Biomedical subjects

Anne Chao

Publications and source records attributed to Anne Chao.

9 recordsLinked to original sources

PubMed2006

Pain relief by applying transcutaneous electrical nerve stimulation (TENS) on acupuncture points during the first stage of labor: a randomized double-blind placebo-controlled trial.

Transcutaneous electrical nerve stimulation (TENS) is one of the non-pharmacological means of pain relief for labor and delivery. We aimed to investigate the efficacy and safety of TENS on specific acupuncture points for reducing pain in the first stage of labor. In this double-blind, placebo-controlled trial, we randomly assigned healthy full-term parturients in active phase of first-stage labor to either TENS on four acupuncture points (Hegu [Li 4] and Sanyinjiao [Sp 6]) (n=52) or the TENS placebo (n=53). Visual analogue scale (VAS) was used to assess pain before and 30 and 60 min after treatment. The primary outcome was the rate of VAS score decrease 3 in each group. A questionnaire was given at 24h post-partum to evaluate the satisfaction of pain relieving method and the willingness to have the same treatment again. Mode of delivery and neonatal effect were measured as secondary outcome. One hundred women were eligible for analysis. TENS group experienced VAS score reduction 3 significantly more common than the TENS placebo group (31/50 [62%] vs 7/50 [14%], P<0.001). Willingness of using the same analgesic method for a future childbirth was also significantly different (TENS: 48/50 [96%] vs TENS placebo: 33/50 [66%], P<0.001). Operative delivery was increased in the TENS group (12/50 [24%] vs 4/50 [8%], P=0.05), but the neonatal outcomes were not different. The application of TENS on specific acupuncture points could be a non-invasive adjunct for pain relief in the first stage of labor.

Acupuncture Analgesia↗

PubMed2006

Analgesic use in intubated patients during acute resuscitation.

BACKGROUND: Pain relief can often be overlooked during a busy trauma resuscitation, especially in patients who are intubated. We sought to investigate qualitative and quantitative aspects of analgesic use in intubated patients during the acute phase of resuscitation. METHODS: We evaluated a retrospective cohort of consecutive adult patients who were intubated during the acute trauma resuscitation (first 6 hours) from January 2001 to May 2002 at a Level I trauma center in the United States. Patient demographics, injuries, vital signs, medications, trauma bay procedures, and disposition status were analyzed. Analgesia was recorded as the type of analgesic, route of administration, elapsed time to receive the first analgesic, total dosage, and time intervals between two successive doses. Fisher's exact test, chi test, and ANOVA were used to analyze data. RESULTS: A total of 120 patients were included. Sixty-one (51%) patients received analgesia during their stay in the emergency department. Using logistic regression analysis, patients who more likely to receive analgesia were those who did not require immediate surgical operation and were transferred to the intensive care unit (odds ratio [OR]=3.91; 95% CI=1.75-8.76) and those who were admitted during the hours of 8 am to 6 pm (OR=3.17; CI=1.40-7.16). Among those patients receiving analgesia, 30 (25%) patients received analgesia within 30 minutes upon arrival. The mean time of receiving the first analgesia dose was 57 minutes. The average morphine equivalent dose given to the patients was 15.7 mg. The most frequently given single dose was 100 mug of intravenous fentanyl. Most of the analgesics (37%) were given between 30 to 60 minutes apart. CONCLUSION: Our findings suggest that patients who are intubated during the acute resuscitation probably receive inadequate analgesia. The inadequacy appears to be in the timing and repetition of administration, rather than the dose. Patients who were transferred early to the intensive care unit were more likely to receive analgesics.

Acute Disease↗

PubMed2006

Abundance-based similarity indices and their estimation when there are unseen species in samples.

A wide variety of similarity indices for comparing two assemblages based on species incidence (i.e., presence/absence) data have been proposed in the literature. These indices are generally based on three simple incidence counts: the number of species shared by two assemblages and the number of species unique to each of them. We provide a new probabilistic derivation for any incidence-based index that is symmetric (i.e., the index is not affected by the identity ordering of the two assemblages) and homogeneous (i.e., the index is unchanged if all counts are multiplied by a constant). The probabilistic approach is further extended to formulate abundance-based indices. Thus any symmetric and homogeneous incidence index can be easily modified to an abundance-type version. Applying the Laplace approximation formulas, we propose estimators that adjust for the effect of unseen shared species on our abundance-based indices. Simulation results show that the adjusted estimators significantly reduce the biases of the corresponding unadjusted ones when a substantial fraction of species is missing from samples. Data on successional vegetation in six tropical forests are used for illustration. Advantages and disadvantages of some commonly applied indices are briefly discussed.

Biodiversity↗

PubMed2005

Modeling animals' behavioral response by Markov chain models for capture-recapture experiments.

A bivariate Markov chain approach that includes both enduring (long-term) and ephemeral (short-term) behavioral effects in models for capture-recapture experiments is proposed. The capture history of each animal is modeled as a Markov chain with a bivariate state space with states determined by the capture status (capture/noncapture) and marking status (marked/unmarked). In this framework, a conditional-likelihood method is used to estimate the population size and the transition probabilities. The classical behavioral model that assumes only an enduring behavioral effect is included as a special case of the bivariate Markovian model. Another special case that assumes only an ephemeral behavioral effect reduces to a univariate Markov chain based on capture/noncapture status. The model with the ephemeral behavioral effect is extended to incorporate time effects; in this model, in contrast to extensions of the classical behavioral model, all parameters are identifiable. A data set is analyzed to illustrate the use of the Markovian models in interpreting animals' behavioral response. Simulation results are reported to examine the performance of the estimators.

Animals↗

PubMed2005

Acute cardiovascular collapse after pericardial drainage in a patient with aortic dissection.

Proximal aortic dissection is frequently associated with cardiac tamponade. The treatment sometimes is difficult. We present a 69-year-old female patient who after repeated episodes of syncope received an open drainage of pericardial effusion that ended in a fatal outcome. She was also known to have mural thrombi in the aorta. However, preanesthetic trransesophageal echocardiography revealed besides pericardial effusion, also dilatation of aortic root which compressed both atria. She developed sudden cardiovascular collapse following drainage of pericardial effusion to which she succumbed in spite of vigorous resuscitation. We suggest that the patients with cardiac tamponade complicated by aortic dissection must receive direct aortic repair together with intraoperative pericardial drainage. Selective or single pericardiocentesis should better be avoided.

Acute Disease↗

PubMed2004

EST analysis of mouse retina and RPE/choroid cDNA libraries.

PURPOSE: cDNA libraries from the mouse retina have recently been reported, but no well characterized library from the retinal pigment epithelium (RPE) or choroid of the mouse has yet appeared in the literature. To complement these libraries and to provide the first mouse RPE/choroid library, we used freshly dissected tissue from adult C57BL/6J mice to construct new retina and RPE/choroid libraries. METHODS: Eyes from 100 six to eight week old C57BL/6J mice were dissected in groups of 10. The whole retina and RPE/choroid were isolated individually and then homogenized before RNA isolation. Over 5000 clones each were sequenced from the unamplified and un-normalized retina and RPE/choroid libraries. All sequences were analyzed using GRIST (GRouping and Identification of Sequence Tags), a bioinformatics program for gene identification and clustering. RESULTS: The RPE/choroid library contained 3145 clusters with 76% of the clusters representing single clones. Nearly 87% of the clusters corresponded to named genes in GenBank, and 8% of the RPE clusters remain unidentified. The retina library contained 3190 clusters of which 78% represented only one clone. Approximately 85% of the clusters matched sequences in GenBank, and 9% of the clusters remain unidentified. The clones most abundant in each library were all well-known sequences and both libraries contained a number of tissue specific or tissue-enhanced genes. CONCLUSIONS: These new libraries should provide a valuable resource for gene discovery and cDNAs for expression analysis and functional studies.

Animals↗

PubMed2004

Abdominal compartment syndrome secondary to ovarian mucinous cystadenoma.

BACKGROUND: Abdominal compartment syndrome secondary to a very large benign ovarian tumor has been rarely reported in gynecology. With the increase of intraabdominal pressure in abdominal compartment syndrome, all major organ systems are adversely affected, causing a potentially fatal condition. CASE: A 43-year-old woman presenting with a tensely distended abdomen developed hypotension, difficulty in ventilation, and anuria. An ovarian tumor complicated by abdominal compartment syndrome was diagnosed, along with hemodynamic decompensation. Prompt resuscitation with immediate surgical removal of the tumor reversed the life-threatening situation. CONCLUSION: Timely aggressive resuscitation, prompt surgical decompression, and intensive perioperative hemodynamic management are required for patients with ovarian mucinous cystadenoma complicated by abdominal compartment syndrome.

Abdomen↗

PubMed2003

Analysis and results of prolonged resuscitation in cardiac arrest patients rescued by extracorporeal membrane oxygenation.

OBJECTIVES: We conducted this study to determine the result of prolonged cardiopulmonary resuscitation (CPR) with extracorporeal membrane oxygenation (ECMO) and the predictive factors for hospital discharge and ECMO weaning. BACKGROUND: Prolonged CPR carries considerable associated mortality and morbidity. As yet, ECMO for prolonged CPR has no definite results. Only small groups of patients and no detailed analysis have been reported. METHODS: Candidates for ECMO resuscitation were patients in cardiac arrest receiving CPR >10 min without return of spontaneous circulation and no absolute contraindication. Venoarterial ECMO was set up during CPR. We reviewed the data of 57 prolonged CPR patients who received ECMO during CPR over a six-year period. RESULTS: The mean duration of CPR was 47.6 +/- 13.4 min and that of ECMO was 96.1 +/- 87.9 h. The rate of weaning was 66.7%, and the survival rate was 31.6%. Multiple-organ failure was the major reason for mortality, despite successful weaning. Among survivors, long-term follow-up revealed 88.9% survival, and only 5.6% had a severe neurologic deficit. The results indicate that a shorter CPR duration, postcardiotomy arrest, myocardial indicators, a hepatic indicator, and lactic acid are significantly correlated with both weaning and survival, whereas late damage (level on the third or seventh day of reperfusion) rather than initial damage (level on the first day) was more predictive of the results. CONCLUSIONS: Prolonged CPR rescue by ECMO provides an acceptable survival rate and outcome in survivors. Our results of the selected cases encourage further investigations of the wider application of ECMO in CPR.

Adult↗

PubMed2002

Estimating the number of species in a stochastic abundance model.

Consider a stochastic abundance model in which the species arrive in the sample according to independent Poisson processes, where the abundance parameters of the processes follow a gamma distribution. We propose a new estimator of the number of species for this model. The estimator takes the form of the number of duplicated species (i.e., species represented by two or more individuals) divided by an estimated duplication fraction. The duplication fraction is estimated from all frequencies including singleton information. The new estimator is closely related to the sample coverage estimator presented by Chao and Lee (1992, Journal of the American Statistical Association 87, 210-217). We illustrate the procedure using the Malayan butterfly data discussed by Fisher, Corbet, and Williams (1943, Journal of Animal Ecology 12, 42-58) and a 1989 Christmas Bird Count dataset collected in Florida, U.S.A. Simulation studies show that this estimator compares well with maximum likelihood estimators (i.e., empirical Bayes estimators from the Bayesian viewpoint) for which an iterative numerical procedure is needed and may be infeasible.

Animals↗