion of the larynx and trachea by thyroid cancer is an uncommon but difficult problem. There is no consensus on indication for or extent of surgery, particularly when there is a requirement for airway reconstruction. From 1989 through 1996, we treated 22 patients with thyroid carcinoma with invasion of the larynx and trachea. Seventeen of these patients had recurrent disease. We applied radioactive iodine therapy after regional ablative surgery to resectable tumors with or without lung metastasis, larynx-preserving surgery to extraluminal or small intraluminal tumors restricted to the short segment of trachea, or total laryngectomy to recurrent tumors deeply invading the cartilage framework of the larynx. We performed arytenoid adduction or thyroplasty in one stage if the recurrent laryngeal nerve was paralyzed or resected intraoperatively. We could get relatively good survival and functional results by aggressive surgical treatment in 20 patients, but the disease was inoperable in 2 patients. It is stressed that head and neck surgeons who have to deal with cancer of the thyroid should not only be familiar with various techniques of airway reconstruction and voice rehabilitation but also must be aware of the biologic behavior of the thyroid carcinoma.

Combined anomaly of intramedullary arteriovenous malformation and lipomyelomeningocele

We report a rare situation in which a lipomyelomeningocele and an intramedullary arteriovenous malformation (AVM) occurred together at the T11-L1 level in a 44-year-old man. MR images showed a hypervascular lesion intradurally and a fatty component extradurally. Spinal angiography revealed this lesion to be an intramedullary AVM with multiple feeding arteries from the right T12 and left T10 intercostal artery and the left L1 lumbar artery, drained by tortuous, dilated, perimedullary veins.

Transient expression of cellular polypyrimidine-tract binding protein stimulates cap-independent translation directed by both picornaviral and flaviviral internal ribosome entry sites In vivo

The regulation of cap-independent translation directed by the internal ribosome entry sites (IRESs) present in some viral and cellular RNAs is poorly understood. Polypyrimidine-tract binding protein (PTB) binds specifically to several viral IRESs. IRES-directed translation may be reduced in cell-free systems that are depleted of PTB and restored by reconstitution of lysates with recombinant PTB. However, there are no data concerning the effects of PTB on IRES-directed translation in vivo. We transfected cells with plasmids expressing dicistronic transcripts in which the upstream cistron encoded PTB or PTB deletion mutants (including a null mutant lacking amino acid residues 87 to 531). The downstream cistron encoded a reporter protein (chloramphenicol acetyltransferase [CAT]) under translational control of the poliovirus IRES which was placed within the intercistronic space. In transfected BS-C-1 cells, transcripts expressing wild-type PTB produced 12-fold more reporter protein than similar transcripts encoding the PTB null mutant. There was a 2.4-fold difference in CAT produced from these transcripts in HeLa cells, which contain a greater natural abundance of PTB. PTB similarly stimulated CAT production from transcripts containing the IRES of hepatitis A virus or hepatitis C virus in BS-C-1 cells and Huh-7 cells (37- to 44-fold increase and 5 to 5.3-fold increase, respectively). Since PTB had no quantitative or qualitative effect on transcription from these plasmids, we conclude that PTB stimulates translation of representative picornaviral and flaviviral RNAs in vivo. This is likely to reflect the stabilization of higher ordered RNA structures within the IRES and was not observed with PTB mutants lacking RNA recognition motifs located in the C-terminal third of the molecule.

Significance of acute multiple brain infarction on diffusion-weighted imaging

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) is superior to conventional MRI in identification of small new ischemic lesions and discrimination of recent infarcts from old ones. Thus, this technique is useful in the detection of acute multiple brain infarcts (AMBI). We sought to determine the frequency and the topographical and etiologic patterns of AMBI detected on DWI.

METHODS

We studied 329 consecutive ischemic stroke patients who underwent DWI and MRI/MR angiography within 4 days of stroke onset. AMBI was defined as noncontiguous high signal intensities on DWI in >1 vascular territory. Stroke mechanism was determined according to the criteria of the Trial of Org 10172 in Acute Stroke Treatment (TOAST).

RESULTS

We detected AMBI in 95 patients (28.9%). AMBI in anterior circulation was found in 62 cases: in 1 hemisphere in 42 (group A) and in bilateral hemispheres in 20 (group B). Twenty-two patients had AMBI in the posterior circulation (group C) and 11 in both anterior and posterior circulations (group D). The most frequent cause of stroke was large-artery atherosclerosis in groups A (33/42), B (9/20), and C (15/22) (P=0.02) and cardioembolism in group D (6/11) (P=0.02). Elevated fibrinogen or hematocrit was significantly associated with group B (P=0.01). In 9 patients in groups B and D, anatomic variations of anterior or posterior cerebral arteries or patent posterior communicating artery contributed to AMBI.

CONCLUSIONS

Different topographical patterns of AMBI are associated with different vascular pathologies and stroke mechanisms. Hemorheologic abnormality or vascular anatomic variations may be contributing factors in the pathogenesis of AMBI in bilateral cerebral hemispheres or in both anterior and posterior circulations.

High cyclooxygenase-2 expression in stage IB cervical cancer with lymph node metastasis or parametrial invasion

OBJECTIVE

The enzymes cyclooxygenase (COX)-1 and -2 are necessary for the synthesis of prostaglandins. COX-2 is usually absent in normal cells and is upregulated and expressed as a product of the "immediate early" gene during inflammatory processes. In previous studies, the expression of COX-2 has been shown to be induced by proinflammatory cytokines, and suggestions have been made that overexpression of COX-2 suppresses apoptosis and is directly related to tumor growth. We have attempted to determine a relationship between tumor invasion and metastasis of uterine cervical cancer and COX and apoptosis by comparing the protein expression of apoptosis, COX-1, and COX-2 in tumor tissues.

METHODS

The subjects were 36 patients who were FIGO stage IB uterine cervical cancer patients who underwent surgery at Ajou University Hospital. There were 12 cases with lymph node or parametrial involvement. All tissues were subjected to immunohistochemical staining for COX-1, -2, and TUNEL method for apoptosis detection, and the following results were obtained.

RESULTS

Tumor tissues confirmed by cytokeratin were separated into tumor surface, tumor stroma, and invasion site portions, in which decreased apoptosis was observed in the invasion sites. COX-2 expression was observed in all tumor tissues and was especially strong in the tumor invasion site. Therefore, it is suggested that COX-2 expression may suppress cell apoptosis at the tumor invasion site. When COX-2 expression was investigated according to the groups with regard to the presence of lymph node or parametrial involvement, there was a statistically significant (Mann-Whitney U test) COX-2 expression difference in the tumor invasion site (P value = 0.040) and the tumor stroma (P value = 0. 028).

CONCLUSIONS

In surgically treated stage IB cervical cancer patients, COX-2 was significantly expressed when lymph node or parametrial involvement was present. These results suggest that the expression of COX-2 in stage IB cervical cancer may downregulate apoptotic processes and thus enhance tumor invasion and metastasis.

Spontaneous programmed cell death of peripheral blood mononuclear cells from HIV-infected persons is decreased with interleukin-15

Interleukin 15 (IL-15) is an important regulatory cytokine in cellular immunity. In vitro replacement of IL-15 has been shown to enhance immunity in Human immunodeficiency virus type 1 (HIV-1) infected lymphocytes. We evaluated the effect of IL-15 on the survival of peripheral blood mononuclear cells of HIV patients by examining in vitro lymphocyte apoptosis, and correlated the process with Bcl-2 and Fas gene regulation. Peripheral blood mononuclear cells (PBMC) from 21 HIV-infected adults and 24 HIV-seronegative healthy individuals were isolated and cultured to determine the effect of escalating doses of IL-15 (0, 1, 10, 100, 1000 ng/mL) on apoptosis. Lymphocyte proliferation assay with (3H) TdR was measured and Bcl-2 and Fas gene regulation was observed. The results were as follows: 1) IL-15 reduced culture induced lymphocyte apoptosis in HIV patients in a dose dependent manner, and reached a plateau level at a concentration of 100 ng/ml; 2) IL-15 significantly reduced the level of apoptosis after 3 days (14%) and 5 days (15%) of culture in HIV patients, while no difference was observed in HIV (-) donors; 3) The percentage of viable cells among the total number of lymphocytes was significantly enhanced by 25% in HIV patients with IL-15; 4) Bcl-2 expression was decreased in HIV patients (53.9 +/- 12.3%) compared to HIV (-) donors (93.0 +/- 3.7%), and IL-15 increased Bcl-2 expression by 21.2 +/- 5.2% in HIV patients; 5) Fas expression was increased in HIV patients (70.2 +/- 4.6%) compared to HIV (-) donors (32.4 +/- 4.3%), and IL-15 increased Fas expression by 8.4 +/- 1.2% in HIV (-) donors. Our findings indicate that IL-15 may influence immunologic abnormalities in HIV infection, particularly its ability to prevent apoptosis of lymphocytes by suppressing the down-modulation of Bcl-2. This may provide an experimental basis for IL-15 immunotherapy.

In vivo proton magnetic resonance spectroscopy of central neurocytomas

OBJECTIVE

The authors report on the metabolic features of central neurocytomas observed during in vivo single-voxel proton magnetic resonance spectroscopy.

METHODS

Volume-selective single-voxel proton magnetic resonance spectroscopy was performed with a 1.5-T unit using a point-resolved spectroscopy sequence (TR/TE = 2000 ms/135 and 270 ms) to obtain spectra of a single 8-cc voxel. The subjects were five patients in the Department of Neurosurgery of Seoul National University Hospital whose central neurocytomas had been diagnosed histologically. The peak intensities of compounds containing choline (Cho), N-acetylaspartate, creatine/phosphocreatine, and lactate were analyzed.

RESULTS

The ratios of Cho to creatine/phosphocreatine and Cho to N-acetylaspartate were significantly higher than ratios in normal brains. A lactate signal was present, and an unidentified signal was also observed at 3.55 ppm, which might have been produced by inositol or glycine.

CONCLUSION

A combination of the signal at 3.55 ppm and a prominent Cho peak seems to be a characteristic feature of central neurocytomas. Volume-selective single-voxel proton magnetic resonance spectroscopy could provide additional information to aid in diagnosing this condition.

Usefulness of single voxel proton MR spectroscopy in the evaluation of hippocampal sclerosis

OBJECTIVE

The purpose of our study was to determine the ability of H-1 MR spectroscopy (MRS) to lateralize the lesion in patients with hippocampal sclerosis.

MATERIALS AND METHODS

Twenty healthy volunteers and 25 patients with intractable temporal lobe epilepsy whose MR imaging diagnosis was unilateral hippocampal sclerosis were included. This diagnosis was based on the presence of unilateral atrophy and/or high T2 signal intensity of the hippocampus. Singlevoxel H-1 MRS was carried out on a 1.5-T unit using PRESS sequence (TE, 136 msec). Spectra were obtained from hippocampal areas bilaterally with volumes of interest (VOIs) of 6.0 cm(3) and 2.25 cm(3) in healthy volunteers, and of either 6.0 cm(3) (n = 14) or 2.25 cm(3) (n = 11) in patients. Metabolite ratios of NAA/Cho and NAA/Cr were calculated from relative peak height measurements. The capability of MRS to lateralize the lesion and to detect bilateral abnormalities was compared with MR imaging diagnosis as a standard of reference.

RESULTS

In healthy volunteers, NAA/Cho and NAA/Cr ratios were greater than 0.8 and 1.0, respectively. In patients, the mean values of these ratios were significantly lower on the lesion side than on the contralateral side, and lower than those of healthy volunteers (p <.05). The overall correct lateralization rate of MRS was 72% (18/25); this rate was lower with a VOI of 6.0 cm(3) than of 2.25 cm(3) (64% versus 82%, p <.05). Bilateral abnormalities on MRS were found in 24% (6/25) of cases.

CONCLUSION

Although its rate of correct lateralization is low, single-voxel H-1 MRS is a useful and promising diagnostic tool in the evaluation of hippocampal sclerosis, particularly for the detection of bilateral abnormalities. To improve the diagnostic accuracy of H-1 MRS, further investigation, including the use of a smaller VOI and measurement of the absolute amount of metabolites, are needed.

MR imaging features of clear-cell meningioma with diffuse leptomeningeal seeding

Clear-cell meningioma is a rare disease entity showing a more aggressive nature, clinically, than those of other subtypes of meningioma. It occurs in younger persons and commonly in the spinal canal. The recurrence rate has been reported to be as high as 60%. We present a case of clear-cell meningioma in a 17-year-old man in whom initial MR imaging showed localized leptomeningeal enhancement that had progressed into the entire subarachnoid space after surgical resection of the primary tumor.

Enhancement of radiosensitivity in human glioblastoma U138MG cells by tetrandrine

Tetrandrine, a natural lipid-soluble alkaloid with a low molecular weight, has both anti-tumor activity and a tissue-protective effect, as demonstrated in our previous studies. We studied tetrandrine to determine whether or not it enhanced radiosensitivity in human glioblastoma U138MG cells. Tetrandrine at concentration of 5.0 and 7.5 eg/ml dramatically enhanced the growth-inhibiting effect of radiation. This effect is dose-dependent on the dose of both tetrandrine and radiation. Moreover, we found that tetrandrine eliminated the cell cycle perturbation induced by radiation. Cells treated with tetrandrine alone as well as with a combination of tetrandrine and radiation became rounded, floated up and grew sparsely under observation under an inverted light microscope, DNA fragmentation was also noted by gel electrophoresis. These findings suggest that tetrandrine has potential as an adjunct to radiotherapy for glioblastoma.

Increase in signal intensities on T1-weighted magnetic resonance images in asymptomatic manganese-exposed workers

OBJECTIVES

To clarify the clinical significance of increased signal intensities on T1 weighted magnetic resonance imaging (MRI) we performed a large-scale epidemiological study on asymptomatic manganese (Mn)-exposed workers with its focus on MRI.

METHODS

We randomly selected 121 male workers out of a total of 750 workers including Mn-exposed, non-exposed manual, and non-exposed clerical workers in the factories. We studied environmental and biological monitoring, neurological examination, and MRI.

RESULTS

The proportion of workers with increased signal intensities among the exposed, the non-exposed manual workers, and the non-exposed clerical workers was 46.1%, 18.8%, and 0%, respectively. Especially, 73.5% of the welders showed increased signal intensities. In no subject, were clinical signs of manganism observed. The pallidal index correlated with blood Mn concentration.

CONCLUSION

Increase in signal intensities on the T1-weighted image reflect recent exposure to Mn, but not necessarily manganism. At which increase of signal intensity, the progression of manganism from Mn exposure occurs, remains to be solved.

Comparison of localizing values of various diagnostic tests in non-lesional medial temporal lobe epilepsy

Though the surgical treatment for medial temporal lobe epilepsy yields a high success rate, more studies are needed in order to determine the most efficacious pre-operative algorithm. The authors studied the relationship between surgical outcome and the localization results of various pre-operative diagnostic tests to assess the predictive value. Seventy-one consecutive patients who had undergone anterior temporal lobectomy with amygdalohippocampectomy with the diagnosis of non-lesional medial temporal lobe epilepsy, who had been followed up more than 24 months, were analyzed retrospectively. Electroencephalogy (EEG), magnetic resonance imaging (MRI), proton emission tomography (PET), single photon emission computed tomography (SPECT), the Wada test, and neuropsychological testing were analyzed. There was no diagnostic test that was found to have a statistically significant relationship between Engel Class I outcome and localization results (P & 0.05). SPECT, neuropsychological testing, and the Wada test all had less predictive values (P < 0.01). EEG and PET had comparable predictive values for Engel Class I with MRI (P & 0.05). No single diagnostic test alone is sufficient to make a diagnosis of non-lesional medial temporal lobe epilepsy. MRI, EEG and PET had comparable predictive values for Engel Class I. SPECT, neuropsychological testing, and the Wada test had less predictive values.

Estimating the ozone formation potential of volatile aromatic compounds in vehicle tunnels

Two vehicle tunnels located in the Taipei area were selected to study the ozone formation potential of volatile aromatic compounds (VACs). Air samples in the two tunnels were collected using canisters. Analysis of VACs was conducted with a gas chromatograph equipped with a mass spectrometer. The total VOCs concentrations in Zefun tunnel ranged from 483.5 to 1032.2 (micrograms/m3) which increased with the increase in traffic volume. In the Lishin tunnel, the total VACs concentration ranged from 356.6 to 1961.3 (micrograms/m3) which was not well correlated with the traffic volume. The most predominant VACs in these vehicle tunnels were toluene and xylenes. Although the traffic volume and types of vehicles were not exactly the same, the characteristic ratios of the VACs concentrations were found to be similar. These results indicated that the existence of a specific characteristic ratio of VAC concentration was affected by the mobile sources. The maximum ozone formation potential resulted from the vehicles in the Lishin motorcycle tunnel which had higher values than the Zefun tunnel and much higher than the SPECIATE databases in the US via weighting the maximum incremental reactivity (MIR) scale.

Effects of long-acting somatostatin analogue (Sandostatin) on manifest diabetic ketoacidosis

Insulin deficiency and counterregulatory hormone excess are the basic process in the development of diabetic ketoacidosis (DKA). Somatostatin, which suppresses the secretion of glucagon and growth hormone, has been known to attenuate the rate of gluconeogesis and ketogenesis in insulin-dependent diabetes mellitus patients. However, the therapeutic efficacy of somatostatin has not been approved to be practical in the treatment of manifest DKA. To examine the additive effect of octreotide, the synthetic long-acting somatostatin analogue SMS 201-995, to conventional treatment of manifest DKA, we compared the correction time of acidosis, ketonuria, and hyperglycemia of patients treated with an intravenous infusion of low-dose insulin (4 units per hour) plus subcutaneous injection of octreotide (50 microg every 6 hours) by low-dose insulin alone. The correction time for hyperglycemia and acidosis did not show any difference between groups (p = 0.089, p = 0.82). However, the time for disappearance of ketonuria of the octreotide-treated group (38.0 +/- 32.0 h) was reduced significantly compared to other group (68.3 +/- 26.0 h) (p = 0.048). These results indicated that the addition of octreotide to conventional treatment of DKA might improve the correction of ketosis, but would not allow more rapid control of acidosis and hyperglycemia in manifest DKA.

The effect of tetrandrine and extracts of Centella asiatica on acute radiation dermatitis in rats

Radiation injury to the skin is one of the major limiting factors in radiotherapy. We designed this study using Sprague-Dawley rats to evaluate the reduction in skin injury achieved using natural products from plant extracts as protection. The acute skin reaction in tetrandrine- and Madecassol-treated animals appeared earlier, but was significantly less severe, than in the control group. The peak skin reactions in the tetrandrine group were less serious than those of the control group at three different radiation doses. At a high dose irradiation, the healing effect of tetrandrine is better than Madecassol and vaseline. The histologic findings indicate that tetrandrine and Madecassol are able to reduce acute radiation reactions by their anti-inflammatory activity.

Sequential change of MR signal intensity of the brain after manganese administration in rabbits. Correlation with manganese concentration and histopathologic findings

RATIONALE AND OBJECTIVES

High signal intensity in the basal ganglia on T1-weighted MR imaging has been reported in chronic manganese (Mn) poisoning. However, the exact meaning of the high signal intensity remains unclear: does it result from Mn itself, secondary pathologic changes of the brain tissue, or both? The goal of this study was to evaluate the sequential change of MR signal intensity and to correlate the MR intensity of the globus pallidus and the hypothalamus with the Mn concentration in the blood and the brain tissue, and with the histopathologic findings.

METHODS

Ten milligrams per kilogram of Mn was administered once a week for 4 weeks to 14 rabbits. The rabbits in the control group (n = 2) were killed without Mn administration; those in group I (n = 4) were killed 1 day after the completion of Mn administration, those in group II (n = 4) were killed at 4 weeks, and those in group III (n = 6) were killed at 8 weeks. Sequential MR imaging, blood and tissue concentration measurement, and pathologic examination were performed. Sequential changes of the percent contrasts, contrast-to-noise ratios, and T1 relaxation times were analyzed with blood and tissue concentrations and histopathologic findings.

RESULTS

The signal intensity of the basal ganglia on T1-weighted imaging was highest 1 day after cessation of Mn administration and sequentially washed out. The contrast, contrast-to-noise ratio, and T1 relaxation time showed significant correlations with blood concentration. Only the T1 relaxation time of the globus pallidus showed a significant correlation with tissue concentration. Histopathologic examination disclosed mild abnormalities in the globus pallidus, thalamus, and hypothalamus.

CONCLUSIONS

The high signal intensity on T1-weighted MR imaging presumably indicates mainly the exposure marker of Mn, although mild pathologic findings were observed.

Craniofacial arteriovenous malformation: preoperative embolization with direct puncture and injection of n-butyl cyanoacrylate

PURPOSE

To evaluate the use of n-butyl cyanoacrylate (NBCA) for preoperative embolization of craniofacial arteriovenous malformation.

MATERIALS AND METHODS

Fourteen patients with craniofacial arteriovenous malformation (forehead [n = 9], deep facial [n = 3], occipital [n = 1], or lip [n = 1] lesion) were treated with injection of NBCA. Forehead lesions were supplied by ophthalmic (n = 6) and/or superficial temporal arteries (n = 7); and facial and scalp lesions, by bilateral internal maxillary (n = 4), facial (n = 2), and/or occipital arteries (n = 1). Lesions were percutaneously punctured with a 20-gauge needle in the area of arteriovenous connection. Direct angiography was performed before and after compression of venous drainage, and NBCA diluted 30%-50% with iodized oil was injected during venous compression.

RESULTS

Postembolization arteriograms showed that six lesions were completely devascularized after single or multiple (one to nine) injections, and five were effectively devascularized (> or = 90%). Although three lesions were 60%-70% devascularized after injection, two of these were successfully extirpated with no notable blood loss. In nine patients, the ophthalmic arterial supply had disappeared after embolization. There were no procedure-related complications.

CONCLUSION

Direct-puncture embolization with NBCA is an effective and safe technique for preoperative devascularization of craniofacial arteriovenous malformation. For safe and effective devascularization, compression of draining venous channels is thought to be important.

Comparison of MR imaging with PET and ictal SPECT in 118 patients with intractable epilepsy

BACKGROUND AND PURPOSE

MR imaging, PET, and ictal SPECT have been studied extensively as individual techniques in the localization of epileptogenic foci, but only a few comparative studies have been done. We evaluated the concordance rates of ictal video/EEG, MR imaging, PET, and ictal SPECT to compare the sensitivities of these imaging methods in the lateralization of epileptogenic foci.

METHODS

The study included 118 consecutive patients who underwent surgery for medically intractable epilepsy and who were followed up for 12 months or more. MR imaging was compared retrospectively with ictal video/EEG, FDG-PET, ictal 99mTc-HMPAO SPECT, and invasive EEG as to their ability to localize the epileptogenic focus; the pathologic findings served as the standard of reference.

RESULTS

MR imaging was concordant with video/EEG, PET, and ictal SPECT in 58%, 68%, and 58% of patients, respectively. With the pathologic diagnosis as the standard of reference, MR imaging, PET, and ictal SPECT correctly lateralized the lesion in 72%, 85%, and 73% of patients, respectively. Of the patients with good outcomes, MR imaging, PET, and ictal SPECT were correct in 77%, 86%, and 78%, respectively. In the good outcome group, MR imaging was concordant with PET and ictal SPECT in 73% and 62% of patients, respectively. Of 45 patients who underwent invasive EEG, MR imaging was concordant with the invasive study in 47%; PET in 58%; and ictal SPECT in 56%. Of 26 patients with normal MR findings, PET and ictal SPECT correctly lateralized the lesion in 80% and 55%, respectively.

CONCLUSION

Overall concordance among the techniques is approximately two thirds or less in lateralizing epileptogenic foci. PET is the most sensitive, even though it provides a broad approximate nature of the epileptogenic zone, which is not adequate for precise surgical localization of epilepsy. PET and/or ictal SPECT may be used as complementary tools in cases of inconclusive lateralization with ictal video/EEG and MR imaging.

Intracranial germinomas: correlation of imaging findings with tumor response to radiation therapy

OBJECTIVE

The purpose of this study was to correlate imaging characteristics of intracranial germinomas with response to radiation therapy.

MATERIALS AND METHODS

Using tumor size at the completion of irradiation, we classified 23 patients with histologically proven germinomas in the pineal gland (n = 6), the suprasellar region (n = 7), and the basal ganglia (n = 10) into two groups: excellent response group (n = 14) and good response group (n = 9). Excellent response was defined as complete resolution or residual tumor less than 1.0 cm in diameter, and good response was defined as residual tumor of 1.0-3.0 cm in diameter. CT (n = 53) and MR (n = 32) images obtained before, during, and after radiation therapy were retrospectively analyzed with particular attention to the location, size, presence of cystic change, and CSF seeding of the tumors.

RESULTS

In all 23 patients, the tumors decreased 85-100% in size at the completion of irradiation with 40-56 Gy. A significant factor in the different responses to irradiation between patients in the excellent and good response groups was cystic change of the tumor. Tumors with cystic components responded more slowly and had larger residual lesions than did tumors without cystic components (p < .01). In eight of 12 cystic tumors, the cystic portion of the tumor responded more slowly than did the solid portion and remained visible on imaging 6-12 months after irradiation. We found no significant differences between the two groups in location, size, and CSF seeding of tumors. In 12 patients with residual lesions at the completion of irradiation, the tumors proceeded to resolve after completion of treatment.

CONCLUSION

In our study, tumor response to radiation therapy correlated negatively with the presence of a cystic region.

Human apolipoprotein E: correlation of polymorphisms and serum lipid concentrations in Chinese

BACKGROUND

The allelic variation of the apolipoprotein E (apoE) gene affects serum lipid concentrations. This study investigates the correlation of apoE polymorphisms and serum cholesterol and triglyceride concentrations in Chinese subjects.

METHODS

DNA from a random sample of 136 unrelated individuals was used for polymerase chain reaction (PCR) amplification of the three apoE alleles. The amplified products were analyzed by Hha1 restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism (SSCP).

RESULTS

Identical genotypes were obtained by both methods in all individuals analyzed. The three apoE alleles examined were in Hardy-Weinberg equilibrium (p = 0.417). The allele frequencies in individuals with cholesterol and triglyceride values of below 200 mg/dl were 8.6% for epsilon 2, 82.8% for epsilon 3 and 8.6% for epsilon 4. When allele frequency between individuals with cholesterol values of below and above 200 mg/dl was compared, there appeared little difference in the epsilon 2 and epsilon 4 alleles between the two groups (p = 0.823). Conversely, a statistically significant difference in the epsilon 2 allele was observed (p = 0.048) between individuals with triglyceride values of below and above 200 mg/dl.

CONCLUSIONS

The results demonstrate that neither the epsilon 2 nor epsilon 4 alleles affect cholesterol values in Chinese subjects, whereas the epsilon 2 allele exerts an influence on serum triglyceride concentrations in Chinese.

N-acetylcysteine increases the biosynthesis of recombinant EPO in apoptotic Chinese hamster ovary cells

Sodium butyrate (NaBu) is known to enhance the rate of biosynthesis of recombinant proteins in Chinese hamster ovary cells (CHO). Here we demonstrate that supplementation with NaBu during rapid growth brings about abrupt death of the cells. The death of the cells is due to apoptosis, as assessed by intranucleosomal DNA fragmentation. The promotion of apoptotic death of the cells could be partially blocked by treatment with the well-known antioxidant, N-acetylcysteine (NAC). Strikingly, the NAC treatment enhanced the production of recombinant EPO two-fold compared with that of the culture without NAC supplementation. These results showed that NaBu treatment supplemented with NAC not only inhibits apoptosis, but also exerts a synergistic effect on the biosynthesis of recombinant EPO.

Subregions within the supplementary motor area activated at different stages of movement preparation and execution

Previous studies have provided evidence that the primary motor area (M1) is involved in actual execution of a motor program, while the premotor area (PreMA) and the supplementary motor area (SMA) play a role in its preparation. We have used the high temporospatial resolution of functional magnetic resonance imaging (fMRI) to study the relationship between stages of a motor program and activation of these motor-related cortical areas. Seven normal volunteers performed a delayed-motor task in which the preparation of finger movements was dissociated in time from movement execution, while event-related fMRI was obtained. The M1 and PreMA showed expected activation associated with execution and preparation stages, respectively. Within SMA, subregions with different temporal profiles of activation were identified: The anterior part became activated early in the preparation period, whereas the posterior part only with movement execution. This supports the notion that the classic SMA consists of the pre-SMA and SMA proper each with different functions.

Focal lesion in the splenium of the corpus callosum in epileptic patients: antiepileptic drug toxicity?

BACKGROUND AND PURPOSE

Discrete focal lesions in the splenium of the corpus callosum on MR images in epileptic patients have received little attention in the literature. Our purpose was to describe these lesions, which may be related to the toxicity of antiepileptic drugs (AEDs), and to discuss the possible mechanisms of their development.

METHODS

We examined six patients with epilepsy whose brain MR imaging findings showed a discrete focal nonhemorrhagic lesion in the splenium of the corpus callosum. The medical records and MR images were reviewed retrospectively with respect to the patients' clinical history, medication, and laboratory findings to determine the etiology of the lesion.

RESULTS

In all six patients MR imaging showed a focal lesion in the splenium of the corpus callosum, which was ovoid in shape and 15 to 19 mm in size. In the three patients who received contrast material, there was no enhancement of the lesion. Four of six patients had a history of medication with dilantin, in two of whom the level of serum dilantin was found to be elevated (22.3 micrograms/mL and 70.4 micrograms/mL, respectively). Vigabatrin was administered in three patients, one of whom took dilantin together with vigabatrin. In two patients, the focal lesion in the corpus callosum disappeared on follow-up MR images after withdrawal of dilantin and/or vigabatrin.

CONCLUSION

A discrete, focal, ovoid, nonhemorrhagic lesion in the splenium of the corpus callosum may be seen on brain MR images of patients with epilepsy. The lesion is considered to be reversible demyelination related to AEDs toxicity.

Brain abscess and necrotic or cystic brain tumor: discrimination with signal intensity on diffusion-weighted MR imaging

OBJECTIVE

The purpose of this study was to determine the differences in signal intensity between brain abscesses and necrotic or cystic tumors on diffusion-weighted MR imaging.

CONCLUSION

Five consecutive patients with proven brain abscesses and four patients with proven cystic or necrotic brain tumors were prospectively evaluated with diffusion-weighted imaging. On diffusion-weighted imaging, brain abscesses showed markedly hyperintense signal in all five patients, whereas necrotic or cystic brain tumors revealed hypointense signal in all four patients. Diffusion-weighted imaging may allow the differentiation of brain abscess from necrotic or cystic brain tumor.

MRI features of choroid plexitis

Four cases of choroid plexitis of the brain (two with cryptococcosis and two with tuberculosis) are presented. The four patients showed either unilateral enlargement (3) or bilateral enlargement (1) and dense enhancement of the choroid plexus in the lateral ventricles (4) and fourth ventricle (1) in association with clinical findings of leptomeningitis. All patients had unilateral cystic dilatation of the temporal horn of the lateral ventricle presumably secondary to entrapment of the temporal horn and extensive oedema around the ipsilateral ventricle.

Sequence analysis and expression of the filamentous phage phi Lf gene I encoding a 48-kDa protein associated with host cell membrane

One viral strand of phi Lf, a filamentous phage of Xanthomonas campestris pv.campestris, the open reading frame (ORF440) behind gene VI was identified as gene I. This gene codes for pI protein (440 aa, 48 kDa) which was shown to be membrane-bound in the phi Lf-infected host cell by Western blot analysis using the antibody raised against the protein expressed in Escherichia coli. Its predicted amino acid sequence has a nucleotide-binding motif in the N-terminal 97 aa and a membrane-spanning domain (aa 221 to 236). These structural features are characteristic of pIs of several filamentous phages which are transmembrane proteins required for phage assembly. Thus far, nine phi Lf genes have been identified which are organized in the order GII-gX-gV-gVII-gIX-gVIII-gIII-gVI-gI, similar to the genome organization of E. coli filamentous phages.

MR of hippocampal sclerosis: comparison of qualitative and quantitative assessments

PURPOSE

Our goal was to compare the diagnostic accuracy of subjective visual assessment versus MR volumetry in evaluating hippocampal sclerosis and to determine whether MR volumetry is needed in the lateralization of this disease process.

METHODS

MR imaging findings were studied retrospectively in 48 patients who underwent surgery for temporal lobe epilepsy and were compared with findings at MR volumetry on an Allegro workstation. Both visual assessment and volumetry were carried out in a blinded fashion with oblique coronal T1-weighted three-dimensional MP-RAGE images obtained on either 1.0-T or 1.5-T units. Normal right-left volumetric differences were recorded in 30 control subjects. The optimum cutoff threshold value for right-left volumetric differences in the sensitivity and specificity of volumetric measurement was obtained from receiver operating characteristic analysis.

RESULTS

Sensitivity, specificity, positive and negative predictive values, and accuracy of visual assessment were 86%, 83%, 86%, 83%, and 85%, respectively. For MR volumetry, with the optimum cutoff threshold value of right-left difference at 0.3 cm3, sensitivity, specificity, positive and negative predictive values, and accuracy were 81%, 82%, 87%, 83%, and 85%, respectively.

CONCLUSION

Visual assessment was slightly superior to or similar to MR volumetry in assessing unilateral hippocampal sclerosis. MR volumetry of the hippocampus may not be needed for the evaluation of most cases of suspected hippocampal sclerosis.

In vivo single-voxel proton MR spectroscopy in intracranial cystic masses

PURPOSE

Our objective was to evaluate the proton MR spectroscopic pattern of the cystic contents of various intracranial masses and to report characteristic spectral patterns that may be helpful in the differential diagnosis of these lesions.

METHODS

We evaluated 40 proton MR spectra obtained from cystic contents of various intracranial cystic masses in 39 patients, including gliomas (n = 14), metastases (n = 3), abscesses (n = 8), cysticercosis (n = 4), epidermoids (n = 3), and others (n = 7). Proton MR spectroscopy was performed on a 1.5-T MR unit using a point-resolved spectroscopic sequence with a 2 x 2 x 2 cm3 volume of interest. Assignment of the resonance peaks was based on previous studies.

RESULTS

Adequate proton MR spectroscopic data were obtained in 35 cases (88%). In most gliomas and metastases, only a lactate resonance was observed. There was a trend toward a higher lactate peak in high-grade gliomas. A few tumors, including malignant gliomas and metastases, showed lipid signal combined with lactate signal. In abscesses, there were various combinations of lactate, acetate, succinate, amino acids (including valine, alanine, and/or leucine), and/or unassigned resonances. In cysticercosis, resonances of lactate, succinate, alanine, acetate, and/or unassigned resonances were observed. Three epidermoid cysts showed only lactate signal. There were no identifiable resonances from the arachnoid and porencephalic cysts.

CONCLUSION

Only lactate is commonly observed in a variety of intracranial cystic masses, except for abscess and cysticercosis, in which resonances of acetate, succinate, amino acids, and/or unassigned metabolites can be seen in addition to a lactate peak.

MRI of CNS parasitic diseases

This article reviews MRI findings of parasitic diseases of the central nervous system (CNS), with emphasis on neurocysticercosis, which is by far the most common CNS parasitic infection worldwide. MRI findings of neurocysticercosis are various, depending on the location (parenchymal, cisternal, ventricular, and spinal forms), and temporal evolutional stages (vesicular, colloid vesicular, granular nodular, and nodular calcified stages) of the worm. Classical findings of each location and stage are presented. Characteristic MRI findings of cerebral toxoplasmosis frequently seen in patients with acquired immunodeficiency syndrome (AIDS), paragonimiasis, and sparganosis that have most commonly been reported in East Asia are also illustrated. MRI is superior to CT scan in the evaluation of most CNS parasitic infections and is nearly diagnostic, particularly in endemic areas. Contrast-enhanced study is essential not only for specific diagnosis of the disease, but also for assessment of the inflammatory activity.

A case of autoimmune cholangitis associated with Sjögren's syndrome and arthropathy

Autoimmune cholangitis (AC) is a recently proposed entity that describes a specific group of patients presenting overlapping features of primary biliary cirrhosis (PBC) and autoimmune hepatitis. The disease is characterized by dinical cholestasis, high titer antinuclear antibody, negative antimitochondrial antibody, and histologically, findings of PBC coexisting with varying degrees of parenchymal inflammation. In this report, we describe a patient with Sjögren's syndrome who fulfilled the diagnostic criteria of AC associated with unique arthropathy compatible with arthritis of PBC. This case illustrates the unusual coexistence of two diseases that may share similar pathogenic processes.

Progression of hypertrophic cardiomyopathy to dilated cardiomyopathy--a case reports and review of the literatures

Left ventricular systolic function in hypertrophic cardiomyopathy (HCMP) does not usually deteriorate even in the end stage of the disease. However, occasionally cases of HCMP progress to a similar form of dilated cardiomyopathy (DCMP) with a decreased systolic function and dilated left ventricle. We report two cases of HCMP which progressed to DCMP during follow-up. Our cases have been documented by serial M-mode echocardiography which shows a prominent decrease in the left ventricular systolic function and a chamber enlargement of the left ventricle. There are various explanations of the pathogenesis of the functional and morphological myocardial deterioration of HCMP progressing to DCMP, and more cases should be studied to determine the pathogenesis and prevention of this end-stage feature of HCMP.

Conservative therapy of adnexal torsion employing color Doppler sonography

STUDY OBJECTIVE

To ascertain if color Doppler sonography (CDS) can detect viability of adnexa in torsion.

DESIGN

Concurrent, nonrandomized study (Canadian Task Force classification II-2).

SETTING

Tertiary medical care center in a university hospital.

PATIENTS

Twenty-seven women suspected of having torsion of the ovary in which a benign tumor was present.

INTERVENTIONS

Color Doppler sonography of the ovarian pedicle suggested torsion. Laparoscopy or laparotomy was performed in 19 patients and confirmed the diagnosis.

MEASUREMENTS AND MAIN RESULTS

We identified a twisted vascular pedicle of the ovarian tumor by CDS in 24 (88%) of 27 women. Pedicle arterial and venous blood flow was observed in 10 women; pathology specimens revealed normal tissue, edema with congestion, or early hemorrhage. In all nine in whom only arterial blood flow or no blood flow was observed, pathology revealed hemorrhagic necrosis. In five women with arterial and venous blood flow the tumor was managed conservatively, either by detorsion or cystectomy, after which no embolism or tumor recurrence was seen at follow-up ultrasonography. Normal follicular development and ovulation occurred in these patients.

CONCLUSION

For women of childbearing age in whom torsion of benign adnexal tumors is suspected, CDS should be performed to confirm the diagnosis and ascertain whether or not pedicle arterial and venous blood flow is present. If such blood flow is detected, the adnexa is considered to be viable and detorsion or cystectomy may be performed, thus preserving the ovary. It is recommended that further studies with a larger group be undertaken to provide a basis for statistical analysis.

Induction of apoptosis in human leukemic U937 cells by tetrandrine

Tetrandrine, a calcium channel antagonist, is a plant alkaloid possessing various pharmacological activities including anti-tumor activity. We studied tetrandrine to determine whether or not this anti-tumor effect occurs through induction of apoptosis. Tetrandrine inhibited both proliferation and clonogenicity of human leukemic U937 cells at an optimal concentration of 2.5 microg/ml. This growth inhibition was dose and time dependent, and accompanied with evidence of apoptotic changes. The characteristic morphological changes of apoptosis were observed in U937 cells under light microscopy and DNA fragmentation was noted by gel electrophoresis. Moreover, flow cytometric detection of surface phosphatidyl serine expression of U937 cells after treatment with tetrandrine confirmed the induction of apoptosis in these cells. The induction of apoptosis by tetrandrine would appear to proceed via non-Ca2+-dependent pathways.

Half-dose gadolinium-enhanced MR imaging with magnetization transfer technique in brain tumors: comparison with conventional contrast-enhanced MR imaging

OBJECTIVE

The purpose of this study was to determine whether half-dose enhanced MR imaging with magnetization transfer (MT) saturation can replace standard-dose enhanced MR imaging without MT saturation in patients who have brain tumors.

SUBJECTS AND METHODS

Three sets of enhanced T1-weighted MR images were prospectively obtained for each of 25 patients with 32 brain tumors; the first conventional MR images without MT were obtained after administration of standard-dose (0.1-mmol/kg) gadopentetate dimeglumine. Within 1 week, patients underwent administration of one half-dose (0.05 mmol/kg) of the contrast medium, and then two sets of enhanced T1-weighted images were obtained with and then without MT. The degree of contrast enhancement was assessed qualitatively for all 32 tumors and quantitatively for 26 tumors. In the quantitative analysis, we compared mean values for tumor-brain contrast-to-noise ratios in three sets of images.

RESULTS

The visual conspicuity of enhancing lesions in half-dose T1-weighted MR images with MT was comparable with that of standard-dose conventional T1-weighted MR images in 43% of cases including most extraaxial tumors. In approximately 75% of cases, the degree of enhancement of the lesions was similar for half-dose T1-weighted images obtained with and without MT. Overall, mean values for tumor-brain contrast-to-noise ratios were significantly lower in half-dose T1-weighted images with MT than in standard-dose T1-weighted images. Also, mean values for tumor-brain contrast-to-noise ratios were significantly higher in half-dose T1-weighted images with MT than in half-dose T1-weighted images without MT.

CONCLUSION

Because half-dose enhanced MR imaging with MT yields enhancement comparable with that of standard-dose enhanced conventional MR imaging in less than 50% of cases, the former technique would replace the latter in only limited cases such as selected extraaxial tumors.

Acyl-adenylate motif of the acyl-adenylate/thioester-forming enzyme superfamily: a site-directed mutagenesis study with the Pseudomonas sp. strain CBS3 4-chlorobenzoate:coenzyme A ligase

4-Chlorobenzoate:coenzyme A (4-CBA:CoA) ligase catalyzes 4-chlorobenzoyl-coenzyme A formation in a two-step reaction consisting of the adenylation of 4-chlorobenzoate with adenosine 5'-triphosphate followed by acyl transfer from the 4-chlorobenzoyl adenosine 5'-monophosphate diester intermediate to coenzyme A. In this study, two core motifs present in the Pseudomonas sp. strain CBS3 4-CBA:CoA ligase (motif I, 161T-S-G-T-T-G-L-P-K-G170, and motif II, 302Y-G-T-T-E306) and conserved among the sequences representing the acyl-adenylate/thioester-forming enzyme family (to which the ligase belongs) were tested for their possible role in substrate binding and/or catalysis. The site-directed mutants G163I, G166I, P168A, K169M, and E306Q were prepared and then subjected to steady-state and transient kinetic studies. The results, which indicate reduced catalysis of the adenylation of 4-chlorobenzoate in the mutant enzymes, are interpreted within the context of the three-dimensional structure of the acyl-adenylate/thioester-forming enzyme family member, firefly luciferase.

Biphasic effects of pu-chung-i-chi-tang on sedation and excitation

The biphasic effects of Pu-Chung-I-Chi-Tang (PCT) on sedation and excitation in acute treatment or after one-week consecutive treatment were studied. The results indicated that PCT produces sedation in acute treatment and excitation after one-week consecutive treatment. The sedative mechanism of PCT in acute treatment might be due to an increase in serotonergic activity and a decrease in dopaminergic activity. However, the excitatory mechanism of PCT after one-week consecutive treatment might involve the increase in dopaminergic activity and the decrease in serotonergic activity.

Protective effect of tetrandrine on normal human mononuclear cells against ionizing irradiation

Tetrandrine, an alkaloid isolated from the plant Stephania tetrandra, at low concentration (2 micrograms/ml) was shown to protect normal human mononuclear cells in vitro against damage due to a single high-dose of ionizing irradiation (10 Gy). The cell survival rate increased from 58.3 +/- 2.2% in the irradiated group to 78.0 +/- 2.6% in the tetrandrine-pretreated group, and similarly, the percentage of necrotic cells declined from 20.7 +/- 2.5% to 10.7 +/- 1.9%, respectively. This protective effect of tetrandrine for cell surviving fraction increased in a dose-dependent manner. Tetrandrine was also found to inhibit inflammatory responses induced by irradiation including the release of superoxide (NBT [nitroblue tetrazolium] reduction decreased from 21.3 +/- 2.3% to 10.2 +/- 2.5%) and phagocytic activity (decreased from 80.7 +/- 3.8% to 50.7 +/- 2.3%, the same range level as that of the control group). However, the alkaloid demonstrated no effect on the production of nitric oxide. In terms of cell morphology, only two types were observed-normal or necrotic cells, and there were no characteristics of programmed cell death. These results indicate that tetrandrine possesses radioprotective activity against 10 Gy of ionizing irradiation and could suppress irradiation-induced inflammatory processes.

Rapid purification and characterization of nucleoside diphosphate kinase isoforms using ATP-sepharose affinity column chromatography

Nucleoside diphosphate kinases (NDP kinases), products of the nm23 gene, catalyze the transfer of the terminal phosphate group of the nucleoside triphosphate to the corresponding diphosphate and may be involved in tumor metastasis suppression, development, and signal transduction. NDP kinase from various sources including human erythrocytes, rat brain tissue and E. coli strain BL21 transformed with pET3C expression plasmids containing nm23-H1 or nm23-H2, were purified in one step to homogeneity using ATP-sepharose affinity column chromatography. This method was applicable for the purification of various NDP kinases which show the same enzymatic activity and immunodetection, but have various molecular weight and quaternary structures.