Search PubMed⌕ Search

Biomedical subjects

J M Lee

Publications and source records attributed to J M Lee.

At least 145 records · Page 8Linked to original sources
PubMed2000

Video-imaging assessment of nasal morphology in individuals with complete unilateral cleft lip and palate.

OBJECTIVE: The purpose of this study was to develop a video-imaging mathematical method to assess nostril morphology. DESIGN: This retrospective study involved two age-matched groups: 28 subjects with complete unilateral cleft lip and palate (CUCLP) and 19 noncleft controls. Nose casts were reproducibly oriented in a jig such that the casts could be rotated about the coronal axis. Video images of the nostrils were captured and then analyzed for area, perimeter, centroid, principal axis, moments about the major and minor axes (I11, I22), anisometry, bulkiness, lateral offset, internostril angle, and rotational angle. RESULTS: All parameters identified nostril asymmetry in both groups. The results of the analyses using anisometry, I11, and I22 showed that, in both groups, one nostril was rounder and one was more elliptical. This asymmetry, however, differed between the two groups, and the difference was primarily based on the degree of ellipticity of the nostrils. Maximum dimension, perimeter, lateral offset, I11, and I22 were more asymmetric in the cleft group. In the control group, the right nostril was more elliptical and had a greater perimeter, and the left-side nostril had a greater bulkiness (enfolding). CONCLUSIONS: The method developed was validated for assessment of nasal morphology in cleft and noncleft samples. Nostril morphology was asymmetric in both groups but more asymmetric in the cleft group than the control group. The dominant influence of the cleft resulted in more elliptical noncleft nostrils and greater nostril shape asymmetry in the cleft group. The validated video-imaging method can now be used to assess the efficacy of treatment on nasal morphology.

Adolescent↗
PubMed2000

Comparing MR imaging and CT in the staging of gastric carcinoma.

OBJECTIVE: The purpose of this study was to assess the usefulness of breath-hold two-dimensional (2D) fast low-angle shot (FLASH) and T2-weighted turbo spin-echo fast MR imaging compared with helical CT in the staging of gastric carcinoma. SUBJECTS AND METHODS: Thirty patients with gastric carcinoma underwent preoperative MR imaging and helical CT. MR imaging at 1.5 T was performed immediately after the intramuscular injection of scopolamine and the oral administration of water or effervescent granules. Breath-hold 2D FLASH T1-weighted images in all three planes, turbo spin-echo T2-weighted axial images, and gadolinium-enhanced fat-suppressed 2D FLASH axial images were included. Helical CT was performed 60 sec after initiation of i.v. contrast medium injection (2.5-3 ml/sec). Two groups of two radiologists each independently analyzed the MR and helical CT findings, and these results were compared with the pathologic findings. RESULTS: For T staging, MR imaging accuracy was higher than that of helical CT (73.3% and 66.7%, respectively); however, the accuracies of the two methods were not significantly different from each other (McNemar test, p > 0.05). Overstaging was noted in 6.7% of cases with MR imaging and 10% with helical CT. Understaging was noted in 20% of cases with MR imaging and 23.3% with helical CT. For N staging, the accuracies of MR imaging and helical CT were 55% and 58.6%, respectively, with no statistical significance (overstaging, 10% and 6.9%; understaging, 34.5% and 34.5%, respectively). CONCLUSION: MR imaging was comparable to helical CT in the T and N staging of gastric cancer.

Adult↗
PubMed2000

CT-guided celiac plexus block for intractable abdominal pain.

Treatment of intractable abdominal pain due to inoperable intraabdominal malignancy is important, and the ineffectiveness of pharmacological agents has led many investigators to recommend chemical neurolysis of the celiac ganglions as a treatment. The author describes the technique and results of celiac plexus neurolysis under CT-guidance with various approach routes, including anterior, posterior and transaortic routes. Twenty-eight patients, ranging in age from 36 to 82 years, have been treated with this procedure. All had inoperable or recurred intraabdominal malignancies and suffered from intractable upper abdominal pain and/or back pain. The author performed the procedure using absolute alcohol by an anterior approach (n=18), posterior approach (n=6) and transaortic approach (n=4). Pain was rated according to a visual analog scale before and after the procedure to gauge treatment success. No major complications occurred. Mild hypotension occurred in five patients (18%) and transient diarrhea in six patients (21%). Twenty-one (75%) of the 28 patients had some relief of pain and 17 of these patients (61%) had good relief of pain after the procedure. The results support that CT-guided celiac plexus block with alcohol is a safe and effective means of pain control in patients with intraabdominal malignancy.

Abdominal Pain↗
PubMed2000

Weber-Christian disease presenting with proptosis: a case report.

Weber-Christian disease (WCD) is a rare inflammatory disease of adipose tissue, which is characterized by painful cutaneous nodules and constitutional symptoms. Although any area of the body containing fat can be affected by WCD, the involvement of retrobulbar fat is uncommon and proptosis is a rare presenting manifestation. We report a case who presented with proptosis of the right eye which is accompanied by painful subcutaneous nodules, high fever and myalgia. Biopsies of retrobulbar tissue and suprapubic nodule showed lobular panniculitis with mixed cellular infiltration, mainly composed of histiocytes and lymphocytes. He responded well to high-dose glucocorticoid.

Adult↗
PubMed2000

Diffuse hepatic hemangiomatosis in an adult.

Diffuse hepatic hemangiomatosis without extrahepatic lesions is extremely rare in adults. A case of diffuse hepatic hemangiomatosis involving right lobe in a 50-year-old woman was presented. The hemangiomatosis was demonstrated by ultrasonography, computerized tomography (CT) and magnetic resonance image (MRI), and was confirmed histopathologically. Although diffuse hepatic hemangiomatosis is a rare disease in adults, its diagnosis should be considered in patients with diffuse tumor growth in one or both hepatic lobes and distinguished from malignant tumors. The present case is the first documented case of diffuse hepatic hemangiomatosis in an adult in Korea.

Female↗
PubMed2000

Malignant craniopharyngioma.

Craniopharyngiomas are histologically and cytologically benign epithelial tumors of the central nervous system that may be locally aggressive and tend to recur after excision. Malignant change in craniopharyngiomas is extremely rare; we found only 4 such reports in the literature. In this report, we describe a case of squamous cell carcinoma arising in a previously benign craniopharyngioma in a 42-year-old woman. The patient was diagnosed with craniopharyngioma in 1982; during the subsequent 15 years she experienced 7 tumor recurrences, for which surgical resections and 3 courses of radiotherapy were performed. In 1998, the tumor recurred with involvement of the nasal cavity and sphenoid and ethmoid sinuses. Histologic evaluation revealed foci of typical adamantinomatous craniopharyngioma associated with a moderately differentiated squamous cell carcinoma. The transition of typical craniopharyngioma to squamous cell carcinoma was well demonstrated, suggesting that carcinoma arose from the underlying craniopharyngioma. Radiation may have been a contributing factor to carcinogenesis in this case.

Adult↗
PubMed2000

Helicobacter pylori eradication therapy: a discrepancy between current guidelines and clinical practice.

BACKGROUND: Consensus guidelines recommend that patients with peptic ulcer disease, and other causes of dyspepsia, should be treated with Helicobacter pylori eradication regimens. However, it has not been firmly established whether physicians have adapted their practice accordingly. OBJECTIVES: (1) To establish the proportion of ulcer-healing prescriptions that H. pylori eradication regimens accounted for, (2) to evaluate the composition of the eradication regimens used, and (3) to compare the prescribing patterns of specialist and primary care practitioners. METHODS: Seven community pharmacy practices were identified, and all prescriptions for individual acid-suppressing agents and eradication regimens were prospectively evaluated over an initial one-month period. Prospective documentation and evaluation of eradication regimens only was then continued for a further three-month period. RESULTS: The prescriptions for 585 patients were evaluated. Proton-pump inhibitors and H2-receptor antagonists accounted for 261 (44.5%) and 307 (52.5%) of prescriptions respectively. H. pylori eradication therapy was prescribed for 17 (2.9%) patients in this initial period. Sixty-six eradication regimens were evaluated over four months: 48/66 (73%) of these were initiated by primary care practitioners and 18/66 (27%) by specialists. Thirteen different combinations of antibiotics and acid-suppressing agents were identified - many of undocumented efficacy. Dual, triple and quadruple regimens accounted for 15 (23%), 48 (72.5%) and 3 (4.5%) of patient prescriptions respectively. CONCLUSION: H. pylori eradication therapy currently accounts for a very small proportion of ulcer-healing medication in clinical practice. Most eradication regimens are initiated by primary care practitioners. In comparison with specialist practices, prescriptions from this source are more likely to be of undocumented efficacy.

Anti-Bacterial Agents↗
PubMed2000

Differential effects of ovariectomy on the mechanical properties of cortical and cancellous bone in rat femora and vertebrae.

The purpose of this study was to evaluate the effects of ovariectomy on the mechanical properties of bone in the aged Sprague-Dawley rat model of osteoporosis. Eight female rats were sacrificed at the start of the study, at the age of four months. Twenty-four remaining rats were then bilaterally ovariectomized (OVX), and another twenty-four served as controls. Eight rats from each group were sacrificed at five, ten or fifteen weeks. The mean density of L1 vertebral bodies from OVX rats was lower than in their control counterparts, as was the compressive modulus, the ultimate compressive stress and the toughness. The second lumbar vertebra from each rat was cored to remove the bulk of the cancellous bone and tested in compression to failure. Ovariectomy did not affect the mechanical properties of the cored vertebrae, suggesting that the mechanically relevant changes take place in the cancellous bone. The gravimetric density and bone mineral density (measured by dual-energy x-ray absorptiometry) of whole femora were lower in OVX rats than control rats. However, the gravimetric density of the cortical bone was unchanged, and when femora were tested to fracture in three-point bending, the mechanical properties of the midshaft were found to be unaffected. This study suggests some limitations to the mature ovariectomized rat model of osteoporosis: mechanically significant loss of cancellous bone occurs in vertebrae much more rapidly than suggested by other studies. Further, there is little evidence of mechanically important bone loss in cortical bone within four months of ovariectomy.

Animals↗
PubMed2000

Necrotizing enterocolitis: experience of 27 cases from a single Korean institution.

Necrotizing enterocolitis (NEC) can involve any site in the gastrointestinal tract and is a fatal complication of immunosuppression. To characterize NEC, clinical and radiological characteristics were analyzed. A total of 27 cases of NEC were identified from January 1993 to August 1998, and medical records were reviewed. NEC was diagnosed by clinical and radiological criteria, and other mimicking conditions were excluded. Of the NEC cases, 22 (81.5%) occurred in patients with underlying hematologic malignancy. All patients complained of abdominal pain and fever at the time of inclusion. Escherichia coli was the most common pathogen identified. The most common finding by computed tomography was single-layered diffuse bowel wall thickening with variable density. Other findings were ascites, fascial thickening, pneumatosis, and mesenteric lymphadenopathy. Of the patients, 25 were treated with antimicrobials with or without recombinant hematopoietic growth factors, and 2 were treated with surgery because of perforation and profound bleeding. Among the 12 patients who died, NEC was the direct cause of death in 7 patients. In conclusion, computed tomography is an effective tool for early diagnosis of NEC. Bowel rest, broad-spectrum antimicrobials, and recombinant hematopoietic growth factors are important aspects of treatment. Surgery should be reserved for complicated cases.

Adolescent↗
PubMed1999

Elevated transglutaminase-induced bonds in PHF tau in Alzheimer's disease.

Transglutaminase-induced epsilon-(gamma-glutamyl)lysine bonds covalently cross-link and polymerize peptides into insoluble high molecular weight protein aggregates resistant to degradation and proteolytic digestion. We investigated the hypothesis that excessive deposition of epsilon-(gamma-glutamyl)lysine bonds is a neuropathological mechanism which induces the polymerization of tau protein into stable aggregates leading to the formation of paired helical filaments (PHFs) which deposit into neurofibrillary tangles in Alzheimer's disease (AD) brain. We demonstrate a significant (45%) elevation in epsilon-(gamma-glutamyl)lysine cross-links in AD cortex as compared to control cortex. In vivo, PHF tau, and high and medium molecular weight neurofilament proteins have significantly greater cross-linking by epsilon-(gamma-glutamyl)lysine bonds in AD brains as compared to controls. The cross-linking of PHF tau occurs both intra-molecularly and inter-molecularly. The inter-molecular cross-linking of tau could account for the formation of high molecular weight tau polymers. These results suggest that transglutaminase-induced cross-linking of tau protein could play a role in the formation and stabilization of neurofibrillary tangles. Inhibition of transglutaminase-induced cross-linking may therefore, provide a novel strategy for the treatment of AD.

Aged↗
PubMed1999

Modification of EWS/WT1 functional properties by phosphorylation.

In many human cancers, tumor-specific chromosomal rearrangements are known to create chimeric products with the ability to transform cells. The EWS/WT1 protein is such a fusion product, resulting from a t(11;22) chromosomal translocation in desmoplastic small round cell tumors, where 265 aa from the EWS amino terminus are fused to the DNA binding domain of the WT1 tumor suppressor gene. Herein, we find that EWS/WT1 is phosphorylated in vivo on serine and tyrosine residues and that this affects DNA binding and homodimerization. We also show that EWS/WT1 can interact with, and is a substrate for, modification on tyrosine residues by c-Abl. Tyrosine phosphorylation of EWS/WT1 by c-Abl negatively regulates its DNA binding properties. These results indicate that the biological activity of EWS/WT1 is closely linked to its phosphorylation status.

Animals↗
PubMed1999

4-Aminopyridine antagonizes the acute relaxant action of metformin on adrenergic contraction in the ventral tail artery of the rat.

The ability of metformin (MF) to acutely relax phenylephrine (PE)-induced contraction in the isolated rat tail artery is reported to be accompanied by repolarization of the arterial smooth muscle cell (SMC) membranes. These membranes contain potassium (K) channels which if opened could mediate such repolarization and resultant relaxation. We have shown that the acute relaxation of rat tail arterial tissue rings by graded levels of MF > or = 0.24 mmol/L is markedly antagonized by a high concentration of tetraethylammonium (TEA; 10 mmol/L) which nonselectively inhibits nearly all K channels. Thus, we tested effects of more selective inhibitors of K channels in the same tissue. We also tested MF for relaxation of contractions induced by high levels of extracellular K. To avoid confounding variables, we also conducted these tests in arterial rings in which endothelium and sympathetic nerve endings had been removed. In the absence of K channel inhibition, half-maximal PE-induced contractions were rapidly relaxed by all levels of MF with an EC50 of 1.7+/-0.2 mmol/L (n=8 rings). 1 mmol/L 4-aminopyridine (4AP) which only inhibits voltage-operated and ATP-sensitive K channels markedly antagonized this relaxation, shifting the EC50 for MF to 7.5+/-0.7 mmol/L (n=8; p < 0.05). TEA at 1 mmol/L (which only inhibits calcium-activated K channels), barium at 20 micromol/L (which only inhibits inward rectifier K channels) and glyburide at 5 micromol/L (which only inhibits ATP-sensitive K channels) did not alter this relaxation. Finally, MF failed to relax contractions produced by elevations of extracellular K to levels high enough to abolish the K gradient across arterial SMC membranes. Thus, acute relaxation of rat tail arterial smooth muscle by MF may be dependent on the transmembrane K gradient and mediated at least in part by specific activation of K efflux through 4AP-sensitive voltage-dependent K channels in arterial SMC membranes.

4-Aminopyridine↗
PubMed1999

Inhibitory effects of chlorophyllin on 7,12-dimethylbenz[a]anthracene-induced bacterial mutagenesis and mouse skin carcinogenesis.

Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, has been used for the treatment of several abnormal human conditions without apparent toxicity. Recent studies have revealed that CHL has the excellent chemopreventive potential. In the present investigation, we have found the inhibitory activities of CHL against 7,12-dimethylbenz[a]anthracene (DMBA)-induced mutagenesis in Salmonella typhimurium TA100 and also on DMBA-initiated and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-promoted mouse skin tumor formation. The incidence and the multiplicity of skin tumors were not significantly decreased in mice by a single topical application of CHL prior to the DMBA treatment, but there was a marked suppression of papillomagenesis in mice treated with CHL during the promotional stage. Furthermore, the formation of DMBA-induced papillomagenesis was reduced in all mice that had received CHL for 6 weeks following treatment with TPA for 6, 18 and 24 weeks. These results indicate that CHL can inhibit both tumor promotion and the progression of papillomagenesis in the two-stage mouse skin carcinogenesis induced by DMBA and TPA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

The Epstein-Barr virus latency BamHI-Q promoter is positively regulated by STATs and Zta interference with JAK/STAT activation leads to loss of BamHI-Q promoter activity.

In Epstein-Barr virus (EBV)-associated tumors in nonimmunocompromised patients, EBV gene expression is highly restricted. EBV-encoded nuclear antigen (EBNA)-1 is expressed, whereas the immunogenic and proliferative EBNAs are not. This pattern of EBNA expression is generated by usage of the BamHI-Q promoter (Qp). We have determined that the JAK/STAT pathway positively regulates Qp activity. In transient-transfection assays, a Qp-CAT reporter was activated by cotransfected JAK-1 and by treatment of cells with the cytokine IL-6. The ability of Qp to bind signal transducer and activator of transcription (STAT) proteins was directly demonstrated by electrophoretic mobility-shift assay, and mutation of potential STAT-binding sites reduced Qp responsiveness to Janus kinase (JAK)-1. Consistent with a role for STATs in Qp function, Qp using Burkitt's lymphoma Rael cells and cultured nasopharyngeal carcinoma (NPC) cells contained nuclear STAT protein. We investigated whether the inability to maintain EBV-positive NPC cell lines in culture was related to Qp activity. Passaging of the NPC cell line HK666 led to activation of expression of BZLF1, which encodes Zta and loss of Qp function. Transient expression assays linked Zta expression to the down-regulation of Qp. Cotransfection of Zta reduced Qp activity in reporter assays. This negative regulation required Zta DNA-binding activity. We provide evidence that Zta up-regulation of p53 leads to p53-mediated interference with JAK/STAT activation of Qp. The data imply that JAK/STAT signaling has a role in EBV-associated malignancies.

B-Lymphocytes↗
PubMed1999

Inhibition of protein kinase A phase delays the mammalian circadian clock.

The suprachiasmatic nuclei (SCN) contain the mammalian circadian clock whose rhythm of firing rate can be recorded in vitro for several days. Application of a protein kinase A (PKA) inhibitor onto the SCN at Zeitgeber time (ZT) 10 on the first day in vitro phase delayed the rhythm of firing rate expressed by SCN neurons on the subsequent day in vitro. Application of the inhibitor (Rp-cAMPS) at other circadian phases did not phase shift the rhythm. These results suggest that during approximately 1 h in the late subjective day the presence and activity of PKA plays a role in setting the phase of the mammalian circadian clock.

Animals↗
PubMed1999

Anti-tumor promoting potential of naturally occurring diarylheptanoids structurally related to curcumin.

In recent years, there have been considerable efforts to search for naturally occurring substances for intervention of carcinogenesis. Many components from medicinal or dietary plants have been identified to possess potential chemopreventive properties. For instance, curcumin, a yellow colouring agent from turmeric (Curcuma longa Linn., Zingiberaceae) has been shown to inhibit tumor formation in diverse animal models. Alpinia oxyphylla Miquel that also belongs to ginger family has been used in oriental herbal medicine. In the present work, we have evaluated the anti-tumor promoting potential of yakuchinone A (1-[4'-hydroxy-3'-methoxyphenyl]-7-phenyl-3-heptanone) and yakuchinone B (1-[4'-hydroxy-3'-methoxyphenyl]-7-phenylhept-1-en-3-one), major pungent ingredients of A. oxyphylla. Thus, topical application of yakuchinone A or B significantly suppressed TPA-induced epidermal ornithine decarboxylase activity. They also reduced TPA-stimulated production of tumor necrosis factor-alpha in cultured human promyelocytic leukemia (HL-60) cells. Both compounds blunted the TPA-induced superoxide generation in differentiated HL-60 cells in a concentration-related manner and also inhibited lipid peroxidation in rat brain homogenates. Furthermore, yakuchinone A and yakuchinone B nullified the activation of the activator protein-1 (AP-1) in immortalized mouse fibroblast cells in culture. These findings indicate that pungent diarylheptanoids from A. oxyphylla have anti-tumor promotional properties that can contribute to their chemopreventive potential.

3T3 Cells↗