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C Houlihan

Publications and source records attributed to C Houlihan.

13 recordsLinked to original sources
PubMed2000

Measurement of iohexol by capillary electrophoresis: minimizing practical problems encountered.

Iohexol is a non-ionic contrast agent, which has been widely described in recent literature as an accurate marker for the measurement of glomerular filtration rate (GFR). Our aim was to establish a capillary electrophoresis assay, based on a previously described method, that had adequate reproducibility to be used as part of a clinical trial. In this paper, we examine the practical aspects, pitfalls and steps we took to achieve a precise and reproducible assay. To minimize laboratory variation, we examined properties such as the use of an internal standard in a capillary electrophoresis separation, alternative deproteinization methods for serum, the most suitable matrix for the dilution of standards and the implementation of suitable quality control material to ensure that run-to-run variability was minimized. The optimized capillary electrophoretic assay of iohexol was found to be robust, with over 860 runs from the one capillary over a 9-month period. Excluding capital costs of the instrument, the consumable cost of the assay is less than A$0.25 per test, with a run time of 5.25 min and a coefficient of variation (CV) of 4.3% at 80 mg/L. The GFR, calculated from the plasma clearance, had a reproducibility of 5.47%.

Acetonitriles↗
PubMed1999

A comparison of the plasma disappearance of iohexol and 99mTc-DTPA for the measurement of glomerular filtration rate (GFR) in diabetes.

BACKGROUND: Changes in glomerular filtration rate (GFR) provide a valuable indicator of the progression of diabetic nephropathy. GFR is most commonly measured by the plasma clearance of radioisotopes, however, use of iohexol, a non-ionic radiocontrast medium, is a recently described alternative and has shown good agreement with inulin clearance. A one-compartment model is used for calculating GFR in most Australian centres but a two-compartment model is more accurate. AIMS: To set up a non-radioisotopic method for assessment of GFR using iohexol, and to compare this with the currently used 99mTc-diethylene-triamine-penta-acetic acid (DTPA) method. Secondly, to compare GFR results using an unmodified one-compartment model with a one-compartment model subjected to the Brochner-Mortensen modification. METHODS: Twenty-one patients with diabetes had assessment of GFR with simultaneous measurements of 99mTc-DTPA and iohexol plasma clearance. Plasma clearance was determined by the slope intercept method and then modified according to the Brochner-Mortensen equation. Plasma iohexol concentrations were determined by capillary electrophoresis. RESULTS: There was no significant difference between iohexol and 99mTc-DTPA derived GFR values, difference 4.3+/-7.7 mL/minute (mean+/-SD). This was despite 99mTc-DTPA protein binding demonstrated in the range of 5-10%. Comparison of GFR results using an unmodified one-compartment model with a Brochner-Mortensen corrected one-compartment model showed higher GFR values with the former, in the range of 20-30% for GFR values > 100 mL/minute. CONCLUSION: Iohexol provides an efficient alternative to radioisotopic methods for serial measurement of GFR in diabetic patients with hyperfiltration, incipient and overt nephropathy. A one-compartment model with its inherent overestimation of GFR should be replaced by the Brochner-Mortensen modified one-compartment model.

Adult↗
PubMed1996

The efficacy of individual computer heart rate indices in detecting acidemia at birth in growth-restricted fetuses.

OBJECTIVE: To determine the efficacy of individual fetal heart rate (FHR) indices, as determined by computer analysis of the FHR tracing, in detecting fetal acidemia at birth in growth-restricted fetuses. METHODS: The study population consisted of 38 growth-restricted fetuses at 26-37 weeks' gestation from pregnancies with abnormal uterine and/or umbilical artery Doppler velocimetry. The 1-hour FHR tracing was analyzed by computer within 4 hours of cesarean birth before the onset of labor. Umbilical artery cord blood was collected at birth, and pH was determined within 5 minutes of collection. RESULTS: On linear regression, the duration of episodes of low variation in minutes (r = -0.77, r2 = 0.59) and short-term (r = 0.72, r2 = 0.52) and long-term (r = 0.69, r2 = 0.47) variation in milliseconds were significantly related to umbilical artery pH at birth, and more so than the number of accelerations of ten (r = 0.57, r2 = 0.32) and 15 (r = 0.38, r2 = 0.14) beats per minute. There were significant differences in computer measurements of FHR accelerations and variation between the umbilical artery pH categories of acidemia (pH less than 7.20), preacidemia (7.20-7.25), and nonacidemia (greater than 7.25). Stepwise regression revealed that episodes of low variation best described the model for predicting umbilical artery pH at birth (P < .001), with no improvement provided by the addition of other computer-analyzed FHR characteristics. CONCLUSION: In this population of growth-restricted fetuses delivered by elective cesarean, the computer indices of duration of episodes of low variation and short-term and long-term variation were significantly associated with umbilical artery pH and predicted umbilical artery acidemia at birth.

Acidosis↗
PubMed1996

The significance of transvaginal ultrasonographic evaluation of the cervix in women treated with emergency cerclage.

OBJECTIVE: Our purpose was to determine whether perioperative transvaginal ultrasonographic evaluation of the incompetent cervix treated with emergency cerclage is predictive of pregnancy outcome. STUDY DESIGN: Twenty-nine women who underwent emergency cerclage at 16 to 26 weeks of gestation had transvaginal ultrasonographic evaluation of the cervix within 48 hours before and after surgery and at least three times thereafter until 28 weeks of gestation. The following measurements were obtained: (1) funnel width, (2) funnel length, (3) endocervical canal length, (4) the distance between the internal and external os, (5) upper cervix (length of closed endocervical canal above the cervical cerclage), (6) lower cervix (endocervical canal length below suture), and (7) cervical index (1+ Funnel length/Endocervical canal length). Values are reported as the median in millimeters, and statistical analysis was performed by use of the Mann-Whitney U test, Wilcoxon signed-rank test, Spearman rank correlation, 2 x 2 contingency tables, and multiple regression analysis with significance set at p < 0.05. RESULTS: Cerclage procedures resulted in significant improvement in postoperative median measurements of funnel width (15 vs 4.0 mm, p < 0.0001), funnel length (29 vs 3 mm, p < 0.0001), and endocervical canal length (2 vs 27 mm, p < 0.0001). There was a significant relationship between gestational age at delivery and the following measurements: preoperative funnel width (r = -0.51, p = 0.007), postoperative endocervical canal length (r = 0.39, p = 0.04), length of the lower cervix (r = 0.39, p = 0.038), and the cervical index (r = -0.39, p = 0.038). An upper cervical length < 10 mm was a good predictor of delivery before 36 weeks of gestation, sensitivity 85.7% (12/14), specificity 66.7% (10/15), positive predictive value 70.6% (12/17), negative predictive value 83% (10/12), and Fisher's exact p = 0.008. Postoperatively all patients had upper cervical lengths < 10 mm by 28 weeks of gestation. Preoperative digital assessments of cervical dilatation before surgery did not correlate with gestational age at birth (r = -0.031, p = 0.36). CONCLUSIONS: In cases of cervical incompetence treated with emergency cerclage, perioperative transvaginal ultrasonographic assessment of the cervix reveals that the procedure results in improved ultrasonographic status of the cervix and that the ultrasonographic cervical findings before and after surgery correlate with pregnancy outcome.

Adolescent↗
PubMed1996

Intrapartum management of multiple gestations.

The proper intrapartum management of multiple gestations continues to be debated in the obstetric community. Ultrasonography is key in this management, through its initial assessment of the fetuses in the labor and delivery suite, observations of the second twin after the first has delivered, and its role in external cephalic version. The proper route of delivery requires further investigation for each combination of twin presentations and estimated fetal weights. It is recommended that the nonvertex second twin that is greater than 24 weeks' gestational age and fewer than 1700 g estimated fetal weight should have an attempt made at ECV and, if unsuccessful, a cesarean section should be performed. In the nonvertex second twin weighing greater than 1700 g, ECV or assisted breech extraction is appropriate. It is believed that all triplet gestations should be delivered abdominally. The use of intravenous nitroglycerin for uterine relaxation in multiple gestations is still experimental but may prove to be useful in the abdominal delivery of the nonvertex fetus. Further research is required to elucidate the most critical issues associated with the labor and delivery management of multiple gestations.

Birth Weight↗
PubMed1995

Sonography and transfundal pressure in the evaluation of the cervix during pregnancy.

Ultrasonographic evaluation of the cervix in pregnancy has provided some insight into premature delivery and pregnancy wastage. Its use has led to the development of cervical length nomograms in uncomplicated singleton pregnancies and to the realization that varying degrees of cervical incompetence exist. In some instances the internal os has been observed to dilate and funnel in the early second trimester while in others these changes occur gradually into the third trimester. Transient cervical changes have been linked to premature delivery and extended ultrasonographic inspection is required for their detection. Although sonography may allow the identification of women who deliver prematurely, it has not demonstrated enough discriminatory power to recommend its routine use for this purpose. Pre- and postoperative inspection of the cervix in elective and emergency cerclage procedures may become influential in outpatient management. A method of functional evaluation of the cervix using transfundal pressure (TFP) has been introduced which may lead to earlier diagnosis of cervical incompetence. The significance of descent of the membranes in response to TFP and sonographic findings consistent with premature cervical changes have not been validated because of surgical intervention performed in response to these findings. Our review concludes that, although sonography of the cervix may be useful in selective cases, more information on the natural history of abnormal cervical sonographic findings and controlled randomized trials are needed before recommendations on surgical intervention can be made.

Cervix Uteri↗
PubMed1994

Acute promyelocytic leukemia in pregnancy: all-trans retinoic acid as a newer therapeutic option.

BACKGROUND: Acute promyelocytic leukemia is a unique subset of acute myelogenous leukemia, characterized by a neoplastic proliferation of promyelocytes and a prompt response to all-trans retinoic acid (tretinoin), which induces differentiation of immature leukemic promyelocytes into mature neutrophils. Because of the high incidence of disseminated intravascular coagulation (DIC) associated with acute promyelocytic leukemia and the danger of exacerbation of DIC with pregnancy, management of acute promyelocytic leukemia during pregnancy requires prompt and careful attention. CASE: A 29-year-old woman in her third trimester was diagnosed with acute promyelocytic leukemia and DIC. The infant was delivered by cesarean and the mother was successfully treated with tretinoin, inducing the leukemic promyelocytes to differentiate into mature granulocytes and possibly reversing the DIC. CONCLUSION: If the fetus can be delivered safely, tretinoin as a single agent is an option for the initial treatment of maternal acute promyelocytic leukemia because it does not suppress the bone marrow and may ameliorate DIC. Because of the danger of hyperleukocytosis, chemotherapy should be added initially if the white blood cell count is greater than 5000/microL. If the fetus cannot be delivered at a viable stage, conventional cytotoxic chemotherapy is the alternative option.

Adult↗
PubMed1994

A new method using vaginal ultrasound and transfundal pressure to evaluate the asymptomatic incompetent cervix.

OBJECTIVE: To evaluate the ability of ultrasound with transfundal pressure to detect the incompetent cervix in pregnant women at risk for this condition. METHODS: One hundred fifty pregnant women with no prior pregnancy losses were scanned transabdominally, and 31 asymptomatic pregnant women with a prior history of cervical incompetency or risk for this condition were scanned transvaginally. The control patients were scanned once between 16-24 weeks, and the patients at risk were studied 73 times between 8-25 weeks. After evaluating the cervix and its internal os, transfundal pressure was applied. Cervical cerclages were placed for cervical funneling and shortening in response to transfundal pressure or for a grossly incompetent cervix on ultrasound evaluation. RESULTS: Transfundal pressure elicited no changes in the internal cervical os of the 150 control patients, of whom 141 delivered at term, two miscarried at 22 and 23 weeks, and seven delivered prematurely (4.7%). Fourteen of the 31 pregnancies at risk for cervical incompetency revealed opening of the internal os or descent of the fetal membranes with transfundal pressure. Thirteen of these 14 pregnancies were treated with cerclage, with nine (64%) proceeding to term, three (21%) delivering prematurely, and two (14%) aborting. The one patient who did not receive a cerclage also aborted. In six cases, the cervix and its internal os appeared normal but the membranes protruded into the endocervical canal in response to transfundal pressure. CONCLUSION: Application of transfundal pressure during transvaginal ultrasound evaluation of the cervix and its internal os may assist in detecting the asymptomatic incompetent cervix.

Cervix Uteri↗
PubMed1991

Clinical and serologic features of herpes simplex virus infection in patients with AIDS.

We studied the natural history of herpes simplex virus (HSV) infection and its association with specific serum antibody in a sample of 68 HIV-infected patients with a first episode of Pneumocystis carinii pneumonia at San Francisco General Hospital in 1986. Seroprevalence was 66 and 77% for HSV-1 and HSV-2 antibody, respectively, by immunoblot assay. Twenty-seven patients had 45 HSV outbreaks diagnosed during 739 patient-months of follow-up. Median frequency of recurrence resulting in a medical visit was once every 6.5 months, and median duration of treated outbreak was 10 days. Fourteen of 48 evaluable patients seropositive for HSV-2 had no outbreak of HSV during a median follow-up of 7.5 months. Our data suggests that neither frequency nor severity of HSV were substantially increased in this group of patients, despite severe immunosuppression caused by HIV. However, validation of these results by a prospective study is required.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Puerperal psychosis mimicking eclampsia.

Puerperal psychosis occurs after delivery in 1-2/1,000 births. It usually presents after delivery, however, it also may present in the antepartum period. We report the third case which presented prior to delivery without a preceding history of maternal puerperal psychosis and the first which presented with catatonia and symptoms of eclampsia. Although uncommon, the first presentation of psychosis during pregnancy should be considered part of the differential diagnosis in pregnant patients presenting with altered mental status after organic causes are excluded.

Adult↗
PubMedDate not supplied

Effects of therapeutic amniocentesis on uterine and umbilical artery velocimetry in cases of severe symptomatic polyhydramnios.

The objective of this study was to determine the effects of removal of amniotic fluid in cases of symptomatic severe polyhydramnios on Doppler waveform indices of the uterine and umbilical arteries and flow velocities of the uterine arteries. Nine women underwent therapeutic amniocentesis during ten pregnancies for symptomatic polyhydramnios due to Beckwith-Wiedemann Syndrome (n = 1), esophageal atresia (n = 2), chorioangioma (n = 1), twin-twin transfusion syndrome (n = 3), a presumed autosomal recessive syndrome (n = 2), and an unbalanced double translocation (n = 1; partial dup 3q and partial del 9p syndrome). An average of 2.78 +/- 0.9 (range 1-4) 1 of fluid were removed at each procedure between the gestational ages of 18 and 34 weeks (mean of 28 weeks). The systolic/diastolic (S/D) ratio, pulsitility index (PI), and resistance index (RI) of the uterine and umbilical arteries were obtained before and after the procedure using color and pulsed Doppler. After angle correction, the peak systolic velocity (PSV) and mean velocity (MV) in centimeters/second (cm/s) of the uterine arteries were also determined. The presence or absence of a uterine artery waveform notch was determined. Dominant uterine arteries were defined as those with lower impedance indices or higher flow velocities. Statistical analysis was performed with the Wilcoxon signed-rank test. Significance was set at P < 0.05. There was a significant increase in the median value of the uterine artery MV (43.8 vs. 81.1 cm/s, P = 0.005) and PSV (74.2 vs. 125.5 cm/s, P = 0.007) after amniocentesis. The uterine S/D (3.0 vs. 1.84, P = 0.007), PI (1.12 vs. 0.68, P = 0.008), and RI (0.60 vs. 0.45, P = 0.005) impedance indices significantly decreased following amniocentesis. When uterine arteries were categorized as dominant vs. nondominant, there were greater improvements in impedance indices and flow velocities in the nondominant uterine arteries. There were three cases of unilateral and one case of bilateral early diastolic notches of the uterine artery waveforms which either resolved (n = 4) or improved (n = 1). There was no effect on the umbilical artery impedance indices. Therapeutic amniocentesis significantly improved uterine artery impedance indices and resulted in improved flow velocities, while there was no effect on umbilical artery waveform indices. The procedure resulted in the disappearance or improvement of the uterine waveform notch. Our findings suggest that in cases of severe polyhydramnios abnormal uterine artery velocimetry may not be due to lack of trophoblastic invasion of the spiral arteries but to increased intrauterine pressure secondary to polyhydramnios.

Amniocentesis↗
PubMedDate not supplied

Effects of narcotic and non-narcotic continuous epidural anesthesia on intrapartum fetal heart rate tracings as measured by computer analysis.

OBJECTIVE: To evaluate the effect of narcotic and non-narcotic continuous epidural anesthesia on intrapartum fetal heart rate (FHR) tracings as measured by computer analysis. METHODS: We studied 37 women with uncomplicated pregnancies at term with reactive FHR tracings. The women were randomized to receive epidural anesthesia with either bupivicaine with fentanyl or bupivicaine alone. One-hour FHR tracings were obtained before epidural anesthesia. Thirty minutes after the initial bolus of the epidural a repeat computer analysis of 60-minute FHR tracing was obtained. Median values are reported for FHR parameters with statistical analysis performed by the Mann-Whitney U and Wilcoxon signed rank tests where appropriate. A power calculation was performed using a power of 90% to determine a required sample size of 28 patients. Statistical significance was set at P < .05. RESULTS: In early first stage of labor, there was no significant difference in pre- and postepidural anesthesia FHR baseline, accelerations of 10 and 15 beats per minute, episodes of high and low variation, and short- and long-term variation when using either narcotic or non-narcotic anesthetic agents. CONCLUSIONS: Thus, the clinician can consider the use of narcotic as well as non-narcotic continuous epidural anesthesia in the dosages used in our study with its attendant advantages without fear of obscuring the fetal heart rate tracing.

Anesthesia, Epidural↗