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Biomedical subjects

J H Ryu

Publications and source records attributed to J H Ryu.

At least 55 records · Page 3Linked to original sources
PubMed2000

Idiopathic pulmonary fibrosis: Impact of oxygen and colchicine, prednisone, or no therapy on survival.

The clinical records of 487 patients seen at Mayo Clinic Rochester (MCR) during 1994 through 1996 who were diagnosed as having idiopathic pulmonary fibrosis of the usual interstitial pneumonia type (IPF/UIP) were reviewed. Computed tomography (CT) had been done in 94.7% of patients and surgical open lung biopsy (OLB) in 20.3%. Median survival was 3.2 yr. We compared survival as a function of treatment program, based on intent to treat at the time of the initial contact within the study window. Treatment advised included colchicine alone in 167, no therapy in 157, prednisone at maintenance dosages alone in 54, colchicine plus prednisone in 71, and other programs in 38. Oxygen therapy was advised in 133 patients. By univariate analysis, worse survival was associated with prednisone therapy compared with no therapy, and with oxygen therapy compared with no oxygen therapy. However, on multivariate analysis, worse survival was associated with older age, male gender, lower diffusing capacity for carbon monoxide (DL(CO)), lower alveolar volume (VA), and a history of worsening pulmonary function. When adjustment was made for these factors, there was no significant difference in survival between those patients treated with colchicine or prednisone and those on no therapy, and no difference between those on oxygen therapy and those without oxygen.

Aged↗
PubMed2000

Pulmonary lymphangioleiomyomatosis in a man.

Pulmonary lymphangioleiomyomatosis (LAM) is an uncommon disease reported to occur exclusively in women. We describe a phenotypically normal man with pulmonary LAM. Fluorescence in situ hybridization (FISH) studies performed on the lung biopsy confirmed a normal XY genotype. Our patient also had stigmata of tuberous sclerosis complex (TSC), including facial angiofibromas and renal angiomyolipoma. Immunohistochemical stains of both LAM and renal angiomyolipoma showed positive immunoreactivity for hamartin (TSC1) and loss of immunoreactivity for tuberin (TSC2). Loss of heterozygosity (LOH) for TSC2 was further demonstrated in the renal angiomyolipoma. Coupled with the results of immunostains, these findings are consistent with TSC2 mutation.

Adult↗
PubMed2000

Polyacetylenes from angelica gigas and their inhibitory activity on nitric oxide synthesis in activated macrophages.

In activated macrophages the inducible form of nitric oxide synthase (i-NOS) generates high amounts of the toxic mediator, nitric oxide (NO) which contributes to the circulatory failure associated with septic shock. Two polyacetylenes were isolated from the medicinal plant Angelica gigas and their structures were elucidated as octadeca-1,9-dien-4,6-diyn-3,8,18-triol (1) and 18-acetoxy-octadeca-1,9-dien-4,6-diyn-3,8-diol (2) by spectroscopic method. These polyacetylenes and their peracetate, 3, 8, 18-triacetoxy-octadeca-1, 9-dien-4, 6-diyn (3) inhibited the production of NO in LPS-activated RAW 264.7 cells by suppressing the i-NOS enzyme expression. These new inhibitors of i-NOS expression may have potential in the treatment of endotoxemia and inflammation accompanied by the overproduction of NO.

Acetylene↗
PubMed2000

High frequency of pulmonary lymphangioleiomyomatosis in women with tuberous sclerosis complex.

OBJECTIVE: To determine the frequency of pulmonary lymphangioleiomyomatosis (LAM), a rare cystic lung disorder that occurs almost exclusively in women of reproductive age, in women with tuberous sclerosis complex (TSC), an inheritable multiorgan hamartomatosis. PATIENTS AND METHODS: In this retrospective cohort study, the medical records of 78 women with definite TSC were reviewed, and pertinent information was recorded, including the demographic data, clinical manifestations, results of lung biopsies and autopsies, and findings on imaging studies of the chest and abdomen. All available computed tomographic (CT) scans of the chest and abdomen were reviewed. RESULTS: Of 78 women with definite TSC seen from 1977 to 1998, 20 (26%) had evidence of LAM. Surgical lung biopsy or autopsy in 7 patients confirmed the diagnosis of their lung disease. Characteristic CT findings of LAM were noted in 13 additional patients. Twelve of these 20 patients with TSC-associated LAM had respiratory symptoms, including exertional shortness of breath and spontaneous pneumothorax, that eventually led to their pulmonary diagnosis. CONCLUSIONS: The frequency of lung involvement (LAM) in women with TSC is substantially higher than previously suspected and may be even higher than reported in this retrospective study. These findings support the recommendation for a screening CT of the chest for all women with TSC.

Adult↗
PubMed1999

Nucleotide sequence analysis of the 3'-terminal region of two Korean isolates of lily symptomless Carlavirus and expression of the coat protein in E. coli.

The 3'-terminal regions of the genomic RNAs of two Korean isolates of the lily symptomless Carlavirus (LSV), LSV-Ko and LSV-KII, were cloned and their nucleotide sequences were determined. The nucleotide sequence analysis and protein analysis by the Western blot revealed that E. coli expressed a 32-kDa protein that is the viral coat protein (CP) for the LSV. The two Korean strains share 98.4% and 98.3% sequence identities at the nucleotide and amino acid levels, respectively. The CP gene of LSV-Ko showed 99.1% and 87.0% nucleotide sequence identities, and 99.0% and 96.6% amino acid sequence identities with those of the Netherlands and the Japanese LSV strains, respectively. A pairwise amino acid sequence comparison revealed a sequence similarity of 29.6% to 69.8% between LSV-Ko and other species of the carlavirus. The 16 kDa protein of LSV-Ko shares 17.6% to 42.7% amino acid similarity with those of 8 other the carlaviruses, and they are variable in the N-terminal region. The Cys repeated zinc finger nucleic acid binding domain was found in the 16 kDa protein for all of the LSV strains. Sequence comparisons of the 7 kDa protein of LSV in the strain level showed significant identities from 100.0% to 98.4%. LSV-Ko shares 21.9% to 42.2% amino acid similarity with those of 8 other carlaviruses, 4 members of the potexviruses, and a closterovirus. LSV is closely related to blueberry scorch virus (BISV) based upon the phylogenetic tree analyses of the three proteins, indicating LSV to be a quite distinct member of the genus Carlavirus.

Amino Acid Sequence↗
PubMed1999

Development of new dihydropyran linker for solid-phase reaction.

The linker which plays a role in connecting a polymer with a scaffold has become an important part in solid-phase reaction. To develop a new linker for alcohols and carbohydrates, dihydropyran moiety was selected in this study. New linker, 1-(4',5'-dihydro-5H-pyranyl)-7-hydroxyheptan-3-one (5) was synthesized via four steps from delta-valerolactone. This can be called as DDHP-linked Wang resin due to double dihy-dropyran rings. To the one pyran ring of new linker 5 was added Wang resin and other alcohols and carbohydrates as scaffolds were then added successfully to the another pyran ring. Carbohydrate and hydroxyl resins were connected via new linker in a 70% loading yield. The detachment of glucose moiety in the presence of PPTS (2 equiv.) in 1:1 n-butanol/1,2-dichloroethane at 60 degrees C for 12 h was carried out quantitatively. When certain combinatorial chemical works are carried out using this dihydropyran linker, Wang resin itself can be recovered. Its fact is particularly very important in industry, because recovered resins can be recycled.

Alcohols↗
PubMed1999

Tolerance of acid-adapted and non-adapted Escherichia coli O157:H7 cells to reduced pH as affected by type of acidulant.

A study was carried out to determine if three strains of Escherichia coli O157:H7 grown (18 h) in Tryptic Soy Broth (TSB) and TSB supplemented with 1.25% glucose (TSBG), i.e. unadapted and acid-adapted cells, respectively, exhibited changes in tolerance to reduced pH when plated on Tryptic Soy Agar (TSA) acidified (pH 3.9, 4.2, 4.5, 4.8, 5.1 and 5.4) with acetic, citric or malic acids. All test strains grew well on TSA acidified with acetic acid at pH > or = 5.4 or malic acid at pH > or = 4.5; two strains grew on TSA acidified with citric acid at pH > or = 4.5, while the third strain grew at pH > or = 4.8. Acid-adapted and control (unadapted) cells differed little in their ability to form visible colonies on TSA containing the same acid at the same pH. However, on plates not showing visible colonies, acid-adapted cells retained higher viability than unadapted cells when plated on acidified TSA. Growth of acid-adapted and control cells of E. coli O157:H7 inoculated into TSB containing acetic acid (pH 5.4 and 5.7) and citric or malic acids (pH 4.2 and 4.5) was also studied. There was essentially no difference in growth characteristics of the two types of cells in TSB acidified at the same pH with a given acid. Tolerance of acid-adapted and control cells on subsequent exposure to low pH is influenced by the type of acidulant. The order of sensitivity at a given pH is acetic > citric > malic acid. When performing acid challenge studies to determine survival and growth characteristics of E. coli O157:H7 in foods, consideration should be given to the type of acid to which cells have been exposed previously, the procedure used to achieve acidic environments and possible differences in response among strains. The use of strains less affected by pH than type of acidulant or vice versa could result in an underestimation of the potential for survival and growth of E. coli O157:H7 in acid foods.

Acids, Acyclic↗
PubMed1999

A sesquiterpene, dehydrocostus lactone, inhibits the expression of inducible nitric oxide synthase and TNF-alpha in LPS-activated macrophages.

Nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha) are the major mediators produced in activated macrophages which contribute to the circulatory failure associated with septic shock. A sesquiterpene lactone compound (dehydrocostus lactone) isolated from the medicinal plant, Saussurea lappa, inhibited the production of NO in lipopolysaccharide (LPS)-activated RAW 264.7 cells by suppressing inducible nitric oxide synthase enzyme expression. This compound also decreased the TNF-alpha level in LPS-activated systems in vitro and in vivo. Thus, dehydrocostus lactone may be a possible candidate for the development of new drugs to treat endotoxemia accompanied by the overproduction of NO and TNF-alpha.

Animals↗
PubMed1999

Suspected non-small cell lung cancer: incidence of occult brain and skeletal metastases and effectiveness of imaging for detection--pilot study.

PURPOSE: To estimate the incidence of occult metastases to the brain and skeleton in patients suspected of having non-small cell lung cancer (NSCLC) (stage higher than T1Nomo) with surgically resectable disease, to assess the accuracy of screening magnetic resonance (MR) imaging and radionuclide bone scanning for help in identifying occult metastases, and to determine the effectiveness of a high dose of MR contrast material. MATERIALS AND METHODS: Twenty-nine patients suspected of having NSCLC localized to the lung or to the lung and regional nodes underwent preoperative MR imaging with contrast material enhancement and radionuclide bone scanning for detection of brain or skeletal metastases. Patients were followed up for 12 months to determine the incidence of clinical metastatic disease. RESULTS: Eight (28%) patients had occult metastatic disease to the brain or skeleton. Brain metastases were identified on MR images in five of six patients. Bone metastases were identified on MR images in four of five patients and on bone scans in three of five patients. MR imaging was no more accurate than bone scanning for skeletal evaluation. A high dose of MR contrast material allowed detection of more metastases and of small lesions. CONCLUSION: Contrast-enhanced MR imaging of the brain is indicated for the exclusion of brain metastases in patients with clinically operable known or possible NSCLC and a large (> 3-cm) lung mass. Skeletal imaging may be indicated if an isolated brain metastasis is detected.

Aged↗
PubMed1999

Meningioma metastatic to the lung.

Meningiomas constitute 15% to 18% of all primary intracranial and intraspinal tumors. Distant extracranial metastases are reported to occur in fewer than 1 in 1000 cases. Of 1992 primary intracranial meningiomas seen at Mayo Clinic Rochester from 1972 through 1994, we identified 3 (0.15%) with documented extracranial metastasis. A review of the literature suggests that previous craniotomy, venous sinus invasion, local recurrences, histological malignancy, and papillary morphology may be risk factors for systemic spread, as demonstrated in our cases. Although rare, metastatic meningioma should be considered in the differential diagnosis of abnormal findings on chest radiography in patients with known or suspected intracranial meningioma.

Adolescent↗
PubMed1999

Behavior of acid-adapted and unadapted Escherichia coli O157:H7 when exposed to reduced pH achieved with various organic acids.

A study was done to determine if various organic acids differ in their inhibitory or lethal activity against acid-adapted and unadapted Escherichia coli O157:H7 cells. E. coli O157:H7 strain EO139, isolated from venison jerky, was grown in tryptic soy broth (TSB) and in TSB supplemented with 1% glucose (TSBG) for 18 h at 37 degrees C, then plated on tryptic soy agar (TSA) acidified with malic, citric, lactic, or acetic acid at pH 5.4, 5.1, 4.8, 4.5, 4.2, and 3.9. Regardless of whether cells were grown in TSB or TSBG, visible colonies were not formed when plated on TSA acidified with acetic, lactic, malic, or citric acids at pH values of < or =5.4, < or =4.5, < or =4.2, or < or =4.2, respectively. Cells not adapted to reduced pH did not form colonies on TSA acidified with lactic acid (pH 3.9) or acetic acid (pH 3.9 and 4.2); however, a portion of acid-adapted cells remained viable on TSA containing lactic acid (pH 3.9) or acetic acid (pH 4.2) and could be recovered in TSB. Inactivation of acid-adapted cells was less than that of unadapted cells in TSB acidified at pH 3.9 with citric, lactic, or acetic acid and at pH 3.4 with malic acid. Significantly (P< or =0.05) higher numbers of acid-adapted cells, compared with unadapted cells, were detected 12 h after inoculation of TSB acidified with acetic acid at pH 3.9; in TSB containing lactic acid (pH 3.9), the number of acid-adapted cells was higher than the number of unadapted cells after 5 h. In TSB acidified at pH 3.9 with citric acid or pH 3.4 with malic acid, significantly higher numbers of acid-adapted cells survived. This study shows that organic acids differ in their inhibitory or lethal activity against acid-adapted and unadapted E. coli O157:H7 cells, and acid-adapted cells are more tolerant than unadapted cells when subsequently exposed to reduced pH caused by these acids.

Adaptation, Physiological↗
PubMed1999

Primary pulmonary lymphoma.

Lymphoproliferative diseases affecting the lung occur over a broad clinical and pathologic spectrum. The clinical presentations and radiologic findings are nonspecific, entailing broad differential diagnoses. Accurate diagnosis requires adequate tissue sampling with appropriate ancillary pathologic studies. The recent delineation of new pathologic entities such as low-grade malignant lymphoma of mucosa-associated lymphoid tissue (MALT type) has aided in the understanding of the pathophysiology, clinical course, and management of patients with pulmonary lymphoma. Significant observations have been made in the clinical management and treatment of these disorders.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Influence of temperature and pH on survival of Escherichia coli O157:H7 in dry foods and growth in reconstituted infant rice cereal.

Factors affecting the ability of Escherichia coli O157:H7 to survive in foods with a(w) less than required for growth have not been fully defined. This study was undertaken to determine the ability of E. coli O157:H7 to survive in a commercial dry infant rice cereal as affected by a(w) (0.35+/-0.04, 0.52+/-0.03 and 0.73+/-0.03), pH (4.0 and 6.8), and temperature (5, 25, 35 and 45 degrees C), and in nine other reduced-a(w) foods. Death of E. coli O157:H7 in cereal was enhanced with increased temperature and decreased pH during a 16- to 24-week storage period. Survival was enhanced at pH 6.8 compared to pH 4.0 in cereal at a(w) 0.34+/-0.04 during initial storage at 5 and 25 degrees C. The effect of temperature (8, 15, 21 and 30 degrees C) on survival and growth of acid-adapted cells of E. coli O157:H7 inoculated into cereal reconstituted with milk or apple juice at two inoculum levels (8.2-12.3 cfu/ml and 82-123 cfu/ml of slurry) was also studied. Growth occurred in cereal reconstituted with milk at all test temperatures and in cereal reconstituted with apple juice at 15, 21 and 30 degrees C. Populations increased by >1 log10 cfu/ml within 3-6 h at 21 and 30 degrees C. Acid-adapted and unadapted cells had similar growth patterns. The effects of temperature and acid adaptation on survival of E. coli O157:H7 in nine commercial foods and food ingredients with pH 4.07-6.49 and a(w) 0.17-0.82 were determined. The pathogen survived in these foods for various lengths of time, depending the storage temperature, with an order of survival of 5 degrees C >21 degrees C >37 degrees C. Survival appeared to be enhanced in foods with highest pH, and acid-adapted cells retained higher viability than unadapted cells in only two of the nine test foods. Of particular importance is the ability of E. coli O157:H7 to survive well in dry foods with a wide range in a(w) and pH, particularly at refrigeration temperature.

Animals↗
PubMed1998

Influence of acid tolerance responses on survival, growth, and thermal cross-protection of Escherichia coli O157:H7 in acidified media and fruit juices.

A study was done to determine survival and growth characteristics of acid-adapted, acid-shocked, and control cells of Escherichia coli O157:H7 inoculated into tryptic soy broth (TSB) acidified with organic acids and three commercial brands of apple cider and orange juice. The three types of cells behaved similarly in TSB acidified with acetic acid; however, in TSB (pH 3.9) acidified with lactic acid, acid-adapted cells were more tolerant than acid-shocked cells which, in turn, were more tolerant than control cells. The ability of the three types of cells to grow after inoculation into acidified TSB, then plated on tryptic soy agar containing sodium chloride was determined. Tolerance of acid-adapted cells and, less markedly, acid-shocked cells to sodium chloride was diminished, compared to control cells. The pathogen showed extraordinary tolerance to the low pH of apple cider and orange juice held at 5 or 25 degrees C for up to 42 days. Growth occurred in one brand of apple cider (pH 3.98) incubated at 25 degrees C. Regardless of test parameters, there was no indication that cell types differed in tolerance to the acidic environment in apple cider or orange juice. Survival of control, acid-adapted, and acid-shocked cells heated in apple cider and orange juice was studied. Within each apple cider or orange juice, D(52 degrees C)-values of acid-adapted cells were considerably higher than those of acid-shocked or control cells, which indicates that heat tolerance can be substantially enhanced by acid adaptation compared to acid shock.

Beverages↗
PubMed1998

Yomogin, an inhibitor of nitric oxide production in LPS-activated macrophages.

In activated macrophages the inducible form of nitric oxide synthase (i-NOS) generates high amounts of toxic mediator, nitric oxide (NO) which contributes to the circulatory failure associated with septic shock. A sesquiterpene lactone compound (yomogin) isolated from medicinal plant Artemisia princeps Pampan inhibited the production of NO in LPS-activated RAW 264.7 cells by suppressing i-NOS enzyme expression. Thus, yomogin may be a useful candidate for the development of new drugs to treat endotoxemia and inflammation accompanied by the overproduction of NO.

Animals↗