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Biomedical subjects

H C Shih

Publications and source records attributed to H C Shih.

At least 19 recordsLinked to original sources
PubMed2006

The effect of an adenosine A1 receptor agonist in the treatment of experimental subarachnoid hemorrhage-induced cerebrovasospasm.

BACKGROUND: Adenosine is a potent vasodilator and an important modulator of cardiovascular function. It has been postulated that nitric oxide (NO) is involved in adenosine-induced vasodilation. This study was designed to examine the effect of an adenosine A1 agonist, N6-cyclopentyladenosine (CPA), in the prevention of subarachnoid haemorrhage (SAH)-induced vasospasm. Method. Experimental SAH was induced in Sprague-Dawley rats by injecting 0.3 mL autogenous blood into the cisterna magna. Intraperitoneal injections of CPA (0.003 mg/kg), or vehicle were administered 5 min and 24 hours after induction of SAH. The degree of vasospasm was determined by averaging the cross sectional areas of the basilar artery 2 days after SAH. Expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in basilar artery were evaluated. Findings. There were no significant differences among the control and treated groups in physiological parameters recorded before sacrifice. When compared with animals in the control group, cross-sectional area of basilar arteries areas in the SAH only, SAH plus vehicle and SAH plus CPA groups were reduced by 19% (p < 0.01), 22% (p < 0.01), and 9% (p = 0.133), respectively. The cross-sectional areas of the CPA-treated group differed significantly from those of the SAH only and SAH plus vehicle group (p < 0.05). Induction of iNOS-mRNA and protein in basilar artery by SAH was not significantly diminished by CPA. The SAH-induced suppression of eNOS-mRNA and protein were relieved by CPA treatment. Conclusions. This is the first evidence to show an adenosine A1 receptor agonist is effective in partially preventing SAH-induced vasospasm without significant cardiovascular complications. The mechanisms of adenosine A1 receptor agonists in attenuating SAH-induced vasospasm may be, in part, related to preserve the normal eNOS expression after SAH. Inability in reversing the increased iNOS expression after SAH may lead to the incomplete anti-spastic effect of CPA.

Adenosine↗
PubMed2003

Effects of changing risk factors on increasing asthma prevalence in southern Taiwan.

The study sought to identify factors with consistent relationships with the prevalence of asthma and postulate causes for the increasing prevalence. Reduplication of prevalence surveys was conducted among children of similar ages (6-12 years) from the same area (Tainan City, Taiwan). A total of 7523 primary school children from 1993 and 7224 from 1997 participated in the study. The reported prevalence of diagnosed asthma increased from 6.46% in 1993 to 8.45% in 1997 (relative risk 1.31, 95% CI 1.16, 1.47). Among all environment- and heredity-related factors examined, only four showed consistent relationships with childhood asthma, and all appeared to be a related hereditary condition. Dander allergy is the only factor that increased correspondingly with the prevalence of childhood asthma; therefore, it seems to be the most likely key factor responsible for the increasing trend. The investigation of the interactive effects imposed by the environment- (dander exposure) and heredity-related (atopic sensitisation) factors are recommended for further studies.

Asthma↗
PubMed2002

Combined use of esmolol and nicardipine to blunt the haemodynamic changes following laryngoscopy and tracheal intubation.

We examined the effect of different combinations of esmolol and nicardipine upon the circulatory response to tracheal intubation. One hundred patients were randomly allocated into five groups of twenty to receive pretreatments of saline or different combinations of esmolol (0.5 or 1.0 mg x kg(-1)) and nicardipine (15 or 30 microg x kg(-1)). Significant tachycardia persisted over a 5-min period after intubation in all five groups compared with baseline levels (p < 0.05). Patients receiving esmolol 1.0 mg x kg(-1) and nicardipine 30 g x kg(-1) showed no significant change in systolic blood pressure after tracheal intubation compared with baseline and significant lower peak systolic blood pressure than those receiving saline (p = 0.023).

Adrenergic beta-Antagonists↗
PubMed2001

Posterior cranial fossa arteriovenous fistula with presenting as caroticocavernous fistula.

We report cases of posterior cranial fossa arteriovenous fistula (AVF) with presenting with exophthalmos, chemosis and tinnitus in 26- and 66-year-old men. The final diagnoses was vertebral artery AVF and AVF of the marginal sinus, respectively. The dominant venous drainage was the cause of the unusual presentation: both drained from the jugular bulb or marginal sinus, via the inferior petrosal and cavernous sinuses and superior ophthalmic vein. We used endovascular techniques, with coils and liquid adhesives to occlude the fistulae, with resolution of the symptoms and signs.

Adult↗
PubMed2001

Hemodynamic response of modified fluid gelatin compared with lactated ringer's solution for volume expansion in emergency resuscitation of hypovolemic shock patients: preliminary report of a prospective, randomized trial.

The objective of this study was to compare the cardiac and hemodynamic responses to a rapid infusion of 1000 ml of modified fluid gelatin (group A) or 1000 ml of lactated Ringer's solution (group B) in emergency room patients suffering from shock. This prospective, randomized, open, noncrossover study was performed at a medical center university hospital in a surgical resuscitation room in the emergency department. The subjects were 34 patients with either hypovolemic or neurogenic shock who were admitted to the emergency room. A resuscitation protocol according to Advanced Trauma Life Support (ATLS) with an additional central venous line or Swan-Ganz catheters for hemodynamic monitoring was used. Physical parameters and hemodynamic variables were measured at baseline and 15 minutes, 30 minutes, and 1 hour after the infusion of each fluid. In both groups the mean arterial blood pressure (MAP), systolic and diastolic pressure, central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP) increased significantly. The CVP and PAOP increased significantly more in the modified fluid gelatin resuscitation group. In patients with traumatic or neurogenic shock due to acute volume deficiency, there was significantly better hemodynamic improvement, judged by CVP and PAOP measurements using the modified fluid gelatin for volume replacement than with lactated Ringer's solution during the first hour of resuscitation.

Adolescent↗
PubMed2001

Warning from Nagano: increase of vulvar hematoma and/or lacerated injury caused by snowboarding.

BACKGROUND: On the basis of the number of women snowboarders whose vulvar injuries we have recently treated, we believe that the cases of vulvar hematoma and lacerated injuries caused by snowboarding have been increasing. To analyze the causal relation between snowboarding and vulvar injuries, we investigated how women were injured during snowboarding. METHODS: During the last three ski-ing seasons at the five hospitals near the ski resorts in Nagano Prefecture, Japan, the clinical charts of all patients with vulvar injuries during snowboarding were reviewed for the number of patients treated, the condition of the patients at diagnosis, and the characteristics of vulvar injuries. All patients were also asked by phone about how their vulvar injury was caused during snowboarding. RESULTS: The number of patients with vulvar injuries during the last three seasons was 16, 14, and 35, respectively. The types of vulvar injuries included hematoma in 33 (51%) patients, hematoma with lacerated injury in 17 (26%), and lacerated injury in the remaining 15 (23%). Of the 65 patients, 45 (69%) needed surgical treatment. Characteristically, 54 (88%) patients were injured when they tumbled onto the binding of the snowboard at the same time that one foot was left off the board and the binding was not turned down but left erect. CONCLUSION: It is important for women snowboarders to realize that in snowboarding there are dangers that may cause vulvar injuries. The prevention of such injuries requires that the binding should be turned down when the foot is left off the board and that snowboarders should try not to tumble onto the board.

Adolescent↗
PubMed2001

Prenatal exposure of testosterone prevents SDN-POA neurons of postnatal male rats from apoptosis through NMDA receptor.

The role of N-methyl-D-aspartate (NMDA) receptor in mediating the effect of testosterone exposure prenatally on neuronal apoptosis in the sexual dimorphic nucleus of the preoptic area (SDN-POA) of rats was studied. The endogenous testosterone was diminished by prenatal stress (PNS) or simulated by testosterone exposure (TE) to understand the effect of testosterone on NR(1) (a functional subunit protein of NMDA receptor) expression and neuronal apoptosis. To further study whether the testosterone, after being converted into estradiol, modulates NR(1) expression, 4-androstein-4-ol-3,17-dione (ATD; an aromatase inhibitor) was used to block the conversion of estradiol from testosterone. The expressions of the NR(1) mRNA and NR(1) subunit protein were quantified by RT-PCR and western blotting analysis, respectively. In addition, a noncompetitive antagonist of NMDA receptor, MK-801, was used to find out whether blockage of NMDA receptor affects the naturally occurring apoptosis in SDN-POA. The results showed the following. 1) Expression of perinatal NR(1) subunit protein in the central part of the medial preoptic area of male rats was significantly higher than that of females, especially on postnatal days 1 and 3. 2) The testosterone level of male fetuses on embryonic day 18 was significantly higher than that of females, while the testosterone level of TE females or PNS males was similar to that of intact males or intact females, respectively. 3) The apoptotic incidence of intact male rats was significantly less than that of females, and the apoptosis was stimulated by PNS in male or inhibited by TE in female. 4) The expression of NR(1) subunit protein could be inhibited by PNS or ATD-treatment in male, while stimulated by TE in female. 5) NR(1) mRNA showed no significant difference among intact male, PNS male, ATD-treated male, TE female and intact female rats. 6) The low apoptotic incidence of male rats was significantly increased when NMDA receptor was blocked by MK-801. These results suggest that testosterone, after being converted to estradiol, may prevent the SDN-POA neurons of male rats from apoptosis through enhancing the expression of NR(1) at the posttranscriptional level.

Animals↗
PubMed2001

Comparison of the metabolic effects of metformin and troglitazone on fructose-induced insulin resistance in male Sprague-Dawley rats.

BACKGROUND AND PURPOSE: Insulin resistance is a hallmark of the development of type 2 diabetes. Metformin and troglitazone are oral antidiabetic agents used to reduce insulin resistance. The aim of this study was to compare the metabolic effects of these two drugs in fructose-induced insulin-resistant rodents. METHODS: Male Sprague-Dawley rats were allocated to receive one of the following four treatments for 6 weeks: normal rat chow (control group, n = 7), high-fructose diet (fructose group, n = 7), high-fructose diet plus metformin (metformin group, n = 8), or high-fructose diet plus troglitazone (troglitazone group, n = 8). Systolic blood pressure (SBP), insulin, free fatty acid (FFA), and triglyceride concentrations were measured as parameters of insulin resistance. Leptin concentration was also measured in the four groups. RESULTS: The fructose group developed significantly elevated SBP, hyperinsulinemia, and hypertriglyceridemia without significant change in body weight or leptin concentration compared with the control group. The metformin group had significantly reduced body weight (397.9 +/- 40.9 vs 470.1 +/- 59.6 g, p < 0.05), insulin concentration (14.8 +/- 10.5 vs 48.4 +/- 15.2 microU/mL, p < 0.05), triglyceride concentration (75.3 +/- 65.5 vs 250.1 +/- 95.7 mg/dL, p < 0.05), and leptin concentration (3.1 +/- 1.5 vs 6.9 +/- 2.0 ng/mL, p < 0.05) without significant change in SBP (147.8 +/- 5.8 vs 152.4 +/- 13.0 mm Hg, p > 0.05) compared with the fructose group. The troglitazone group had significantly reduced SBP (137.8 +/- 9.2 vs 152.4 +/- 13.0 mm Hg, p < 0.05), insulin concentration (15.0 +/- 13.6 vs 48.4 +/- 15.2 microU/mL, p < 0.05), FFA concentration (38.9 +/- 22.7 vs 78.7 +/- 24.6 mg/dL, p < 0.05), triglyceride concentration (67.6 +/- 32.4 vs 250.1 +/- 95.7 mg/dL, p < 0.05), and leptin concentration (4.4 +/- 2.0 vs 6.9 +/- 2.0 ng/mL, p < 0.05) without significant change in body weight (452.5 +/- 32.8 vs 470.1 +/- 59.6 g, p > 0.05) compared with the fructose group. The metabolic effects of metformin and troglitazone on insulin, FFA, triglyceride, and leptin concentrations were not significantly different. However, metformin treatment resulted in significantly lower body weight (397.9 +/- 40.9 vs 452.5 +/- 32.8 g) and troglitazone treatment in significantly lower SBP (137.8 +/- 9.2 vs 147.8 +/- 5.8 mm Hg) compared to the fructose group, after adjusting for basal values (p < 0.05). CONCLUSIONS: Both metformin and troglitazone were comparably effective in reducing insulin resistance. Metformin treatment caused body weight reduction but was not effective in reducing SBP. Troglitazone treatment lowered SBP but did not reduce body weight.

Animals↗
PubMed2001

Positive association of ankylosing spondylitis with homozygous HLA-B2704, but protection with B2705 in Taiwan Chinese.

The study was undertaken to determine the effects of HLA-B27 subtypes on susceptibility to ankylosing spondylitis (AS) in Taiwan Chinese, a polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method was developed for subtyping of HLA-B27. In this series, there are 62 patients with AS who were tested HLA-B27 positive serologically and 738 normal persons over the age of 65. Among the 738 normal controls, 42 (5.7%) were HLA-B27 positive. There were six (14.3%) homozygous for B2704, 18 (42.9%) heterozygous for B2704, 2 (4.8%) double heterozygous for B2704 and B2705, one (2.3%) double heterozygous for B2704 and B2706, 2 (4.8%) homozygous for B2705, 11 (26.1%) heterozygous for B2705, and 2 (4.8%) heterozygous for B2706. In our patients with AS, 37 (59.7%) were homozygous for B2704 and 25 (40.3%) were heterozygous for B2704. The HLA-B27 carrier rate in Taiwan healthy old persons is estimated at 5.7%. Susceptibility to AS is determined by homozygosity for B2704. However, B2705 may be an indicator of protection against AS in Taiwan Chinese.

Aged↗
PubMed2000

Anti-aging effects of the traditional Chinese medicine bu-zhong-yi-qi-tang in mice.

Among the "alternative medicines," which may ably supplement modern Western medicine in the treatment of certain diseases, the holistic approach and mild nature of the majority of Traditional Chinese Medicine (TCM) may make it particularly suitable for the treatment of diseases associated with old age, as the general health of elderly patients is already compromised. The TCM formulation of bu-zhong-yi-qi-tang (B.Z.Y.Q.T.), prescribed mainly for the improvement of circulation and in particular that to the gastroenteric regions, may have anti-aging effects. In the present study, possible anti-aging effects of B.Z.Y.Q.T. were studied using normal (ICR) mice and the Dull, P/8 and R/1 strains of the Senescence Accelerated Mouse (S.A.M.). Following repeated oral administrations of B.Z.Y.Q.T. at 250 and 500 mg/kg the test mice were assessed for (1) endurance (2) learning and memory (3) neuromuscular coordination and (4) changes in the levels of monoamines in the brain. The results indicated that B.Z.Y.Q.T. improved endurance in all strains in a dose-dependent manner. At the higher dose of 500 mg/kg, it improved memory in the R/1 and P/8 S.A.M. mice. In prolonged rota-rod tests, which assessed both motor coordination and endurance, B.Z.Y.Q.T. significantly improved performance in the P/8 S.A.M. mice. Elevated dopamine and noradrenaline were observed in cortical tissues of the S.A.M./Dull and ICR mice respectively with the high dose of 500 mg/Kg, B.Z.Y.Q.T. Taken together, the results indicated that B.Z.Y.Q.T. appeared to exert anti-aging effects in mice and elevation in certain monoamines in brain cortical tissues. How and whether the monoamines changes after B.Z.Y.Q.T. treatment might be related to the behavioral effects await further investigation.

Aging↗
PubMed1999

Selective association between a macrocyclic nickel complex and extrahelical guanine residues.

Nickel-dependent recognition and oxidation of guanine have been linked in part through the paramagnetic effects of nickel on the NMR of model oligonucleotide duplexes. Direct interaction between nickel and guanine N7 had originally been postulated from correlations between the efficiency of guanine oxidation and the environment surrounding its N7 position. (1)H and (31)P NMR spectra of DNA containing a single, isolated extrahelical guanine are consistent with selective binding of nickel to the N7 of this unique base over a background of nonspecific association to the phosphate backbone. The presence of a macrocyclic complex or simple salt of nickel did not detectably alter the structure of the duplex or extrahelical residue. Accordingly, nickel appeared to bind the extrahelical guanine N7 within the major groove as indicated by paramagnetic effects on the proton signals of nucleotides on the 5' but not 3' side of the nickel binding site. Similar (1)H NMR analysis of DNA containing a dynamic equilibrium of extrahelical guanine residues also suggested that the nickel complex did not affect the native distribution of structures. Oxidation of these sites by a nickel-mediated pathway consequently reflected their solvent accessibility in a general and metal-independent manner. The close proximity of the extrahelical guanines produced a composite of paramagnetic effects on each adjacent nucleotide resulting from both direct and proximal coordination of nickel.

Chromium Alloys↗
PubMed1999

Noninvasive evaluation of blunt abdominal trauma: prospective study using diagnostic algorithms to minimize nontherapeutic laparotomy.

A prospective study was performed to investigate the feasibility and benefit of evaluating blunt abdominal trauma (BAT) without diagnostic peritoneal lavage (DPL) or other invasive methods. Diagnostic algorithms were designed by using ultrasonography (US) as a screening method. For unstable patients, a free fluid >/= 2 mm thickness on US images over any one of the intraperitoneal spaces (bilateral subphrenic, Morrison, and Douglas pouch) was used as an indicator for laparotomy. For stable patients, any intraabdominal free fluid detected by US was used as an indicator for further investigations. Computed tomography served as a principal complementary method. To further clarify the clinical results, the rate of nontherapeutic laparotomy (NTL) was compared with that from a previous 5-year review done before this study. During studying period of 1 year, 170 patients were consecutively enrolled. There was no delayed diagnosis, and 66 patients were found to have BAT; 17 patients were initial unstable, among whom 15 had free fluid shown by US and 13 patients had confirmed BAT. Eight of the unstable patients with free fluid on US were saved from NTL, of whom six had retroperitoneal hematoma. There was no NTL in unstable patients. Twenty-two patients underwent laparotomy. Two laparotomies done for a suspicion of bowel injury turned out to be NTL. The rate of NTL in the present study was significant lower than that in a previous review (9.1% vs. 32.2%, p = 0.025). Hence following well designed algorithms, noninvasive evaluation of BAT can proceed with safety, and NTL is minimized.

Abdominal Injuries↗
PubMed1999

Superoxide production of neutrophils after severe injury: impact of subsequent surgery and sepsis.

To evaluate the early variations of superoxide production of neutrophils (SPN) in injured patients, SPN was serially measured on the first, third, and seventh day after severe injury (injury severity score of >16). For patients receiving subsequent surgery, SPN was measured again on the first postoperative day. Eighteen patients were studied. Six had subsequent surgery within 1 day (early operation); 6 had surgery 3 days after injury (late operation); 6 did not have surgery (nonoperation). SPN increased on the first day and recovered from the third day after injury in all three groups. In patients who had surgery, SPN did not significantly increase on the first postoperative day. Eight patients developed sepsis, 4 of whom had early multiple organ dysfunction (EMOD). On the last measurement, mean SPN was suppressed in septic patients with EMOD, whereas it was elevated in septic patients without EMOD. Patients with EMOD also had a higher injury severity score. In conclusion, subsequent surgery after injury has no effect on the priming of neutrophils. While late priming of neutrophils in injured patients coincides with the development of sepsis, suppression of SPN is found in septic patients with EMOD that frequently results from severe injury.

Adolescent↗
PubMed1999

The advisability of implementing cholesterol screening in school-age children and adolescents with a family history of cardiovascular disease and hyperlipidaemia.

BACKGROUND: The family basis of coronary heart disease is well recognized and it is important for family physicians to assess whether children have elevated cholesterol levels. OBJECTIVES: We aimed to evaluate the advisability of implementing cholesterol screening in children with a family history of cardiovascular disease and hyperlipidaemia. METHODS: We conducted a cross-sectional study in Taiwan from February to June 1996. There were 47,800 students in the population. A total of 4520 students were recruited by two-stage sampling. All the participants were required to fill out a structured questionnaire. RESULTS: The response rate was 92.5%. Our results show that 16-18% of the children had a positive family history of cardiovascular disease or hyperlipidaemia. Children with a family history of hyperlipidaemia were significantly more likely to have elevated total cholesterol and low-density lipoprotein cholesterol than those without such a history (both odds ratios: 1.4, P < 0.05). Positive predictive values of hyperlipidaemia were less than 13% based on family history. More than 75% of children with abnormal lipid levels would be missed. CONCLUSIONS: The data suggest that parents' self-reported family history is an ineffective means of identifying children with elevated serum lipid levels in Taiwan. Further research and modification of current National Cholesterol Education Program Panel guidelines for selective cholesterol screening in children may be warranted.

Analysis of Variance↗
PubMed1999

Dermatoses in cement workers in southern Taiwan.

Construction workers are known to have occupational dermatoses. The prevalence of such dermatoses was unknown in Taiwanese construction workers. The objective of this study was to determine the work exposure, prevalence of skin manifestations, and sensitivity to common contact allergens in cement workers of southern Taiwan. A total of 1147 current regular cement workers were telephone-interviewed about skin problems during the past 12 months, work exposure, and personal protection. Among those interviewed, 166 were examined and patch tested with common contact allergens. A high % of cement workers reported skin problems in the past 12 months. More men (13.9%) reported skin problems possibly related to work than women (5.4%). Prevalence was associated with lower use of gloves, duration of work as cement worker, and more time in jobs involving direct manual handling of cement, especially tiling. A high % of dermatitis was noted in the 166 workers examined, which correlated with reported skin problems. On patch testing, construction workers had a high frequency of sensitivity to chromate. Sensitivity to chromate or cobalt was associated with reported skin problems, or dorsal hand dermatitis on examination. These workers' dermatitis was under-diagnosed and inadequately managed. It is concluded that cement workers in southern Taiwan had a high prevalence of skin problems related to cement use. Protective measures, work practice, and physician education should be improved to prevent or manage such problems.

Adult↗
PubMed1999

Safety of distilled water as an irrigating fluid for transurethral resection of the prostate.

BACKGROUND: Irrigating fluid is necessary for transurethral resection of the prostate (TURP). Initially, distilled water was used as irrigating fluid and some advantages and complications were noted. Although other solutions were used to substitute for distilled water, we collected data for changes in electrolytes and hematocrit (Hct) during surgery to evaluate the safety of distilled water as irrigating fluid for TURP with suprapubic trocar cystostomy. METHODS: Fifty-three patients who underwent TURP using distilled water as irrigating fluid were investigated. TURP was performed with suprapubic trocar cystostomy routinely. Preoperative and postoperative blood samples were collected and analyzed for electrolytes and Hct to study any changes during surgery. RESULTS: The change in plasma sodium concentration was not statistically significant, but the decreases in blood Hct and plasma potassium concentration were statistically significant. There was no major operative complication and no clinical-evident related postoperative renal impairment. CONCLUSIONS: Distilled water is a relatively safe solution as an irrigating fluid for TURP under drainage with suprapubic trocar cystostomy, but attention must be paid to the inevitable blood loss during surgery.

Aged↗
PubMed1998

Modulation of ceramide-activated protein phosphatase 2A activity by low molecular weight aromatic compounds.

Protein phosphatase 2A (PP2A) is one of the most important and abundant serine/threonine phosphatases in mammalian tissues and plays a role in gene expression, cell division, and signal transduction. PP2A is activated by ceramide, which is produced by the hydrolysis of membrane sphingomyelin in response to a variety of stress-related stimuli. To further study the role of ceramide-mediated signal transduction in cellular processes such as senescence and apoptosis, we designed and synthesized a series of low molecular weight aromatic compounds, mainly of the isoquinolone and tetralone classes, and evaluated their ability to inhibit enzymes known to be activated by ceramide. Those enzymes studied were ceramide-activated protein kinase, protein kinase C zeta and PP2A. Of these, only PP2A was found to be inhibited. A few of the compounds inhibited both ceramide-activated as well as basal PP2A activity. In addition, several of the compounds activated PP2A by up to 300% above basal enzyme activity, but only in the presence of ceramide. Thus, modulation (both inhibition and activation) of the catatylic activity of ceramide-activated PP2A is demonstrated by certain low molecular weight aromatic compounds.

Blotting, Western↗