Biomedical subjects
Publications and source records attributed to H C Lin.
Complication of endoscopic variceal injection sclerotherapy for esophageal variceal hemorrhage is not unusual. However, sclerotherapy complicated panophthalmitis was never reported before. We report such an unusual complication and discuss its possible mechanism and treatment.
Expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated both by the HTLV-1 Tax transactivator and by cellular transcriptional factors binding to the viral long terminal repeat (LTR), suggesting that cellular signals may play a role in regulating viral expression. Treatment of cells chronically infected with HTLV-1, which express low levels of HTLV-1 RNAs and Tax protein, with phorbol esters (i.e., phorbol12-myristate 13- acetate [PMA]), phytohemagglutinin (PHA), sodium butyrate, or combinations of cytokines resulted in induction of HTLV- 1 gene expression. PMA or PHA treatment following cotransfection of HTLV-1 Tax expression plasmids resulted in synergistic activation of HTLV-1 LTR-directed gene expression, apparently involving tyrosine ki- nase- mediated pathways. These results suggest that cellular activation stimuli may cooperate with HTLV-1 Tax to enhance expression of integrated HTLV-1 genomes and thus may play a role in the pathogenesis of HTLV-1 disease.
The present study compares the rates of Ca2+ uptake and Cd2+ accumulation in tilapia (Oreochromis mossambicus) between larvae preexposed to Cd2+ and naive larvae. Preexposure to Cd2+ induces some form of adaptation that attenuates the effects of Cd2+ later on. Exposure to Cd2+ decreased the uptake of Ca2+ but did not suppress the accumulation rate of Cd2+. A 12-fold increase in 96-h half-maximal lethal concentration was found in tilapia larvae preexposed to 0.45 microM Cd2+ from hatching for 3 days in comparison with naive 3-day-old larvae. The effects of Cd2+ on Ca2+ influx kinetics in larvae preexposed to 0.18 microM Cd2+ for 3 days were examined. The Michaelis constant for Ca2+ in the 0.18 microM Cd2+ preexposed larvae did not change significantly in the presence of Cd2+, whereas maximal velocity increased by approximately 23%. An enhanced Ca2+ uptake efficiency ( approximately 18%) was found in these Cd2+-acclimated larvae. The criterion that determines the survival of tilapia larvae encountering Cd2+ challenge is the degree of interference with Ca2+ homeostasis instead of the absolute amount of Cd2+ accumulated.
The portal hypotensive effects of prazosin and DL-028 (chem- ical name: 3-[[4-(2-methoxyphenyl)piperazin-1-yl]methyl]- 2, 3-dihydroimidazo[1,2-c]quinazolin-5(6H)-one(27b)), a synthetic alpha1-adrenoceptor antagonist, were assessed in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation in Sprague-Dawley rats. Two weeks after ligation, when the hyperdynamic state was stabilized the rats were anesthetized after an overnight fast and cannulated for measuring mean arterial pressure (MAP), portal venous pressure (PVP), cardiac index (CI) and heart rate (HR). Both DL-028 and prazosin (1, 3.3 and 10 microgram/kg) induced dose-dependent decreases of PVP and MAP after intravenous infusion, with effects lasting for longer than 30 min. The maximum percentage reduction of PVP after DL-028 was 10, 10 and 15%, respectively, for the dosages given (1, 3.3 and 10 microgram/kg), and 5, 12 and 25%, respectively, after prazosin. CI was not changed by either drug. HR was not changed by either drug except DL-028 at 10.0 microgram/kg with a bradycardiac effect. Our results showed that both DL-028 and prazosin reduced PVP in portal hypertensive rats.
Nitric oxide (NO) plays an important role in resistance to Mycobacterium tuberculosis infection. Our aim was to determine whether inducible NO synthase (iNOS) expression and generation of reactive nitrogen intermediates (RNI) by alveolar macrophages (AM) are increased in patients infected with M. tuberculosis. NO levels in the exhaled air of 19 active pulmonary tuberculosis (TB) and 14 control subjects were measured using a chemiluminescence NO analyser. The expression of iNOS on AM was studied by labelling AM with anti-mac iNOS polyclonal antibody analysed with a flow cytometer. The spontaneous generation of RNI by cultured AM was also measured. Data are presented as mean+/-SEM. The level of NO in exhaled air was higher in patients with active TB (16.2+/-1.2 parts per billion (ppb)) compared to control subjects (6.5+/-0.9 ppb), p<0.0001. Exhaled NO decreased with anti-TB treatment. Compared to control subjects (29.0+/-4.5 fluorescence intensity (FI)), iNOS expression on AM was upregulated in TB patients (86.3+/-12.5 FI) p<0.001 and the capacity for spontaneous generation of nitrite was enhanced. Nitrite production was inhibited by N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of iNOS. The expression of iNOS on AM was related to the concentration of exhaled NO (r=0.66, p<0.001) and the nitrite generation capacity of AM (r(s)=0.77, p<0.001). We conclude that the increase in exhaled nitric oxide observed in patients with active pulmonary tuberculosis is due to an upregulation of inhaled NO synthase expression in alveolar macrophages which have an enhanced capacity for nitric oxide production.
OBJECTIVES: To study the outcome at 2-year corrected age of infants who participated in a double-blind controlled trial of early (<12 hours) dexamethasone therapy for the prevention of chronic lung disease (CLD). METHODS AND MATERIALS: A total of 133 children (70 in the control group, 63 in the dexamethasone-treated group) who survived the initial study period and lived to 2 years of age were studied. All infants had birth weights of 500 to 1999 g and had severe respiratory distress syndrome requiring mechanical ventilation within 6 hours after birth. For infants in the treatment group, dexamethasone was started at a mean age of 8.1 hours and given 0.25 mg/kg every 12 hours for 1 week and then tapered off gradually over a 3-week period. The following variables were evaluated: interim medical history, socioeconomic background, physical growth, neurologic examinations, mental and psychomotor development index score (MDI and PDI), pulmonary function, electroencephalogram, and auditory and visual evoked potential. RESULTS: Infants in the control group tended to have a higher incidence of upper respiratory infection and rehospitalization than did the dexamethasone-treated group because of respiratory problems. Although there was no difference between the groups in somatic growth in girls, the dexamethasone-treated boys had significantly lower body weight and shorter height than the control boys (10.7 +/- 3.0 vs 11.9 +/- 2.0 kg; 84.9 +/- 5.7 vs 87.5 +/- 4.8 cm). The dexamethasone-treated group had a significantly higher incidence of neuromotor dysfunction (25/63 vs 12/70) than did the control group. The dexamethasone-treated infants also had a lower PDI score (79 +/- 26) than did the control group (87 +/- 23), but the difference was not statistically significant. Both groups were comparable in MDI, incidence of vision impairment, and auditory and visual evoked potential. Significant handicap, defined as severe neurologic defect and/or intellectual defect (MDI and/or PDI </= 69), was seen in 22 children (31.4%) in the control group and 26 (41.2%) in the dexamethasone-treated group. CONCLUSIONS: Although early postnatal dexamethasone therapy for 4 weeks significantly reduces the incidence of CLD, this therapeutic regimen cannot be recommended at present because of its adverse effects on neuromotor function and somatic growth in male infants, detected at 2 years of age. A longer follow-up is needed. If early dexamethasone therapy is to be used for the prevention of CLD, the therapeutic regimen should be modified. The proper route of administration, the critical time to initiate the therapy, and the dosage and duration of therapy remain to be defined further.
OBJECTIVE: Hyperamylasemia with a presumptive diagnosis of acute pancreatitis has been reported following organophosphate poisoning but there are no large-scale studies incorporating more specific diagnostic criteria. METHODS: Retrospective review of the medical records of 159 patients with a diagnosis of organophosphate poisoning over 3 years. Serum amylase, pancreatic amylase, salivary amylase, lipase and cholinesterase levels, and the clinical manifestations were analyzed. RESULTS: Serum amylase data was available for 121 of the 159 study patients. Hyperamylasemia (amylase > or = 360 U/L) was found in 44 patients (36%). Lipase was measured in 28 patients with hyperamylasemia; 9 of 28 had hyperlipasemia (lipase > or = 380 U/L). The finding of hyperamylasemia was closely related to clinical severity and presence of shock. A presumptive diagnosis of painless acute pancreatitis was diagnosed by hyperlipasemia associated with hyperamylasemia, clinical severity, serum LDH, and leukocyte counts. Two patients with presumptive pancreatitis died. Shock, coma, and hypoalbuminemia were the factors predicting fatality. CONCLUSIONS: Hyperamylasemia is frequent in severe organophosphate poisoning. However, hyperamylasemia is not synonymous with acute pancreatitis and pancreatic amylase is not a reliable parameter in the diagnosis of organophosphate-induced pancreatitis due to its low sensitivity and specificity. Lipase assay is indicated in patients with hyperamylasemia for early diagnosis of pancreatitis. Proper image studies and even pathological examination are also needed to confirm the extent of pancreatic injury. With prompt diagnosis and appropriate treatment, a complete recovery can be anticipated unless the patient has otherwise unrelated complications.
BACKGROUND: Mucus impaction in the airways impairs ventilation and exercise tolerance in patients with bronchiectasis. Parameters for evaluating the ventilatory dynamic change have been limited by variable cofactors. We developed a tool to evaluate the changes directly on images of a ventilation scan. MATERIALS AND METHODS: We used a 133Xenon ventilation washout scan to assess the time of half clearance (T1/2) of the regions of interest (ROIs) corrected by that of a control area (CA) as T1/2ROI/CA. We then compared the ventilation washout scan with high-resolution computer tomography (HRCT) scoring to assess the severity of bronchiectasis, as well as conducting 6-minute walking tests or spirometry for the evaluation of the clinical response to a 3-day course of chest physiotherapy. Nine patients with bronchiectasis and mucus hypersecretion were enrolled in this study. RESULTS: The functional impairments by mucus impaction or air trapping were well documented in the ventilation washout scan, which not only provided an anatomical image but also dynamic profiles. The ratios of T1/2ROI/CA were significantly correlated to the corresponding scoring of HRCT (3.45 +/- 0.85 vs 7.50 +/- 1.51, r2 = 0.61, p = 0.023, n = 8). The improvement in T1/2ROI/CA (from 3.45 +/- 0.85 to 2.60 +/- 0.59, p = 0.022, n = 9) was paralleled by an increase in the 6-minute walking test (from 310.4 +/- 43.2 m to 352.4 +/- 45.1 m, p = 0.028, n = 7). CONCLUSION: The 133Xenon scan may be used to evaluate the heterogeneity of ventilation abnormalities and the efficacy of clinical therapy directly in patients with bronchiectasis.
The National Cheng Kung University (NCKU) Hospital operates a comprehensive integrated hospital information system. This was designed and installed as an integral component of the building of the hospital, which opened in 1988. The information system provides a service to all staff in the hospital, administrative and clinical, across the whole of the hospital. To make sure that the information is accessible, where and when it is needed, a comprehensive communications network consisting of both hardware and software mechanisms supports the information system. This paper explores the requirements for a computerised image system for endoscopy and assesses two approaches to the implementation of such a system, as a stand-alone system and as a subsystem of the NCKU hospital information system already in place. The latter would satisfy the original design specification of developing a single system to cover all aspects of hospital operation but places additional demands on the endoscopy systems designer to ensure integration. Both operational modes are set out in the paper and their implications assessed.
An open-labeled and randomized trial was conducted to compare the efficacy and safety of once daily cefpodoxime proxetil suspension (10mg/kg/day) and thrice daily cefaclor (45mg/kg/day) in the treatment of acute otitis media in children. A total of 57 children aged from 6 months to 9 years were enrolled; 23 were treated with cefpodoxime and 34 with cefaclor. Satisfactory clinical outcome, either cure or improvement, was achieved at the end of treatment in 90% of patients in the cefaclor group and 95% of patients in the cefpodoxime group (p > 0.05). Clinical recurrence was identified at the follow-up visits in one case of the cefaclor group (3%), and none in the cefpodoxime group (p > 0.05). These drugs were well tolerated by 14/21 (67%) in the cefpodoxime-treated group and 27/32 (84%) in the cefaclor-treated group. The incidence of adverse events was slightly higher in the cefpodoxime group than in the cefaclor group, however the difference did not reach statistical significance (p > 0.05). The daily cost of once-daily cefpodoxime was lower than that of thrice-daily cefaclor. We conclude that cefpodoxime administered once daily is as effective and safe as cefaclor administered thrice daily in the treatment of acute otitis media in children. The less dosing frequency and lower daily price of cefpodoxime provide additional benefits.
OBJECTIVE: To evaluate analgesic effects after epidural administration of medetomidine to cows, compared with effects of lidocaine hydrochloride and 0.9% NaCl solution. ANIMALS: 6 adult beef cows. PROCEDURE: 3 treatments were administered to each cow, with a 1-week interval between subsequent treatments. Treatments consisted of 5 ml of physiologic saline (0.9% NaCl) solution; 0.2 mg of lidocaine/kg of body weight, not to exceed 100 mg (5 ml); and 15 micrograms of medetomidine/kg, diluted with 0.9% NaCl solution to provide a volume of 5 ml. Epidural injections were given in the first or second coccygeal space. Heart rate, respiratory rate, and arterial blood pressure values were recorded before injection, 5 and 10 minutes after injection, and at 10-minute intervals thereafter. Onset and duration of analgesia, sedation, and ataxia were recorded. A repeated-measures ANOVA was used to detect differences between treatments. RESULTS: Epidural administration of 0.9% NaCl solution did not induce analgesia. Lidocaine induced analgesia within 5 to 20 minutes, which lasted 10 to 115 minutes (mean +/- SD, 43.3 +/- 37.2 minutes). Heart rate decreased during lidocaine-induced analgesia. Heart and respiratory rates decreased, but blood pressure remained unchanged, after medetomidine administration. Medetomidine induced analgesia within 5 to 10 minutes, which lasted 412 +/- 156 minutes. Mild to moderate sedation and moderate ataxia were observed. Two cows became recumbent, but were easily coaxed to stand. Medetomidine-induced salivation and increased frequency of urination were observed in all cows. CONCLUSIONS AND CLINICAL RELEVANCE: Epidural administration of medetomidine induced prolonged analgesia that was suitable for perineal surgery, postoperative analgesia, and relief of continuous straining.
BACKGROUND: Laboratory diagnosis of disseminated intravascular coagulation (DIC) is difficult in patients with cirrhosis of the liver due to the complicated hemostatic changes of DIC. More recently, newer molecular hemostatic markers have been used to improve the diagnosis of DIC. This study evaluated the ability of the more advanced hemostatic tests to diagnose DIC in patients with cirrhosis of the liver. METHODS: A series of hemostatic tests and parameters including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), factor VIII assay, antithrombin (AT) activity, fibrinogen, plasminogen, protamine sulfate test (PST), fibrin (ogen) degradation product (FDP), D-dimer, thrombin-antithrombin complex (TAT) (measured by modified antithrombin, ATM), euglobulin lysis test (ELT) and platelet count were performed in 51 patients with cirrhosis of the liver. A diagnosis of DIC was made according to the following parameters and criteria: a) platelets less than 80 x 10(9)/l; b) PT greater than 1.5, c) APTT greater than 1.3; d) TT greater than 24 sec; e) AT less than 60%; f) ATM greater than 14.7 ng/ml (normal, mean +/- 3 SD); g) fibrinogen less than 1.50 g/l; h) positive PST; i) D-dimer greater than 1.0 microgram/ml; j) FDP greater than 20 micrograms/ml; k) ELT less than 150 min; l) plasminogen less than 50%. DIC was diagnosed if six or more of the above items were present, and at least two of them were item (a) to (h), and at least two were item (g) to (l). RESULTS: Although eight patients had results that fitted the diagnostic criteria of DIC by using the more advanced tests, only two of them were diagnosed with DIC by conventional testing. The concentration of factor VIII in these eight patients did not markedly decrease. CONCLUSIONS: New tests are not necessary to improve the diagnosis of DIC in patients with cirrhosis of the liver.
OBJECTIVE: To determine a dose of medetomidine that will induce sedation in llamas, to assess effects of medetomidine sedation on arterial blood gas variables, and to determine efficacy of atipamezole in reversing medetomidine-induced sedation. DESIGN: Prospective, randomized clinical trial. ANIMALS: 15 clinically normal adult llamas. PROCEDURE: 9 llamas received various doses of medetomidine (0.01, 0.02, or 0.03 mg/kg [0.005, 0.009, or 0.014 mg/lb] of body weight, i.m.). Heart and respiratory rates and sedative effects were recorded. Using the lowest dose that induced deep sedation, 6 different llamas were used to assess effects of medetomidine on arterial blood gas variables. These same 6 llamas were later given atipamezole (0.125 mg/kg [0.057 mg/lb], i.v.) 30 minutes after medetomidine injection. Heart and respiratory rates, sedative effects, and time from atipamezole injection to standing were recorded. RESULTS: Sedation began 6.67 +/- 1.15 minutes (mean +/- SD) after medetomidine administration (0.03 mg/kg, i.m.). Arterial blood gas variables measured 30 and 60 minutes after injection were not different from baseline. Llamas that did not receive atipamezole remained recumbent for 91.50 +/- 24.68 minutes. After atipamezole administration, llamas were able to stand in 5.80 +/- 3.27 minutes. CLINICAL IMPLICATIONS: Medetomidine induced light to deep sedation in a dose-dependent manner in clinically normal llamas. A dose of 0.03 mg/kg induced deep sedation with a short period of analgesia. Atipamezole rapidly reversed effects of medetomidine, and llamas recovered quickly and were soon able to stand.
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Dynamins comprise a family of GTPases that participate in the early stages of endocytosis. The GTPase activity of neuronal specific dynamin I is stimulated by microtubules, negatively charged phospholipid vesicles, and Src homology 3-containing proteins, including Grb2. These activators were previously shown to bind to a proline/arginine-rich domain (PRD) in the carboxyl-terminal region of the enzyme. Dynamin II, which is ubiquitously expressed, had not been purified or characterized previously. In this study, the enzymatic properties of rat dynamin II and of D746, a dynamin II truncation mutant lacking the PRD, have been characterized. Dynamin II has a higher basal activity than dynamin I, but the two types of dynamin are stimulated similarly by microtubules, Grb2, and phospholipids. D746 is not activated by microtubules or Grb2, highlighting the significance of the PRD for these interactions, but it is activated by phospholipid vesicles containing phosphatidylserine or phosphatidylinositol-4,5- bisphosphate. Moreover, in contrast to previous reports, the PRD appears not to be required for phospholipid-stimulated self-assembly of dynamin, which is a key element in the regulation of its activity. Similar results were obtained with bovine brain dynamin I that had been subjected to limited proteolytic digestion to remove the PRD. Our data highlight the potential involvement of dynamin pleckstrin homology domains in the regulation of GTPase activity by phospholipids.
Tetrandrine is a calcium channel antagonist with reported anti-hypertensive effect. The present study aimed to investigate the hemodynamic effects of chronic tetrandrine treatment on normotensive Sprague-Dawley rats. Animals were allocated into one of the two groups: tetrandrine group and vehicle group. Tetrandrine (20 mg/kg) or vehicle was administered by gavage every 12 hours for consecutive 8 days. After 8 days of tetrandrine treatment, systemic hemodynamics and organ blood flows were measured on the next morning after an overnight fast, using radioactive microsphere method. Mean arterial pressure (96 +/- 2 vs. 118 +/- 4 mmHg) and systemic vascular resistance (254 +/- 35 vs. 369 +/- 5 dyn.sec.cm5 x 10(3)/100 g body wt) were significantly decreased in the tetrandine group as compared to the vehicle group. The cardiac-index (35.2 +/- 2.7 vs. 25.5 +/- 0.8 mL/min/100 g body wt) was increased in the tetrandrine group. The portal venous pressure, portal tributary blood flow, portal territory vascular resistance, renal blood flow, renal vascular resistance, heart rate and body weight were similar between the two groups. In conclusion, long-term treatment of tetrandrine reduced mean arterial pressure and systemic vascular resistance but did not change splanchnic or renal hemodynamics in normal rats.
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Anesthetic effects of xylazine, butorphanol, tiletamine-zolazepam, and isoflurane in ratites (9 emus, 3 rheas, 6 ostriches) were determined. Anesthetic treatments included 4 regimens: induction and maintenance of anesthesia with isoflurane, preanesthetic tranquilization with xylazine and butorphanol followed by induction and maintenance of anesthesia with isoflurane, induction of anesthesia with tiletamine-zolazepam and maintenance with isoflurane, and preanesthetic tranquilization with xylazine and butorphanol followed by induction of anesthesia with tiletamine-zolazepam and maintenance with isoflurane. None of the birds developed irreversible adverse effects, but 2 developed brady cardia (1 was treated with atropine and responded) and 2 others developed transient apnea. Intravenous administration of tiletamine-zolazepam produced rapid and smooth induction of anesthesia in adult ostriches.