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Biomedical subjects

Y Lee

Publications and source records attributed to Y Lee.

At least 433 records · Page 24Linked to original sources
PubMed1992

[Intramuscular meperidine for the prevention of shivering in spinal anesthesia].

Intravenous meperidine 25mg has been employed effectively to treat shivering following regional anesthesia and general anesthesia. The study was designed to evaluate the effectiveness of intramuscular meperidine for the prevention of shivering in spinal anesthesia. The series consisted of 60 patients who were divided into 2 groups with 30 patients in each, undergoing lower abdominal or lower extremity surgery. All patients were given diazepam 0.1mg/kg i.v. for anxiolysis when they came to the operating room. In a double blind and randomized fashion, patients in the study (meperidine) group received meperidine 25mg IM (= 0.5ml). In the control group 0.9% N/S 0.5ml IM was given instead. All patients received spinal anesthesia 15 minutes later. Measurement of the levels of sensory loss to pinprick was made. The ambient temperature and the rectal temperature were continuously monitored to evaluate the effect of the change in body temperature on shivering during operation. The degree and the occurrence of shivering were carefully evaluated and recorded by a blind-trust observer. There was no significant difference in maximal analgesic level, ambient temperature and change of rectal temperature during operation between the groups. Shivering occurred in 17 patients (56.7%) in the saline group with an onset time of 7.9 +/- 2.5min following spinal anesthesia. In the meperidine group, shivering occurred only in 3 patients (10%) with an onset time of 54 +/- 29.5min after spinal anesthesia. There was a significantly lower incidence of shivering in the meperidine group than in the saline group (p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1992

[Schizophrenia and factitious cheilitis: a case report].

Factitious Cheilitis is a rare skin disorder which has been seen in patients with emotional disturbances, particularly in cases with neurotic and personality disorders. However, there have been no reports of factitious cheilitis seen in cases of schizophrenia. This study reports on a case of schizophrenic disorder, where the patient was observed to develop factitious cheilitis whilst subject to unstable psychiatric conditions. The case reported here is of a 59 year-old female widow, who has experienced the delusion of being controlled, the delusion of being possessed. Been subject to auditory hallucination and vague somatic pain for eight years and had a very poor psychotropic drug compliance. Observation revealed frequent licking of the lips unrelated to drug-induced dyskinesia, but as a possibly linked response to hallucination whilst subject to an intense unstable emotional and painful state. Factitious cheilitis was proved with biopsy of the lips and pathological findings of acanthosis, hyperkeratosis and parakeratosis. After psychiatric and dermatologic care, her cheilitic condition improved. This study demonstrates that factitious cheilitis can be seen in a schizophrenic patient, specifically where hallucination and emotional instability coupled with long-term licking of the lips can result in factitious cheilitis. The relationship of skin disorder and psychiatric illness is discussed.

Cheilitis↗
PubMed1992

[The clinical and pathological features of siblings with infantile neuroaxonal dystrophy--early neurological, radiological, neuroelectrophysiological and neuropathological characteristics].

The clinical and pathological features of siblings with infantile neuroaxonal dystrophy were reported. Early clinical symptoms were marked hypotonia in legs, mental regression and poor vision. Laboratory data were normal except for the mild elevation of GOT and LDH in serum and cerebrospinal fluid. MRI showed progressive atrophy of cerebellar vermis and brainstem. EEG showed a progressive increase in the amount and amplitude of the fast activities over the age of 3 years. Auditory brainstem response (ABR) showed progressive worsening with no response by 2 years and 6 months. Somatosensory evoked potentials (SEP) showed no cortical response by 4 years. Nerve conduction velocity (NCV) of both motor and sensory nerves was within normal limits. Pathologically, spheroid bodies were found in the axons of central and peripheral nerves, remarkably in brainstem and dorsal column. MRI, ABR and SEP findings were clinically useful, suggestive of the degeneration of brainstem.

Adolescent↗
PubMed1991

Specific cholinergic destruction in the basal magnocellular nucleus and impaired passive avoidance behavior of rodents.

A nerve growth factor (NGF)-diphtheria toxin conjugate (NGDT) was found to selectively abolish or depress the activity of NGF receptor-bearing cholinergic neurons of the basal magnocellular nucleus (BMN). Bilateral cortical injections of NGDT impaired the retention of passive avoidance behavior in mice. A memory deficit was also revealed when cortical injections of NGDT were administered after the acquisition of a passive avoidance response. Thus, retrograde destruction of BMN cholinergic neurons by the cortical injection of NGDT interfered with both learning and memory processes. The animal model outlined here should be useful in analyzing the pathogenesis of Alzheimer's disease and the functions of the cholinergic system in the BMN.

Animals↗
PubMed1991

Localization of basic FGF-like immunoreactivity in the hypothalamo-hypophyseal neuroendocrine axis.

We examined the localization of basic fibroblast growth factor (basic FGF) in the adult rat brain by immunohistochemical and Western blotting analysis using a specific antibody against a synthetic basic FGF fragment (N-terminal 12 residues). The antibody did not cross-react with acidic FGF. Basic FGF-like immunoreactivity was located exclusively in the neuronal elements and had very heterogeneous distribution. Immunoreactive cell bodies were observed in the paraventricular, supraoptic and circular nuclei of the hypothalamus. Numerous immunoreactive neuronal processes originating from these basic FGF-positive cells extended lateroventrally and then caudally to the internal layer of the median eminence. In addition, the neurohypophysis contained a significant number of basic FGF-like immunoreactive fibers. Western-blotting analysis revealed that the hypothalamus and the hypophysis contained a main band of basic FGF immunoreactive with an apparent molecular weight of 17 kDa. These results show that the hypothalamo-hypophyseal neuroendocrine pathway contains basic FGF.

Amino Acid Sequence↗
PubMed1991

Diacylglycerols induce both ion pumping in patch-clamped guard-cell protoplasts and opening of intact stomata.

Stomatal guard cells in leaves regulate the apertures of microscopic pores through which photosynthetic gas exchange and water vapor loss occur. Environmental signals, including light, high humidity, and low CO2 concentrations, open stomata by increasing the volume of guard cells. Activation of a plasma membrane H+ pump initiates K+ and Cl- influx, accompanied by malate synthesis, resulting in osmotic water flow into the guard cells, a bowing apart of the guard-cell pair, and consequent stomatal opening. Physiological and electrophysiological techniques were employed to investigate the possibility that a second-messenger lipid, 1,2-diacylglycerol, is involved in the transduction of opening stimuli. The synthetic diacylglycerols 1,2-dihexanoylglycerol and 1,2-dioctanoylglycerol enhanced light-induced stomatal opening in Commelina communis and induced stomatal opening under darkness, whereas an isomer with no known second-messenger role, 1,3-dioctanoylglycerol, did not affect stomatal responses. 1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine (H-7), an inhibitor of protein kinase C, the enzyme typically activated by 1,2-diacylglycerol in animal cells, inhibited light-stimulated stomatal opening and enhanced dark-induced stomatal closure. N-[(2-Methylamino)ethyl]-5-isoquinolinesulfonamide (H-8), which inhibits cyclic nucleotide-dependent protein kinases preferentially over lipid-dependent protein kinases such as protein kinase C, had little effect on stomatal apertures. Whole-cell patch clamping of guard-cell protoplasts of Vicia faba revealed that 1,2-dihexanoylglycerol and 1-oleoyl-2-acetylglycerol activated an ATP-dependent, voltage-independent current, suggesting activation of an electrogenic ion pump such as the H+ pump. Diacylglycerol or functionally similar lipids may act through protein phosphorylation to provide the intracellular signals that mediate H+-ATPase activation and stomatal opening in response to light or other opening stimuli.

Journal Article↗
PubMed1991

Effects of light stimuli on the release of dopamine from interplexiform cells in the white perch retina.

Interplexiform cells are centrifugal neurons in the retina carrying information from the inner to the outer plexiform layers. In teleost fish, interplexiform cells appear to release dopamine in the outer plexiform layer after prolonged darkness that modulates the receptive-field size and light responsiveness of horizontal cells (Mangel & Dowling, 1985; Yang et al., 1988a, b). It has been proposed that interplexiform cells may also release dopamine upon steady illumination because horizontal cells' receptive fields shrink in the light (Shigematsu & Yamada, 1988). Here, we report the shrinkage of the receptive fields of horizontal cells seen in the presence of background illumination is not blocked by dopamine antagonists, indicating that dopamine does not underlie the receptive-field size changes observed during steady illumination. Flickering light, however, does appear to stimulate the release of dopamine from the interplexiform cells, resulting in a marked reduction of horizontal cell receptive-field size. Taken together, experiments on horizontal cells indicate that dopamine is released from interplexiform cells in the teleost retina after prolonged darkness and during flickering light, but that dopamine release from interplexiform cells during steady retinal illumination is minimal.

Animals↗
PubMed1991

Heat-induced morphological alterations in non-tolerant and thermotolerant cells.

CHO cells were heated at 43 degrees C or 45 degrees C for various durations up to 300 min. Survival values varied from 5 x 10(-1) to 10(-7). Unheated, non-tolerant control cells were compared with cells made thermotolerant (TT) by incubating at 37 degrees C for 6 or 12 h after treatment with either sodium arsenite (100 microM-As) or 45.5 degrees C for 10 min, respectively. Groups also were included in which heat-induced TT cells were heated at 43 degrees C for 5 h immediately before they were challenged at 45 degrees C; in these groups, cycloheximide was sometimes added to inhibit protein synthesis before and/or during heating at 43 degrees C. Morphological alterations were quantified immediately and at various times after heating by using phase-contrast microscopy to determine the percentage of cells that were severely blebbed and rounded. About 800 cells were analysed per datum point. When effects of heat on thermotolerant cells were compared with effects of heat on non-tolerant cells, heat-induced thermotolerance (HTT) was observed by an increase in survival, and by a reduction in the percentage of cells with morphological alteration observed immediately after the challenging heat. After the As treatment, very little thermotolerance was observed for morphological alterations immediately after the challenging heat, although thermotolerance was observed for survival. However, as the cells were incubated for 12 or 24 h at 37 degrees C after the challenging heat treatment, recovery from morphological alterations was observed in the As-TT cells. Possible mechanisms for the difference between HTT and As-TT are discussed.

Adaptation, Physiological↗
PubMed1991

Use of mutant RNAs in studies on yeast 5S rRNA structure and function.

The expression of mutant yeast 5S rRNA genes in vivo is reviewed as a basis for further studies on the structure, function, and regulation of the ribosomal 5S rRNA. Specific base substitutions, insertions, or deletions can result in substantial structural changes which can be detected readily by gel electrophoresis, permitting the assay of mutant RNA synthesis and utilization. Furthermore, the use of high and low copy shuttle vectors, as well as alternate growth conditions, permits a wide adjustment of the mutant RNA concentration. Under optimized conditions more than 80% of the cell's RNA can be replaced with mutant molecules. The application of this strategy to studies on the biosynthesis and structure of the 5S rRNA are demonstrated through recently isolated mutations.

Base Sequence↗
PubMed1991

A sex-specific cytochrome P-450(F-1) colocalized with various neuropeptides in the paraventricular and supraoptic nuclei of female rats.

Numerous cells containing P-450(F-1) were detected in the magnocellular and parvocellular neurons of the paraventricular nucleus of the hypothalamus. Electron microscopic analysis of immunoreactive neurons has shown that P-450(F-1) immunoreactivity is present on the Golgi apparatus and rough endoplasmic reticulum. In the paraventricular nucleus, the P-450(F-1)-positive magnocellular neurons frequently contained oxytocin and some of them also contained CRF. Vasopressin was colocalized with P-450(F-1), but these neurons did not express CRF. In the supraoptic nucleus, P-450(F-1) was colocalized with oxytocin or CRF in single neurons, but not with vasopressin. No cells exhibiting the colocalization of both P-450(F-1) and somatostatin were observed in these nuclei. The results of the present study concerning colocalization of P-450 and peptides suggest that P-450(F-1) is involved in the hypothalamo-hypophyseal neuroendocrine function in the female rat.

Animals↗
PubMed1991

A survival study of surgically treated lung cancer in Korea. Lung Cancer Surgical Study Group.

Survival rate over a 5-year period were studied in a series of 658 proven primary lung cancer patients treated by thoracic surgeons at 8 institutes during the period from 1976 to 1987 in Korea. The study was designed as a multi-center cooperative work for the statistical analysis of the followup result. Clinical data of age, sex, morbidity, and staging of the tumor were assessed in 540 patients to evaluate their 5-year survival rates. Eventually, 405 resectable patients were analyzed by stage, cell type, surgical procedure, and TNM status. The 5-year actuarial survival rates by stage in the resectable group were: stage I 39.7%, II 30.6% III A 16.3%, III B 6.7%, and IV 0%. The 5-year survival rates by cell type were: squamous cell 31.9%, adenocarcinoma 21.2%, large cell 11%, and small cell 6%. The survival rates by surgical procedures were: lobectomy 30.7% and pneumonectomy 25.7%. The survival rates by TNM status in the operable group were: T1 34.7%, T2 26.8%, T3 7.5%, T4 5%; N1 23%, N2 10%, N3 3%; MO 21%, and M1 0%, respectively. The overall actuarial 5-year survival rate in the group of 405 resectable patients was 25.9%.

Adult↗
PubMed1991

[Clinical assessment of laryngeal mask airway in general anesthesia with spontaneous breathing].

The laryngeal mask airway (LMA) is a new form of oropharyngeal airway that provides an alternative to endotracheal intubation and face mask anesthesia in certain cases. Once the patient is adequately anesthetised, it can be inserted blindly without recourse to laryngoscopy. The advantages over standard mask anesthesia are: better airway control, minimal leakage of anesthetic gases, and it frees the anesthetist's hands, as no mandibular support is needed. LMA does not guarantee against the risk of aspiration and it is not recommended for use in patients who may have risk of gastric regurgitation. Our preliminary study revealed that a clear and clinical satisfactory airway was obtained in 98.2% of patients. According to the intraoperative respiratory minute volume and arterial blood gases, the patency of the airway did not deteriorate during the course of the anesthesia. Blood pressure and heart rate were compared on induction in group I and II. Succinylcholine 1 mg/kg, thiopentone 4-6 mg/kg and fentanyl 2 micrograms/kg were used in group I while using the same dosage of succinylcholine and thiopentone without fentanyl for group II. We found no significant differences in vital signs between the two groups.

Anesthesia, General↗
PubMed1991

[Changes in arterial pressure and heart rate during laryngeal mask insertion in hypertensive patients: comparison with endotracheal intubation].

The pressor response associated with laryngoscopy and endotracheal intubation may be harmful to patients with ischemic heart disease, hypertension or cerebrovascular disease. The Brain laryngeal mask airway can be inserted blindly and avoid the need for laryngoscopy. Our preliminary study compared the pressor response of tracheal intubation (T group) with that of laryngeal mask insertion (L group) in 19 and 33 hypertensive patients respectively. We also divided the patients of L group into sub-groups I (n = 16) and II (n = 17). All patients in T group and sub-group I were induced with fentanyl, thiopentone and succinylcholine while in subgroup II patients were induced with the same dosage of thiopentone and succinylcholine without fentanyl. The changes of blood pressure and heart rate exhibited a similar but attenuated pattern of response with laryngeal mask insertion in comparison with tracheal intubation. We also found no significant difference in pressor response between sub-group I and sub-group II in L group. In sum, laryngeal mask insertion may therefore offer some advantages over tracheal intubation in the anesthetic management of hypertensive patients in whom less pressor response is of particular concern.

Adult↗
PubMed1991

[Resection of mediastinal teratoma in a patient with cardiac tamponade due to pericardial perforation].

Benign teratoma of the mediastinum causes a variety of complications if left untreated, but reports of pericardial perforation have been rare. We report a case of mediastinal teratoma that perforated the pericardium and induced clinical cardiac tamponade. The patient was a 46-year-old male, who was admitted due to sudden chest pain. Since chest CT and echocardiography suggested perforation of the pericardium by a mediastinal teratoma, pericardial drainage was carried out. However, heart failure could not be resolved, and the tumor was resected on the 5th hospital day. From the intraoperative and pathologic findings, mature type mediastinal teratoma was found to have perforated the pericardium, causing massive influx of yellowish fluid from the cyst of the tumor. There have been only 10 cases reported to date in Japan and abroad in which mediastinal teratoma was complicated by cardiac tamponade.

Cardiac Tamponade↗
PubMed1990

Different ontogenetic profiles of cells expressing prepro-neurotensin/neuromedin N mRNA in the rat posterior cingulate cortex and the hippocampal formation.

The ontogeny of the expression of prepro-neurotensin/neuromedin N messenger RNA (prepro-NT/NN mRNA) in the rat posterior cingulate cortex (retrosplenial cortex) and the hippocampal formation was investigated using in situ hybridization histochemistry. In the primordium of the posterior cingulate cortex and the hippocampal formation, prepro-NT/NN mRNA was first expressed on embryonic day 17, and was found in the subiculum, layers II-III in areas 29a and 29b, and layer VI in the posterior cingulate cortex at birth. Expression was also observed in the CA1 field. In the adult rat, the expression of prepro-NT/NN mRNA was reduced in the posterior cingulate cortex, and only a few positive cells were seen here. However, the CA1 field and the subiculum still contained numerous positive cells.

Animals↗
PubMed1990

Efficient expression and utilization of mutant 5 S rRNA in Saccharomyces cerevisiae.

The expression of mutant 5 S rRNA genes in vivo is examined as a basis for further studies on the control, structure, and function of the ribosomal 5 S RNA. Specific single base substitutions (e.g. positions 98 or 99) or short insertions can result in substantial structural changes that can easily be detected by gel electrophoresis and permit the assay of mutant RNA synthesis and utilization. In addition, the use of high and low copy shuttle vectors as well as alternate growth conditions permits the adjustment of mutant RNA levels in vivo. Despite the high genomic copy number for the 5 S rRNA gene, under optimized conditions as much as 80% of the cellular 5 S RNA can be mutant, and RNA structure analyses indicate that some of these RNAs can readily be assembled into the ribosome structure resulting in an in vivo ribosome population which is also approximately 80% mutant. The results indicate that plasmid integrated 5 S rRNA genes are preferentially expressed and suggest that additional features of the chromosome structure regulate 5 S rRNA gene expression in vivo.

Base Sequence↗