In vivo newly translated polypeptides are sequestered in a protected folding environment

Molecular chaperones play a fundamental role in cellular protein folding. Using intact mammalian cells we examined the contribution of cytosolic chaperones to de novo folding. A large fraction of newly translated polypeptides associate transiently with Hsc70 and the chaperonin TRiC/CCT during their biogenesis. The substrate repertoire observed for Hsc70 and TRiC is not identical: Hsc70 interacts with a wide spectrum of polypeptides larger than 20 kDa, while TRiC associates with a diverse set of proteins between 30 and 60 kDa. Overexpression of a bacterial chaperonin 'trap' that irreversibly captures unfolded polypeptides did not interrupt the productive folding pathway. The trap was unable to bind newly translated polypeptides, indicating that folding in mammalian cells occurs without the release of non-native folding intermediates into the bulk cytosol. We conclude that de novo protein folding occurs in a protected environment created by a highly processive chaperone machinery and is directly coupled to translation.

Intracranial acute arterial ischemia of the anterior circulation: evaluation with three-dimensional time-of-flight magnetic resonance angiography

BACKGROUND

Stroke has been the second most common cause of death, after cancer, in Taiwan since 1983. The cost of stroke to society in terms of morbidity, mortality and economics is profound. Heightened interest in the early diagnosis and treatment of acute stroke challenges neuroimagers to optimize available modalities and to develop new techniques for the evaluation of cerebrovascular disease. The aim of this study was to investigate the effectiveness of magnetic resonance angiography (MRA) in conjunction with spin-echo imaging in patients with acute brain infarction of the anterior circulation.

METHODS

Magnetic resonance imaging and three-dimensional Fourier transformed time-of-flight MRA studies, performed on 50 patients within one week after the onset of cerebral ischemia, were retrospectively reviewed and correlated with clinical records. Five of the 50 MRAs were considered nondiagnostic and excluded because of poor patient cooperation.

RESULTS

In 41 of the 45 cases, the area of infarct corresponding to the clinical deficit at the time of study was identified on T2-weighted spin-echo images. Arterial occlusions or severe stenoses that corresponded to ischemic manifestations were identified with MRA in 37 of the 45 patients. A focal discontinuity with decreased arterial caliber corresponded to stenosis and nonvisualization of distal branches represented arterial occlusion. MRA provided information for 23 cases not obtained from the MR images.

CONCLUSIONS

Vascular lesions demonstrated on intracranial MRA show a high correlation with infarct distribution. MRA, which provides information adjunctive to conventional MR imaging in a majority of cases, is concluded to be an important component of the complete evaluation of brain infarction.

Intracranial cystic cavernous angioma: a case report

We present a case of cystic cavernous angioma in an 18-year-old woman with the chief complaint of acute onset of seizures. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a tumor with a slightly enhanced solid calcified portion and a large cystic portion. The patient was well without recurrence 6 months after surgery. The importance of MR imaging in the differential diagnoses is emphasized.

Primary intracranial leiomyoma: case report

We present a case of intracranial parenchymal leiomyoma in a 20-year-old woman with a chief complaint of numbness and a painful sensation over the right limbs for several years. CT and MRI revealed an intensely enhancing calcified mass. The patient was well, without recurrence, 2 years after surgery.

Contracture of the deltoid muscle: imaging findings in 17 patients

OBJECTIVE

A retrospective review of the MR images and radiographs of 26 shoulders in 17 patients suffering from contracture of the deltoid muscle was used to establish the characteristic imaging findings.

MATERIALS AND METHODS

Deltoid muscle contractures in 26 shoulders in 17 patients encountered over a 4-year period are reported. The history of intramuscular injection and clinical symptoms and signs are detailed. Imaging studies including routine radiographs (24 shoulders), MR images (25 shoulders), and computed arthrotomograms (two shoulders) were reviewed. On MR images, the winging angle of the scapula (angle between the axis of the scapular body and the coronal plane of the chest) and the diameter of the lesion were measured and compared with data derived from 24 age-matched control subjects.

RESULTS

Diagnostic MR features of deltoid muscle contracture include fibrotic cord in the deltoid muscle, especially its middle portion, extending from the superior acromial surface to the deltoid tuberosity, and winging of the scapula (increased winging angle of the scapula). Characteristic radiographic features include abduction contracture, winging of the scapula, lateral down-sloping of the acromial process, and a superior acromial enthesophyte.

CONCLUSION

MR images are sensitive and accurate in the diagnosis of contracture of the deltoid muscles. Characteristic features also allow accurate routine diagnosis on radiographs.

Serotype-specific identification of polioviruses by PCR using primers containing mixed-base or deoxyinosine residues at positions of codon degeneracy

We have developed a method for determining the serotypes of poliovirus isolates by PCR. Three sets of serotype-specific antisense PCR-initiating primers (primers seroPV1A, seroPV2A, and seroPV3A) were designed to pair with codons of VP1 amino acid sequences that are conserved within but that differ across serotypes. The sense polarity primers (primers seroPV1S, seroPV2S, and seroPV3S) matched codons of more conserved capsid sequences. The primers contain mixed-base and deoxyinosine residues to compensate for the high rate of degeneracy of the targeted codons. The serotypes of all polioviruses tested (48 vaccine-related isolates and 110 diverse wild isolates) were correctly identified by PCR with the serotype-specific primers. None of the genomic sequences of 49 nonpolio enterovirus reference strains were amplified under equivalent reaction conditions with any of the three primer sets. These primers are useful for the rapid screening of poliovirus isolates and for determining the compositions of cultures containing mixtures of poliovirus serotypes.

Genotype-specific RNA probes for direct identification of wild polioviruses by blot hybridization

We have developed RNA probes for the direct identification of wild poliovirus isolates by blot hybridization. The probes are complementary to sequences of the first 30 to 32 codons of VP1, which evolve more extensively (approximately 1.5-fold) than the rest of VP1. To illustrate our general approach, we describe the design of probes specific to each of four major genotypes recently endemic (1981 to 1991) to the Americas: Andean type 1, Brazil type 1, Brazil type 3, and Central America-Mexico type 3. A wild isolate of each genotype was selected according to molecular and epidemiologic criteria to be representative of the principal lineages in circulation. Variable VP1 sequences of the representative isolates were amplified by the reverse transcriptase PCR and were inserted into a plasmid vector containing a T7 promoter. The in vitro transcripts, labeled with digoxigenin, served as probes. These formed stable hybrids only with RNAs of isolates of the corresponding genotypes. Hybrids were detected by a sensitive chemiluminescence assay, capable under normal diagnostic conditions of detecting specific wild poliovirus sequences in samples containing up to a 100-fold excess of Sabin vaccine strain-related sequences of the same serotype.

Disseminated miliary cerebral candidiasis

We present a case of disseminated intracranial infection by Candida albicans in a 5-year-old girl who had fever and a change of consciousness after surgery for complex congenital heart malformation. MR imaging revealed multiple small ring-enhancing hemorrhagic abscesses. One year after antifungal treatment, the abscesses and ventriculomegaly were almost completely resolved. The patient was discharged in a stable but vegetative condition.

Cadmium-induced oxidative cellular damage in human fetal lung fibroblasts (MRC-5 cells)

Epidemiological evidence suggests that cadmium (Cd) exposure causes pulmonary damage such as emphysema and lung cancer. However, relatively little is known about the mechanisms involved in Cd pulmonary toxicity. In the present study, the effects of Cd exposure on human fetal lung fibroblasts (MRC-5 cells) were evaluated by determination of lipid peroxidation, intra-cellular production of reactive oxygen species (ROS), and changes of mitochondrial membrane potential. A time- and dose-dependent increase of both lactate dehydrogenase leakage and malondialdehyde formation was observed in Cd-treated cells. A close correlation between these two events suggests that lipid peroxidation may be one of the main pathways causing its cytotoxicity. It was also noted that Cd-induced cell injury and lipid peroxidation were inhibited by catalase and superoxide dismutase, two antioxidant enzymes. By using the fluorescent probe 2',7'-dichlorofluorescin diacetate, a significant increase of ROS production in Cd-treated MRC-5 cells was detected. The inhibition of dichlorofluorescein fluorescence by catalase, not superoxide dismutase, suggests that hydrogen peroxide is the main ROS involved. Moreover, the significant dose-dependent changes of mitochondrial membrane potential in Cd-treated MRC-5 cells, demonstrated by increased fluorescence of rhodamine 123 examined using a laser-scanning confocal microscope, also indicate the involvement of mitochondrial damage in Cd cytotoxicity. These findings provide in vitro evidence that Cd causes oxidative cellular damage in human fetal lung fibroblasts, which may be closely associated with the pulmonary toxicity of Cd.

Squamous cell carcinoma of esophagus with diffuse mucin-secreting component: a clinicopathologic study

BACKGROUND

Primary esophageal squamous cell carcinomas with a diffuse mucin-secreting component are not common, and the cases reported are few. The nomenclature for this group of tumors is complex and the histogenesis of these tumors is confused. Therefore, further investigation is needed.

METHODS

Twelve cases have been collected from pathology files of Veterans General Hospital-Taipei from 1965 to 1995. Clinicopathologic relationship, histopathological and immunohistochemical features of these cases were analyzed and compared with the reported literature concerning this entity.

RESULTS

The age, sex and prognosis for patients of this group, and the size and site of the tumors were not different from that of pure squamous cell carcinoma. The tumors continuously connected with esophageal squamous epithelium, and intraepithelial dysplasia were present in 83% cases. Positive anticarcinoembryonic antigen staining was also demonstrated in squamous epithelium, dysplastic epithelium and tumor cells with either squamous or adenomatous differentiation.

CONCLUSIONS

It is believed that esophageal squamous cell carcinoma with diffuse mucin-secreting component is close to the squamous cell carcinoma.

Percutaneous transsplenic catheterization of the portal venous system

PURPOSE

To evaluate the safety and feasibility of transsplenic portal vein catheterization.

MATERIAL AND METHODS

Under ultrasonic guidance, percutaneous transsplenic splenic vein catheterization was performed in 17 patients. Two of the patients had minimal and 5 moderate ascites. In 11 patients, the platelet counts were over 50000/mm3 and the coagulation time normal or mildly prolonged, while 6 patients had either platelet counts of less than 50000/mm3 or moderately prolonged coagulation level.

RESULTS

Transsplenic portal catheterizations were successfully performed in 16 of the 1/patients (one failed because of small splenic size). Procedure-related complications occurred in 3 patients with 2 requiring one unit of packed RBC transfusion. The third patient accumulated minimal fluid in the left pleural space. Imaging studies within one week of the procedure were made in 8 patients. These examinations revealed an intrasplenic hematoma in 2 patients. One patient had a small amount of hemoperitoneum. No major complications occurred.

CONCLUSION

Transsplenic portal venous catheterization is a safe and feasible procedure.

Correlation of high-resolution CT and pulmonary function in bronchiolitis obliterans: a study based on 24 patients associated with consumption of Sauropus androgynus

OBJECTIVE

An outbreak of Sauropus androgynus-associated bronchiolitis obliterans occurred in Taiwan in the summer of 1995. We undertook a study of the correlation between high-resolution CT findings and pulmonary function testing in patients from this outbreak.

MATERIALS AND METHODS

We evaluated inspiratory-expiratory high-resolution CT scans of 24 patients with S. androgynus-associated bronchiolitis obliterans. The presence of bronchiectasis was assessed by two visual scores (a bronchial dilatation score and a bronchiectasis extent score). Extent of air-trapping was assessed visually and given a score. We also used computer software to assess the extent of air-trapping and generate scores of dynamic attenuation. Spirometry, plethysmography, and diffusion capacity of each patient were also obtained.

RESULTS

All four scores had statistically significant correlation with forced expiratory volume in 1 sec (FEV1) (p < .05 for both bronchiectasis scores; p < .001 for both air-trapping scores). The two air-trapping scores had statistically significant correlation with forced vital capacity and diffusion capacity. We found the scores for dynamic attenuation had the greatest correlation with FEV1 (r = .85). We also found that mosaic attenuation was notable on expiratory CT scans alone in nine patients (type 1 air-trapping) and on both inspiratory and expiratory CT scans in 15 patients (type 2 air-trapping). In the latter group, FEV1 was significantly lower (p < .01).

CONCLUSION

Findings from high-resolution CT of air-trapping were more important than findings of bronchiectasis when correlating pulmonary function with S. androgynus-associated bronchiolitis obliterans. Type 2 air-trapping suggested a more severe air-flow obstruction than did type 1. Scores for quantitative attenuation generated by computer software were helpful in assessing air-trapping and correlating it with pulmonary function. These findings may apply to patients with bronchiolitis obliterans from other causes.

Percutaneous transsplenic catheterization of the portal venous system

PURPOSE

To evaluate the safety and feasibility of transsplenic portal vein catheterization.

MATERIAL AND METHODS

Under ultrasonic guidance, percutaneous transsplenic splenic vein catheterization was performed in 17 patients. Two of the patients had minimal and 5 moderate ascites. In 11 patients, the platelet counts were over 50000/mm3 and the coagulation time normal or mildly prolonged, while 6 patients had either platelet counts of less than 50000/mm3 or moderately prolonged coagulation level.

RESULTS

Transsplenic portal catheterizations were successfully performed in 16 of the 1/patients (one failed because of small splenic size). Procedure-related complications occurred in 3 patients with 2 requiring one unit of packed RBC transfusion. The third patient accumulated minimal fluid in the left pleural space. Imaging studies within one week of the procedure were made in 8 patients. These examinations revealed an intrasplenic hematoma in 2 patients. One patient had a small amount of hemoperitoneum. No major complications occurred.

CONCLUSION

Transsplenic portal venous catheterization is a safe and feasible procedure.

Group-specific identification of polioviruses by PCR using primers containing mixed-base or deoxyinosine residue at positions of codon degeneracy

We have developed a method for differentiating polioviruses from nonpolio enteroviruses using PCR. A pair of panpoliovirus PCR primers were designed to match intervals encoding amino acid sequences within VP1 that are strongly conserved among polioviruses. The initiating primer hybridizes with codons of a 7-amino-acid sequence that has been found only in polioviruses; the second primer matches codons of a domain thought to interact with the cell receptor. The panpoliovirus PCR primers contain mixed-base and deoxyinosine residues to compensate for the high degeneracy of the targeted codons. All RNAs from 48 vaccine-related and 110 wild poliovirus isolates of all three serotypes served as efficient templates for amplification of 79-bp product. None of the genomic sequences of 49 nonpolio enterovirus reference strains were amplified under equivalent reaction conditions. Sensitivities of poliovirus detection were as low as 100 fg (equivalent to approximately 25,000 genomic copies or 25 to 250 PFU) when the amplified products were visualized by ethidium bromide fluorescence. These degenerate PCR primers should aid in the detection of all polioviruses, including those wild poliovirus isolates for which genotype-specific reagents are unavailable.

Langerhans' cell histiocytosis (histiocytosis-X) in a women with typical ultrastructure of Birbeck's granule: a case report

A 28-year-old woman was admitted to our hospital with the chief complaint of progressive gingival swelling with easy bleeding and loosening of teeth for about two years. The liver and spleen were not enlarged and there were no lymphadenopathy. The hemogram was normal. The skull X-ray showed floating teeth. CT scan of face showed destructive bony lesions over maxilla and left mandible with adjacent soft tissue swelling. Pathologic examination of the gingiva revealed that the oral mucosal tissue was heavily infiltrated with histiocyte-like Langerhans' cells. The Langerhans' cells showed positive immunostain for S-100 protein. Under electron microscope, ultrastructure of the Langerhans' cells revealed typical intracytoplasmic tennnis racquet-shaped structure with a central zipper-like striation (Birbeck's granules). Langerhans' cell histiocytosis was diagnosed. She received rdiotherapy with a total dose of 1,000 cGy in fractions and oral chemotherapeutic drugs. Painful gingival swelling subsided gradually. She was followed at our OPD for the past 10 months and there was no evidence of local recurrence. Langerhans' cell histiocytosis is a rare disease. The relevant literature about its distinct pathologic features, clinical course and treatment is reviewed.

Computed tomography in the diagnosis of organic bowel obstruction

BACKGROUND

This study examined the usefulness of computed tomography (CT) scan for cases of organic intestinal obstruction, with two simple criteria.

METHODS

One hundred and thirteen patients with clinical suspicion of bowel obstruction were referred for CT scans. A line was drawn between the dilated proximal, and the collapsed distal bowels. A careful search was conducted on this line for obstructive lesions. The results were reported to be organic obstruction if there was an abrupt change of caliber (Criterion I) or a soft tissue mass around the dilated bowel (Criterion II). The judgement based on the CT findings.

RESULTS

Eighty-eight cases proved to have bowel obstruction. With Criterion I, the sensitivity was 59.1%, and specificity, 88% with Criterion II, the sensitivity was 56.3% and specificity 100%. If either of them was considered to be a positive sign of organic obstruction, the sensitivity was 100%, the specificity 88% and the accuracy 97.3%. The nature of the obstructions were precisely predicted in 76 patients (86%).

CONCLUSIONS

With these two simple criteria, CT scan can achieve high accuracy and is a recommendation in virtually every instance when intestinal obstruction is suspected.

Adenosquamous carcinoma and schneiderian papilloma-like lesion in a mature cystic teratoma of the ovary: a case report

Malignant transformation is uncommon in the mature cystic teratoma of ovary, in which adenosquamous carcinoma is even rarer. It seldom combines with papillary lesion, like schneiderian papilloma of upper airway. We report such a rare case of mature cystic teratoma undergoing malignant change, with the pictures of both adenosquamous carcinoma and schneiderian papilloma.

Experience with transjugular intrahepatic portosystemic shunts for gastroesophageal variceal bleeding

BACKGROUND

Variceal bleeding is a major life-threatening complication of cirrhosis of the liver. Transjugular intrahepatic portosystemic shunts (TIPS) have been accepted as an effective method for portal decompression. Experiences here with the use of TIPS for control of gastroesophageal variceal bleeding is presented.

METHODS

Sixteen TIPS procedures were performed for 15 patients who suffered from intractable gastroesophageal variceal bleeding. Nine cases (60%) were hepatitis-related cirrhosis of liver, four (27%) were alcoholic liver cirrhosis and two were cryptogenic in origin. Liver function tests revealed four patients were Child-Pugh's classification A, five were B and six, C. Twelve cases had received failed endoscopic management of varices; and one patient had recurrent variceal bleeding after devascularization. TIPS procedure was performed electively in nine cases and, as an emergency in six cases.

RESULTS

Fifteen of the 16 TIPS procedures attempted were successfully performed. The technically successful rate was 94% (15/16), but two cases with successful TIPS procedure expired at the end of the procedure from hypovolemic shock and acute respiratory distress, respectively; thus the completely successful rate was 81% (13/16), The initial bleeding control rate was 83% (5/6) for the six patients with active bleeding. Portal venous pressure was significantly decreased from 30.8 +/- 5.8 mmHg before TIPS to 21.7 +/- 6.0 mmHg after the procedure (P < 0.01) and the porto-systemic pressure gradient also significantly decreased from 23.0 +/- 3.6 mmHg to 11.9 +/- 2.7 mmHg after TIPS (P < 0.01). Recurrent variceal bleeding was noted in four patients (33%) and that was managed by percutaneous transluminal angioplasty (PTA) of shunt, placement of additional stent, second TIPS procedure and a devascularization operation. Hepatic encephalopathy was noted in three patients (25%) after TIPS.

CONCLUSIONS

TIPS is an effective method to control variceal bleeding caused by portal hypertension, especially when endoscopic or surgical management has failed or is contraindicated.

Azygos blood flow in cirrhosis: measurement with MR imaging and correlation with variceal hemorrhage

PURPOSE

To evaluate magnetic resonance (MR) measurement of azygos blood flow (ABF) in assessment of risk of variceal hemorrhage in cirrhosis.

MATERIALS AND METHODS

ABF in 50 patients with cirrhosis and 20 healthy control subjects was evaluated with phase-contrast cine MR imaging at the transaxial subcarinal plane. Group 1 included nine patients with cervical-drainage varices draining into brachiocephalic vein; group 2 included 41 patients with varices draining into azygos vein and was subdivided as group 2A, 15 patients with variceal hemorrhage, and group 2B, 26 without variceal hemorrhage.

RESULTS

Azygos flow rate and velocity were increased in patients compared with that in control subjects. ABF in group 2A was faster than that in group 2B (cutoff, 15 cm/sec; sensitivity, 80%; specificity, 89%). Group 1 had ABF close to that of group 2B, but variceal hemorrhage occurred in seven of nine patients in group 1 versus 15 of 41 patients in group 2 (78% vs 37%; P = .029).

CONCLUSION

Patients with cirrhosis with cervical-drainage varices or ABF greater than 15 cm/sec may have higher risk for variceal hemorrhage.

Genetic and topological analyses of the bop promoter of Halobacterium halobium: stimulation by DNA supercoiling and non-B-DNA structure

The bop gene of wild-type Halobacterium halobium NRC-1 is transcriptionally induced more than 20-fold under microaerobic conditions. bop transcription is inhibited by novobiocin, a DNA gyrase inhibitor, at concentrations subinhibitory for growth. The exposure of NRC-1 cultures to novobiocin concentrations inhibiting bop transcription was found to partially relax plasmid DNA supercoiling, indicating the requirement of high DNA supercoiling for bop transcription. Next, the bop promoter region was cloned on an H. halobium plasmid vector and introduced into NRC-1 and S9, a bop overproducer strain. The cloned promoter was active in both H. halobium strains, but at a higher level in the overproducer than in the wild type. Transcription from the bop promoter on the plasmid was found to be inhibited by novobiocin to a similar extent as was transcription from the chromosome. When the cloned promoter was introduced into S9 mutant strains with insertions in either of two putative regulatory genes, brp and bat, no transcription was detectable, indicating that these genes serve to activate transcription from the bop promoter in trans. Deletion analysis of the cloned bop promoter from a site approximately 480 bp upstream of bop showed that a 53-bp region 5' to the transcription start site is sufficient for transcription, but a 28-bp region is not. An 11-bp alternating purine-pyrimidine sequence within the functional promoter region, centered 23 bp 5' to the transcription start point, was found to display DNA supercoiling-dependent sensitivity to S1 nuclease and OsO4, which is consistent with a non-B-DNA conformation similar to that of left-handed Z-DNA and suggests the involvement of unusual DNA structure in supercoiling-stimulated bop gene transcription.

Binding specificity of post-activated neocarzinostatin chromophore drug-bulged DNA complex studied using electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry (ESI-MS) was employed to characterize the binding specificity of a bulged 22-mer DNA hairpin with a post-activated neocarzinostatin chromophore (NCS-Chrom) having two similar forms, where 2a has an H in a location for which 2b has it replaced by a CH2OH group. Specific binding of 2a to the bulged 22-mer DNA was observed whereas little binding was detected for 2a to non-bulged DNA 19-mer and 12-mer duplexes. The stoichiometry of the 22-mer DNA complex with 2a was determined to be predominantly 1:1. Substitution of hydrogen in 2a for the hydroxymethylene group in 2b dramatically reduced the binding strength to the 22-mer DNA. Little complex formation was observed for 2b and 22-mer DNA based upon the ESI-MS data, consistent with earlier fluorescence studies. The results indicate that ESI-MS can be a sensitive technique for probing conformational specificity in studies of biomolecular binding.

Chorea-ballismus with nonketotic hyperglycemia in primary diabetes mellitus

PURPOSE

To describe the neuroimaging (Ct, MR, and single-photon emission CT [SPECT]) findings in a series of patients with chorea-ballismus associated with nonketotic hyperglycemia in primary diabetes mellitus and to correlate the imaging findings with the clinical presentation.

METHODS

The neuroimaging and clinical data from 10 patients with chorea-ballismus associated with nonketotic hyperglycemia in primary diabetes mellitus were evaluated. Family and drug histories, as well as other causes of chorea, were excluded. All 10 patients had CT, 5 also had MR imaging, and 3 had SPECT examinations. Three had follow-up CT and MR imaging studies, and MR findings were correlated with CT findings in 5 cases. Two experienced neuroradiologists, aware of the diagnosis but blinded to the clinical status of the patients, evaluated all images and reached a consensus as to the final interpretation.

RESULTS

CT studies in 9 of 10 patients showed a hyperdense putamen and/or caudate nucleus; in 1, the CT findings were normal. T1-weighted MR images in all 5 patients who had MR imaging (including the patient with a normal CT study) showed hyperintense lesions without significant T2 signal alternation at the basal ganglia. In all 3 of the patients who had SPECT studies of the brain, the scans revealed hypoperfusion at corresponding areas. All 3 follow-up studies depicted resolution of the lesions in the abnormal basal ganglia. Increased hypointensity on T2-weighted and gradient-echo T2*-weighted images was also observed in the sequential MR images. In all patients, the initial side of involvement correlated well with the neuroimaging findings. The chorea resolved within 2 days after treatment of the hyperglycemia in 9 patients.

CONCLUSION

In patients with chorea-ballismus associated with nonketotic hyperglycemia in primary diabetes mellitus, CT and T1-weighted MR images show unilateral or bilateral lesions of the putamen and/or caudate. SPECT scans show hypoperfusion. These findings may be related to petechial hemorrhage and/or myelin destruction. Early recognition of these imaging characteristics may facilitate diagnosis of primary diabetes mellitus with hyperglycemia and prompt appropriate therapy.

Carcinosarcoma of the salivary gland on CT

Three cases of carcinosarcoma of the salivary gland, two in the submandibular gland, and one in the parotid, were investigated with CT and exhibited a variety of findings. The density of the tumors was lower than that of normal submandibular tissue. A calcification was found in one case. One case showed extensive lymphadenopathy. The parotid lesion had low central density with an enhancing margin.

Mesoblastic nephroma: a case report

Mesoblastic nephroma is a rare tumor of kidney characterized by interlacing bundles of spindle mesenchymal cells. The tumor usually occurs in the newborn, and scarcely in the old child. In this article, the authors report a case of an unusual age, a 12-year-old boy, with mesoblastic nephroma which was found by routine physical examination.

Identification of vaccine-related polioviruses by hybridization with specific RNA probes

We developed RNA probes for the identification of poliovirus isolates by blot hybridization. Two sets of vaccine strain-specific probes were prepared. They complemented variable genomic domains within (i) the 5'-untranslated region and (ii) the amino-terminal codons of VP1. An enterovirus group probe (EV/5UT) matching highly conserved 5'-untranslated region sequences was used to estimate the quantities of poliovirus (or enterovirus) RNA in the samples. Poliovirus sequences amplified from Sabin strain virion RNA templates by PCR were inserted into the pUC18 plasmid vector. The antisense PCR primer for each probe set contained sequences encoding a T7 promoter. Hybrids were detected by a sensitive nonisotopic method. RNA probes were labeled by incorporation of digoxigenin-uridylate into the transcripts. The binding of probe to immobilized poliovirus RNAs was visualized by hydrolysis of the chemiluminescent substrate 4-methoxy-4-(3-phosphate-phenyl)-spiro-(1,2-dioxetane-3,2'-adamant ane) catalyzed by alkaline phosphatase conjugated to anti-digoxigenin (Fab) fragments. The specificities of the probes were evaluated with a panel of poliovirus isolates that had previously been characterized by sequence analysis. The RNAs of vaccine-related isolates hybridized with the appropriate probe sets. Wild polioviruses representing a broad spectrum of contemporary genotypes were recognized by the inabilities of their genomes to form stable hybrids with the Sabin strain-specific probes.

Specific binding of the biradical analog of neocarzinostatin chromophore to bulged DNA: implications for thiol-independent cleavage

The enediyne anticancer antibiotic neocarzinostatin chromophore generates a single, site-specific break at a bulge in DNA in a thiol-independent reaction, involving intramolecular drug activation under general base catalysis [Kappen, L. S., & Goldberg, I. H. (1993) Biochemistry 32, 13138-13145]. As part of an effort to elucidate the three-dimensional structure of the active complex formed between the labile drug and bulged DNA, we have studied the binding of stable drug products generated in the course of the cleavage reaction with oligodeoxynucleotides containing the bulged structure. By use of fluorescence quenching, we have found that one drug product, which is also formed in the absence of bulged DNA and most closely resembles the biradical intermediate in the cleavage reaction, specifically binds bulged DNA with a Kd in the low micromolar range and competitively inhibits the cleavage reaction. Other drug products, including one formed only in the presence of bulged DNA, fail to bind to the bulged DNA. Implications of these results for the proposed mechanism of bulge-specific cleavage and for the role of the DNA bulge in generating a unique drug product are discussed.

Transcatheter arterial embolization with or without cisplatin treatment of hepatocellular carcinoma. A randomized controlled study

BACKGROUND

This randomized controlled study was objectively designed to evaluate the utility cisplatin (50 mg) in transcatheter arterial embolization (TAE) for treatment of hepatocellular carcinoma (HCC).

METHODS

From May 1991 to July 1993, 46 patients were included in the study. All had a pathologic verification of HCC. Clinically, all of the patients were considered inoperable. However, these patients satisfied eligibility criteria for TAE. The patients were divided into two groups by random sampling. In group I, 22 patients received TAE with the regimen of cisplatin (50 mg) mixed with Lipiodol 5-15 ml followed by gelfoam pieces. In group II, 24 patients, as a controlled group, used the regimen of Lipiodol and gelfoam (Spongostan Film, Ferrosan, Denmark) pieces only, without adding any anticancer drug. The two groups were evaluated by a series of imaging studies and various clinical examinations before and after TAE. Subsequently, TAE was performed every 2 or 3 months for all patients until there was no visible tumor, or the patient could not sustain further TAE, or the patient died.

RESULTS

In group I, TAE was administered 61 times (average 28 times for each patient), and in group II, 73 times (average 3 times for each patient). The 1-year and 2-year survival rates of group I were 52.5% and 26.2%, and group II were 72.5% and 39.5%. Statistically, there was no significant difference in survival curves and survival rates between these two groups. Tumor response rate of group I was 68% (15/22) and group II was 67% (16/24). There was no significant difference in tumor response between these two groups. The liver and renal function studies after TAE also showed no significant difference between these two groups.

CONCLUSIONS

Based on this controlled study, the authors conclude that the addition of cisplatin does not enhance the therapeutic effect of TAE for treatment of HCC.

Mouse neurovirulence determinants of poliovirus type 1 strain LS-a map to the coding regions of capsid protein VP1 and proteinase 2Apro

Poliovirus type 1 strain LS-a [PV1(LS-a)] is a OV variant adapted to mice by multiple passages through mouse and monkey tissues. To investigate the molecular basis underlying mouse neurovirulence of PV1(LS-a), a cDNA of the viral genome containing nucleotides 112 to 7441 was cloned, and the nucleotide sequence was determined. Compared with that of the mouse avirulent progenitor PV1(Mahoney), 54 nucleotide changes were found in the genome of the PV1(LS-a) virus, resulting in 20 amino acid substitutions in the virus polyprotein. Whereas the nucleotide changes were scattered throughout the genome, the amino acid substitutions were largely clustered in the capsid proteins and, to a certain extent, in the virus proteinase 2Apro. By in vitro mutagenesis, PV1(LS-a)-specific capsid mutations were introduced into a cDNA clone of PV1(Mahoney). We show that neither the individual amino acid mutations nor combinations of mutations in the region encoding VP1 conferred to PV1(Mahoney) the mouse-adapted phenotype of PV1(LS-a). Chimeric cDNA studies demonstrated that a recombinant type 1 virus containing the PV1(LS-a) sequence from nucleotide 2470 to nucleotide 3625 displayed a neurovirulent phenotype in mice. Further dissection of this region revealed that mouse neurovirulence of PV1(LS-a) was determined by multiple mutations in regions encoding both viral proteinase 2Apro and capsid protein VP1. The mouse neurovirulent viruses, PV1(LS-a), W1-M/LS-Pf [nucleotides 496 to 3625 from PV1(LS-a)], and W1-M/LS-NP [nucleotides 2470 to 3625 from PV1(LS-a)], showed increased sensitivity to heat treatment at 45 degrees C for 1 h. Surprisingly, the thermolabile phenotype was also displayed by a recombinant of PV1(Mahoney) carrying a PV1(LS-a) DNA fragment encoding the N-terminal portion of 2Apro. This suggests that base substitutions in the region encoding 2Apro affected capsid stability, thereby contributing to the neurovirulence of the virus in mice.

Transcatheter arterial embolization with or without cisplatin treatment of hepatocellular carcinoma. A randomized controlled study

BACKGROUND

This randomized controlled study was objectively designed to evaluate the utility cisplatin (50 mg) in transcatheter arterial embolization (TAE) for treatment of hepatocellular carcinoma (HCC).

METHODS

From May 1991 to July 1993, 46 patients were included in the study. All had a pathologic verification of HCC. Clinically, all of the patients were considered inoperable. However, these patients satisfied eligibility criteria for TAE. The patients were divided into two groups by random sampling. In group I, 22 patients received TAE with the regimen of cisplatin (50 mg) mixed with Lipiodol 5-15 ml followed by gelfoam pieces. In group II, 24 patients, as a controlled group, used the regimen of Lipiodol and gelfoam (Spongostan Film, Ferrosan, Denmark) pieces only, without adding any anticancer drug. The two groups were evaluated by a series of imaging studies and various clinical examinations before and after TAE. Subsequently, TAE was performed every 2 or 3 months for all patients until there was no visible tumor, or the patient could not sustain further TAE, or the patient died.

RESULTS

In group I, TAE was administered 61 times (average 28 times for each patient), and in group II, 73 times (average 3 times for each patient). The 1-year and 2-year survival rates of group I were 52.5% and 26.2%, and group II were 72.5% and 39.5%. Statistically, there was no significant difference in survival curves and survival rates between these two groups. Tumor response rate of group I was 68% (15/22) and group II was 67% (16/24). There was no significant difference in tumor response between these two groups. The liver and renal function studies after TAE also showed no significant difference between these two groups.

CONCLUSIONS

Based on this controlled study, the authors conclude that the addition of cisplatin does not enhance the therapeutic effect of TAE for treatment of HCC.

The clinicopathological correlation of epithelial subtyping in thymoma: a study of 112 consecutive cases

The clinicopathological features of 112 thymomas collected from the surgical pathological files of Taipei Veterans General Hospital from 1961 to 1991 were investigated to determinate the clinical efficacy of epithelial subtyping. All thymomas were categorized based on the Müller-Hermelink system into three subtypes: cortical thymoma, mixed thymoma, and medullary thymoma. The former was further subclassified into organoid thymoma, conventional cortical thymoma, and well differentiated thymic carcinoma (WDTC) according to the systems of Pescarmona and Kirchner. The association of each subtype with sex, age at diagnosis, clinical stage, presence of myasthenia gravis, and length of survival was studied. As classified by the Müller-Hermelink system, the cortical thymomas as a whole tended to occur in younger patients and were more frequently associated with myasthenia gravis than the medullary thymomas. The cortical thymomas also showed a propensity to be invasive in nature, whereas the medullary thymomas generally behaved as benign tumors. Further subclassification of cortical thymomas into organoid thymoma, conventional thymoma, and WDTC did not provide more information about clinical behavior. By Kaplan-Meier's actuarial survival analyses none of the epithelial subtypes displayed a statistically significant influence on prognosis. It is concluded that staging remains the most important factor affecting the patient's outcome. Because of the existence of many intermediate forms and the deficiency of clinical relevance, the subclassification of cortical thymomas should be interpreted as a morphological continuum rather than as distinct histological variants.

Molecular dynamics simulation of a leucine zipper motif predicted for the integrase of human immunodeficiency virus type 1

We have used the molecular dynamics (MD) simulation package AMBER4 to search the conformation of a peptide predicted as a leucine zipper motif for the human immunodeficiency virus type 1 integrase protein (HIV IN-LZM). The peptide is composed of 22 amino acid residues and its location is from Val 151 to Leu 172. The searching procedure also includes two known alpha-helices that served as positive controls--namely, a 22-residue GCN4-p1 (LZM) and a 20-residue poly (L-alanine) (PLA). A 21-residue peptide extracted from a cytochrome C crystal (CCC-t) with determined conformation as a beta-turn is also included as a negative control. At the beginning of the search, two starting conformations--namely, the standard right-handed alpha-helix and the fully stretched conformations--are generated for each peptide. Structures generated as standard alpha-helix are equilibrated at room temperature for 90 ps while structures generated as a fully stretched one are equilibrated at 600 K for 120 ps. The CCC-t and PLA helices are nearly destroyed from the beginning of equilibration. However, for both the HIV IN-LZM and the GCN4-p1 LZM structures, there is substantial helicity being retained throughout the entire course of equilibration. Although helix propagation profiles calculated indicate that both peptides possess about the same propensity to form an alpha-helix, the HIV IN-LZM helix appears to be more stable than the GCN4-p1 one as judged by a variety of analyses on both structures generated during the equilibration course. The fact that predicted HIV IN-LZM can exist as an alpha-helix is also supported by the results of high temperature equilibration run on the fully stretched structures generated. In this run, the RMS deviations between the backbone atoms of the structures with the lowest potential energy (PE) identified within every 2 ps and the structure with the lowest PE searched in the same course of simulation are calculated. For both the HIV IN-LZM and the GCN4-p1 LZM, these rms values decrease with the decrease of PE, which indicates that both structures are closer in conformations as their PEs are moved deeper into the PE well.

The study of health effects of vinyl chloride air pollution on population

A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR), gamma-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3 for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control, but no gamm-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs.

Use of quantitative CT to predict postoperative lung function in patients with lung cancer

PURPOSE

To evaluate the effectiveness of quantitative computed tomography (CT) for predicting postoperative lung function in patients with lung cancer.

MATERIALS AND METHODS

Preoperative spirometry and conventional CT of the chest were performed in 38 patients. A postprocessing CT program was applied to quantitate the volume of whole-lung parenchyma with attenuations of -500 to -910 HU; this was defined as total functional lung volume (TFLV). The regional functional lung volume (RFLV) of the lobes or lung to be resected was quantitated separately. CT-predicted postoperative forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were derived by multiplying the preoperative spirometry values by (1 - RFLV/TFLV).

RESULTS

CT-predicted values correlated well with postoperatively measured results (FEV1: r = .93, P < .001; FVC: r = .86, P < .001) in patients who underwent pneumonectomy or lobectomy, regardless of the patient's preoperative ventilation status.

CONCLUSION

This method is effective in the prediction of postoperative FEV1 and FVC in patients undergoing pulmonary resection.

Distribution of wild type 1 poliovirus genotypes in China

Poliomyelitis remains an important public health problem in China. Most cases and outbreaks are associated with wild type 1 polioviruses. To obtain an overview of type 1 poliovirus transmission in China, partial genomic sequences were compared for 24 case isolates from 12 provinces. Because polioviruses evolve rapidly during infection of humans, the genetic relationships among isolates provide a measure of the extent of epidemiologic linkage among cases. The observed genetic relationships were complex: six different genotypes, apparently derived from five separate endemic origins, were found. One genotype was recombinant, having noncapsid sequences derived from the Sabin type 1 vaccine strain and capsid sequences derived from a genotype indigenous to several northern and eastern provinces. Some isolates from geographically separate provinces were closely related; other isolates were related to wild polioviruses found in neighboring countries. The combination of epidemiologic and virologic analyses may facilitate the development of more effective strategies for poliomyelitis eradication.

A spectrophotometric assay for alpha-ketoaldehydes using horse liver alcohol dehydrogenase

alpha-Ketoaldehydes have been extensively employed as reagents for the chemical modification of arginine residues in proteins, and to probe for putative anion recognition sites. A major disadvantage in their use is instability, as alpha-ketoaldehydes are prone to hydration, oxidation, and polymerization. These reagents are typically supplied as the aldehyde hydrates which are relatively stable, but must be purified and standardized prior to analytical use. The known chemical, spectroscopic, and enzymatic methods for quantitating alpha-ketoaldehydes are not practical for routine analysis due principally to their high detection limits and sensitivity to interfering substances. Surprisingly, alpha-ketoaldehydes have not been reported as substrates for the alcohol dehydrogenases. We have discovered that phenylglyoxal and several related alpha-ketoaldehydes are good substrates for horse liver alcohol dehydrogenase (HLADH). The second order rate constants (kcat/Km) are within a factor of 10 of that for the reduction of acetaldehyde, a known good substrate for HLADH. The enzymatic reduction reaction is stoichiometric with the oxidation of NADH, resulting in a rapid, convenient, and sensitive method for the spectrophotometric quantitation of alpha-ketoaldehydes, with a submicromolar detection limit for phenylglyoxal. The sole product of phenylglyoxal reduction has been identified as alpha-hydroxyacetophenone. The ketone functional group is not reduced, and the enzymatic reaction is essentially irreversible as alpha-hydroxyacetophenone is not oxidized to phenylglyoxal by HLADH in the presence of NAD+.

[Hematometra in patients with cervical cancer--its CT presentation and clinical significance]

Cervical cancer is the most common gynecologic malignancy in Chinese. Clinical staging has been traditionally used in cervical cancer, according to international Federation of Gynecology and Obstetrics (FIGO) staging classification. Computed tomography was an adjunctive modality for detecting paraaortic lymph nodes in preoperative evaluation. But CT has failed to accurately define the extent of parametrial and vaginal invasion. Here, an attempt has been made to define indirect clues alerting to invasive cervical cancer. Hematometra can be seen in CT as a dilated uterine cavity with retention of significant fluid. The incidence of hematometra was 5% (5/101) in control group, and 26% (22/84) in cervical cancer. Hematometra cannot be more specific for cervical cancer, with an accuracy of 64%, sensitivity of 82% and specificity of 61%. Hematometra was found to have a statistically high relationship with high cancer staging and uterine invasion. The Chi-square values were 14.8 (P < 0.005) in high cancer staging, and 19.8 in uterine invasion. The accuracy of hematometra was 65% in high cancer staging, and 74% in uterine invasion. Hematometra was more common in postmenopause women, with accuracy elevated to 80% for uterine invasion. This is probably related to senile atrophy or endophytic growth of the cervix into the uterus as well as to hormone replacement. These were five false positive instances of hematometra, all unrelated to cervical cancer. They presented with marked fluid and a solid mass in the uterine cavity, and included endometrial adenocarcinoma, uterine myoma and leiomyosarcoma. None of cervical cancer showed a solid mass in a dilated uterine cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Genotype-specific in vitro amplification of sequences of the wild type 3 polioviruses from Mexico and Guatemala

The extensive nucleotide sequence heterogeneity among independent genotypes of wild polioviruses permits the systematic design of genotype-specific molecular reagents. We have prepared two sets of polymerase chain reaction (PCR) primer pairs specific for the genotype of wild poliovirus type 3 recently endemic to Mexico and Guatemala. Nucleotide sequences of a representative wild type 3 virus isolated in Mexico in 1989 differed from the corresponding Sabin 3 (Leon 12 a1b) sequences at 167 of 900 positions within the VP1 region. From the sequence data, wild virus-specific primer pairs were designed to complement regions of high mismatch (greater than 33%) with Sabin 3 templates. Primer binding sites were spaced along the genome so that the predicted amplification products (142 bp and 163 bp) could be easily resolved electrophoretically from the products generated with our Sabin strain-specific primers (Sabin 1: 97 bp; Sabin 2: 71 bp; Sabin 3: 53 bp). RNAs of all wild type 3 poliovirus isolates from Mexico and Guatemala obtained over a 13-year period (1977-1990) served as efficient templates for amplification of the 142-bp and 163-bp products. Genomic templates derived from vaccine-related polioviruses and most heterologous wild polioviruses were inactive under equivalent reaction conditions. Amplifications generating a 114-bp product with a broadly reacting primer pair, matching highly conserved sequences in the 5'-noncoding region, provided a positive control for the presence in samples of poliovirus (or enterovirus) RNAs. Selective amplification of wild Mexico-Guatemala type 3 poliovirus sequences was obtained with either primer set in reactions containing large stoichiometric excesses (up to 10(6)-fold) of vaccine-related RNAs. We have used wild genotype-specific PCR primer sets to facilitate identification of wild polioviruses present in both clinical and environmental samples.

[Acute abdomen with intraperitoneal bowel perforation-demonstration by CT scan]

Ninety-eight cases of surgically proved bowel perforation in VGH-Kaohsiung within one year were reviewed. Among them, 25 patients received abdominal CT scans before operation. Free gas or fluid could be demonstrated with CT scan in 80% of cases though sometimes the fluid was too scanty to be well recognized. Local abscess formation with or without tumor mass lesion (n = 3), local fluid accumulation (n = 1) and negative CT findings (n = 1) constituted the remaining 20% of cases. The recognition of perforation sites depended on direct evidences of perforation such as ulceration, abscess formation and tumor mass lesion (32%), or indirect evidences including hematoma formation, dependent extraluminal gas accumulation and phlegmonous reaction (12%). An inexplicable localized extraluminal fluid accumulation might also suggest a possibility of hollow organ perforation and lead to the recognition of perforation site in the absence of free gas (4%). Absence of extraluminal fluid or gas can not completely rule out the possibility of hollow organ perforation (4%). Massive free air, especially with an air-fluid level, suggested a possibility of upper abdominal perforation. The perforation hole located at the anterior wall of stomach produced more free gas than that located at posterior wall. Air-fluid levels could never be identified in the cases of lower gastrointestinal perforations. Local bowel wall thickening and the distribution of free gas contributed little to the recognition of perforation site. Extravasation of oral contrast media sometimes led to the diagnosis of gastrointestinal perforation but was not necessary to be noted around the perforation hole and did little contribution to the perforation site recognition.(ABSTRACT TRUNCATED AT 250 WORDS)

[MRI of adrenal tumors]

Within a two and half years period, we collected a total of twenty three cases of adrenal tumors diagnosed by MRI. They included: one cystic case, twelve cases (13 lesions) of adenoma, two cases (3 lesions) of hyperplasia, four cases of pheochromocytoma, three cases of metastases, and one case of adenocarcinoma. Except for the case of adrenal cyst which was followed for one and a half years, all the other twenty two cases were proved by operation and pathology. The benign adenoma and hyperplasia were small in size, and had relative isointensities to the liver in the T1WI and the T2WI. On the contrary, the malignant tumors and pheochromocytoma, all had inhomogeneous signal intensities, showed relatively lower in signal intensities in T1WI and higher in T2WI as compared with the liver. In T2WI, the tumor to liver signal intensity ratio of adenoma and hyperplasia were less than 1.80, whereas the malignant tumors and pheochromocytoma were larger than 1.80. In comparing fifteen cases with Gd-DTPA intravenous injection, all of the benign adenoma did not show an increase in signal intensity, but the malignant tumors and pheochromocytoma showed increase in signal intensity. We concluded that we could primarily differentiate the nature of adrenal tumors by their change in signal intensities between T1WI and T2WI, by measuring the tumor to liver signal intensity ratio or by Gd-DTPA IV injection. Today, although adrenal gland MRI examination is more time consuming and expensive, it is more valuable for highly clinically suspected adrenal lesions with equivocal results after CT or sonogram study.(ABSTRACT TRUNCATED AT 250 WORDS)

[Differentiation between primary hepatocellular carcinoma and hemangioma on MRI]

Most of the primary hepatocellular carcinoma and hemangioma in TIWI are having low signals. Hemangioma is relatively lower in signal intensity than primary hepatocellular carcinoma, but they are really no so easy compare by bare eye. On the contrary, in T2WI, hemangioma is more brighter than primary hepatocellular carcinoma. So, by compare the variety shows from T1WI to T2WI, we can differentiated between primary hepatocellular carcinoma and hemangioma. By measuring the signal intensity in non-tumor area, there are no marked different in T1WI and T2WI, but hemangioma, as compare with primary hepatocellular carcinoma in signal intensity, is lower in T1WI and much higher in T2WI. Such results are all having statistic significant with p value less than 0.05. In measuring the different in signal intensity or ratio between tumor and non-tumor areas, there were mark different in T2WI and whereas there were no different in T1WI. By using two-point method, the T2-relaxation is measured in twenty eight cases of primary hepatocellular carcinoma and thirteen cases (twenty four lesions) of hemangioma. We found that there were nearly equal in nontumor areas, but there were mark different in T2-relaxation. In comparison with intravenous injection of Gd-DTPA in 10 cases of primary hepatocellular carcinoma and six cases of hemangioma, the latter were having similar dynamic CT appearance. Enhancement of signal intensity was found starting from peripheral part to central area. The primary hepatocellular carcinoma were having none of the above phenomenon. The liver MRI study is still expensive and time consuming.(ABSTRACT TRUNCATED AT 250 WORDS)

[Computed tomography for evaluation of hepatocellular carcinoma after treatment with transarterial chemoembolization]

Totally 135 series of computed tomography (CT) and angiographic examination were performed in 53 patients with proved hepatoma treated by TAE. CT examination was performed four to six weeks after TAE, and a comparative angiographic examination was performed within three weeks after CT examination. The pictures of CT scanning were read to determine 1). the grading of lipiodol retention inside the tumor, 2). the presence/absence of filling defect in the tumor margins coated by lipiodol, 3). the presence/absence of residual tumor tissue within or surrounding the main tumor, and 4). the presence/absence of developed satellite nodules. In comparison with angiographic findings, CT demonstrated 96.3% specificity and 58.2% sensitivity in the grading of lipiodol filling, and 96.3% specificity and 65.7% sensitivity in the tumor margins of lipiodol coating. However, it was difficult for CT to detect small nodules, especially those less than 1 cm in diameter. We find no statistically significant association between newly developed satellite nodules and grading of lipiodol retention inside the tumor or tumor margins of lipiodol coating. Therefore, when CT pictures reveal filling defect over the margins of the tumor coated by lipiodol or less-than-50% lipiodol filling inside the tumor, repeated angiography and further treatment with TAE are suggested.

Transcatheter arterial chemoembolization for hepatocellular carcinoma

The factors relating to the duration of survival were analyzed for 329 cases of hepatocellular carcinoma (HCC) treated by transcatheter arterial chemoembolization (TACE) between January 1, 1983, and December 31, 1990. The cumulative survival value obtained was slightly higher but not statistically significantly higher in these 329 cases as compared with the 129 cases reported in 1989. This improvement was probably attributable to careful selection of the patients on the basis of the clinical Child's status and to improvement of the superselective angiotechnique used in the present study. The overall cumulative 1-, 2-, and 3-year survival values in this series were 50%, 25%, and 15%, respectively. The median duration of survival was 12.7 months (Kaplan-Meier method). The 1-, 2-, and 3-year survival values determined for 190 patients in Child's group A, for 95 patients in Child's group B, and for 44 patients in Child's group C were 60%, 30%, and 20%; 35%, 20%, and 10%; and 35%, 20%, and 10%, respectively. Analyses were also carried out according to the tumor's type and size, the integrity of the tumor capsule, and the patency of the portal vein. Our results disclosed that a better outcome in terms of the median survival period and the survival value was favored by the following factors: a single lesion measuring less than 5 cm in diameter, an intact capsule, a patent portal vein, and a good clinical status. It is also essential that all patients who have undergone TACE be periodically evaluated by ultrasonography, CT, and angiography to determine whether repeated chemoembolization is necessary.

Prenatal diagnosis of intrauterine infection with parvovirus B19 by the polymerase chain reaction technique

Human parvovirus B19 is a recently recognized cause of fetal hydrops and death. Efforts to characterize the natural history of fetal infection with this virus have been hampered by the lack of sensitive and specific tests for diagnosis in utero. Using the highly sensitive polymerase chain reaction (PCR) assay, we determined the fetal infection status in 56 pregnancies by testing amniotic fluid, fetal serum, and maternal serum for B19 DNA and antibodies. Factors associated with a high risk of B19 infection were fetal disease, exposure to persons with erythema infectiosum, or signs or symptoms of acute B19 infection. Fifteen women (27%) were B19 IgM-positive, a status suggesting recent infection; the positivity of all of the corresponding fetal specimens for B19 DNA in the PCR was indicative of fetal infection. In four of these cases, serial ultrasonographic examinations documented spontaneous resolution of fetal hydrops. Twenty-four women (43%) were IgG-positive and IgM-negative; this pattern suggested prior infection. The PCR gave positive results, consistent with recent maternal infection, in four of these cases. Seventeen women (30%) were IgG-negative and IgM-negative, a pattern suggesting no prior infection; the PCR results in four cases were indicative of a possible early maternal infection or a possible atypical immune response. The PCR is a sensitive and rapid method for the diagnosis of intrauterine infection with human parvovirus B19 and promises to facilitate studies of the natural history and treatment of this infection.

Detection and identification of vaccine-related polioviruses by the polymerase chain reaction

We have used the polymerase chain reaction (PCR) to obtain sensitive detection and identification of poliovirus RNA genomes. Primer pairs were designed to permit identification of each Sabin poliovaccine strain by the electrophoretic mobilities of the amplified DNA products (Sabin 1: 97 bp; Sabin 2: 71 bp; Sabin 3: 44 bp). The compositions of samples containing mixtures of vaccine strains could be readily determined by PCR. When the amplified products were visualized by ethidium bromide fluorescence, as few as 250 genomic copies in the original sample could be detected. When PCR was used in combination with strain-specific 32P-labeled oligonucleotide probes, the limit of detection was less than or equal to 2.5 poliovirus genomes, exceeding the sensitivity of poliovirus isolation in cell culture by at least 100-fold. PCR amplifications may be performed on virion RNAs extracted directly from clinical specimens, potentially eliminating the requirement for virus isolation in routine identifications while yielding reliable results within 8 h.

[MRI of white matter pathways]

CT scan shows some relatively large white matter pathways such as corpus callosum or internal capsule, while MRI provides more sophisticated display of cerebral white matter pathways, based partly on difference in the water content, which improves contrast resolution of structures that cannot be appreciated on CT scanning. The white matter shows slightly high signal intensity in T1WI as compared with the peripheral gray matter. In contrast, it is relatively low signal intensity in long TR sequence. The signal intensity is correlated with myelination, density of myelin fibers and possibly iron deposition. In this study, we collected data on 30 patient, aged from 3 to 60 years average 38 years of normal MRI study of the brain. We routinely obtained T1 Weighted image (T1WI, TR/TE 500-600/20 msec), dual echoes image of proton density image (PDI, TR/TE 2000-3000/20 msec), T2 weighted image (T2WI, TR/TE 2000-3000/80-120 msec), in axial and coronal sections. In some cases sagittal section was also imaged. We identified the white matter pathways based on the data from the axial and coronal sections of 2 autopsy specimens. We also consulted several textbooks and literature reviews of gross and MRI anatomy. The following white matter pathways could be clearly observed on MRI: 1. Projection fibers: corona radiata and internal capsule; 2. Commissural fibers: corpus callosum and anterior commissure; 3. Associated fibers: superior occipito-frontal fasciculus, superior longitudinal fasciculus, ucinate fasciculus, cingulum bundle, optic radiation fornix and mammillothalamic tract.

[Magnetic resonance imaging of ovarian cystic teratoma]

Two patients with ovarian cystic teratoma were imaged using real-time ultrasound and 1.0-T magnetic resonance imaging (MRI) devices. The ultrasound appearance of cystic teratoma varies with the internal contents. If bone or teeth is present, highly echogenic foci with posterior shadow will be identified. The cysts may contain solid areas, septa and fluid-fluid levels. The dermoid cyst filled with fat showing characteristic echogenic appearance might confused with the pelvic fact tissue. MRI is well suited to the evaluation of pelvic disorders. The T1 and T2 relaxation times in different tissues might present with different signal intensities by changing the pulse sequences. Fat, with its relatively short T1 and long T2 times, appears bright on the T1-weighted images (short TE and TR) and T2-weighted images (long TE and TR). However, old hemorrhage has the MRI characteristics of short T1 and long T2 times as fat. The inversion recovery sequence with short inversion time (STIR) will suppress signal from fat tissue and this is of particular value in differentiating dermoid from hemorrhagic cyst. MRI is quite efficient in cases where ultrasound study is equivocal or difficult in the technique.

Transcriptional induction of purple membrane and gas vesicle synthesis in the archaebacterium Halobacterium halobium is blocked by a DNA gyrase inhibitor

We have investigated the expression of the bacteriorhodopsin gene (bop) and the gas vesicle protein gene (gvpA) in the extremely halophilic archaebacterium Halobacterium halobium, using primer-directed reverse transcription of RNA to quantify message levels. The level of gvpA gene transcript was found to increase about 5-fold from early to mid-logarithmic growth phase, while the level of bop gene transcript increased about 20-fold from mid-logarithmic to stationary phase. Transcriptional induction of both the gvpA and bop genes was significantly reduced by aeration and almost completely blocked by the DNA gyrase inhibitor novobiocin.

Reversible dedifferentiation and redifferentiation of a melanized cell line from a goldfish tumor

We reported previously the isolation of a melanized cell line that can undergo reversible dedifferentiation and redifferentiation. A heavily pigmented cell line, designated as P15, originally isolated by fish serum-induced melanization of some GEM 81 cells, cloned and serially passaged in fish serum medium, became noticeably less pigmented after several months in fetal calf serum medium and completely unpigmented after another year in the same medium. Addition of fish serum to the medium of this dedifferentiated cell line, designated P15D, induced pigmentation within a week. This re-induced pigmented cell line, designated as P15DI, became unpigmented when cultured in fetal calf serum medium for one month. We report here that the dedifferentiation of P15 occurs in two stages. One week after withdrawal of fish serum, the specific activity of tyrosinase of the culture dropped by approximately 70% and remained at this reduced level for at least one month. After one year, the specific activity of tyrosinase had dropped to a barely detectable level and the culture became completely unpigmented (P15D). Electron microscopic studies showed that the P15D cells have no melanosomes, probably no large vesicles for melanosome formation, but some dopa-positive trans-Golgi network (TGN). Addition of fish serum to the growth medium of P15 cultures led to a steady increase in the specific activity of tyrosinase, detectable after one day. There was also an increase in the amount of dopa-positive TGN within one day. Melanosomes first appeared after three days and became numerous after one week. Upon removal of fish serum, these re-induced cells (P15D1) underwent a rapid decrease in the specific activity of tyrosinase, reaching, after eight days, the basal level seen in P15D cells. We also report that a protein designated as p75 (Mr approximately 75,000), previously shown to be associated with melanosomes in two melanized cell types of goldfish origin, is present in all melanized cell lines, including P15 and P15DI but absent in unmelanized cell lines, including P15D.