Biomedical subjects

J N Lee

Publications and source records attributed to J N Lee.

At least 37 records · Page 2Linked to original sources

PubMed2000

Differential and constitutive expression of neuronal, inducible, and endothelial nitric oxide synthase mRNAs and proteins in pathologically normal human tissues.

Nitric oxide (NO) is produced by NO synthases (nNOS, iNOS, and eNOS) expressed in various human tissues and depending on the amount of NO produced in each tissue, the physiological function of NO is determined. However, due to the difficulty in obtaining normal human tissues, little is known about the basal levels of each of the three NOS mRNAsand proteins expressed constitutively in various human tissues. Results of the present study indicate that the basal levels of each of the three NOS mRNAs and proteins expressed in various regions of brain and peripheral tissues are different both in their sizes and in their contents. In Northern blot analysis, two different-sized mRNAs were found for each NOS isozymes: for the nNOS, approximately 12 and <12 kb mRNAs; for the iNOS, 4.2 and 4.5 kb mRNAs; for the eNOS, 4.2 and 4.4 kb mRNAs. In the Western blot, several different-sized NOS proteins were detected ( approximately 160, approximately 140, and approximately 130 kDa for nNOS; approximately 130 kDa for iNOS and eNOS) with tissue-specific expression patterns. These differential expression patterns of NOS mRNAs and proteins were caused by alternative splicing in the open-reading frame, and 5'- and/or 3'-untranslated regions of NOS mRNAs. These results suggest that regulation for differential expression of the three NOS genes in various human tissues may occur by alternative splicing of the NOS mRNAs in tissue-specific patterns.

3' Untranslated Regions↗

PubMed2000

Laparoscopically assisted vaginal hysterectomy using the light-endorsed transvaginal section technique versus the conventional method: a preliminary study.

Laparoscopically assisted vaginal hysterectomy (LAVH) is now being used by an increasing number of gynecologists. However, problems, such as the long operating time, the inherent difficulty of the technique, and limitations of the skills of the surgeons, still exist. Pelvic adhesion, especially in the vesicouterine reflection, may increase the difficulty and morbidity of the operation. We here describe a simple technique, called light-endorsed transvaginal section (LETS), which can facilitate the effectiveness and safety of LAVH. We have designed prospective studies to compare results obtained in 50 cases treated using LAVH plus LETS (study group) with those obtained in 50 cases treated by conventional LAVH (control group). We further divided the study group into 25 'complicated' cases (with pelvic adhesion) and 25 'easy' cases (without pelvic adhesion). The results show that the LETS technique is a simple, safe, and easy way of increasing the efficacy of LAVH, especially as a supplement to LAVH in the presence of pelvic adhesions.

Adult↗

PubMed2000

Methods to enhance tolerances of Chlorella KR-1 to toxic compounds in flue gas.

Possible methods to minimize the toxic effects of SOx and NOx on the growth of a highly CO2 tolerant and fast-growing microalga, Chlorella sp. KR-1, were investigated. Maintaining the pH of the culturing media at an adequate value was quite important to enhancing the tolerances of the microalgae to SOx and NOx. Controlling the pH by adding an alkaline solution, using a low flow rate of gas fed to the culture, and using a high concentration of inoculating cells were effective methods to maintaining the proper pH of the culture. Controlling the pH was the most effective method but could be applied only for some specific microalgae.

Air Pollutants↗

PubMed1999

Cholesterol biosynthesis from lanosterol. Molecular cloning, tissue distribution, expression, chromosomal localization, and regulation of rat 7-dehydrocholesterol reductase, a Smith-Lemli-Opitz syndrome-related protein.

The cDNA encoding the 471-amino acid rat 7-dehydrocholesterol reductase (DHCR), an enzyme that has been implicated in both cholesterol biosynthesis and developmental abnormalities (e.g. Smith-Lemli-Opitz syndrome) in mammals, has been cloned and sequenced, and the primary structure of the enzyme has been deduced. The DHCR gene was mapped to chromosome 8q2.1 by fluorescence in situ hybridization. Rat DHCR, calculated molecular mass of 54.15-kDa polypeptide, shares a close amino acid identity with mouse and human DHCRs (96 and 87%, respectively) as compared with its other related proteins (e.g. fungal sterol Delta14-reductase) and exhibits high hydrophobicity (>68%) with 9 transmembrane domains. Five putative sterol-sensing domains were predicted to be localized in transmembrane domains 4-8, which are highly homologous to those found in 3-hydroxymethylglutaryl-CoA reductase, sterol regulatory element-binding protein cleavage-activating protein, and patched protein. The polypeptide encoded by DHCR cDNA was expressed in yeast as a 55.45-kDa myc-tagged fusion protein, which was recognized with anti-myc monoclonal antibody 9E10 and shown to possess full DHCR activity with respect to dependence on NADPH and sensitivity to DHCR inhibitors. Northern blot analysis indicates that the highest expression of DHCR mRNA was detected in liver, followed by kidney and brain. In rat brains, the highest level of mRNA encoding DHCR was detected in the midbrain, followed by the spinal cord and medulla. Feeding rats 5% cholestyramine plus 0.1% lovastatin in chow resulted in both approximately a 3-fold induction of DHCR mRNA and a 5-fold increase of the enzymic activity in the liver. When rats were fed 0.1% (w/w) AY-9944 (in chow) for 14-days, a complete inhibition of DHCR activity and a significant reduction in serum total cholesterol level were observed. However, the level of hepatic DHCR mRNA fell only slightly, suggesting that AY-9944 may act more rapidly at the protein level than at the level of transcription of the DHCR gene under these conditions.

Amino Acid Sequence↗

PubMed1999

A huge pancreatic cystic adenoma misdiagnosed as an ovarian cyst.

Pancreatic cyst mimicking an ovarian cyst ultrasonographically has not yet been reported. We report an elderly woman with such a huge pancreatic cyst whose initial presentation was low abdominal pain. Ultrasound showed a hypoechoic cyst measuring 13.6 x 13.2 x 11.8 cm occupying pelvic cavity. She received laparotomy under the impression of ovarian cyst. Interestingly, the cyst was found to have originated from the pancreas. Total cyst excision was performed and pathologic report was pancreatic microadenoma. The patient's postoperative course was unremarkable.

Adenoma↗

PubMed1999

A mullerian duct remnant myoma misdiagnosed as ovarian cancer in a woman with vaginal agenesis--a case report.

Leiomyoma are very common in the normal uterus; however, they are rather rare in mullerian duct remnant. We report a case of mullerian duct remnant leiomyoma associated with vaginal agenesis. The mass had papillary growth with cystic-solid components by ultrasound. Ovarian cancer was suspected preoperatively. Finally, a fibroid with hyalinization and chondroid metaplasia was diagnosed histopathologically. To the best of our knowledge, this is the first case of mullerian duct remnant leiomyoma with degeneration, mimicking ovarian cancer by ultrasound. We provide the clinical details of this case and discuss a diagnostic pitfall.

Adult↗

PubMed1999

Analysis of referral initiatives, severity of illness and return to care of older women with cervical cancer.

BACKGROUND: Cervical cancer is a worldwide malignancy particularly prevalent in older women. Due to the increasing population ratio of older women and their more complicated illnesses, doctors in Taiwan are concerned about the care of older patients with cervical cancer. Few studies have been performed on the association between referral initiative and illness severity upon referral as well as the tendency of older patients with cervical cancer to return to the referring doctor and to the consultant at the medical center for follow-up. The purpose of this study was to investigate the referral association by adjusting for confounding variables. METHODS: This study included 214 women aged 65 years and over with cervical cancer diagnosed between 1987 and 1995. Patients were referred to a tertiary teaching hospital by 71 primary care gynecologists. The International Federation of Gynecology and Obstetrics clinical stage and clinical severity were assessed in each patient. Histopathologic results were reviewed to confirm the diagnosis. RESULTS: Of all the cervical cancer referrals, 20.2% were initiated by patients or families and 79.8% were initiated by primary care doctors. No statistically significant differences were found in the Basic Activities of Daily Living or Instrumental Activities of Daily Living between doctor- and patient-initiated referrals. High Geriatric Depression Scale and low Mini-Mental State Examination were associated with doctor-initiated referrals. Higher cancer stage and greater clinical severity of patients with cervical cancer was found in patient- rather than doctor-initiated referrals. After adjusting for marriage, family type, medical payment, mental status, cancer stage and clinical severity, the data showed that, if the referral was initiated by a primary care doctor, older patients with cervical cancer had a similar likelihood to return to both the primary care doctor and the tertiary teaching hospital for follow-up. CONCLUSIONS: If a referral was initiated by a doctor, older women with cervical cancer were not only likely to return to their consulting physician at the medical center, but also likely to return to their primary care doctor. Continuous care is more likely to occur when the primary care doctor initiated the referral.

Aged↗

PubMed1999

Correlation of arterial and end-tidal carbon dioxide in spontaneously breathing patients during ambulatory gynecologic laparoscopy.

Laparoscopy can be performed while patients are under total intravenous anesthesia (TIVA), or sedated and breathing spontaneously through the normal airway. Respiratory monitoring is difficult when patients are sedated or anesthetized, however. The purposes of this study were to evaluate the reliability of end-tidal carbon dioxide (ETCO2) measurement for monitoring arterial carbon dioxide pressure (PaCO2), and to assess the PaCO2/ETCO2 gradient among patients receiving TIVA while breathing spontaneously through the normal airway. Sixty patients were divided into two groups: group 1 patients (n = 30) received general anesthesia with controlled ventilation, while group 2 patients (n = 30) received TIVA with spontaneous breathing through the normal airway; ETCO2 was sampled through a 10-French suction catheter inserted into the nasopharynx via the nasal airway. Arterial blood gas and ETCO2 were recorded at the time of preinduction, induction, CO2 insufflation, and change to Trendelenburg tilt position (20 degrees-30 degrees), and at 10-minute intervals thereafter. The results showed that ETCO2 was highly correlated with PaCO2 in group 1 (correlation coefficient r = 0.85), but not in group 2 (r = 0.55). In group 2, the PaCO2/ETCO2 gradient increased as time elapsed, with significant differences (p < 0.05) between the values at induction and those at 30 minutes after the change to the Trendelenburg position and thereafter. These results indicate that the ETCO2 and PaCO2 values correlate well during the first 20 minutes after the change to the Trendelenburg position in laparoscopy patients receiving TIVA with spontaneous breathing, but that PaCO2 monitoring is still necessary.

Adult↗

PubMed1998

Mutations in the Delta7-sterol reductase gene in patients with the Smith-Lemli-Opitz syndrome.

The Smith-Lemli-Opitz syndrome (SLOS) is an inborn disorder of sterol metabolism with characteristic congenital malformations and dysmorphias. All patients suffer from mental retardation. Here we identify the SLOS gene as a Delta7-sterol reductase (DHCR7, EC 1.3.1. 21) required for the de novo biosynthesis of cholesterol. The human and murine genes were characterized and assigned to syntenic regions on chromosomes 11q13 and 7F5 by fluorescense in situ hybridization. Among the mutations found in patients with the SLOS, are missense (P51S, T93M, L99P, L157P, A247V, V326L, R352W, C380S, R404C, and G410S), nonsense (W151X), and splice site (IVS8-1G>C) mutations as well as an out of frame deletion (720-735 del). The missense mutations L99P, V326L, R352W, R404C, and G410S reduced heterologous protein expression by >90%. Our results strongly suggest that defects in the DHCR7 gene cause the SLOS.

Amino Acid Sequence↗

PubMed1998

Molecular cloning and expression of the human delta7-sterol reductase.

Inhibitors of the last steps of cholesterol biosynthesis such as AY9944 and BM15766 severely impair brain development. Their molecular target is the Delta7-sterol reductase (EC 1.3.1.21), suspected to be defective in the Smith-Lemli-Opitz syndrome, a frequent inborn disorder of sterol metabolism. Molecular cloning of the cDNA revealed that the human enzyme is a membrane-bound protein with a predicted molecular mass of 55 kDa and six to nine putative transmembrane segments. The protein is structurally related to plant and yeast sterol reductases. In adults the ubiquitously transcribed mRNA is most abundant in adrenal gland, liver, testis, and brain. The Delta7-sterol reductase is the ultimate enzyme of cholesterol biosynthesis in vertebrates and is absent from yeast. Microsomes from Saccharomyces cerevisiae strains heterologously expressing the human cDNA remove the C7-8 double bond in 7-dehydrocholesterol. The conversion to cholesterol depends on NADPH and is potently inhibited by AY9944 (IC50 0.013 microM), BM15766 (IC50 1.2 microM), and triparanol (IC50 14 microM). Our work paves the way to clarify whether a defect in the delta7-sterol reductase gene underlies the Smith-Lemli-Opitz syndrome.

Amino Acid Sequence↗

PubMed1998

Pharmacokinetic and pharmacodynamic profile of donepezil HCl following multiple oral doses.

AIM: The aim of this study was to characterize the pharmacokinetics and pharmacodynamics of donepezil HCl, a new, chemically distinct and specific acetylcholinesterase (AChE) inhibitor for the treatment of Alzheimer's disease, following multiple-dose administration. METHODS: This was a double-blind, randomized, placebo-controlled, multiple-dose study in healthy male volunteers (n=27). Three dose levels were investigated in sequential order: 1, 3 and 5 mg. Each dose was administered orally, once a day, for 21 consecutive days. Donepezil concentrations in plasma were quantified by HPLC. Pharmacodynamic activity was determined by the radioenzymatic measurement of erythrocyte membrane acetylcholinesterase (rbc-AChE) inhibition. RESULTS: The pharmacokinetic disposition of donepezil was observed to be dose proportional. The mean terminal disposition half-life was 79.5+/-19.0 h which resulted in a slow approach to steady state (14-21 days). A four- to sixfold increase in donepezil plasma concentration was observed during this time; however, no further increase was evident after achievement of steady state. The mean donepezil plasma concentration at steady state (Css) was 14.2 ng ml(-1). Neither the rate of accumulation nor the rate of clearance was dose dependent. Inhibition of rbc-AChE was directly correlated with donepezil concentration over a wide concentration range, with the higher concentrations showing the expected hyperbolic relationship. Donepezil was well tolerated by all subjects with no clinically significant changes in laboratory or physical parameters observed at any dose. CONCLUSIONS: The pharmacokinetics of donepezil were found to be dose proportional following the administration of multiple doses to healthy volunteers. A predictable relationship was also observed between plasma donepezil concentrations and rbc-AChE inhibition. The half-life of donepezil makes it suitable for once-daily dosing.

Administration, Oral↗

PubMed1998

Hysteroscopic resection of vaginal septum in an adolescent virgin with obstructed hemivagina.

This article reports on one patient with a double uterus, unilateral vaginal obstruction, with hemi-haematocolpos and ipsilateral renal agenesis. Early accurate diagnosis followed by the excision of the obstructing vaginal septum offers complete relief of symptoms, while preserving reproductive capacity. Unlike conventional excision of vaginal septum, we used resectoscope excision with cutting electrode under continuous pure distilled water irrigation. The postoperative course was uneventful, and haematocolpos and severe dysmenorrhoea disappeared. The resected vaginal area revealed re-epithelialization by hysteroscope follow-up one year after resection. With advancements in resectoscopic operation, evaluation and treatment of vaginal disorders in babies and virgins is very feasible.

Child↗

PubMed1998

Adenosine-stimulated intracellular calcium increase in cultured human uterine myocyte.

The effect of adenosine on intracellular free calcium concentration ([Ca2+]i) was studied in human uterine myocyte. Adenosine 10(-6) M elicited a rapid followed by a maintained increase in [Ca2+]i in Fluo-3-loaded myocytes. Compared with basal [Ca2+]i level, adenosine induced a 2.6-fold increase in the absence of extracellular calcium, and a 2.4-fold increase in the presence of extracellular calcium. There was no significant difference between the two groups in the initial response. After depletion of intracellular calcium stores by repetitive caffeine (10 mM) applications, adenosine could not induce increase in [Ca2+]i. The initial rise could be induced in the absence of extracellular calcium, whereas the maintained phase after 120 s of adenosine application was dependent on the presence of extracellular calcium. The maintained phase response was 1.39- and 0.90-fold compared with basal [Ca2+]i level in the presence and absence of extracellular calcium respectively. There was significant (p < 0.01) maintenance of [Ca2+]i in the presence of extracellular calcium, which appeared to be associated with calcium influx. The data suggest that in human uterine myocytes, adenosine stimulates release of Ca2+ from intracellular stores and influx of extracellular Ca2+ through Ca2+ entry pathway.

Adenosine↗

PubMed1998

[Unification of Oriental and Western medicine with study on Oriental and Western medicine].

In Korea the system of medical management has been bifurcated into two parts since the restoration of nation from Japanese after World War II. One is 'Western Medicine' and the other is 'Oriental Medicine' like Chinese but not like Japanese. The authors attempted to study on the unification of both medicines to prevent the confusion of medicare for people. The major part of medical care is accomplished by Western medicine among people in Korea and China. However, Oriental medicine is still present as well as college of Oriental medicine in small number. There have been long struggles between two parts of medicine because of each assertions for the theories. The ancient medicine has been likely to have its characteristics either in Western or Oriental medicine although in many countries were succeeded by Western medicine except a few Asian countries such as Korea and China. In Japan since the license of Oriental(herb) medicine was ceased about one hundred years ago, the Western medicine has been authorized by law until today and the herb is the secondary medicine as a kind of folk treatment as well as continuous and enormous study for scientification. In only China and Korea this herb medicine has been kept to use as a part of medicine by law though China has developed combined medicine to use both Western and Oriental medicine by one physician since previous prime minister Chou En-Lai around the year 1950 who made a recommendation to the two medical societies, Western and Oriental. This fact has a big sense to establish the unification of two medicines in near future in Korea as well as China. For this accomplishment of medical unification both parts of medicine require sincere and enormous efforts to study the theory and practice of herb medicine even from now on. This unification of two medicines will provide the best medicare in most convenient way to the people in the world creating new world medicine like the third medicine including alternative medicine. The acupuncture is changing to a new method in Western medicine especially applying into anesthesia and pain clinic in even USA and Western countries at this time. In conclusion the unification of the Western and Oriental medicine will provide the most reasonable and practical medicare including alternative medicine to people in the world. Because the Oriental medicine will be used at least separately to supplement the Western medicine by one physician.

Asia↗

PubMed1998

Characterization of pulsatile secretion of gonadotropin and prolactin in women with normal menstrual cycle, secondary amenorrhea and polycystic ovary syndrome (PCOS).

To characterize the episodic fluctuations of serum LH, FSH and PRL in women with normally cycling, secondary amenorrhea and polycystic ovary syndrome (PCOS), four groups of women were studied: group I (N = 8) consisted of normal women in the follicular phase of the cycle; group II (N = 10) of women with secondary amenorrhea and positive progesterone withdrawal bleeding; group III (N = 8) of women with secondary amenorrhea and negative progesterone withdrawal bleeding; group IV (N = 9), women with polycystic ovary syndrome (PCOS). Blood samples were obtained at 15 minute intervals for 4 hours during one admission day. Ovarian steroids were measured to evaluate the baseline endocrine environment in each group. Distinct pulsatile fluctuations of serum LH, FSH and PRL were observed in all subjects. These pulses showed a high degree of coincidence in LH with FSH and LH with PRL in each group. However, the mean (+/- SD) frequencies of LH in group III and group IV were significantly lower (P < 0.01) and higher (P < 0.01) than in group I, respectively. The mean frequencies of FSH in groups III and IV were lower (P < 0.05), as compared with those of group I. The mean amplitude of LH in group IV was significantly higher (P < 0.001) than in group I. These results suggest that loss of the regulatory pulsatility of gonadotropin releases may be a contributory cause to anovulation and secondary amenorrhea. The concomitant pulsatile releases of gonadotropin and PRL are essential to reproductive function and their regulatory controls in the follicular phase may be mediated through a common neuroendocrine mechanism in normal and hypogonadal women.

Adult↗

PubMed1998

Assessment of hypothalamic-pituitary function by hormonal pulsatility, gonadotropin-releasing hormone and thyrotropin-releasing hormone testing in women with euprolactinemic secondary amenorrhea.

To evaluate the integrated hypothalamic-pituitary function of euprolactinemic secondary amenorrhea, blood samples of 23 patients were taken every 15 min for 4 hours in examination of pulsatile LH, FSH, PRL secretions and then 2 hours GnRH, TRH tests were performed. Nine normal cycling women (group I) served as the controls. Thirteen amenorrheic women (group II) revealed responsive bleeding to progestin injection and the other 10 women (group III) were nonresponsive. The LH frequency, amplitude, and LH response to GnRH of groups II and I were comparable, whereas delta PRL after TRH in group II (60.8 +/- 18.9 ng/ml) exhibited a significantly (P < 0.05) exaggerated response, as compared with that of group I (43.6 +/- 11.4 ng/ml). The LH frequency (1.3 +/- 0.4/4h) and amplitude (1.7 +/- 0.4 mIU/mL) of group III were significantly lower (P < 0.01) than those in group I (2.4 +/- 0.5 and 2.5 +/- 0.5, respectively), but their delta LH and delta FSH responses to GnRH showed no differences from those of controls. The frequency, amplitude of PRL and delta PRL response to TRH in group III were no significant difference with those of group I. These results suggest that masked PRL hypersecretion and loss of the regulatory pulsatility of gonadotropin release may be responsible in part for the causes resulting to euprolactinemic secondary amenorrhea. The analysis of these hormonal environments is useful for the understanding of clinical perspectives, pathophysiology and management.

Adult↗

PubMed1996

Effects of adenyl purines in human uterine arteries and uterine myometrium.

This in vitro study was undertaken to investigate the effects of adenyl purines in human uterine myometrium and uterine arteries. Segments of uterine myometrium and uterine arteries obtained at hysterectomy were isolated and mounted in tissue chambers. The muscle activity was recorded by polygraph. Adenyl purines agonists, such as adenosine, N-[(R)-1-methyl-2 phenylethyl]-adenosine (R-PIA) and 5-N-ethylcarboxamide adenosine (NECA) produced concentration-dependent contraction in human uterine myometrium. The potency order was NECA = R-PIA > adenosine. Adenosine A1 receptor antagonist: 1, 3-dipropyl-8-cyclopentylxanthine (DPCPX) blocked the effect of adenosine in human uterine myometrium. Otherwise, adenyl purines induced dose-dependent relaxation in human uterine artery precontracted by phenylephrine (PE, 10(-5)M). The potency gradient was NECA > R-PIA > adenosine; the results indicate adenyl purine induces uterine myometrium contraction via A1 receptor. However, adenosine causes uterine artery relaxation by A2 receptor.

Adenosine↗

PubMed1995

Reduction of phase error ghosting artifacts in thin slice fast spin-echo imaging.

Fast spin-echo (FSE) imaging techniques are very sensitive to the relative phase between the 90 degrees (excitation) RF pulse and the 180 degrees (refocusing) RF pulses. In this paper, it is demonstrated that a phase shift can be created between the excitation and refocusing pulses in such a manner that the received signal is divided into two components of distinctly different phase shifts. The nature of these two components is reviewed. It is demonstrated that ghosting artifacts will occur when images are reconstructed from this received signal. The ghosting is shown to be object dependent. A correction technique is presented which calculates the phase errors among different echoes based on measurements from a single echo train acquired without phase encoding gradients. The results in both phantom and human studies show that this method is capable of reducing the ghosting artifact in thin slice FSE images.

Algorithms↗