Self-assembly of the infectious bursal disease virus capsid protein, rVP2, expressed in insect cells and purification of immunogenic chimeric rVP2H particles by immobilized metal-ion affinity chromatography

A gene encoding a structural protein (VP2) of a local strain (P3009) of infectious bursal disease virus (IBDV) was cloned and expressed using the baculovirus expression system to develop a subunit vaccine against IBDV infection in Taiwan. The expressed rVP2 proteins formed particles of approximately 20-30 nm in diameter. Those particles were partially purified employing sucrose density gradient ultracentrifugation, and the purified particles were recognized by a monoclonal antibody against the VP2 protein of IBDV P3009. To facilitate the purification of the particles, the VP2 protein was engineered to incorporate a metal ion binding site (His)(6 )at its C-terminus. The chimeric rVP2H proteins also formed particles, which could be affinity-purified in one step with immobilized metal ions (Ni(2+)). Particle formation was confirmed by direct observation under the electron microscope. The production level of rVP2H protein was determined to be 20 mg/L in a batch culture of Hi-5 cells by quantifying the concentration of the purified proteins. The chicken protection assay was performed to evaluate the immunogenicity of the rVP2H protein. When susceptible chickens were inoculated with the recombinant rVP2H proteins (40 microg/bird), virus-neutralizing antibodies were induced, thereby conferring a high level of protection against the challenge of a very virulent strain of IBDV. In conclusion, the most significant finding in this work is that both of the expressed rVP2 and rVP2H proteins can form a particulate structure capable of inducing a strong immunological response in a vaccinated chicken.

Role of hsfA gene on host-specificity by Bradyrhizobium japonicum in a broad range of tropical legumes

Bradyrhizobium japonicum mutant strain NAD163, containing a 30-kb deletion mutant encompassing the hsfA gene, was inoculated onto a broad range of legume species to test host-specificity. Most legume species formed ineffective nodules except Vigna angularis var. Chibopat and Glycine max var. Pureunkong. A hsfA insertion mutant, BjjC211, gave similar results to strain NAD163, implying that many legume species require HsfA for host-specific nitrogen fixation. To determine whether other genes in the deleted region of NAD163 are also necessary, the hsfA gene was conjugally transferred into the NAD163 mutant. The transconjugant formed effective nodules on the host legume plants, which earlier had formed ineffective nodules with mutant NAD163. Thus, we conclude that the hsfA gene in the 30-kb region is the only factor responsible for host-specific nitrogen fixation in legume plants.

Posterior calcaneal displacement osteotomy for adult acquired flatfoot

The authors retrospectively reviewed 24 patients who underwent posterior calcaneal displacement osteotomy (PCDO) for posterior tibial tendon dysfunction and adult acquired flatfoot deformity from 1991 to 1996. The average follow-up was 27 months. Analysis consisted of preoperative and postoperative evaluation of radiographs, as well as postoperative subjective results. Ancillary procedures included flexor digitorum longus tendon transfer (n = 19), tendo Achilles lengthening (n = 21), tibialis anterior tendon transfer (n = 5), naviculocuneiform joint arthrodesis (n = 4), and first metatarsocunieform joint arthrodesis (n = 1). The talo-first metatarsal angle on the lateral view decreased from a preoperative average of 22.13 degrees to a postoperative average of 8.50 degrees. The talo-first metatarsal angle on the anteroposterior view decreased from an average preoperative value of 22.96 degrees to a postoperative average of 11.04 degrees. In all cases, talar head coverage at the talonavicular joint improved. Subjective results were categorized as good (n = 17), satisfactory (n = 5), and poor (n = 2). Complications included sural neuritis (n = 6), Achilles tendon rupture (n = 2), difficulty with fixation (n = 2), and undercorrection of deformity (n = 2). Patients who had higher preoperative and postoperative talo-first metatarsal angles on either the anteroposterior or lateral radiographs had significantly poorer outcomes (p = .0403, p = .002, p = .009, p = .001, respectively). In addition, those patients who had medial column fusions had statistically significant poorer subjective results (p = .015). Patients who had flexor digitorum longus (FDL) tendon transfers did significantly better than those patients who did not have FDL transfer (p = .004). The authors conclude that the posterior calcaneal displacement osteotomy is a reasonable option for management of posterior tibial tendon dysfunction in the adult acquired flatfoot.

Prevalence and risk factors of low quantitative ultrasound values of calcaneus in Korean elderly women

Quantitative ultrasound (QUS) of bone is a new radiation-free, low-cost method that measures both bone mass and bone quality. This study was performed to establish the normative data of QUS for Korean women and to determine the prevalence and risk factors of low quantitative ultrasound values in a Korean elderly population. We studied 238 healthy women aged 20-29 years working at a hospital, and 552 women over 50 years of age living in six villages of Chung-Up district, a rural area of South Korea, using QUS measurement of bone. Broadband ultrasound attenuation and speed of sound were measured at the calcaneus, and an index combining these factors (stiffness index) was calculated. T-score was calculated from the data of young normal subjects. Of the 552 elderly women, 34.2% had T-scores between -1.0 and -2.5, and 11.8% had T-scores below -2.5. The prevalence of low quantitative ultrasound values increased with older age, longer duration following menopause, lower body mass index, younger age at menopause and smoking. In multiple logistic regression analysis, age (odds ratio = 1.40 per 5 years, P < 0.05), duration following menopause (odds ratio = 1.35 per 5 years, P < 0.05) and body mass index (odds ratio = 0.78 per quartile, P < 0.05) were independently associated with low quantitative ultrasound values. These results suggested that quantitative ultrasound measurement of the calcaneus could be a useful tool for epidemiological surveys of bone mass.

TWIST, a basic helix-loop-helix transcription factor, can regulate the human osteogenic lineage

Basic helix-loop-helix (bHLH) transcription factors have been shown to play an important role in controlling cell type determination and differentiation. TWIST, a member of the bHLH transcription factor family, is involved in the development of mesodermally derived tissue, including the skeleton. We examined the role of human TWIST in osteoblast metabolism using stable expression of sense and antisense TWIST in human osteoblast HSaOS-2 cells. Changes in morphology and osteogenic phenotype characterized these stable clones. Cells that overexpressed TWIST exhibited a spindle shaped morphology, reduced levels of alkaline phosphatase, a reduced proliferation rate, and failed to respond to basic fibroblast growth factor (bFGF). In contrast, those that underexpressed TWIST demonstrated a cuboidal epithelial-like morphology characteristic of differentiated osteoblasts. TWIST antisense cells exhibited increased levels of alkaline phosphatase and type I collagen mRNA, initiated osteopontin mRNA expression, and had a reduced proliferation rate. These results indicate that TWIST overexpressing cells may de-differentiate and remain in an osteoprogenitor-like state, and antisense TWIST cells progress to a more differentiated mature osteoblast-like state. Therefore, the level of TWIST can influence osteogenic gene expression and may act as a master switch in initiating bone cell differentiation by regulating the osteogenic cell lineage.

An Application of Percolation Theory to the Electrolyte Penetration through Porous Water-Swollen Cellulose Triacetate Membrane

Permeability coefficients P of KCl through porous cellulose triacetate (CTA) membranes were measured as a function of the water volume fraction V(W) and diffusion coefficients D were determined using solubility parameters K and a membrane thickness d from the relationship of P = KD/d. D increased with an increase in V(W). D especially increases abruptly around V(W) = 0.5, which corresponds to 2% triethylene glycol (TEG) content. The percolation theory was applied to the experimental results under the conditions D(A) = D (V(W) = 1) = 1.8 x 10(-5) cm(2) s(-1), D(B) = D(V(W) = 0) = 1.8 x 10(-8) cm(2) s(-1), coordination number (Z) = 2.5, 3, 3.5, and 4, and packing fraction f = 1.0. A good fit was obtained at Z = 3.5 because the experimental and calculated results also shifted at the same V(W) below V(W) = 0.5. It is suggested that a phase inversion, that is, change of a discontinuous water phase to a continuous water phase, occurs around V(W) = 0.5. Above V(W) = 0.5, the experimental results agree well with the calculated line for Z = 3 or Z = 2.5 which means that the coordination numbers decrease with an increase in water content. It is thought that V(W) is overestimated because it is hard to completely wipe off the excess water quickly from the membrane surface. Z = 3.5 means that a pore can connect in 3.5 directions. Copyright 1999 Academic Press.

A Minnesota multiphasic personality inventory profile of ChunDoSunBup qi-trainees: a preliminary study

The aim of this study is to explore the effects of ChunDoSunBup Qi-training on personality traits. Twenty-six normal healthy subjects (mean age = 26.58 +/- 6.56) and 26 CDSB Qi-trainees (mean age = 27.74 +/- 5.21) participated in this study. Analysis of MMPI profiles showed that CDSB Qi-trainees scored significantly lower on Depression (D), Hysteria (Hy), Paranoia (Pa), Schizophrenia (Sc) and Frequency (F) and significantly higher on the Correction (K) Scales. In addition, CDSB Qi-trainees reported a significantly lower Cook-Medley Hostility (Ho) scale than that of controls. This preliminary study suggests that CDSB Qi-training may be effective in protection as well as restoration of emotional, psychological symptomatology and personality trait disorder.

Multiple origins of the spinocerebellar ataxia 7 (SCA7) mutation revealed by linkage disequilibrium studies with closely flanking markers, including an intragenic polymorphism (G3145TG/A3145TG)

Spinocerebellar ataxia 7 (SCA7) is a neurodegenerative disease characterised by the association of cerebellar ataxia and, in most patients, progressive macular degeneration leading to loss of autonomy and blindness. The patients die after 5-30 years of evolution. The cause of the disease has been identified as a (CAG)n repeat expansion in the coding sequence of the SCA7 gene on chromosome 3p. De novo mutations occur on intermediate-sized alleles carrying from 28 to 35 CAG repeats. Neomutations explain the persistence of the disease in spite of the great instability of the repeat sequence which results in the appearance of juvenile onset patients and the extinction of the disease within families. This rare disorder has been reported in a wide variety of countries and ethnic groups. In a large number of SCA7 families (n = 41) of different origins, we have determined the haplotypes segregating with the mutation of several microsatellite markers close to the SCA7 gene and of a new intragenic polymorphism (G3145TG/A3145TG). Four different haplotypes were found for centromeric markers (G3145TG/A3145TG-D3S1287-D3S3635) in the majority of the kindreds from four different geographic regions: A-2-4 in Korea; A-3-6 in North Africa, B-3-6 in continental Europe and A-4-6 in the UK and USA. The haplotypes in the Jamaican, Filipino, Brazilian and German families were different, suggesting that independent regional founders are at the origin of the SCA7 mutation in each population. Two different haplotypes were observed, however, in two families from the same rural area in central Italy in which de novo SCA7 mutations on intermediate alleles have been observed, suggesting the existence of different pools of at-risk chromosomes in this population.

Detection of RET/PTC oncogene rearrangements in Korean papillary thyroid carcinomas

The prevalence of RET/PTC rearrangement in papillary thyroid carcinomas has been found to vary widely in different populations. Recent studies, however, have reported no significant geographical difference between Asian and Western countries. In addition, there are some disagreements about the correlation of RET/PTC expression with clinical aggressiveness. We have performed this study in order to examine the prevalence of RET/PTC-1, RET/PTC-2, and RET/PTC-3 rearrangements in Korean papillary thyroid carcinomas, and to ascertain its clinical relevance. Thyroid tumors from 31 patients histologically confirmed to be papillary carcinomas were included in this study. To find rearrangements, we utilized reverse transcription-polymerase chain reaction (RT-PCR) and automated direct sequencing. Initial and follow-up clinical data were obtained from the patients' medical records. We identified two tumors containing RET/PTC-1 (2/31, 6.5%) and two containing RET/PTC-2 (2/31, 6.5%). However, we could not find RET/PTC-3 rearrangement in any patients (0/31). In conclusion, we report RET/PTC rearrangements in 4 of 31, (12.9%) Korean patients with papillary thyroid carcinomas, a higher prevalence than previously reported in this population.

Species names in phylogenetic nomenclature

Linnaean binomial nomenclature is logically incompatible with the phylogenetic nomenclature of de Queiroz and Gauthier (1992, Annu. Rev. Ecol. Syst. 23:449-480): The former is based on the concept of genus, thus making this rank mandatory, while the latter is based on phylogenetic definitions and requires the abandonment of mandatory ranks. Thus, if species are to receive names under phylogenetic nomenclature, a different method must be devised to name them. Here, 13 methods for naming species in the context of phylogenetic nomenclature are contrasted with each other and with Linnaean binomials. A fundamental dichotomy among the proposed methods distinguishes those that retain the entire binomial of a preexisting species name from those that retain only the specific epithet. Other relevant issues include the stability, uniqueness, and ease of pronunciation of species names; their capacity to convey phylogenetic information; and the distinguishability of species names that are governed by a code of phylogenetic nomenclature both from clade names and from species names governed by the current codes. No method is ideal. Each has advantages and drawbacks, and preference for one option over another will be influenced by one's evaluation of the relative importance of the pros and cons for each. Moreover, sometimes the same feature is viewed as an advantage by some and a drawback by others. Nevertheless, all of the proposed methods for naming species in the context of phylogenetic nomenclature provide names that are more stable than Linnaean binomials.

Expression of rat BTG(3) gene, Rbtg3, is regulated by redox changes

The Rbtg3 gene was isolated by PCR (polymerase chain reaction) cloning from the cDNA library of Rat1 fibroblasts that were stimulated with TPA (12-O-tetradecanoylphorbol-13-acetate) or various growth factors for 3h and was found to be a rat homologue of mouse BTG3 and human ANA genes. The Rbtg3 gene had unique DNA sequences in the 5'-UTR and 3'-UTR that contained four ATTTA and one TTATTTA(T/A)(T/A) nonamer motif, and also a polyA addition site. Nucleotide homology of Rbtg3 with BTG3 and ANA was 88.5 and 76.6%, respectively. Expression of Rbtg3 was investigated in SD rats as well as cell lines derived from mouse--SW3T3, NIH3T3 fibroblasts--and rat--Rat1, 3Y1 fibroblasts and PC12--cells. Rbtg3 was highly expressed in brain but barely in lung, kidney, thymus and spleen. The constitutive expression level was high in SW3T3, Rat1 and 3Y1 fibroblasts, but very low in NIH3T3 fibroblast and PC12 cells. However, in all cells tested, Rbtg3 was proved to be one of the primary response genes superinduced by TPA (50ng/ml)+cycloheximide (CHX, 10 microgram/ml). Expression of Rbtg3 was induced by H(2)O(2) (500mM) up to fourfold in PC12 cells and was blocked by pretreatment of NAC (N-acetyl-L-cysteine, 10mM). The induction was ninefold in 3Y1 fibroblasts by menadione (25mM) treatment for 1h, whereas it was reduced to a third of the control level in SW3T3 fibroblast by the same treatment. Rbtg3 was not expressed in NIH3T3 cells but minimally regulated by redox changes as compared with rapid and strong induction of TIS21/BTG2 mRNAs after TPA or H(2)O(2) stimulation. The above results indicate that Rbtg3 is one of many redox-regulated genes as well as a primary response gene.

Acute inflammation of the proliferative zone of gastric mucosa in Helicobacter pylori gastritis

The neutrophilic infiltration has been regarded to represent the activity of Helicobacter pylori gastritis. It may involve the epithelium and/or lamina propria. The incidence and degree of the two types of infiltration do not correlate with each other frequently. We correlated the two types of neutrophilic infiltration with H. pylori infection and other pathologic parameters respectively in 300 randomly selected gastric biopsies as well as serial biopsies from a separate group of 95 patients who were treated for H. pylori infection. The "random biopsies" had chronic gastritis of various degrees, and the organisms were identified in 239 cases (79.7%); in the "treated group," the organisms disappeared completely in 62 cases (65.3%). Characteristically, the intraepithelial neutrophilic infiltration was predominantly localized to the proliferative zone of the gastric mucosa (zone 2) where the density of H. pylori was considerably lower than the surface epithelium. In the "random biopsies," both acute epithelial and interstitial neutrophilic infiltration correlated significantly (p < 0.01) with the H. pylori infection. In the "treated group," however, only acute epithelial inflammation correlated significantly (p < 0.01) with the eradication of infection while acute interstitial inflammation did not. Acute epithelial inflammation was no less frequently present in advanced chronic gastritis than in early chronic gastritis. Acute epithelial inflammation of the proliferative zone is a characteristic pathologic finding of H. pylori gastritis, and appears to be directly associated with the pathogenesis of H. pylori gastritis and its progression.

Wet gauze in CO2 laser resurfacing

The development of scanning CO2 laser systems has enabled rapid and uniform facial resurfacing in photoaged and acne scarred skin. A problem faced by the laser surgeon is making the scanner pattern produced by these lasers fit the cosmetic unit to be resurfaced. This may be achieved by the use of wet gauze to absorb the energy of the unwanted portion of the scanner pattern. The wet gauze is folded to lie along the cosmetic unit boundary and the scanner pattern rotated until it conforms to the required shape. On the eyelids, saline soaked cotton tipped applicators are used to lift the eyelashes away from the path of the laser beam. This allows treatment of the entire lower eyelid cosmetic unit without damage to the eyelashes.

Allogeneic hematopoietic transplantation for mantle-cell lymphoma: molecular remissions and evidence of graft-versus-malignancy

BACKGROUND

The presence of a graft-versus-tumor effect has been well established for various hematological malignancies but not for mantle-cell lymphoma (MCL). We report preliminary results suggestive of a graft-versus-lymphoma effect in such patients post allogeneic hematopoietic transplantation.

PATIENTS AND METHODS

Sixteen patients with the diffuse type of MCL received allogeneic transplantation. Three had blastic features. Fifteen had an HLA-identical and one, a one HLA antigen mismatched sibling donor. Fifteen had stage IV disease. Eleven patients were previously treated, including one who failed prior autologous transplantation. Five patients were newly diagnosed and received transplantation after cytoreduction with three to eight courses of HYPER-CVAD (fractionated cyclophosphamide, doxorubicin, vincristine, dexamethasone) alternating with high-dose methotrexate and cytarabine.

RESULTS

Eleven patients received high-dose cyclophosphamide 120 mg/kg and total body irradiation (TBI) (12 Gy given in four daily fractions). Three patients were not eligible for TBI and received the BEAM regimen. Twelve (85.7%) achieved complete and two (14.3%) partial response. Two additional patients received a nonablative preparative regimen consisting of cisplatin, cytarabine and fludarabine. One failed to engraft and later relapsed. The other patient had progressive disease one month post transplant but later achieved complete remission now durable for 14+ months after developing graft-versus-host disease (GVHD). Residual lymphoma was assessed in seven patients by polymerase chain reaction assay (PCR) for bcl-1 or immunoglobulin gene rearrangement. All had detectable disease at the time of transplant. When tested within four months post transplant, four of these patients attained molecular remission. One of the three molecular non-responders converted to a negative PCR status seven months later and one fluctuates between positive and negative PCR fourteen months post transplant. Overall survival (OS) and failure-from-progression (FFP) at three years were both 55% (95% confidence interval (95% CI): 28%-83%). For patients with chemosensitive disease, FFP and OS at one year were both 90% (95% CI: 71%-100%) compared with 44% (95% CI: 1%-88%) (P = 0.04) for those who were refractory to conventional chemotherapy at the time of transplantation. There were six deaths. These were related to GVHD (three cases), infection (one case), multiorgan failure (one case), and graft failure (one case).

CONCLUSIONS

This report demonstrates the potential efficacy of allogeneic hematopoietic transplantation for MCL and provides the first evidence suggestive of graft-versus-malignancy in MCL. Data supportive of this concept include 1) achievement of remission concomitant with GVHD, 2) the conversion from a positive PCR status early after transplant to negative PCR status over time and 3) that the only relapse was in a patient who failed to engraft.

Variability of polymerase chain reaction detection of the bcl-2-IgH translocation in an international multicentre study

BACKGROUND

The capacity of the polymerase chain reaction (PCR) to detect very low numbers of cells bearing a t(14;18) translocation has led to its application in assessment of the results of treatment for follicular lymphoma, and suggestions that therapy might be guided by molecular studies. To test the reliability of PCR a collaborative study was undertaken to compare results from different laboratories in Europe and North America.

METHODS

Twenty laboratories with records of publication in molecular diagnostics were sent blood from normal donors with varying numbers of t(14;18)-bearing cells added from a cell line with a translocation in the major breakpoint region (MBR) of the bcl-2 gene. Samples contained 1000, 100, 10, 1 or 0 cells per ml of whole blood and were sent blinded in duplicate. PCR methodology varied widely, with the total number of amplification cycles between 30 and 70, and 13 different primers used for the MBR region. Twelve laboratories used nested PCR and eight single round amplification.

RESULTS

The sensitivity of nested and single round PCR was similar at 100 cells/ml but below this the nested method proved significantly more sensitive. The false positive rate was 28%, with 11 samples from 9 laboratories reported as positive when no t(14;18) cells were added. PCR product size and sequence analysis showed that false positives were due to contamination from cell-line DNA rather than background translocations in the donors. There was no significant difference in false positive rates between nested and single round techniques.

CONCLUSION

The polymerase chain reaction to detect bcl-2-IgH rearrangements is presently carried out with widely disparate results. Further effort is required to bring forward a standard PCR protocol which can be re-tested in different laboratories to improve accuracy and reproducibility. The application of quantitative techniques such as real-time PCR may resolve many of the problems presently encountered.

Mini-detachable snare ligation for the treatment of esophageal varices

BACKGROUND

We manufactured and studied the usefulness of a newly designed mini-detachable snare in the treatment of esophageal varices. The use of a multiple rubber band ligator, although generally effective and well tolerated, has certain limitations, including high cost, reduced visual field, and inadvertent band release.

METHODS

We performed a prospective randomized controlled trial of the use of mini-detachable snare ligation vs. multiple band ligation in patients with recent or active esophageal variceal bleeding. The outcomes assessed were immediate hemostasis and rates of recurrent bleeding, eradication, and recurrence.

RESULTS

From March 1997 to October 1998, 103 patients were entered into this trial; 46 underwent mini-detachable snare ligations and 57 multiple band ligations. Among patients with active bleeding, hemostasis was achieved in 6 of 7 (86%) in the mini-detachable snare ligation group and 11 of 13 (85%) in multiple band ligation group. Recurrent bleeding after initial treatment occurred in 2 of 46 (5.5%) in the mini-detachable snare ligation group and 3 of 57 (5.3%) in the multiple band ligation group. Esophageal varices were eradicated or reduced to grade I in 4.8 +/- 2.1 and 4.5 +/- 1.9 sessions in the mini-detachable snare ligation group and multiple band ligation group, respectively. The recurrence rate was 5 of 46 (11%) and 6 of 57 (11%) in the mini-detachable snare ligation group and multiple band ligation group during a follow-up period of 6 and 16 months, respectively. No serious complication occurred in either group.

CONCLUSION

The mini-detachable snare is a new device that provides safe and effective treatment for esophageal varices that is comparable to multiple band ligation.

Birth after the injection of sperm and the cytoplasm of tripronucleate zygotes into metaphase II oocytes in patients with repeated implantation failure after assisted fertilization procedures

OBJECTIVE

To assess the technique of injecting a single sperm and cytoplasm obtained from tripronucleate zygotes into metaphase II oocytes for the treatment of patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.

DESIGN

Clinical study.

SETTING

Private infertility clinic.

PATIENT(S)

Patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.

INTERVENTION(S)

The metaphase II oocytes of recipients were injected with their husbands' spermatozoa and cytoplasm aspirated from the tripronucleate zygotes of donors.

MAIN OUTCOME MEASURE(S)

Fertilization after cytoplasm and sperm injection, embryo development, and successful pregnancy.

RESULT(S)

In total, 62 metaphase II oocytes from nine recipients were injected. Of the 62 injected oocytes, 3 (5%) degenerated and 43 (69%) had two pronuclei 18 hours after injection. Thirty-nine oocytes with two pronuclei cleaved to the two-cell to six-cell stage after another 24 hours of culture. All cleaved embryos were transferred into the uteruses of recipients. Four clinical pregnancies occurred in four recipients. No abnormal chromosomes were observed after amniocentesis and karyotyping in all pregnancies. Five healthy infants were born.

CONCLUSION(S)

Injection of the cytoplasm of tripronucleate zygotes may enhance the clinical pregnancy rate in patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.

Cloning and analysis of the aroB gene encoding dehydroquinate synthase from Corynebacterium glutamicum

The aroB gene encoding dehydroquinate synthase of Corynebacterium glutamicum has been cloned by complementation of an aro auxotrophic mutant of Escherichia coli with the genomic DNA library. The recombinant plasmid contained a 1.4-kb fragment that complemented the Escherichia coli dehydroquinate-synthase-deficient mutant. The nucleotide sequences of the subcloned DNA has been determined. The sequences contain an open reading frame of 360 codons, from which a protein with a molecular mass of about 38 kDa could be predicted. This is consistent with the size of the AroB protein expressed in E. coli. Alignment of different prokaryotic and eukaryotic aroB gene products reveals an overall identity ranging from 29 to 57% and the presence of several highly conserved regions.

Evaluation and management of lateral ankle injuries

The diagnosis and management of lateral ankle injuries require the physician to obtain an accurate history, complete a thorough physical examination, and institute appropriate treatment protocol. Labeling all acute lateral ankle injuries as ankle sprains can lead to long-term mechanical and functional instability and chronic pain around the ankle. Appropriate and aggressive functional rehabilitation of the acute ankle limits the postinjury convalescence and need for surgical reconstruction. If surgical repair of the chronic or acute ankle is warranted, the Brostrom-Gould procedure serves as a highly successful anatomic repair. Lateral ankle tenodesing procedures also are effective; however, in most cases, the loss of rearfoot motion limits this procedure to a secondary reconstructive procedure.

c-Myc expression is related with cell proliferation and associated with poor clinical outcome in human gastric cancer

We underwent protein assay for Myc expression in 76 human gastric cancer tissues using immunohistochemistry. Expression of Myc protein was analyzed according to proliferative indices measured by flow cytometry. Levels of Myc protein expression was evaluated by correlating with biologic and clinical parameters. In 36 (47.4%) of 76 primary gastric cancers, overexpression of Myc was observed. We could observe expression of Myc protein in a significant portion of early gastric cancer (42.9%). Expression of Myc protein was demonstrated to be more frequent in poorly differentiated cancer cells (p=0.043). However, expression of Myc protein had little influence over progress or extent of the disease. Expression of Myc protein was significantly correlated with increased proliferative activity (p=0.032) and patients with high levels of Myc expression had poor disease-free survival. In a certain proportion of human gastric cancer, Myc protein may function as a regulator of cancer cell growth and expression of Myc may represent an aggressive phenotype of gastric cancer.

Comparison of Gadomer-17 and Gd-DTPA in image quality of contrast-enhanced MR angiographies using flow phantom model

The purpose of this study was to compare the image quality of 3D-TOF MR angiography (MRA) using Gadomer-17 with that using Gd-DTPA in a flow phantom model, and to present preliminary data about the proper dose concentration of Gadomer-17. In the visual analysis of vessel conspicuity, we compared the quality of pre- and post-contrast MIP images. For quantitative analysis, the signal intensities were measured in the axial base 3D-TOF images, and then the relative contrast enhancement was calculated. The results of our studies were that: 1. Maximal signal intensities were obtained at 1 mmol/L of Gadomer-17 and 4 mmol/L of Gd-DTPA. 2. Flow-related signal loss was decreased by Gd-DTPA proportional to the concentration, but Gadomer-17 did not show such a dose accumulative effect. In conclusion, after comparing the results of Gd-DTPA, it was clear that improved MRA images and higher signal intensities of vessels were obtained when lower concentrations of Gadomer-17 were used.

Regulation of selection of liver nodules initiated with N-nitrosodiethylamine and promoted with nodularin injections in fischer 344 male rats by reciprocal expression of transforming growth factor-beta1 and its receptors

To investigate how glutathione-S-transferase placental form (GST-P)+ hyperplastic nodules (HNs) are selected and to determine the driving force for progression or regression of HNs, changes in transforming growth factor-beta1 (TGF-beta) and its receptors were examined during hepatocarcinogenesis initiated by N-nitrosodiethylamine (DEN) and promoted by nodularin. The induction of TGF-beta1 expression in the GST-P+ HNs was dependent on nodularin injections for 10 wk, which started the third week after DEN initiation. The kinetics of TGF-beta1 induction during carcinogenesis were quite different from that of simple regeneration after partial hepatectomy (PH): hepatocytes initiated with DEN alone induced TGF-beta1 expression for 24 d, and subsequent stimulation by PH on the fourteenth day after DEN initiation super-induced TGF-beta1 mRNA (50 times that of the control level), as opposed to a transient expression for less than 5 d by PH alone. GST-P+ HNs did not express TGF-beta receptors I (RI) and II (RII) during the early stage of carcinogenesis, whereas the surrounding hepatocytes strongly expressed both of these receptors. On cessation of nodularin injection, however, the expression of RI and RII in the HNs changed significantly: RII+ nodules appeared, and the number and area of RII+/- nodules were significantly increased at 10 wk after the cessation. These findings indicate that induction of TGF-beta expression in GST-P+ HNs might be a strong selection pressure that allows outgrowth of RII- nodules during liver carcinogenesis.