Production of a desulfurization biocatalyst by two-stage fermentation and its application for the treatment of model and diesel oils

For the production of oil-desulfurizing biocatalyst, a two-stage fermentation strategy was adopted, in which the cell growth stage and desulfurization activity induction stage were separated. Sucrose was found to be the optimal carbon source for the growth of Gordonia nitida CYKS1. Magnesium sulfate was selected to be the sulfur source in the cell growth stage. The optimal ranges of sucrose and magnesium sulfate were 10-50 and 1-2.5 g x L(-1), respectively. Such a broad optimal concentration of sucrose made the fed-batch culture easy, while the sucrose concentration was maintained between 10-20 g x L(-1) in the actual operation. As a result, 92.6 g x L(-1) of cell mass was acquired by 120 h of fed-batch culture. This cell mass was over three times higher than a previously reported result, though the strain used was different. The desulfurization activity of the harvested cells from the first stage culture was induced by batch cultivation with dibenzothiophene as the sole sulfur source. The optimal induction time was found to be about 4 h. The resting-cell biocatalyst made from the induced cells was applied for the deep desulfurization of a diesel oil. It was observed that the sulfur content of the diesel oil decreased from 250 mg-sulfur x L-oil(-1) to as low as 61 mg-sulfur x L-oil(-1) in 20 h. It implied that the biocatalyst developed in this study had a good potential to be applied to a deep desulfurization process to produce ultra-low-sulfur fuel oils.

Drug-resistant tuberculosis in a tertiary referral teaching hospital of Korea

BACKGROUND

Resistance of Mycobacterium tuberculosis strains is an increasing problem worldwide. Our purpose was to determine the prevalence of drug resistance (DR) and risk factors of DR in patients with tuberculosis and to assess the clinical characteristics and socioeconomic status of patients with drug-resistant tuberculosis.

METHODS

We retrospectively studied drug susceptibility tests and clinical and socioeconomic records for 308 cases of culture-positive Mycobacterium tuberculosis infection, diagnosed at Mokdong Hospital, Ewha Womans University from March, 1995 to February, 2000.

RESULTS

DR to at least one drug was identified in 75 (24.4%); the rate of primary DR, 18.7% and acquired DR, 39.3%. Multi-drug resistance (MDR) was identified in 31 (10.1%); primary MDR, 7.0% and acquired MDR, 21.4%. The risk factors of DR were previous TB treatment, pulmonary involvement and associated medical illness. DR group showed lesser adherence to treatment than the drug-sensitive group. DR group showed more frequent self-interruption of medication, lower completion rate of treatment and higher failure rate of follow-up than the drug-sensitive group. In previously treated tuberculosis patients, higher rate of overall DR and MDR, larger number of resistant drugs and more frequent self-interruption of medication were observed than newly diagnosed patients. Among DR group, acquired DR (ADR) group was older, less educated and treated for longer duration and had more advanced disease than primary DR group.

CONCLUSION

Previously treated tuberculosis is a most important risk factor for DR. DR group, especially ADR, showed less compliance with treatment. More proper education and attention to prevent self-interruption should be given to a previously treated group. In TB prevalent areas, it should be considered to obtain initial drug susceptibility testing in high risk of DR.

Knowing the dancer from the dance: R-gene products and their interactions with other proteins from host and pathogen

Cloning of plant disease resistance genes is now commonplace in model plants. Recent attention has turned to how the proteins that they encode function biochemically to recognize their cognate Avirulence protein and to initiate the disease-resistance response. In addition, attention has turned to how the Avirulence proteins of pathogens might alter susceptible hosts for the benefit of the pathogen, and what plant proteins might be required for that process.

Stress fracture of the proximal tibia after total knee arthroplasty: a case report

Stress fracture of the proximal tibia after total knee arthroplasty (TKA) is very rare. We found only 16 cases in a review of the literature. We report the case of a 76-year-old obese woman who sustained a stress fracture of the right proximal tibia without trauma 18 months after TKA. Pain developed in the proximal medial aspect of the tibia during walking. Physical examination showed tenderness of the proximal medial aspect of the tibia and varus deformity of 15 degrees during stress test of the knee. Roentgenography 4 weeks after symptom onset showed an obvious stress fracture line. Treatment with bed rest and above-the-knee plaster cast immobilization for 8 weeks was successful. The causes of this rare complication may include increased level of activity after TKA, generalized osteoporosis, and varus deformity of the knee.

[Production of transgenic lamb integrated with modified human anti-trypsin gene]

This experiment is to produce the human mAAT(modified anti-trypsin) which cures the emphysema specifically through mammalian galactophore of transgenic goat. 56 goats were selected as donor for superovulation by FSF + LH microinjection in this experiment. The pronucleic embryos were injected with human mAAT gene after fertilization in vivo, and transferred to the donors or receptors directly. The superovulation was better in March and May than in December with the number of ovulation of 19.50, 21.70 and 16.06, and number of fertilized embryos of 4.31, 6.48 and 3.57 per-animal respectively. The pregnant rates were 18.18% and 25% respectively after transferred to donors and receptors with natural estrus. The donors also can be used as the embryo receptor with no remarkable decrease of pregnant rate. 29 lamb were labored. 4 positive transgenic lamb were checked by PCR, PCR-Southern and Southern analysis. The integrated efficiency of foreign DNA was 13.79% with microinjection of high copy number of foreign DNA fragment.

Corneal neovascularization

Corneal neovascularization (NV) is a sight-threatening condition usually associated with inflammatory or infectious disorders of the ocular surface. It has been shown in the field of cancer angiogenesis research that a balance exists between angiogenic factors (such as fibroblast growth factor and vascular endothelial growth factor) and anti-angiogenic molecules (such as angiostatin, endostatin, or pigment epithelium derived factor) in the cornea. Several inflammatory, infectious, degenerative, and traumatic disorders are associated with corneal NV, in which the balance is tilted towards angiogenesis. The pathogenesis of corneal NV may be influenced by matrix metalloproteinases and other proteolytic enzymes. New medical and surgical treatments, including angiostatic steroids, nonsteroidal inflammatory agents, argon laser photocoagulation, and photodynamic therapy have been effective in animal models to inhibit corneal NV and transiently restore corneal "angiogenic privilege."

Microvascular decompression in trigeminal neuralgia: a correlation of three-dimensional time-of-flight magnetic resonance angiography and surgical findings

We analyzed 104 patients with trigeminal neuralgia who underwent microvascular decompression and who were followed up for more than 12 months during the period from January 1992 to June 1998. In this recent series, we utilized three-dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA) for all patients with trigeminal neuralgia. A 3D-TOF MRA was beneficial in treatment planning and in predicting surgical outcome by demonstrating cranial nerve compression as well excluding other etiologies such as tumor or vascular lesions. The patients were followed up for 1-7 years (mean 5.7 +/- 1.2 years). Initial pain relief was complete in 89 patients (85.6%) and partial in 12 patients (11.5%). There were three primary failures (2.9%). The acceptable pain relief rate (complete relief: 79.8%, partial relief: 11.5%) was determined in the long-term follow-up of surgical results. Pain recurred in 6 patients (5.8%). The mean time to recurrence was 48 months (36-93 months). There were no serious or annoying complications such as anesthesia dolorosa.

Management of multiple level spondylolysis of the lumbar spine in young males: a report of six cases

The most common procedure for surgical treatment of lumbar spondylolysis is intertransverse processes spinal arthrodesis with instrumentation. However, this procedure is associated with significant morbidity on long-term follow up. Direct repair of spondylolysis is an alternative method for preservation of motion segment and anatomic continuity in young adults with multiple level spondylolysis. From 1992 through 1998, six soldiers with a diagnosis of multiple level spondylolysis who complained of persistent low back pain were treated in our hospital. Spondylolysis involved two levels in five cases and three levels in one case. All patients underwent serial roentgenography of the lumbar spine and a staged pars interarticularis infiltration test with bupivacain 0.5%. Five patients underwent direct repair of the pars interarticularis defects with hook screws, translaminar screws, and bone graft, while one patient received conservative treatment. All surgically treated patients had either good or excellent results at a mean of 34.4 months follow-up. One patient who was treated nonsurgically still complained of sport restriction at 16 months follow-up. Direct repair of multiple pars interarticularis defects after a positive staged pars infiltration test can restore anatomic stability, relieve back pain, and preserve a greater range of motion of the lumbar spine in young patients with intact disc height.

Importance of the host genetic background on immune responses to Helicobacter pylori infection and therapeutic vaccine efficacy

In order to investigate the role of host factors in Helicobacter pylori infection and immunity, two different strains of inbred mice, C57BL/6 and BALB/c, were infected with a standard H. pylori strain, SS1. A month later, infected mice were immunized orally with whole-cell lysates of H. pylori SS1 and cholera toxin on days 1, 3, 6, 30, and 54. Ten days after the last immunization, mice were sacrificed and the stomach was collected to assess H. pylori colonization density by quantitative culture. H. pylori SS1 colonization was significantly greater in C57BL/6 than in BALB/c (P<0.02 and P<0.003 at 2 and 13 weeks post-inoculation, respectively). Colonization in C57BL/6 persisted at equivalent levels for 13 weeks but the colonization density in BALB/c decreased significantly during this period. In contrast to the pattern of bacterial colonization, antibody responses following H. pylori SS1 infection were greater in BALB/c than in C57BL/6, suggesting that host factors may modulate the immune responses to H. pylori infection. Following therapeutic immunization, H. pylori colonization in BALB/c mice was also significantly reduced (P<0.03), while no significant differences in bacterial density were observed in C57BL/6. These observations collectively demonstrate the great importance of host factors in H. pylori infection and the development of effective immune responses.

Microvascular decompression of the facial nerve for the treatment of hemifacial spasm: preoperative magnetic resonance imaging related to clinical outcomes

BACKGROUND

The objective of this study was to investigate the role of preoperative three dimensional short-range magnetic resonance angiography (3D-TOF MRA) in predicting the clinical outcomes following microvascular decompression for the treatment of hemifacial spasm.

METHOD

Preoperative magnetic resonance (MR) imaging was performed on all patients with hemifacial spasm (564 cases) between January 1992 and September 1998. Of the 564 patients, 440 patients were included in this retrospective study. The presence of vascular contact, offenders, and anomalies in the vertebro-basilar system, were determined by 3D-TOF MRA prior to microvascular decompression of the facial nerve. The preoperative findings were compared with the surgical findings and clinical outcomes. Findings. A correlation was found between the clinical outcome (p < 0.01) and the presence of a vascular indentation at the root entry zone (REZ) of the facial nerve. A shift of the vertebrobasilar system to the symptomatic side was found in 214 (48.6%) patients with hemifacial spasm, compared to only 10 (13.5%) patients in the control group (p < 0.01). The unilateral vertebral artery was observed in 43 (9.8%) patients with hemifacial spasm and in 8 (10.8%) of the control patients. A hypoplasia of the artery was found in 8 (1.8%) patients with hemifacial spasm and in 1 (1.4%) control patient. The compressing offenders in the patients, discovered by MRI in conjunction with MRA, were as follows: 45.9% (202 patients) in the anterior inferior cerebellar artery (AICA), 34.8% (153 patients) in the posterior inferior cerebellar artery (PICA), 12.5% (55 patients) in the vertebral artery (VA) and 6.8% (30 patients) in multiple vessels. In contrast to the compressing offenders seen on the MRA, the offenders confirmed during surgery were as follows: 43% (189 patients) in the AICA, 36.4% (160 patients) in the PICA, 1.4% (6 patients) in the VA, 19% (84 patients) in multiple vessels, and 0.2% (1 patient) in the vein. In our long-term follow-up series of the 440 patients with hemifacial spasm, an excellent surgical outcome was obtained in 86.3% of cases and a good outcome was achieved in 6.4% (mean follow-up duration, 45.5 months).

INTERPRETATION

Preoperative 3D-TOF MRA can identify the relationship between the facial nerve and adjacent vessels in patients with a hemifacial spasm and assist in preoperative planning. This study suggests that 3D-TOF MRA is useful for selecting appropriate patients for surgical treatment and, to some extent, as an additional role for predicting the clinical outcome.

Inflammatory pseudotumor-like follicular dendritic cell tumor: a distinctive low-grade malignant intra-abdominal neoplasm with consistent Epstein-Barr virus association

Follicular dendritic cell (FDC) tumors are uncommon neoplasms that can involve lymph nodes or extranodal sites. They can exhibit a broad spectrum of histologic appearances and behavior, but the intra-abdominal ones usually pursue an aggressive course. The purpose of this study was to characterize a distinctive variant of FDC tumor morphologically mimicking inflammatory pseudotumor through analysis of the clinicopathologic features of 11 cases. The patients included 10 women and one man (age range, 19-61 years; median age, 40 years) who presented with abdominal discomfort or pain. Six patients had systemic symptoms such as marked weight loss, fever, or malaise. All tumors occurred in intra-abdominal sites: liver (n = 7), spleen (n = 3), and peripancreatic region (n = 1). Of the nine patients with follow-up data, six were alive and well, one developed recurrence at 9 years, and two had repeated recurrences over many years. Grossly, the tumors were usually solitary and fleshy, punctuated by areas of hemorrhage and necrosis. Histologically, in a background of abundant lymphocytes and plasma cells were dispersed spindle or ovoid cells with vesicular nuclei and distinct nucleoli. The degree of nuclear atypia was variable, and some nuclei could be grotesque or resemble Reed-Sternberg cells. Focally, spindle cell fascicles could be formed. The atypical cells were immunoreactive for FDC markers such as CD21/CD35, CD23, and CNA.42. In situ hybridization for Epstein-Barr virus (EBV)-encoded RNA was positive in all cases, remarkably highlighting the spindle cells and their atypia. EBV-latent membrane protein-1 was expressed commonly, albeit often focally and weakly. Therefore, inflammatory pseudotumor-like FDC tumor represents a distinctive variant of FDC tumor that differs from conventional FDC tumor in the following aspects: marked female predominance; selective localization in intra-abdominal sites, especially the liver and spleen; frequent presence of systemic symptoms; indolent behavior despite an intra-abdominal location; dispersed distribution of tumor cells and prominent lymphoplasmacytic infiltration; and consistent association with EBV.

Hybrid nanogels for sustainable positive thermosensitive drug release

A hybrid nanogel has been developed based on interpenetrating networks of thermosensitive poly(N-isopropylacrylamide) gels and tailored nanoporous silica. A sustainable positive thermo-responsive drug release profile is obtained. When the temperature rises, the polymer gel shrinks, squeezing the drug into the porous channels, and at the same time, opening the pores to the outside media. The drug slowly diffuses out of the porous channels. The overall release rate can be adjusted by changing the composition of the nanogel.

The impact of a multidisciplinary breast cancer center on recommendations for patient management: the University of Pennsylvania experience

BACKGROUND

Advances in the diagnosis and treatment of breast carcinoma have led to a multidisciplinary approach to management for patients with breast carcinoma. To assess the effect of this approach, the authors performed an evaluation for a cohort of patients examined in a multidisciplinary breast cancer center.

METHODS

An analysis was performed for the records of 75 consecutive women with 77 breast lesions examined in consultation in a multidisciplinary breast cancer center between January and June 1998. Each patient's case was evaluated by a panel consisting of a medical oncologist, surgical oncologist, radiation oncologist, pathologist, diagnostic radiologist, and, when indicated, plastic surgeon. A comprehensive history and physical examination was performed, and the relevant mammograms, pathology slides, and medical records were reviewed. Treatment recommendations made before this evaluation were compared with the consensus recommendations made by the panel.

RESULTS

For the 75 patients, the multidisciplinary panel disagreed with the treatment recommendations from the outside physicians in 32 cases (43%), and agreed in 41 cases (55%). Two patients (3%) had no treatment recommendation before consultation. For the 32 patients with a disagreement, the treatment recommendations were breast-conservation treatment instead of mastectomy (n = 13; 41%) or reexcision (n = 2; 6%); further workup instead of immediate definitive treatment (n = 10; 31%); treatment based on major change in diagnosis on pathology review (n = 3; 9%); addition of postmastectomy radiation treatment (n = 3; 9%); or addition of hormonal therapy (n = 1; 3%).

CONCLUSIONS

The multidisciplinary breast cancer evaluation program provided an integrated program in which individual patients were evaluated by a team of physicians and led to a change in treatment recommendation for 43% (32 of 75) of the patients examined. This multidisciplinary program provided important second opinions for many patients with breast carcinoma.

Endosurgery and the senior pediatric surgeon

BACKGROUND

Endosurgery is difficult for the senior pediatric surgeon to master because the technique has a steep learning curve, lacks tactile sense, uses elongated instruments, and is ergonomically tiring.

METHODS

The senior author, starting at age 53, has performed more than 300 endoscopic procedures at both children and community hospitals. A full year was required to master laparoscopic Nissen fundoplications. Conversion to open procedures from bleeding and enterotomies were committed in the first year of endosurgery. Facility with endosurgery is gained by performing common and frequent procedures as appendectomies.

CONCLUSION

The advantages of endosurgery in pain control and shortened hospitalization make the technique deserving of commitment by the senior pediatric surgeon.

Microvascular decompression of the facial nerve for hemifacial spasm in youth

OBJECTS

The goal of this study was to investigate the differences between clinical findings in youth and in adulthood on microvascular decompression (MVD) of the facial nerve for the treatment of hemifacial spasm (HFS).

METHODS

We retrospectively evaluated 855 patients who underwent MVD from January 1985 to July 1999. In our series of 33 young HFS patients, all patients had definite offending vessels. Interestingly, pathologic tortuous vertebral artery as a possible etiology was more rarely observed in young HFS patients (1/33 patients, 3.0%) than in adult patients (61/822 patients, 7.4%) (P < 0.05). We did not observe any atomical variations of the vessels or any arachnoidal thickening around the root entry zone and cerebellopontine cistern in youths. Furthermore, young HFS patients did not necessarily have poorer surgical outcomes than adult HFS patients.

CONCLUSIONS

Our results suggest that the cause and progress of HFS are the same in youth as in adulthood, even though the pathogenesis of early onset remains unclear.

Evaluation of minimally invasive approaches to achalasia in children

BACKGROUND

Achalasia is an uncommon disease in children, but when present can result in severe disabling symptoms often requiring surgical intervention. This report describes the authors' experience with thoracoscopic (TH) and later laparoscopic Heller (LH) myotomy for definitive treatment of this disease.

METHODS

Nine patients with achalasia were referred for surgical therapy. Ages ranged from 5 to 17 years and weight from 23 to 78 kg. All had undergone at least one dilatation with recurrence of symptoms. The first 4 were treated by TH and the last five by LH. The 5 LH procedures also included a partial fundoplication.

RESULTS

All procedures were completed successfully using minimally invasive techniques. Operating times averaged 95 minutes for TH and 62 minutes for LH. One patient undergoing TH had a small esophageal perforation repaired primarily. The other 3 TH patients were started on clear liquids within 1 day and discharged on day 2. One patient had recurrent symptoms at 6 months and underwent a LH for an incomplete TH. All 5 LH patients were discharged on postoperative day 1. One had an esophageal perforation 4 days after operation requiring laparoscopic repair. Seven of 9 patients are asymptomatic. Studies of pH levels in 2 asymptomatic TH patients show mild gastroesophageal reflux (GER).

CONCLUSIONS

Minimally invasive Heller myotomy is a safe and effective procedure in children. TH results in a slightly longer operating time and hospital stay and, without a partial fundoplication, also may be associated with a higher incidence of silent GER. From these results, we prefer LH with a Dor fundoplication for treatment of achalasia in children.

[Study on reversed-phase high performance liquid chromatography separation condition and determination method of organic acids]

The pH values of the mobile phase which affect the chromatographic behavior of organic acids in RP-HPLC have been studied. It was considered that the problem of organic acids on an RP-HPLC column was dissociation. The equation for finding the optimum pH of mobile phase was pHlimit of colunm < or = pH < or = pKa -2. In addition the effects of contents of methanol and acetonitrile in mobile phase were studied. By using the formula the mobile phases used for the analysis of organic monobasic acids--formic, acetic, propionic and butyric acid and of organic dibasic acids--propane diacid, butane diacid, pentane diacid and hexane diacid were proposed. For the analysis of the monobasic acids, the wavelength of UV-detector was set at 210 nm and the mobile phase was a mixture of phosphate buffer solution(15 mmol/L, pH 2.1)-methanol(85:15, V/V) and at a rate of 1.5 mL/min and the column was Diamond C18, 150 mm x 4.6 mm i.d.. The average coefficient of correlation was 0.9997 and RSD was less than 0.90%. The mobile phase for organic dibasic acids was a mixture of phosphate buffer solution (20 mmol/L, pH 2.1)-methanol(75:25, V/V). The other conditions were the same as for organic monobasic acids. The average coefficient of correlation was 0.9998 and RSD was less than 0.70%.

The impact of a multidisciplinary breast cancer center on recommendations for patient management: the University of Pennsylvania experience

BACKGROUND

Advances in the diagnosis and treatment of breast carcinoma have led to a multidisciplinary approach to management for patients with breast carcinoma. To assess the effect of this approach, the authors performed an evaluation for a cohort of patients examined in a multidisciplinary breast cancer center.

METHODS

An analysis was performed for the records of 75 consecutive women with 77 breast lesions examined in consultation in a multidisciplinary breast cancer center between January and June 1998. Each patient's case was evaluated by a panel consisting of a medical oncologist, surgical oncologist, radiation oncologist, pathologist, diagnostic radiologist, and, when indicated, plastic surgeon. A comprehensive history and physical examination was performed, and the relevant mammograms, pathology slides, and medical records were reviewed. Treatment recommendations made before this evaluation were compared with the consensus recommendations made by the panel.

RESULTS

For the 75 patients, the multidisciplinary panel disagreed with the treatment recommendations from the outside physicians in 32 cases (43%), and agreed in 41 cases (55%). Two patients (3%) had no treatment recommendation before consultation. For the 32 patients with a disagreement, the treatment recommendations were breast-conservation treatment instead of mastectomy (n = 13; 41%) or reexcision (n = 2; 6%); further workup instead of immediate definitive treatment (n = 10; 31%); treatment based on major change in diagnosis on pathology review (n = 3; 9%); addition of postmastectomy radiation treatment (n = 3; 9%); or addition of hormonal therapy (n = 1; 3%).

CONCLUSIONS

The multidisciplinary breast cancer evaluation program provided an integrated program in which individual patients were evaluated by a team of physicians and led to a change in treatment recommendation for 43% (32 of 75) of the patients examined. This multidisciplinary program provided important second opinions for many patients with breast carcinoma.

Functional studies of the bacterial avirulence protein AvrPto by mutational analysis

Pseudomonas syringae pathovars expressing avrPto are avirulent on plants expressing the resistance gene Pto. Over 85 mutants of avrPto were generated with multiple strategies, and several assays were used to characterize AvrPto function. Only a core of 95 amino acids of the 164 residues was sufficient for binding Pto in the yeast two-hybrid system. Only nine of 65 mutant proteins of AvrPto with amino acid substitutions, created in planta and in vitro, did not interact with Pto in the Gal4 yeast two-hybrid system, suggesting that AvrPto can tolerate many nonconservative substitutions and still interact with Pto. These nine and 12 additional substitution mutants of AvrPto were characterized further. The ability to elicit a hypersensitive response and the effect on pathogenesis in planta for these 21 mutants of AvrPto were strongly correlated with recognition by Pto in the yeast two-hybrid system. Analyses of two proteins with substitutions H54P or D52G/L65P indicated that these residues may be required for delivery into the host cell and protein stability in the bacterial cytoplasm, respectively. The mutants that no longer interacted with Pto and had modified activities in planta were predicted to have changes in their secondary structure.

Stress fracture of the femoral neck in young adult: report of four cases

Stress fracture of the femoral neck is an uncommon injury. If the diagnosis is missed or delayed and fracture displacement results, serious complications such as avascular necrosis of the femoral head, nonunion or varus deformity may occur. Treatment depends on the type of stress fracture. Compression and tension stress fractures can be successfully treated with conservative management or prophylactic internal fixation using multiple screws. Displaced stress fractures are an orthopedic emergency, requiring prompt surgical intervention. Poor outcomes after fracture displacement have been reported by many authors. We present four cases demonstrating three types of stress fracture of the femoral neck. It is hoped that these case reports will serve to increase practitioner awareness of this injury and emphasize the need for careful diagnosis and treatment of this potentially problematic injury.

Multiple high-grade bronchial dysplasia and squamous cell carcinoma: concordant and discordant mutations

Loss of heterozygosity (LOH) involving chromosomes 3p, 5q, 9p, or 17p and aberrant expression or mutation of p53 are reported previously in selected bronchial dysplasias and squamous cell cancers (SCCs). Yet, comprehensive analyses of LOH patterns at these chromosomal sites and of p53 alterations are not reported for histologically normal bronchial epithelium, high-grade bronchial dysplasia, and SCC present in the same pulmonary resections. Whether concordant or discordant genetic changes are detected in these bronchial tissues, especially when multiple high-grade dysplastic bronchial lesions are present, was studied. Genomic DNA was microdissected from eight pulmonary SCCs and high-grade dysplastic lesions that were associated with SCC. In four cases, two independent high-grade dysplastic bronchial lesions were identified. When available, histologically normal bronchial epithelium was microdissected. Germ-line genomic DNA was isolated from normal lymph nodes. LOH was assessed for 15 microsatellite markers on chromosomes 3p, 5q, 9p, or 17p, sites frequently deleted in lung cancers. Immunohistochemical p53 expression was studied and correlated with p53 DNA sequence analyses. Progressive LOH for these markers was found when SCCs were compared with high-grade dysplasia and histologically normal bronchial epithelium present in the same resections. Histologically normal bronchial specimens had LOH in up to 27% of informative markers. High-grade dysplastic lesions exhibited LOH for 18-45% and SCC had LOH for 18-73% of the markers. Common regions of LOH were found in some dysplasias compared with SCCs. In other dysplasias, discordance was found relative to SCCs, especially for p53 mutations. In cases with a single or second high-grade dysplasia associated with SCC, heterogeneity in LOH markers was detected. These concordant and discordant changes were consistent with convergent and divergent clonal selection pathways in pulmonary squamous cell carcinogenesis. Some histologically normal bronchial epithelial tissues had genetic changes more similar to those in the SCCs than in dysplastic lesions. DNA loss or mutations accumulate in SCC, but discordant genetic changes can exist in the same carcinogen-exposed bronchial tissues. These findings have implications for lung cancer prevention trials.

[Preparation of novel magnetic dextran affinity adsorbents and their application to purify urokinase]

The reverse phase suspension and embedment technique were adopted to prepare magnetic dextran microsphere (MDMS). The dispersion medium was mixture of some organic solvents. Span-80 was used as stabilizer. The aqueous dextran with magnetic fluid was suspended in dispersion medium with epichlorohydrin as cross-linking reagent. The mixture was stirred for 30 minutes at room temperature and then heated at 70 degrees C for 4 hours, MDMS was thus obtained. MDMS was activated by epichlorohydrin on which 6-aminohexanoic acid, glycine or ethylene diamine was bonded as spacers. Then it was coupled with p-aminobenzamide, L-arginine methyl ester or guanidohexanoic acid and five magnetic affinity adsorbents were prepared. The MDMS was polydisperse particles with the size of 50-300 meshes and the content of Fe3O4 was about 6.2 per cent in the MDMS. Influence of some parameters such as viscosity and density of organic phase, the volume ratio of organic and aqueous phase, the quantity of surfactant and stirring speed on preparing MDMS was studied. Magnetic affinity adsorbents were used to purify crude urokinase in a bath mode and the effect of coupling reagents and ligands on results of purification was discussed. The bioactivity recovery was 40.0 to 60.7 per cent, the purification-fold was between 14.9 and 32.8, and the adsorptive capacity varies from 89 mg to 121 mg per milliliter of adsorbent.

Cloning and characterization of a 22 kDa outer-membrane protein (Omp22) from Helicobacter pylori

Helicobacter pylori is a causative agent of gastritis and peptic ulceration in humans. As the first step towards development of a vaccine against H. pylori infection, we have attempted to identify protective antigens. A potential target of vaccine development would be a H. pylori specific protein, which is surface-exposed and highly antigenic. We identified a 22 kDa outer-membrane protein (Omp22) from H. pylori, which was highly immunoreactive. By screening a H. pylori genomic DNA library with rabbit anti-H. pylori outer-membrane protein antibodies, the omp22 gene was cloned and 1.4 kb of the nucleotide sequence was determined. One open reading frame, encoding a 179-residue polypeptide, was identified and the amino acid sequence deduced showed homology with peptidoglycan-associated lipoproteins. The sequence was conserved among other H. pylori strains. Omp22 protein is expressed as a precursor polypeptide of 179 residues and undergoes lipid modification and cleavage of an 18 amino acid signal peptide to yield a mature protein. Omp22 protein in H. pylori as well as recombinant Omp22 protein expressed in E. coli was localized into the outer membrane and exposed on the cell surface. Omp22 may have the potential as a target antigen for the development of a H. pylori vaccine.

Factors related to complete occlusion of arteriovenous malformations after gamma knife radiosurgery

OBJECT

The authors sought to evaluate the effects of gamma knife radiosurgery (GKS) on cerebral arteriovenous malformations (AVMs) and the factors associated with complete occlusion.

METHODS

A total of 301 radiosurgical procedures for 277 cerebral AVMs were performed between December 1988 and December 1999. Two hundred seventy-eight lesions in 254 patients who were treated with GKS from May 1992 to December 1999 were analyzed. Several clinical and radiological parameters were evaluated.

CONCLUSIONS

The total obliteration rate for the cases with an adequate radiological follow up of more than 2 years was 78.9%. In multivariate analysis, maximum diameter, angiographically delineated shape of the AVM nidus, and the number of draining veins significantly influenced the result of radiosurgery. In addition, margin radiation dose, Spetzler-Martin grade, and the flow pattern of the AVM nidus also had some influence on the outcome. In addition to the size, topography, and radiosurgical parameters of AVMs, it would seem to be necessary to consider the angioarchitectural and hemodynamic aspects to select proper candidates for radiosurgery.

Nitric oxide augments release of chemokines from monocytic U937 cells: modulation by anti-inflammatory pathways

Nitric oxide (NO) appears to act as an inflammatory mediator on monocytic cells. Exogenous NO augmented release of chemokines from human promonocytic U937 cells and peripheral blood mononuclear cells. Pharmacological strategies aiming at modulation of NO-induced release of interleukin-8 (IL-8) were investigated in U937 cells in detail. Release of IL-8 was down-regulated by transforming growth factor beta2 (TGF-beta2), by the protein tyrosine-kinase inhibitor genistein, and via rises in intracellular cyclic AMP, generated by prostaglandin E(2), rolipram, pentoxifylline, forskolin, or dibutyryl-cyclic AMP. In addition, incubation with the synthetic glucocorticoid dexamethasone or suppression of activity of p38 mitogen-activated protein (MAP) kinases by SB-203580 modulated release of IL-8. Activation of p38 MAP kinases was confirmed by the demonstration of an augmented appearance of phosphorylated p38 in the presence of NO. The present data suggest that exposure to exogenous NO resembles activation of U937 cells by proinflammatory stimuli. The anti-inflammatory cytokine TGF-beta2, as well as anti-inflammatory or immunosuppressive agents such as genistein, pentoxifylline, rolipram, dexamethasone, and SB-203580 modulate inflammatory, chemokine-inducing actions of NO.