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Biomedical subjects

H Ryu

Publications and source records attributed to H Ryu.

At least 37 records · Page 2Linked to original sources
PubMed1999

Potentiation of cholecystokinin and secretin-induced pancreatic exocrine secretion by endogenous insulin in humans.

To investigate the effects of endogenous insulin on pancreatic exocrine secretion in humans, we evaluated the pure pancreatic juice obtained by endoscopic cannulation of the main pancreatic duct in 21 healthy subjects (14 men and seven women). Samples of pancreatic juices were collected after intravenous injection of either glucose (50%, 40 ml), secretin (0.25 CU/kg), and cholecystokinin-8 (CCK) (40 ng/kg), or a combination of glucose, secretin, and CCK in six 5-min periods. The responses of plasma glucose, insulin, and C-peptide to intravenous administration of glucose were measured. After infusion of glucose, the plasma insulin and C-peptide levels were significantly increased and remained at high levels during 30-min experiments, intravenous administration of secretin and CCK resulted in significant increases of pancreatic secretion including volume, bicarbonate, and protein output. When glucose was simultaneously administered with secretin and CCK, pancreatic secretion was significantly increased, more than the effects achieved by the secretin and CCK. However, glucose alone did not increase basal pancreatic secretion. These observations suggest that endogenous insulin intensifies pancreatic secretion stimulated by secretin and CCK in humans.

Adult↗
PubMed1999

Effects of ChunDoSunBup Qi-training on growth hormone, insulin-like growth factor-I, and testosterone in young and elderly subjects.

We observed the response of plasma growth hormone (GH), insulin-like growth factor-I (IGF-I) and testosterone (T) to an acute period of ChunDoSunBup (CDSB) Qi-training. Although the basal level of GH was not different between the two groups, after the portion of the training in which the subjects were physically active (the mid-training point), plasma GH levels increased by 7.26 fold (p < 0.05) in the elderly trainees and by 1.66 fold (p < 0.05) in the young. In response to CDSB Qi-training, IGF-I levels in the young increased significantly at mid-training point, but there were no increase in the elderly. Significant correlations existed between GH and IGF-I levels in the young subjects, but not in the elderly. The T level at the mid-training point increased significantly in elderly subjects but not in the young. These results suggest that CDSB Qi-training is a potential method for modulating of the secretion of growth factor in the young and the elderly, but that the elderly IGF-I response does not equal that of the young. In addition, our study suggests CDSB Qi-training may be one mode of therapy applicable to growth factor related disorders such as GH deficiency in children and osteoporosis in the elderly, especially women.

Aged↗
PubMed1999

A Minnesota multiphasic personality inventory profile of ChunDoSunBup qi-trainees: a preliminary study.

The aim of this study is to explore the effects of ChunDoSunBup Qi-training on personality traits. Twenty-six normal healthy subjects (mean age = 26.58 +/- 6.56) and 26 CDSB Qi-trainees (mean age = 27.74 +/- 5.21) participated in this study. Analysis of MMPI profiles showed that CDSB Qi-trainees scored significantly lower on Depression (D), Hysteria (Hy), Paranoia (Pa), Schizophrenia (Sc) and Frequency (F) and significantly higher on the Correction (K) Scales. In addition, CDSB Qi-trainees reported a significantly lower Cook-Medley Hostility (Ho) scale than that of controls. This preliminary study suggests that CDSB Qi-training may be effective in protection as well as restoration of emotional, psychological symptomatology and personality trait disorder.

Adult↗
PubMed1999

Neurovascular decompression for trigeminal neuralgia in elderly patients.

The operative findings and outcomes of neurovascular decompression for trigeminal neuralgia were compared between patients aged 75 years and older (elderly group, 17 patients) and patients aged under 75 years (nonelderly group, 115 patients). There were no statistically significant differences in the operative findings or outcomes between the two groups, except in the percentage of patients who had been treated with carbamazepine. Neurovascular decompression for trigeminal neuralgia can be performed in elderly patients with the same operative results as in nonelderly patients. If other treatments (especially carbamazepine treatment) prove ineffective, neurovascular decompression should be considered in elderly patients before they become too old to undergo surgery. However, neurovascular decompression in elderly patients requires great care, as the venous system, including the superior petrosal vein, should be preserved and retraction of the cerebellum should be avoided whenever possible to maintain correct blood circulation in the cerebellum and brainstem.

Aged↗
PubMed1999

Magnetic resonance cisternography used to determine precise topography of the facial nerve and three components of the eighth cranial nerve in the internal auditory canal and cerebellopontine cistern.

OBJECT: The detailed anatomy of intracranial structures has been studied mainly in cadavers, but the absence of cerebrospinal fluid and blood pressure in these models distorts normal spatial relationships. The authors investigated the rotation of the facial nerve (FN), superior vestibular nerve (SVN), inferior vestibular nerve (IVN), and cochlear nerve (CN) in the internal auditory canal (IAC) and cerebellopontine cistern in human volunteers and compared their results with those reported in cadaver studies. METHODS: The IACs and cerebellopontine cisterns of 30 normal adults (34 sides) were examined using magnetic resonance (MR) cisternography with a heavily T2-weighted two-dimensional fast spin-echo technique. The positions of the four components were unaffected by the presence of the meatal loop of the anterior inferior cerebellar artery in the IAC. The spatial relationship between the FN and SVN was quite constant, but the spatial relationship between the CN and SVN was quite variable: the former changed position, mainly in the IAC, on nine (26.5%) of 34 sides, and in the cerebellopontine cistern on the other sides (73.5%), conflicting with findings in cadaver studies. CONCLUSIONS: It is more accurate to describe the CN and IVN as coursing beneath the SVN in either the IAC or cerebellopontine cistern, rather than stating that the three components rotate, as reported in cadaver studies. The MR cisternography studies provided quite detailed information about the topography of the four components and the relationship between the blood vessels and cranial nerves in the IAC and the cerebellopontine cistern.

Adult↗
PubMed1998

Cerebral blood flow autoregulation following subarachnoid hemorrhage in rats: chronic vasospasm shifts the upper and lower limits of the autoregulatory range toward higher blood pressures.

We sought to determine whether chronic vasospasm following subarachnoid hemorrhage (SAH) would abolish the cerebral blood flow (CBF) autoregulation in anesthetized Sprague-Dawley rats. SAH was induced by intracisternal injection of autologous blood; in control animals saline was injected instead. CBF was measured 48 h after SAH, that is during chronic vasospasm, by laser-Doppler flowmetry over the frontal cortex under condition of hypertension (SAH, n = 6; control, n = 8) or hypotension (SAH, n = 6; control, n = 6). Hyper- and hypotension were induced by increasing mean arterial blood pressure (MABP) stepwise from 90 to 180 mmHg with phenylephrine (0.1-10 micrograms/min i.v.), or by decreasing it from 90 to 40 mmHg by controlled hemorrhage. An autoregulatory index (AI) expressed as delta CBF (%) per 10 mmHg increase or decrease in MABP was employed to analyze CBF response. CBF remained constant (-7 < AI < 7) at MABPs ranging from 60 to 130 mmHg in the control group and from 70 to 140 mmHg in the SAH group, showing CBF autoregulation. In the SAH group, that is, the upper and the lower limits of autoregulatory range were increased by 10 mmHg (p < 0.05). SAH did not increase intracranial pressure significantly (control 9.2 +/- 0.67 vs. SAH 10.0 +/- 1.05 mmHg, n = 5) 48 h after SAH was induced. These results indicate that, during chronic vasospasm, SAH does not abolish the autoregulation process but raises its lower and upper blood pressure limits. The capacity of spastic cerebral arteries to dilate in case of hypotension decreased, while their tolerance to hypertension increased.

Animals↗
PubMed1998

Atypical hemifacial spasm.

Among 155 cases of hemifacial spasm (HFS), the authors found two cases of atypical HFS (1.3%) in which spasm started with the orbicularis oris and buccinator muscles, and gradually spread upward to involve the orbicularis occuli muscle, whereas the reverse process is usually seen in cases of typical HFS. The compression site in cases of atypical HFS is the posterior/rostral aspect of the facial nerve (FN), whereas it was the anterior/caudal aspect of the FN in all cases of typical HFS except for one. The meatal loop of the anterior inferior cerebellar artery (AICA) compressed the FN when the vessel passed between the FN and the eighth cranial nerve (8th N). These findings suggest that the topographical organization in the FN in the cerebellopontine cistern may be reversed to a peripheral distribution: the fibres on the posterior/rostral side of the FN innervate the lower part of the facial muscles, and those in the anterior/caudal side of the nerve innervate the upper part of the facial muscles. When examining patients with HFS, we must very carefully determine whether patients have typical or atypical HFS, to determine whether blood vessels (usually the meatal loop of the AICA) between the FN and the 8th N as well as at the root exit zone of the FN are to be decompressed.

Adult↗
PubMed1998

Neurovascular compression syndrome of the eighth cranial nerve. What are the most reliable diagnostic signs?

Forty-three surgical cases were retrospectively analyzed to establish diagnostic criteria and operative indications for vertigo and tinnitus due to neurovascular compression (NVC) of the eighth cranial nerve (8th N). Many NVC syndromes were mistakenly diagnosed as Ménière's disease or benign paroxysmal positional vertigo. NVC was confirmed in 31 of the 43 patients. Neurovascular decompression (NVD) resulted in complete recovery or marked improvement of subjective symptoms in all 19 cases with vertigo (100%), and in 19 of 29 patients with tinnitus (65.5%). Multiple factor analysis revealed that abnormal caloric responses have high diagnostic value for vertigo due to NVC. Vertigo due to NVC is of short duration (a few sec to a few min.) in the early phase of the disease, which becomes longer and hearing becomes impaired as the history of NVC lengthens. Low pitch pulsatile and high pitch continuous tinnitus are probably due to NVC and are cured by NVD if hearing is still preserved. Tinnitus associated with hemifacial spasm is strongly indicative of NVD. Decompression of the 8th N should be performed in the early phase of disease, since cochlear and vestibular functions are irreversibly impaired if NVC continues for a long period of time.

Adult↗
PubMed1998

Effects of chundosunbup Qi-training on psychological adjustments: a cross-sectional study.

This cross-sectional investigation evaluated the trend of psychological changes by ChunDoSunBup (CDSB) Qi-training using a self-report inventory of emotional distress, Symptom Check List-90-Revision (SCL-90-R). 41 normal healthy subjects (mean age = 20.98 +/- 5.39) and 123 CDSB Qi-trainees (divided into three groups, Q1, Q2 and Q3) participated in this study. Group Q1 has received 1-4 months CDSB Qi-training (age 21.95 +/- 7.82, n = 41); Q2 has 5-12 months Qi-training (age 20.0 +/- 7.75, n = 41); and Q3 has more than 13 months Qi-training (age 22.68 +/- 6.72, n = 41). Our results show that Qi-trainees over 13 months had significantly lower scores compared to controls. A significant negative correlation was found between the Qi-training period and all SCL-90-R subscales except phobic anxiety. These results suggest that CDSB Qi-training is effective in protection as well as reduction of psychological symptomatology.

Adult↗
PubMed1998

Acute effects of chundosunbup qi-training on blood concentrations of TSH, calcitonin, PTH and thyroid hormones in elderly subjects.

The present study investigated how the systemic treatment of a programmed exercise, ChunDoSunBup (CDSB) Qi-training, affects the secretion of thyroid and parathyroid hormones in elderly subjects (10 male and 5 female). Plasma concentrations of thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), parathyroid hormone (PTH), ionized calcium, and calcitonin were determined. CDSB Qi-training induces a slight increase in TSH. Both T4 and T3 were increased at the mid-time of CDSB Qi-training (p < 0.05). There were significant correlations only between T3 and T4 at mid-training. This shows that increase in the plasma level of T3 was associated with the secretion of T4. The plasma concentrations of calcitonin and PTH were increased at mid-time and post-time of CDSB Qi-training. But ionized calcium was decreased slightly by CDSB Qi-training. These results suggest that Qi-training modulates the secretion of thyroid hormones, calcium metabolism, and parathyroid hormones in the elderly. However, whether the long-term practice of CDSB Qi-training might change bone metabolism and have longitudinal effects on the thyroid hormone of the elderly need further investigation.

Aged↗
PubMed1998

Neurovascular decompression of the eighth cranial nerve in patients with hemifacial spasm and incidental tinnitus: an alternative way to study tinnitus.

OBJECT: The authors sought to clarify the clinical characteristics of tinnitus resulting from neurovascular compression (NVC) of the eighth cranial nerve. METHODS: The authors explored the eighth cranial nerve in the cerebellopontine cistern during neurovascular decompression (NVD) of the facial nerve in 10 patients with hemifacial spasm who suffered from incidental tinnitus on the same side. The diagnosis of NVC of the eighth cranial nerve was confirmed in all patients. This condition was found in only seven of 114 patients with hemifacial spasm alone, indicating that NVC of the eighth cranial nerve is one of the causes of tinnitus (p < 0.001, chi-square test). The tinnitus resolved or was markedly improved after NVD of the eighth cranial nerve in eight patients (80%). Both pulsatile and continuous tinnitus responded well to NVD. All patients experienced various degrees of sensorineural hearing disturbance, but other neurotological examinations provided poor diagnostic value. CONCLUSIONS: It is the authors' opinion that sensorineural hearing loss and positive findings on magnetic resonance imaging are the most reliable evidence for the presence of tinnitus caused by NVC of the eighth cranial nerve.

Adult↗
PubMed1998

Hemifacial spasm caused by vascular compression of the distal portion of the facial nerve. Report of seven cases.

It is generally accepted that hemifacial spasm (HFS) and trigeminal neuralgia are caused by compression of the facial nerve (seventh cranial nerve) or the trigeminal nerve (fifth cranial nerve) at the nerve's root exit (or entry) zone (REZ); thus, neurosurgeons generally perform neurovascular decompression at the REZ. Neurosurgeons tend to ignore vascular compression at distal portions of the seventh cranial nerve, even when found incidentally while performing neurovascular decompression at the REZ of that nerve, because compression of distal portions of the seventh cranial nerve has not been regarded as a cause of HFS. Recently the authors treated seven cases of HFS in which compression of the distal portion of the seventh cranial nerve produced symptoms. The anterior inferior cerebellar artery (AICA) was the offending vessel in five of these cases. Great care must be taken not to stretch the internal auditory arteries during manipulation of the AICA because these small arteries are quite vulnerable to surgical manipulation and the patient may experience hearing loss postoperatively. It must be kept in mind that compression of distal portions of the seventh cranial nerve may be responsible for HFS in cases in which neurovascular compression at the REZ is not confirmed intraoperatively and in cases in which neurovascular decompression at the nerve's REZ does not cure HFS. Surgical procedures for decompression of the distal portion of the seventh cranial nerve as well as decompression at the REZ should be performed when a deep vascular groove is noticed at the distal site of compression of the nerve.

Adult↗
PubMed1997

Subarachnoid hemorrhage impairs cerebral blood flow response to nitric oxide but not to cyclic GMP in large cerebral arteries.

Nitric oxide (NO) increases 3',5'-cyclic guanosine monophosphate (cGMP) in vascular smooth muscle and increases cerebral blood flow (CBF). In early stages of cerebral ischemia, NO plays a beneficial role in sustaining CBF. Subarachnoid hemorrhage (SAH), one of the main causes of ischemia, may impair vascular reactivity to NO. To test the hypothesis, 48 h after SAH was induced in rats, we examined the CBF response to the NO donor, SIN-1 (3-morpholinosydnonimine). We measured CBF by laser-Doppler flowmetry in association with: (1) intracarotid injection (for 30 min) of SIN-1 (1.5 mg/kg), 8-bromo-cGMP (7.5 mg/kg), papaverin (1.5 mg/kg) or vehicle; (2) cortical superfusion (for 90 min) of SIN-1 (10(-5) M) or vehicle through the cranial window. Hypotension produced by these vasodilators was controlled with phenylephrine. Vehicle alone did not change CBF throughout the measurement. Intracarotid infusion of SIN-1 (n = 6/group) increased CBF up to 128.6 +/- 3.9% and 111.9 +/- 2.9% in the control group and the SAH group, respectively. SAH significantly attenuated the response (P < 0.05, ANOVA). SAH did not affect the CBF increases elicited by intracarotid administration of cGMP or papaverin, or cortical superfusion of SIN-1. We conclude that during chronic vasospasm SAH disturbs the pathway between NO release and cGMP production in large cerebral arteries. The impairment accounts for the fragility of the brain in the face of ischemia following SAH.

Animals↗
PubMed1997

Nitric oxide inhibits capping in HL-60 cells.

In the present study, we investigated the effect of nitric oxide (NO) on capping, which is associated with the actin polymerization in HL-60 cells (human promyelocytic leukemia cells). We first assessed the effect of NO on the patching and capping by using anti-human LFA-1 monoclonal antibody. Samples were analyzed by a fluorescence microscope. As expected, NO inhibited the percentage of capping dose dependently. We compared the effect of NO on capping with cytochalasin D (CD) and observed that CD also inhibits the capping in HL-60 cells. We next examined the effect of NO on the F-actin content. For assays of F-actin content, the FITC labelled phalloidin was permeabilized and stained in HL-60 cells. The bound fluorescence quantified by flow cytometry using a FACStar. There was a decrease in the F-actin formation in NO treated cells. Taken together, these data indicate that NO inhibits the capping on cellular membrane by decreasing the intracellular F-actin formation in HL-60 cells. We suggest that the formation of capping linked with actin polymerization at the inner leaflet of plasma membrane may be regulated by NO.

Actins↗
PubMed1997

Involvement of intracellular Ca2+ during growth hormone-induced priming of human neutrophils.

Growth hormone (GH) primes and augments O2- production in neutrophils. The exact signaling of the priming pathway by GH has not been demonstrated. In this study, we investigated intracellular signaling of priming by recombinant human growth hormone (rGH) in human neutrophils. A low concentration of rGH (10-100 ng/ml) significantly enhanced the O2- production from neutrophils triggered with N-formyl-1-methionyl-1-leucyl-1-phenylalanine in a dose-dependent manner. Recombinant GH directly increased the fluorescence intensity of intracellular Ca2+ labeled with fluo 3-AM in neutrophils. The change of fluorescence intensity of cytosolic Ca2+ was dependent on the rGH concentration. The peak level of fluorescence intensity was observed at 3 to 5 min after treatment with rGH. The priming effect of rGH on O2- production via Ca2+ was abrogated by Ca2+ channel blockers such as dentrolene and verapamil. Furthermore, preincubation with genistein, a tyrosine kinase inhibitor, blocked the rGH-induced increases in Ca2+ and O2- production. This finding suggests that GH can act through the increase of intracellular Ca2+ as a priming agent to activate neutrophils for an enhanced respiratory burst.

Adult↗