Biomedical subjects

J Lee

Publications and source records attributed to J Lee.

At least 811 records · Page 45Linked to original sources

PubMed1998

Association of the Ban I dimorphic site at the human cytosolic phospholipase A2 gene with schizophrenia.

There is evidence of increased phospholipid breakdown in cell membranes of patients suffering from schizophrenia. This may be related to increased levels of the enzyme cytosolic phospholipase A2 (cPLA2) which have been reported in schizophrenic subjects. We have identified a Ban I dimorphic site on the first intron of the cPLA2 gene. Schizophrenic subjects were found to have a significant excess of the A2/A2 homozygote relative to healthy control subjects. Genetically determined alterations in phospholipase activity may thus underlie the reported abnormalities of phospholipid metabolism in schizophrenia.

Cytosol↗

PubMed1998

Optimization of acid suppression for patients with peptic ulcer bleeding: an intragastric pH-metry study with omeprazole.

OBJECTIVE: To study whether an intravenous infusion dose of omeprazole (80 mg + 8 mg/h) during 24 h can be subsequently reduced with maintained effect. Second, to study the effect of oral omeprazole 20 mg given once or twice daily up to day 10, after cessation of a 3-day intravenous infusion (80 mg + 8 mg/h). DESIGN: Prospective, randomized, partly blinded study. METHODS: Twelve Helicobacter pylori(+) patients and 12 H. pylori(-) subjects were included. In part I the patients received omeprazole, 80 mg + 8 mg/h, during 24 h followed by 8, 4 or 2 mg/h. In part II the subjects received 80 mg + 8 mg/h during 3 days followed by 20 mg omeprazole orally, once or twice daily until day 10. Intragastric pH was measured. RESULTS: All H. pylori(+) patients showed a rapid increase of intragastric pH with a mean intragastric pH of 6.7 during the second half of the first day. After the subsequent dose reduction, the mean pH decreased to 6.1-6.2. Patients continuing on 8 mg/h showed the best results. Likewise, all H. pylori(-) subjects showed a rapid and sustained reduction of intragastric acidity during the infusion. Subsequent dose reduction to 20 mg once daily led to a stable fraction of time with pH > 3 of 72%. CONCLUSIONS: Omeprazole given as a continuous infusion of 80 mg + 8 mg/h for 72 h followed by omeprazole 20 mg once daily raised the intragastric pH to and above levels alleged to allow haemostasis in patients with peptic ulcer bleeding and subsequent healing of the ulcer.

Adult↗

PubMed1998

Oral or parenteral administration of replication-deficient adenoviruses expressing the measles virus haemagglutinin and fusion proteins: protective immune responses in rodents.

The genes encoding the measles virus (MV) haemagglutinin (H) and fusion (F) proteins were placed under the control of the human cytomegalovirus immediate early promoter in a replication-deficient adenovirus vector. Immunofluorescence and radioimmune precipitation demonstrated the synthesis of each protein and biological activity was confirmed by the detection of haemadsorption and fusion activities in infected cells. Oral as well as parenteral administration of the H-expressing recombinant adenovirus elicited a significant protective response in mice challenged with MV. While the F-expressing adenovirus failed to protect mice, cotton rats immunized with either the H- or F-expressing recombinant showed reduced MV replication in the lungs. Antibodies elicited in mice following immunization with either recombinant had no in vitro neutralizing activity, suggesting a protective mechanism involving a cell-mediated immune response. This study demonstrates the feasibility of using oral administration of adenovirus recombinants to induce protective responses to heterologous proteins.

Adenoviridae↗

PubMed1998

Regional brain activation in humans during respiratory and blood pressure challenges.

1. The aim of the present study was to determine the brain sites mediating aspects of respiratory and cardiovascular control in adult humans using non-invasive functional magnetic resonance (fMRI) procedures, thereby avoiding the spatial and temporal sampling limitations associated with classic neural assessment techniques. 2. We examined activity changes across the entire brain following application of respiratory loads and upon induction of blood pressure and heart rate alterations. Magnetic resonance signals were visualized with a 1.5 Tesla scanner in healthy volunteers (22-52 years of age) using procedures that optimally assess changes in brain tissue microcirculation. Images were collected during a Valsalva manoeuvre, inspiratory loading, hypercapnia, cold pressor challenges to the hand and forehead and during intervening baseline states. 3. Image values from experimental conditions were compared with corresponding baseline values on a pixel-by-pixel basis to identify brain regions in which the experimental conditions produced physiological activation. 4. Ventilatory and pressor challenges elicited significant changes in regional image signal intensity in areas within the orbital cortex, amygdala, hypothalamus and hippocampus. Cerebellar, medullary and pontine areas were also recruited. However, while particular brain regions were only activated during specific stimuli, other regional signal changes occurred with multiple experimental manipulations. 5. The findings indicate that respiratory and cardiac challenges elicit discrete activity changes over multiple brain sites. Activated regions include structures not often related to respiratory or cardiovascular regulation, such as the cerebellum; a prominent role for limbic forebrain structures in mediating the response is also suggested. The fMRI visualization procedures may greatly assist in the determination of neural structures that mediate respiratory and cardiovascular control in humans.

Adult↗

PubMed1998

Müllerian cysts of the mesentery and retroperitoneum: a case report and literature review.

Müllerian cyst of the mesentery and retroperitoneum is an extremely rare disease entity. Only two photomicrograph reports have been published. A 47-year-old Korean woman presented with abdominal distention. A mesenteric cystic mass, measuring 25 x 23 x 18 cm, was found between the liver and right adnexa without any connection with adjacent organs. The cyst was multilocular with gray-white, rubbery walls of relatively uniform 0.2 cm thickness. Microscopically, the lining cells were ciliated and cuboidal to low columnar with an incomplete lining of smooth muscle bundles, adipose tissues, lymphovascular spaces, and lymphocytic aggregates. Ultrastructurally, the lining cells had intercellular junctions, and cilia or microvilli on their luminal surface. The lining cells were immunoreactive for cytokeratin, epithelial membrane antigen and vimentin. To the best of our knowledge, this is the first demonstration of ultrastructural and immunohistochemical findings of Müllerian cyst of the mesentery and retroperitoneum in the English literature.

Cysts↗

PubMed1998

Randomized controlled trial comparing same-day discharge with hospital stay following haemorrhoidectomy.

BACKGROUND: A randomized controlled trial was conducted to compare traditional hospital stay haemorrhoidectomy (STAY) with same-day discharge haemorrhoidectomy (DAY) with regard to costs, clinical outcome and patient satisfaction. METHODS: A total of 54 consecutive patients were randomized to either STAY or DAY groups. A standardized excision of three piles was performed and the wounds were left open. The DAY patients went home on the same day but the STAY patients remained in hospital until their bowels had opened. A linear analogue pain score and patient satisfaction questionnaire were administered. During a mean follow-up of 60.5 (standard error of mean = 1.2) weeks, the complications and the total medical costs were recorded RESULTS: There were no differences in the age and sex distributions in both groups (STAY: 11 men, 16 women; mean age 40.6 (+/- 1.8) years; DAY: 10 men, 17 women; mean age 40.6 (+/- 1.9) years). Despite accounting for any readmissions, the DAY patients accumulated shorter total hospitalization stays (P < 0.001) and incurred less total medical costs (P = 0.04). The pain scores, analgesia requirements, postoperative complications, patient satisfaction and time taken off work were not different between the two groups. However, more patients in both groups preferred to stay after surgery if they should need another haemorrhoidectomy. CONCLUSIONS: Haemorrhoidectomy (with excision of three piles) can be safely performed as a day procedure, with reduced hospitalization and medical costs.

Adult↗

PubMed1998

Gastrointestinal mucormycosis mimicking ischemic colitis in a patient with systemic lupus erythematosus.

This report describes the case of a 42-yr-old woman with systemic lupus erythematosus who presented with septic shock. Initially, a source of infection could not be found and the patient was started on stress dose corticosteroids and antibiotics. A CAT scan revealed thickened colon and endoscopy revealed possible ischemic colitis. She soon developed peritonitis, and was taken to surgery where gastrointestinal mucormycosis was found. The patient died despite amphotericin therapy.

Adult↗

PubMed1998

Masking by sinusoidally amplitude-modulated tonal maskers.

In experiment 1, masking patterns were obtained with a tonal masker that was sinusoidally amplitude modulated (SAM) at a rate of 8 Hz and a depth (m) of 1.0. The signal was centered at a masker peak or masker valley. Masker frequency (fm) was 750, 1350, or 2430 Hz, and signal frequency (fs) ranged from 0.8 to 1.62 fm. Thresholds were generally higher for a signal in a masker peak than in a masker valley. The magnitude of this peak-to-valley (PV) difference was governed by fs/fm, rather than by fs, and was largest for fs > fm. The PV differences were smallest at the lowest fm, at least when fs > fm. In experiment 2, growth-of-masking functions were measured (fm = 1350 Hz, fs = 1.44fm). The masker was modulated at a depth (m) of 1.0, 0.75, or 0.50. These thresholds were compared with those obtained with an unmodulated masker in forward or simultaneous masking. The comparisons suggest that thresholds for a signal at a peak of an 8-Hz SAM masker are due to simultaneous masking, while those in a valley are due primarily to forward masking when m = 1.0 or simultaneous masking when m = 0.75 or 0.50. For these masker depths, the PV difference first increased but then decreased as masker level increased from 60 to 90 dB SPL. This was a consequence of the slope of the masking function for peak placement changing from a value greater than 2.0 to a value of 1.0 at the highest signal levels (an effect that was also observed with the unmodulated simultaneous masker), a result that may be understood in terms of basilar membrane nonlinearity.

Adult↗

PubMed1998

Psychophysical suppression as a function of signal frequency: noise and tonal maskers.

Physiological studies have suggested that the basal region of the cochlea is more nonlinear than the apical region. To evaluate this possibility psychophysically, suppression was investigated across signal frequency (250, 500, 1000, 2000, and 4000 Hz) in a forward-masking paradigm using both noise and tonal maskers/suppressors. Masker duration was 200 ms, signal duration was 20 or 40 ms, and signal delay was 0 or 20 ms; the longer delay was necessary to eliminate potential confusion effects observed with the (narrow-band) noise masker. When using a noise masker (spectrum level of 40 dB), suppression was determined by comparing the threshold in the presence of a broadband masker with that in the presence of a critical band (ERB) masker. When using a tonal masker (masker level of 50 dB SPL, suppressor level of 70 dB SPL, with the suppressor frequency being 1.2 times the masker/signal frequency), suppression was determined by comparing the threshold in the presence of the masker plus suppressor with that in the presence of the masker alone. The magnitude of suppression was determined either by the measured change in signal threshold or by the inferred change in masker level. Regardless of how suppression was quantified, for both masker types, the amount of suppression increased as signal frequency increased up to about 1000 Hz, but then reached an asymptote or decreased somewhat as signal frequency increased to 4000 Hz. The magnitude of suppression was much larger with a noise masker than with a tonal masker, which could be a result of the different number of components in the masker which might serve as a suppressor.

Adult↗

PubMed1998

Determinants of human immunodeficiency virus type 1 envelope glycoprotein activation by soluble CD4 and monoclonal antibodies.

Infection by some human immunodeficiency virus type 1 (HIV-1) isolates is enhanced by the binding of subneutralizing concentrations of soluble receptor, soluble CD4 (sCD4), or monoclonal antibodies directed against the viral envelope glycoproteins. In this work, we studied the abilities of different antibodies to mediate activation of the envelope glycoproteins of a primary HIV-1 isolate, YU2, and identified the regions of gp120 envelope glycoprotein contributing to activation. Binding of antibodies to a variety of epitopes on gp120, including the CD4 binding site, the third variable (V3) loop, and CD4-induced epitopes, enhanced the entry of viruses containing YU2 envelope glycoproteins. Fab fragments of antibodies directed against either the CD4 binding site or V3 loop also activated YU2 virus infection. The activation phenotype was conferred on the envelope glycoproteins of a laboratory-adapted HIV-1 isolate (HXBc2) by replacing the gp120 V3 loop or V1/V2 and V3 loops with those of the YU2 virus. Infection by the YU2 virus in the presence of activating antibodies remained inhibitable by macrophage inhibitory protein 1beta, indicating dependence on the CCR5 coreceptor on the target cells. Thus, antibody enhancement of YU2 entry involves neither Fc receptor binding nor envelope glycoprotein cross-linking, is determined by the same variable loops that dictate enhancement by sCD4, and probably proceeds by a process fundamentally similar to the receptor-activated virus entry pathway.

Animals↗

PubMed1998

Evidence of linkage of the inflammatory bowel disease susceptibility locus on chromosome 16 (IBD1) to ulcerative colitis.

Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) of unknown aetiology which are characterised by chronic inflammation of the gastrointestinal tract. Epidemiological studies suggest the presence of a genetic component in the aetiology of both CD and UC. A susceptibility gene for Crohn's disease has recently been mapped to the pericentromeric region of chromosome 16 (IBD1), and this finding has been replicated in two subsequent studies. Although CD and UC are distinct clinical entities, the fact that both disorders occur in a significant proportion of families with multiple cases of IBD suggests that overlapping sets of susceptibility genes may be involved. We have addressed this question for IBD1 by typing eight microsatellite markers from the locus in 70 kindreds affected with either UC only or with both UC and CD and analysing the data for linkage by both non-parametric and parametric methods. Evidence for linkage was detected in families affected with only UC, with a mean proportion of 0.70 affected sib pairs sharing alleles identical by descent at D16S3136 (p=0.01), and a peak non-parametric linkage score of 2.02 at D16S3120 with the GENEHUNTER program (p=0.02). The estimated sib relative risk attributable to IBD1 in these families was 1.46. Surprisingly, no evidence of linkage was detected in the families affected with both UC and CD (p>0.2). The data suggest that IBD1 may also contribute to susceptibility to ulcerative colitis, and that it is likely to be located in the 12 cM interval between D16S419 and D16S409.

Chromosomes, Human, Pair 16↗

PubMed1998

Improved oxygenation following adenosine infusion in persistent pulmonary hypertension of the newborn.

Six consecutive cases of persistent pulmonary hypertension of the newborn (PPHN) were treated with adenosine following failure of conventional therapy, excluding inhaled nitric oxide. A rise in arterial PO2 >20 mm Hg occurred in 5 of 6 cases within 30 min of commencing adenosine infusion. Individual maximal increases in PaO2 ranged from 31 to 131 mm Hg. Three neonates survived and 3 died. Amongst deaths, intensive support was withdrawn in a preterm neonate due to severe arthrogryposis/pulmonary hypoplasia. Of the remaining 2, the improvement in oxygenation persisted until death occurred from causes unrelated to adenosine. Side effects related to adenosine (bradycardia, hypotension, prolonged bleeding time) did not occur. Due to its ease of availability, administration and extremely short half-life, adenosine may be an important therapeutic option in PPHN.

Adenosine↗

PubMed1998

Increased mortality after successful treatment for Hodgkin's disease.

PURPOSE: To determine the impact of treatment toxicity on long-term survival in pediatric Hodgkin's disease. PATIENTS AND METHODS: We studied late events in 387 patients treated for pediatric Hodgkin's disease on four consecutive clinical trials at St Jude Children's Research Hospital from 1968 to 1990. Relative risks, actuarial risks, and absolute excess risks for cause-specific deaths were calculated. RESULTS: As of April 1997, 316 (82%) of patients were alive, with a median follow-up of 15.1 (range, 2.9 to 28.6) years. In this cohort, which represented 5,623 person-years of follow-up, 71 fatal events resulted from Hodgkin's disease (n=36), second malignancies (n=14), infections (n=7), accidents (n=7), cardiac disease (n=6), and asphyxiation (n=1). The 5-year estimated event-free survival (EFS) for the entire cohort was 79.6%+/-2.1 %, which declined to 63.1%+/-4.4% by 20 years. Cumulative incidences of cause-specific deaths at 25 years were 9.8%+/-1.6% for Hodgkin's disease, 8.1%+/-2.6% for second malignancy, 4.0%+/-1.8% for cardiac disease, 3.9%+/-1.5% for infection, and 2.1%+/-0.8% for accidents. Standardized incidence ratios showed excess risk for all second malignancies (12; 95% confidence interval [CI], 8 to 17), acute myeloid leukemia (81; 95% CI, 16 to 237), solid tumors (11; 95% CI, 7 to 16), and breast cancer (33; 95% CI, 12 to 72). Standardized mortality ratios also showed excess mortality from cardiac disease (22; 95% CI, 8 to 48) and infection (18; 95% CI, 7 to 38). CONCLUSION: Compared with age- and sex-matched control populations, survivors of pediatric Hodgkin's disease who were treated before 1990 face an increased risk of early mortality related to second cancers, cardiac disease, and infection.

Adolescent↗

PubMed1998

Leuprolide, a gonadotropin-releasing hormone agonist, reestablishes spermatogenesis after 2,5-hexanedione-induced irreversible testicular injury in the rat, resulting in normalized stem cell factor expression.

2,5-Hexanedione (2,5-HD) exposure in the rat produces irreversible testicular atrophy, a model of human male infertility that can be used for mechanistic and therapeutic studies. Following testicular injury by 2,5-HD, stem cell factor (SCF), a Sertoli cell-derived growth factor that binds the c-kit receptor on spermatogonia, is altered in its expression, changing from predominantly membrane SCF to predominantly soluble SCF. The goals of this study were 2-fold: first, evaluate leuprolide, a GnRH agonist, as a therapy for 2,5-HD-induced testicular atrophy, and second, examine changes in SCF expression during testicular injury and following recovery from injury. Rats exposed to 2,5-HD showed a nearly complete testicular atrophy that could be reversed by leuprolide therapy. Using RT-PCR, preferential expression of membrane SCF was associated with spermatogenesis, whereas soluble SCF expression was associated with atrophy. In conclusion, 2,5-HD exposure altered the form of SCF expressed and disrupted spermatogenesis; leuprolide therapy allowed recovery of spermatogenesis, which correlated with a normalization in growth factor expression in an otherwise irreversibly atrophic testis.

Animals↗

PubMed1998

Photography at the Department of Conservation, National Museum of Denmark.

The department's three photographers undertake photography to document the work of the department, both in the studio and on location. Applied photographic techniques are employed (ultra-violet, infra-red, macrophotography) and photographic processing for archival permanence is adapted to high volume monochrome machine printing.

Denmark↗

PubMed1998

Arthritic manifestations of inflammatory bowel disease.

Inflammatory bowel disease (IBD) is commonly associated with arthritic manifestations. They are divided into three clinical categories; peripheral arthritis, spondylitis, and sacroiliitis. To evaluate the incidence of arthritis associated with IBD in Korea, we retrospectively reviewed one hundred and twenty-nine patients with IBD, 77 with ulcerative colitis (UC) and 52 with Crohn's disease (CD). Arthritis occurred in twenty-two patients (17.1%); 15 with UC(19.6%), 7 with CD (13.5%). Patients with arthritis had more active inflammations and all were seronegative except one patient. Peripheral arthritis was found in twenty patients (15.5%) and more common in UC (19.6%) than in CD (9.6%). Joint involvements tended to be monoarticular or pauciarticular, and most frequently developed in the knee and ankle. Spondylitis was diagnosed in one patient (1.6%) who showed HLA B27 positivity. Radiographic sacroiliitis was observed in eight patients (6.2%) who revealed HLA B27 negativity. Both peripheral arthritis and sacroiliitis were found in six patients (4.6%). In CD, arthritis occurred in 20% of the patients with colonic involvement but in none of the patients without colonic involvement. In conclusion, arthritis was frequent in patients with IBD. Peripheral arthritis was more common in patients with UC than CD. All the patients with CD and arthritis had colonic involvement.

Adult↗

PubMed1998

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

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

Autoimmune Diseases↗

PubMed1998

Expression of osteopontin and osteonectin in breast cancer.

Osteopontin (OP) and osteonectin (ON) are bone matrix proteins produced by mammary and other cancers. These proteins may play a role in tumor invasion and metastasis through integrin-mediated signal transduction. We evaluated expressions of OP and ON in 253 resected infiltrating ductal carcinoma of the breast, using immunohistochemical staining and follow-up data. OP and ON were detected 87.4% and 54.2% of 253 cases, respectively. The OP and ON positive staining were localized in the cytoplasm of carcinoma cells. OP and ON did not correlate with various clinicopathological parameters, such as age, lymph node involvement, tumor size, histologic grade, expression of p53 and estrogen receptor (ER). In the multivariate model, lymph node involvement and histologic grade were statistically significant prognostic factors. Assessed by a log rank test, the 5-year-survival rates of OP and ON positive groups and their negative groups were not statistically different. In conclusion, OP and ON immunopositivity of infiltrating ductal carcinomas of the breast provide no additional prognostic information in this study.

Adult↗