Search PubMed⌕ Search

Biomedical subjects

J H Sohn

Publications and source records attributed to J H Sohn.

At least 55 records · Page 3Linked to original sources
PubMed1998

Combination chemotherapy of oral 5'-deoxy-5-fluorouridine and cisplatin in advanced gastric cancer: a phase II study.

This study was designed to test the activity and feasibility of 5'-deoxy-5-fluorouridine (5'-DFUR) and cisplatin combination therapy in the treatment of advanced gastric cancer. Nineteen patients with inoperable and/or metastatic gastric cancer, which was histologically proven, were orally administered 5'-DFUR 1,200 mg/m2 on days 1 to 4 and days 15-18 combined with 70 mg/m2 of cisplatin being repeated every 4 weeks. Five partial responses (PRs) were achieved. Seven patients had stable disease and 6 progressed on therapy. The overall response rate was 27.7% (95% confidence interval: 9.69% to 53.5%). The median survival duration of all 18 patients was 25 weeks (9-64). The majority of patients had WHO grade I/II toxicity, but there was no treatment-related death. These data support that the combinations of oral 5'-DFUR and cisplatin are well tolerable and have a moderate activity with low toxicity in the treatment of advanced gastric cancer.

Administration, Oral↗
PubMed1998

A case of Behçet's syndrome with supeior vena cava syndrome.

Behçet's syndrome is a multi-systemic and chronic disorder that affects many organs. It has been suggested that the diagnosis was based on the presence of the 'major' and 'minor' clinical criteria. When thromobophlebitis, arthritis, central nervous system or gastrointestinal lesions are also present. Behçet's syndrome will be thought to be present in the appropriate geographic area. We report a case of superior vena cava syndrome caused by Behçet's disease in a 40-year-old man with recurrent oral aphthous ulcers and skin rashes on the anterior chest wall. There were multiple thrombosis of the superior vena cava, innominate and subclavian veins. This patient also had a solitary cecal ulcer with an ileocecal fistula and downhill varix. The chest CT, veno-cavography, pulmonary angiography and colon study were taken and follow-up was performed.

Adult↗
PubMed1997

Interhemispheric modulation of sensory transmission in the primary somatosensory cortex of rats.

Single unit responses of the primary somatosensory (SI) cortical neurons to the stimulation of the forepaw single digit were monitored in anesthetized rats before and after subcutaneous injection of lidocaine to an ipsilateral homologous receptive field (IHRF). Quantitative determination of the temporal changes of afferent sensory transmission was done by analyzing poststimulus time histograms of unit responses. Temporary deafferentation to the IHRF induced immediate, but reversible suppression of afferent sensory transmission in the SI cortex and this suppression lasts up to 35 min post-deafferentation period (during 10-15 min, -21.81 +/- 5.9%, P < 0.01). This result suggests that temporary absence of afferent inflow from the digit to the SI cortex may exert interhemispheric modulation of afferent sensory transmission in the opposite somatosensory cortex of anesthetized rats.

Afferent Pathways↗
PubMed1997

Changes in alpha wave and state anxiety during ChunDoSunBup Qi-training in trainees with open eyes.

We investigated the effects of ChunDoSunBup (CDSB) Qi-training, one of the Korean popular Qi-training systems, on EEG patterns, activation coefficients and state anxiety in 13 trainees with open eyes. CDSB Qi-training procedure consists of 3 stages: sound exercise, reciting Chunmoon, which is similar to a mantra; haeng-gong, a kind of body motion; and mediation. Compared to the control state (resting state before Qi-training), subjects reported less state anxiety, their activation coefficients decreased significantly during sound exercise and meditation in the occipital regions. Mean relative power and changes of mean absolute power of alpha wave increased significantly during sound exercise and meditation in the occipital regions. These results suggest that sound exercise and meditation in ChunDoSunBup Qi-training may reduce activation of the visual cortex and influence the thalamus and other functions of the brain. These could reduce anxiety levels and modulate the psychological, neurological, and physiological functions in man.

Adult↗
PubMed1997

Flat depressed early colon cancer--a case report.

A flat depressed early colon cancer (FDEC) is characterized by non-polypoid growth pattern, no association of adenomatous tissues and a tendency of even small lesions toward submucosal invasion and lymph node metastasis. It supports de novo carcinogenesis of colorectal cancer, although most colorectal cancers arise in pre-existing adenoma (adenoma-carcinoma sequence). There have been few reports of small depressed cancers because of the difficulty in colonoscopic detection and the rapid development to ulcerating advanced cancers. We report a case of flat depressed early colon cancer confined to mucosa detected by indigo carmine contrast colonoscopy.

Colonic Neoplasms↗
PubMed1996

A novel autonomously replicating sequence (ARS) for multiple integration in the yeast Hansenula polymorpha DL-1.

Several autonomously replicating sequences of Hansenula polymorpha DL-1 (HARSs) with the characteristics of tandem integration were cloned by an enrichment procedure and analyzed for their functional elements to elucidate the mechanism of multiple integration in tandem repeats. All plasmids harboring newly cloned HARSs showed a high frequency of transformation and were maintained episomally before stabilization. After stabilization, the transforming DNA was stably integrated into the chromosome. HARS36 was selected for its high efficiency of transformation and tendency for integration. Several tandemly repeated copies of the transforming plasmid containing HARS36 (pCE36) integrated into the vicinity of the chromosomal end. Bal 31 digestion of the total DNA from the integrants followed by Southern blotting generated progressive shortening of the hybridization signal, indicating the telomeric localization of the transforming plasmids on the chromosome. The minimum region of HARS36 required for its HARS activity was analyzed by deletion analyses. Three important regions, A, B, and C, for episomal replication and integration were detected. Analysis of the DNA sequences of regions A and B required for the episomal replication revealed that region A contained several AT-rich sequences that showed sequence homology with the ARS core consensus sequence of Saccharomyces cerevisiae. Region B contained two directly repeated sequences which were predicted to form a bent DNA structure. Deletion of the AT-rich core in region A resulted in a complete loss of ARS activity, and deletion of the repeated sequences in region B greatly reduced the stability of the transforming plasmid and resulted in retarded cell growth. Region C was required for the facilitated chromosomal integration of transforming plasmids.

Base Sequence↗
PubMed1995

Responses from new receptive fields of VPL neurones following deafferentation.

Single unit recordings were made from the ventral posterior lateral thalamus of anaesthetized rats to characterize responses to the activation of new receptive fields induced by either local anaesthesia or amputation. Receptive fields confined to single digits were identified and evoked unit responses to the stimulation of single digits were quantitated before and after deafferentation. Although both methods of denervation rapidly induced similar new receptive fields from the adjacent single digit, they exhibited quite different temporal changes of the evoked unit responses from new receptive fields. This difference in the evoked unit responses from the new receptive fields may be related to either the different nature or the outcome of the two types of deafferentation.

Afferent Pathways↗
PubMed1995

Epithelial healing time and rate of the cornea after myopic epikeratoplasty.

This study was performed to investigate the corneal epithelial healing time and rate according to the method for promoting the reepithelization after myopic epikeratoplasty. A prospective study was conducted on 30 myopic epikeratoplasties which were divided into 3 groups according to the method for promoting the epithelial healing. The groups consisted of 10 eyes with pressure patches, 10 eyes with Acuvue disposable contact lens (CL) and 10 eyes with SeeQuence disposable CL. The cornea epithelial healing time were 3.4, 3.5 and 3.4 postoperative days for the pressure patch, Acuvue CL and SeeQuence CL groups, respectively. The corneal epithelial healing rates during postoperative 1, 2, and 3 days were 0.33, 0.78, and 0.44 mm2/hour for the pressure patch group; 0.24, 0.92 and 0.37 mm2/hour for the Acuvue CL group; and 0.30, 0.79 and 0.38 mm2/hour for the SeeQuence CL group. These results suggest that a disposable contact lens may not hinder epithelial healing compared with a pressure patch.

Adult↗
PubMed1994

Optimization of the expression system using galactose-inducible promoter for the production of anticoagulant hirudin in Saccharomyces cerevisiae.

We have tried to optimize the galactose-inducible gene expression system for the overproduction of the potent thrombin-specific inhibitor, hirudin, in a genetically engineered yeast, Saccharomyces cerevisiae. The expression and secretion of hirudin were directed by the galactose-inducible promoter, GAL10, and the mating factor alpha pre-pro leader sequence. The initial hirudin expression level in shake-flask culture was 2.3 mg 1-1. Modification of the expression vector and optimization of culture conditions, including the induction conditions, improved the level of hirudin gene expression and secretion into the culture supernatant more than 20-fold (50 mg 1-1) in a 4-1 scale batch cultivation. The expression and secretion level of hirudin seemed to be partially dependent on cell growth when galactose was used as a carbon source. Overexpression of the transcriptional activator, GAL4, appeared to have only negative effects on the expression of the hirudin gene and lacZ directed by the GAL10 promoter in the strain used in this study, unlike the previously reported examples. The complex medium containing yeast extract used for the increase of the cell mass and hirudin level did not show any detrimental effect on plasmid stability and did not complicate the downstream purification of hirudin from the culture supernatant. Moreover, the complex medium could greatly improve the hirudin productivity and reduce the degradation of hirudin produced in the culture supernatants.

Animals↗
PubMed1994

Effects of intracameral carbachol and acetylcholine on early postoperative intraocular pressure after cataract extraction.

We performed a randomized, prospective study to evaluate the effect of intraoperative, intracameral carbachol or acetylcholine on early postoperative intraocular pressure(IOP) after extracapsular cataract extraction(ECCE) and posterior chamber lens(PCL) implantation. Fifty-six eyes of 56 patients scheduled for routine ECCE and PCL implantation were randomly assigned into three groups: (1)carbachol infusion (19 eyes) (2) acetylcholine infusion (15 eyes) (3)balanced salt solution (BSS) infusion (control, 22 eyes). We compared the preoperative IOP, early postoperative IOP, postoperative 24 hours IOP and postoperative 1 week IOP. In the measurement of early postoperative IOP, IOP was measured at least twice at 3, 6 or 9 hours postoperatively. There was no significant difference in IOP between the three groups preoperatively, at postoperative 3 hours, and 1 week. At postoperative 6 hours, both the carbachol infusion group and acetylcholine infusion group were significantly different from the BSS infusion group. At postoperative 9 and 24 hours, only carbachol infusion group had a significant difference from BSS infusion group in suppression of postoperative IOP increase. Our results suggest that intraoperative, intracameral administration of carbachol or acetylcholine prevents early postoperative IOP increase, and that carbachol has a more lasting effect.

Acetylcholine↗
PubMed1990

Lesions of the cerebellar interpositus nucleus abolish both nictitating membrane and eyelid EMG conditioned responses.

Both nictitating membrane extension and eyelid EMG activity were measured during classical conditioning of rabbits to tone-airpuff pairings. Both measures were highly correlated. Over trials, learning criterion was met earlier with eyelid EMG activity than with nictitating membrane extension. Within a trial, eyelid EMG preceded and was more robust than nictitating membrane extension. The rabbits were lesioned in the cerebellar interpositus nucleus and then trained for up to 26 days. Detailed analyses of tone alone trials demonstrate that the lesion abolished conditioned responses for both measures. These data confirm that conditioned responses are abolished by lesion of the cerebellar interpositus nucleus.

Animals↗
PubMed1989

Stimulation of the periaqueductal gray matter inhibits nociception at the supraspinal as well as spinal level.

Stimulation of the periaqueductal gray matter (PAG) is known to modulate nociception at the spinal level. Several studies have suggested that nociception may also be modulated via ascending projections from the PAG. To study this hypothesis, the descending pathway was selectively disrupted immediately caudal to the PAG in 28 rats. Twenty-eight additional rats served as non-lesioned controls. All animals were chronically implanted with a stimulating electrode in the PAG, and antinociception was assessed using tests involving spinally and supraspinally mediated responses (tail-flick and hot-plate tests, respectively). Significantly fewer lesioned than non-lesioned rats showed stimulation-produced analgesia (SPA) in the tail-flick test (4 of 28 vs 14 of 28, respectively). In contrast, no significant difference in the incidence of SPA occurred between lesioned and non-lesioned rats in the hot-plate test. These findings demonstrate that nociception can be modulated at the supraspinal, as well as spinal, level.

Animals↗
PubMed1989

Characterization of stimulation-produced analgesia from the nucleus tractus solitarius in the rat.

Electrical stimulation of the commissural region of the nucleus tractus solitarius (NTS) inhibits the tail-flick reflex evoked by noxious heat. This antinociception can be measured in the awake or pentobarbital anesthetized rat at current intensities that do not induce overt behavioral side effects. Glutamate microinjections into the NTS, but not immediately surrounding the NTS, also inhibit the tail-flick reflex, demonstrating that activation of NTS cell bodies, and not fibers of passage, mediates antinociception from this region. In contrast, morphine microinjections into the NTS have no effect on the tail-flick reflex in anesthetized rats. These findings provide further evidence that the NTS is involved in the modulation of nociception.

Analgesia↗
PubMedDate not supplied

Relationship between p53-associated proteins and estrogen receptor status in ovarian serous neoplasms.

We studied the immunoexpression of p14ARF, MDM2, and p53, in addition to relationships between those protein expressions and estrogen receptor (ER)alpha in ovarian serous tumors including benign (n= 23), borderline (n= 41), and malignant (n= 94). The aberrant expressions of p14ARF, MDM2, and p53 were observed in 19.6% (31/158), 47.5% (75/158), and 39.9% (63/158) of cases, respectively. The expression of MDM2 was significantly higher in borderline tumors compared to benign (P= 0.04) and malignant (P < 0.01) tumors. p53 expression in borderline tumors was uncommon, and p14ARF expression loss was mainly observed in carcinomas. Altered expression of p14ARF, MDM2, and p53 shows significant relationship with stage. Overexpression of MDM2 (P= 0.01) and loss of p14ARF expression (P= 0.04) were significantly associated with ER expression. Our results suggest that alteration of p14ARF-MDM2-p53 pathway proteins may contribute significantly to the tumorigenesis of ovarian serous neoplasms, and ER is involved in cellular regulation of p14ARF-MDM2-p53 pathway in ovarian serous neoplasms.

Adolescent↗
PubMedDate not supplied

Fine needle aspiration cytologic findings of breast mucinous neoplasms: differential diagnosis between mucocelelike tumor and mucinous carcinoma.

OBJECTIVE: To report the cytologic findings of mucocelelike tumor and mucinous carcinoma. STUDY DESIGN: All mucinous neoplasms diagnosed by fine needle aspiration and confirmed by histologic examination were reviewed to detect the cytologic findings helpful for the differentiation. The cytologic findings were correlated with the histologic findings. RESULTS: Cytologically, mucinous carcinomas were highly cellular and showed many single epithelial cells and variably formed epithelial cell clusters in abundant extracellular mucin. Malignant cells exhibited round, atypical nuclei; granular chromatin; and small nucleoli. Mucocele like tumor showed low cellularity with scanty, monolayered, small sheets of epithelial cells and abundant, extracellular mucin. Myoepithelial cells were present within the epithelial cell sheets. Tumor cells were usually small, with uniform, round nuclei; fine chromatin; and absence of nucleoli. CONCLUSION: Cytologic findings of mucocelelike tumor and mucinous carcinoma were different in cellularity, shape of cell clusters and nuclear features, although mucocelelike tumors having a carcinoma component were similar to mucinous carcinoma. Awareness of the cytologic findings of breast mucinous neoplasms is important to make a specific diagnosis.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

Clinical value of olfactory function tests after endoscopic sinus surgery: a short-term result.

Functional endoscopic sinus surgery (FESS) is now the surgical procedure of choice for treating chronic sinusitis in patients of all ages. We performed the olfactory function test before and after FESS and assessed its clinical value. From February 1996 through July 1996, 50 bilateral sinusitis patients had received FESS, butanol threshold test, and odor identification test, performed preoperatively, at postoperative 1 month, and at postoperative 2 months. We analyzed preoperative computed tomography to determine the grade of sinusitis and status of the olfactory cleft. The status of the olfactory cleft significantly influenced the preoperative olfactory threshold score (p < 0.001). At 2 months postoperatively, the subjective symptoms of the patients were improved in 96% and objective olfactory threshold were improved in 68% of patients. There was no correlation between subjective symptoms and olfactory threshold improvement. Our study suggests that the olfactory threshold test may help predict the result of FESS, but for more accurate and reliable assessment, we should consider other objective methods like anterior rhinomanometry, acoustic rhinometry, ciliary beat frequency, and postoperative endoscopic findings.

Adolescent↗
PubMedDate not supplied

Increases in intraocular pressure during hemodialysis in eyes during early postvitrectomy period.

BACKGROUND AND OBJECTIVES: To identify risk factors for intraocular pressure (IOP) increases during hemodialysis (HD) in the early postoperative period following pars plana vitrectomy (PPV). PATIENTS AND METHODS: Comparisons of 36 vitrectomized eyes of 22 diabetics undergoing maintenance HD with those of 138 eyes of 69 nonoperated patients. Serial IOPs were measured before PPV, after PPV/before dialysis, and during dialysis. Serum osmolarity and blood pressure were also recorded. RESULTS: In 20 of 36 operated eyes (55.6%) and 18 of 138 nonoperated eyes (13.0%) IOP was increased (> or =4 mm Hg) during HD. In the operated group, marked increases (> or =7 mm Hg) were noted in 9 eyes and ocular pain in 5 eyes. Eyes with pre-existing outflow obstruction and/or acute postoperative outflow compromise carried high risks. No correlation with changes in serum osmolarity or blood pressure was found. CONCLUSION: Monitoring of IOP during HD seems warranted when diabetics with pre-existing outflow obstruction and/or postoperative outflow compromise, undergo HD following PPV.

Adult↗