Biomedical subjects

G Lai

Publications and source records attributed to G Lai.

At least 19 recordsLinked to original sources

PubMed2004

Examining chronic kidney disease management in a single center.

AIMS: The management of patients with chronic kidney disease in outpatient clinics was assessed for the ability to achieve targets of care advocated in clinical practice guidelines. METHODS: 272 records of outpatients with increased serum creatinine (> or = 1.5 mg/dl for women, > or = 2.0 mg/dl for men) were reviewed for details of their assessment and management. Prevailing data on blood pressure, anemia, bone disease and lipid status as well as therapeutic changes were evaluated. RESULTS: The subjects were aged 64 +/- 18 years, serum creatinine 2.6 +/- 1.1 mg/dl, and calculated GFR (MDRD formula) 19.2 +/- 9.9 ml/min. Median UproV was 1.0 (0.024 - 12.4) g/day. Causes of CKD were diabetes (33.5%), HTN (8.8%), GN (19.5%), and adult PKD (3.3%). Treatment targets were BP < 130/85 mmHg, Hct > or = 36%, serum Ca++ > or = 8.5 mg/dl, serum Po4 < 4.5 mg/dl and cholesterol < 200 mg/dl. Of the patients with abnormal findings, mean values for SBP were 153 +/- 17 mmHg, DBP 93 +/- 6 mmHg, Hct 31.7 +/- 2.9%, Ca++ 8.0 +/- 0.7 mg/dl, PO4 5.6 +/- 1.0 mg/dl, and cholesterol 236 +/- 37 mg/dl. Only a minority of patients with abnormal values had their treatment altered. Furthermore, only 54% of patients with hypertension were treated with either ACEi or ARB therapy. Finally, only 6% of patients with hypercholesterolemia had fasting lipid levels measured. CONCLUSION: This data suggests that treatment of patients with CKD has improved, but that many opportunities exist to optimize their care.

Adult↗

PubMed2001

Perflubron emulsion reduces inflammation during extracorporeal circulation.

The recovery from cardiac surgery and cardiopulmonary bypass can be complicated by an acute inflammatory response. Circulating blood through an extracorporeal circuit (ECC) contributes to this complication. Perfluorocarbon-based blood substitutes (PFCs) are under investigation for use as a component of the ECC "prime" solution, because PFCs increase the oxygen-carrying capacity of the diluted blood. Some PFCs may provide the additional benefit of attenuating the ECC-induced inflammatory response. Earlier, we reported that perflubron emulsion (PFE, Alliance Pharmaceutical Corp.) reduced neutrophil (PMN) activation in vivo. However, the potential of PFE to reduce ECC-induced PMN activation has not been investigated. In this study, we used a small-scale ECC model to quantify the extent of PMN activation during circulation and to examine if PFE treatment attenuated PMN activation. ECC circuits were filled with a mixture of blood and Plasmalyte. Two groups were studied: an untreated group containing blood plus PlasmaLyte and a treated group in which some of the Plasmalyte was substituted with PFE (4.5 g/100 ml). Hematology and measures of whole blood PMN activation were made from blood samples taken periodically throughout the 120-min ECC circulation period. We found, for the untreated group, a significant decrease in the number of circulating PMNs and an increase in PMN activation with time. PMN activation was demonstrated as a significant increase in the expression of the PMN adhesion protein CD11b (P < 0.05) and an increase in PMN oxygen free radical production (reactive oxygen species (ROS)). After 120 min of circulation, the PMNs remained capable of a significant response to a second inflammatory stimulus, but PFE treatment significantly attenuated the fMLP-induced increase in PMN ROS at t = 120 min (P < 0.05). These results suggest that PFE may have dual utility in cardiac surgery, to increase oxygen delivery and to serve as an antiinflammatory agent.

Animals↗

PubMed2000

Work stress among six professional groups: the Singapore experience.

Recent developments in stress research have called for attention to how social structures influence the stress and coping processes. This paper examines the experience of work stress among professionals in Singapore and argues that workers' experiences in the workplace are influenced not only by individual personality and job nature, but also by structural forces shaping the profession, the social organization of work institutions and the development of the economy. Data were collected from a survey of professionals in Singapore conducted in 1989-1990. The sample consisted of 2570 men and women from six different professions and para-professions, namely general practitioners, lawyers, engineers, teachers, nurses and life insurance personnel. Results showed that performance pressure and work-family conflicts were perceived to be the most stressful aspects of work. These two stressors also significantly contributed to the experience of overall work stress. Further, stress arising from work-family conflicts, performance pressure and poor job prospects was negatively associated with the level of work satisfaction. These findings were discussed in the contexts of increasing professionalization and de-professionalization and the growing emphases on productivity and efficiency in a quickly developing economy.

Adult↗

PubMed1999

Validation of a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) for the evaluation of coronary flow reserve: comparison with intracoronary Doppler flow wire.

OBJECTIVES: We tested the hypothesis that coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) as assessed by a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) is in agreement with CFR measurements assessed by intracoronary Doppler flow wire. BACKGROUND: Contrast-enhanced transthoracic second harmonic echo Doppler is a novel noninvasive method to detect blood flow velocity and reserve in the LAD. However, it has not yet been validated versus a gold-standard method. METHODS: Twenty-five patients undergoing CFR assessment in the LAD by Doppler flow wire were also evaluated by contrast-enhanced transthoracic Doppler to record blood flow in the distal LAD at rest and during hyperemia obtained by adenosine i.v. infusion. In five patients CFR was evaluated twice (before and after angioplasty). RESULTS: As a result of the combined use of i.v. contrast and second harmonic Doppler technology, feasibility in assessing coronary flow reserve equaled 100%. The agreement between the two methods was high. In fact, in all but five patients the maximum difference between the two CFR measurements was 0.38. Overall, the prediction (95%) interval of individual differences was -0.69 to +0.72. Reproducibility of CFR measurements was also high. The limits of the agreement (95%) between the two measurements were -0.32 to +0.32. CONCLUSIONS: Coronary flow reserve in the LAD as assessed by contrast-enhanced transthoracic echo Doppler along with harmonic mode concurs very closely with Doppler flow wire CFR measurements. This new noninvasive method allows feasible, reliable and reproducible assessment of CFR in the LAD.

Adenosine↗

PubMed1997

[The three-dimensional titanium miniplate rigid fixation in the treatment of fracture of maxilla].

The three-dimensional (3-D) Titanium miniplate system is one of the newest internal rigid fixation for the maxillo-mandibular surgery in recent years. The geometry of the plate assures a good stability in the three-dimensions of the fracture sits. Thirty patients suffering from maxillo-mandibular fractures had been operated on using the 3-D Titanium miniplates since 1991. The group of the patient included 16 cases of mandibular fractures, 8 cases of maxillary fractures and 6 cases of maxillo-mandibular fracture. All of the patient had very good result without any complication. The follow-up was 6 months to 3 years. The 3-D Titanium miniplate as an ideal easy to use, good resistance against torque forces and, compact forms of the miniplate were the some of the advantages. Clinical examples had been provided to illustrate the actual usage of the 3-D miniplate in the field of the surgical treatment for the maxillo-mandibular fracture. It is the author's opinion that the internal rigid fixation by 3-D Titanium miniplates is a promising method of treating fractures of the maxilla and is to be better tolerated by the patients and surgeons.

Adolescent↗

PubMed1996

Stress in the life course: a life history approach.

This article examines the relationship between stress and distress in the life course, emphasizing the time elapsed between the event and measurement of psychological distress. Stressors are conceptualized as either distal or proximal based on how recently they occurred. Distal stressors are further classified as status changes or undesirable life changes. Using a life history calendar approach, we examine stressors occurring over a 15-year-period. We explore whether distal stressors affect current depressive symptomatology above and beyond the effect of more recent stressors and how these stressors vary in frequency and affect over 3 empirically defined age groups. While some events decrease in frequency over age, others occur consistently across age groups. Most important, distal stressors significantly impact current depressive symptomatology, independent of proximal stressors. Types of distal stressors affecting depression vary over age, indicating that the stage of life at which a stressor occurs is a significant determinant of the stressor's effect on depression.

Adult↗

PubMed1996

Stimulation of megakaryocytopoiesis in mice by human modified C-reactive protein (mCRP)

The prototypic human acute phase reactant, C-reactive protein (CRP), and a structurally modified form of CRP (mCRP) were studied as agents which could stimulate thrombopoiesis in both in vitro and in vivo mouse models. mCRP, but not the widely studied (native) pentameric form of CRP, demonstrated significant megakaryocyte colony-stimulating activity. This activity was measured in plasma clot cultures incubated with pokeweed mitogen-stimulated spleen cell conditioned medium (PWM-SCM). mCRP increased the number of mouse megakaryocyte colonies in a dose-dependent manner. While significantly more colonies were observed in mCRP-treated cultures compared to controls, the kinetics of megakaryocyte growth and maturation were similar to those measured in cultures stimulated with PWM-SCM lacking mCRP. A low level of megakaryocyte growth-promoting activity was noted when mCRP was added to plasma clot cultures not incubated with spleen cell conditioned medium. However, the most striking activity of mCRP was in potentiating stimulated megakaryocyte colony formation (i.e., as a Meg-POT factor). In in vivo experiments, mCRP injected subcutaneously into normal mice resulted in significant increases in blood platelet numbers compared to control mice receiving sham injections. These results suggest that a modified form of CRP has thrombopoietic activity in both in vitro and in vivo mouse models, Therefore, one important biological role for CRP during an acute-phase response might be to contribute, after a structural modification, to the hematopoietic regulation of blood platelets.

Acute-Phase Reaction↗

PubMed1995

Urban stress in China.

The stress-distress model is examined in the context of a Chinese urban center, Tianjin. Conceptually, the relationship between stress (as reflected in life events) and distress (as reflected in depressed symptoms) is hypothesized to hold across societies. At the same time, the measures of stress must reflect the social reality of a particular community of society. In the case of urban China, the politically-imposed stratification system arranges individuals and family lives around work units. These work units dictate all aspects of the life of the worker and his or her family, ranging from housing, major purchases, access to local and distance facilities, schooling and employment for children, to retirement pension and funeral expenses. As a result, relationships in the work context are expected to produce stress-inducing conflicts. Results from a community survey of Tianjin residents in 1986 support both the generality of the stress-distress model and the specificity of the effects of work-related stressors.

Adjustment Disorders↗

PubMed1995

Work and family roles and psychological well-being in urban China.

A theoretical framework that delineates the relationships between work and family roles and psychological well-being is derived from U.S. research and utilized to examine the relationships of work and family stress with psychological well-being in urban China. Data from a sample of 733 married and employed individuals in urban Shanghai confirm the general model of the link between work and family stress and psychological distress. Due to the centrality of work roles for the Chinese, work stress exerts a stronger relationship on psychological well-being than does family stress. Furthermore, the Chinese are more vulnerable to stress arising from interpersonal conflicts than from role demands. In addition, gender differences are found in the relationship between role stress and distress. Women tend to experience more family demands than men. Women's mental health status is tied similarly to stress arising from work and family roles, whereas men are more vulnerable to work stress than family stress. However, Chinese women do not report significantly greater generalized distress than men.

Adult↗

PubMed1994

Treatment tolerance of elderly cancer patients entered onto phase II clinical trials: an Illinois Cancer Center study.

PURPOSE: Past research that has compared cancer treatment tolerance between elderly and nonelderly cancer patients has been contradictory. Some investigators concluded that there is no difference between the groups, while others demonstrated elderly patients experienced less tolerance to treatment. As a result, some physicians discriminate against elderly cancer patients by not entering them onto clinical trials out of a belief that they will not tolerate the therapy. METHODS: An analysis was performed using the Illinois Cancer Center (ICC) data base, which contains treatment information for all patients registered onto phase II trials. A maximum of 672 cases was available for evaluation of 11 treatment-related variables. RESULTS: The results demonstrated no significant differences between elderly and nonelderly patients for the following seven treatment-related variables: performance status (PS), number of dose reductions, number of treatment interruptions, total days of delay, best response, reason off-study, and number of grade 3 or greater toxicities. Minor differences were detected for number of courses and number of dose escalations. CONCLUSION: Based on these results, elderly patients should not be denied access to cancer clinical trials relative to age alone.

Aged↗

PubMed1994

Electron holographic observation of thin biological filaments.

A non-staining bacterial flagellum filament only 24 nm in diameter has been observed clearly by using a phase-shifting electron holographic technique. This method produces a sufficiently high contrast in-focus image that could never be obtained by ordinary transmission electron microscopic (TEM) methods.

Flagella↗

PubMed1993

[Update on laparoscopic surgery: on the treatment of hydatid cyst of the liver and peritonitis caused by a perforated duodenal ulcer].

Laparoscopic surgery represents a real innovation with respect to the traditional laparotomic way of access, owing to its undeniable advantages, both intraoperative and postoperative. This new technique reduces the complications connected with the surgical wound and with forced allerement. Therefore it allows the patient's fast recovery. Laparoscopic surgery application ground get's wider and wider every day: in fact, the authors report two medical cases, one of elective surgery (treatment of a hidatid cyst of the liver) and the other in emergency surgery (peritonitis due to perforated duodenal ulcer), both obtaining a positive result about the clinical and the postoperative timing of recovery.

Duodenal Ulcer↗

PubMed1993

Morphology of adult white donkeys of Asinara.

The phenotype of the Asinara white donkey has the following somatic characteristics: white coat, pink skin and glabrous areas, straight profile, body not very rounded on account of relatively slight muscular development, large head, eyes with irises of a pink-blue colour, short thin neck, not very pronounced withers, straight, average length dorsolumbar region, prominent angular rump higher than the withers, short chest, wide hind quarters, well developed abdomen, short sturdy limbs, light-coloured hooves. The somatometric measurements and the zoometric indexes show small-sized subjects with a hardy bone structure, of compact build with morphological homogeneity between the sexes. The donkeys are of the mesomorph type, more developed lengthwise than in height.

Adaptation, Physiological↗

PubMed1992

Effect of calcium antagonists on exercise tests.

The aim of this study was to investigate the anti-ischemic and antianginal activity and the duration of the new dihydropyridine calcium blocker nisoldipine (NIS) in patients with stable angina pectoris. The research was carried out on 16 patients, all male, 41-68 (mean of 58) years of age, with stable angina pectoris and fixed ischemic threshold (variations < 15%). After a 10-day washout period, patients were randomized to treatment with either 10 mg of nisoldipine or placebo (PL), twice daily for 21 days, according to a double-blind, crossover design. Patients underwent maximal symptom-limited exercise testing at 10 W/min on a bicycle ergometer, twice during the washout period, and once at the end of each treatment period, 3 and 12 h after oral administration of the drugs. In comparison with placebo, nisoldipine increased the ischemic threshold (N, 704 +/- 45 s; PL, 548 +/- 35 s; p < 0.01) and anginal threshold (N, 766 +/- 44 s; PL, 699 +/- 42 s; p < 0.01) for at least 12 h, and the ST-segment depression significantly decreased at maximal work (PL, 2.4 +/- 0.1 mm; N, 1.8 +/- 0.2 mm; p < 0.01) and at maximal common work (PL, 2.4 +/- 0.1 mm; N, 1.15 +/- 0.2 mm; p < 0.01). Similar to placebo the rate-pressure product was not significantly changed at higher submaximal effort after N, but it was significantly increased at the level of ischemic threshold, suggesting an increase in coronary blood flow to ischemic zones. Nisoldipine possesses anti-ischemic and antianginal activity lasting at least 12 h. This activity seems to be due to an increase in coronary blood flow to ischemic zones.

Adult↗

PubMed1992

[PTFE in reconstructive surgery on the face].

The employment of synthetic materials instead of autologous tissues (cartilaginous, adipose tissue, etc.) is already well codified and widely spread: the only restraint to their use is represented by biocompatibility which is not always satisfactory. Prosthesis should be clinically inert and inalterable with time, easy to sterilize, intraoperatively mouldable, and, from the aesthetic point of view, unrecognizable at touch. Since PTFE is widely used in general surgery (vascular prosthesis, aortobifemoral bypass, ect.) we have employed it in plastic surgery obtaining good results in the correction of malar depressions, and in harmonizing the final result of a rhinoplasty or of a labial plasty. All patients showed to well tolerate the material employed without any evident inflammatory reaction and with stable results at long-term follow-up.

Adult↗

PubMed1991

[Effects of benazepril, a new ACE inhibitor, in effort angina pectoris].

The aim of this study was to evaluate the anti-ischemic efficacy of 2 different doses of benazepril (B), a new ACE-inhibitor, 10 and 20 mg, given per os. Fifteen male patients gave informed, written consent; they were aged 40-67 years, with stable effort angina pectoris and were randomly given, in double-blind condition, a tablet containing B 10 mg, B 20 mg or placebo (PL), once a day, according to a 3 x 3 latin square design. Bicycle exercise tests were performed on the same day, 2 and 10 hours after the last drug intake. B 10 mg and B 20 mg, in patients with stable effort angina, compared to placebo, increased ischemic threshold and decreased ischemic ST depression at maximal work, after 2 hours but not after 10 hours. In conclusion B 10 mg and B 20 mg showed anti-ischemic activity 2 hours after drug intake.

Adult↗

PubMed1991

[Transdermal nitroglycerin in stable effort angina. I. Therapeutic effect and duration of the action of a single dose. Comparison with placebo and isosorbide dinitrate].

To assess the efficacy of 2 doses of a transdermal system for nitroglycerin, 10 and 20 mg (NTTS 10 and NTTS 20) and isosorbide dinitrate 40 mg (ISD 40) on exercise tolerance test, a double-blind within patients placebo (PL) controlled study was performed: 12 male patients, aged 47-71 years, with stable effort angina, with fixed ischemic threshold, received, according to a 4 x 4 latin square design, NTTS 10, NTTS 20, ISD 40 and PL, at 7.00 am on 4 consecutive days. Bicycle exercise tests were performed 4 and 12 hours post-dosing, after which the systems were removed. NTTS 10 and 20 and ISD 40 increased significantly ischemic threshold, anginal threshold and decreased maximal ST depression at the fourth hour. Only NTTS 10 and NTTS 20 showed antiischemic activity after 12 hours. During exercise, at the fourth and twelfth hour, there was no significant difference in rate-pressure product between placebo and NTTS 10 and 20 and ISD 40. Therefore the antiischemic activity of these drugs was not related to a decrease of myocardial oxygen consumption. In conclusion, in comparison with PL, NTTS 10, 20 and ISD 40 had antiischemic and antianginal activity at the fourth hour, while at the twelfth hour this activity was observed only after NTTS 10 and 20, without differences between the 2 doses.

Administration, Cutaneous↗

PubMed1991

[Transdermal nitroglycerin in stable effort angina. II. Administration of continuous high doses and alternate high-low doses. Absence of tolerance].

Aim of this study was to evaluate the efficacy of 2 different schedules of nitroglycerin (N), given by means of transdermal therapeutic system (TTS): continuous (20 mg patch at 8.00 am and at 8.00 pm NTTS/c) and high/low doses therapy (20 mg patch at 8.00 am and 10 mg at 8.00 pm NTTS/a), respectively. Eighteen volunteers, gave informed, written consent; male patients, aged 57 +/- 2 years, with stable effort angina pectoris, were randomly given, in double-blind condition, NTTS/c, NTTS/a or placebo (PL), each for 1 week period, according to a 3 x 3 latin square design. Bicycle exercise tests were performed on the first and on the last day of each period of the study, 12 hours after the last patch. NTTS/c and NTTS/a increased ischemic threshold and decreased the ischemic depression ST at maximal common work, compared to placebo, without differences between tests performed at 1 and 7 day. In conclusion, NTTS/a showed antiischemic activity after 7 days, so no tolerance was observed in those patients.

Administration, Cutaneous↗