Biomedical subjects

W L May

Publications and source records attributed to W L May.

At least 19 recordsLinked to original sources

PubMed2001

Effects of long-term cigarette smoking on the human locus coeruleus.

BACKGROUND: It has been hypothesized that cigarette smoking among subjects with major depression is a form of self-medication. To explore a possible biological basis for this hypothesis, noradrenergic proteins in the locus coeruleus (LC) were measured in long-term cigarette smokers and in nonsmokers. The LC was studied because elevated amounts of alpha2-adrenoceptors and tyrosine hydroxylase have been observed postmortem in the LCs of subjects with major depression or who commit suicide, and because long-term administration of antidepressant drugs to rats down-regulates these proteins in the LC. METHODS: Postmortem LCs were obtained from long-term cigarette smokers (n=7) and from nonsmokers (n = 9), all of whom lacked diagnoses of major depression. Amounts of tyrosine hydroxylase immunoreactivity and radioligand binding to the norepinephrine transporter, monoamine oxidase A, and alpha2-adrenoceptors were measured. RESULTS: Amounts of tyrosine hydroxylase immunoreactivity and radioligand binding to alpha2-adrenoceptors were significantly lower (approximately 60% and 40%, respectively) along the axis of the LCs of long-term smokers compared with nonsmokers. Smoking had no statistically significant effects on binding to monoamine oxidase A or to the norepinephrine transporter. CONCLUSION: This is the first demonstration that cigarette smoking affects noradrenergic proteins in the LC. The direction of these changes is opposite to that observed when comparing subjects who have major depression with normal controls and the same as that produced by long-term antidepressant treatment in animals. If the present observations reflect long-term effects of smoking on premortem noradrenergic biochemistry, smoking-induced changes in LC biochemistry may strengthen the smoking habit among subjects with major depression.

Antidepressive Agents↗

PubMed2001

The myth of transient hypertension: descriptor or disease process?

The objective of this study is to describe the incidence of transient hypertension and to evaluate if transient hypertension is associated with increased maternal or fetal morbidity as compared to other hypertensive disorders of pregnancy and normotensive controls. Data were collected from all deliveries at the University of Mississippi Medical Center from July 1, 1996 through January 1, 1997. Patients were grouped according to ACOG criteria for pregnancy induced hypertension. Specific maternal and fetal morbidities were compared among the groups and controls. There were 1489 deliveries during the study period. Nearly 30% of patients met the criteria for transient hypertension. There were no significant differences between patients with transient hypertension and controls in regard to maternal and fetal outcomes. Transient hypertension occurs more often than expected, however, it appears to be of limited clinical significance.

Adult↗

PubMed2001

Change in platelet count predicts eventual maternal outcome with syndrome of hemolysis, elevated liver enzymes and low platelet count.

OBJECTIVE: To profile the rates of change for platelets and lactate dehydrogenase (LDH) in patients with the syndrome of hemolysis, elevated liver enzymes and low platelet count (HELLP) to reflect and possibly predict disease severity. METHODS: Serial determinations of the platelet count and serum LDH were analyzed retrospectively for 545 patients with HELLP syndrome and 94 severely pre-eclamptic patients. A repeated measures (mixed model) analysis of variance (ANOVA) was utilized to estimate the rates of change for LDH and platelets in each group. RESULTS: Patients who developed class 1 or 2 HELLP syndrome exhibited a rapid deterioration in platelet count of 45-50,000/microl per day compared to 30,000/microl per day for class 3 and non-HELLP severe pre-eclampsia. For LDH, values increased at a rate of approximately 1400 IU/l per day, 600 IU/l per day, 300 IU/l per day and 200 IU/l per day for patients with classes 1, 2 and 3 and for non-HELLP severe pre-eclampsia, respectively. CONCLUSION: The rate of change of platelets and LDH appeared to correlate well with eventual syndrome severity and this can be used to enhance patient assessment beyond the value of a single test for either laboratory parameter.

Adult↗

PubMed2001

Physicians' reliance on specialists, therapists, and vendors when prescribing therapies and durable medical equipment for children with special health care needs.

OBJECTIVES: Physicians who care for children with special (health care) needs (CWSN) often must prescribe therapies and/or specialized, durable medical equipment (DME). Given this responsibility and the increasing scrutiny of prescribing practices by various oversight agencies, understanding the extent to which pediatricians rely on their own expertise when prescribing therapies and DME is an important area of research. METHODS: As part of an ongoing investigation of physician preparedness for and practice in prescribing therapies, DME, or procedures for CWSN, we mailed surveys to practicing pediatricians in each of 2 states-Ohio and Mississippi-and to a senior resident at all identified pediatric residency-training programs. The surveys polled recipients as to who they would rely on themselves-specialists, therapists or vendors-to make prescription decisions for a variety of therapies and DME of increasing complexity. We report results as proportions of returned and completed questionnaires. Comparisons among the 3 groups (pediatricians from Ohio and Mississippi and residents) were made with the use of chi(2) analysis. RESULTS: For some categories of therapy and DME, physicians and residents reported that they would take an active role in prescription decisions, and their reliance on specialty consultation increased appropriately with the increasing complexity of the device or therapy. However, respondents generally seemed to share responsibility rather than rely on themselves as sole decision makers for most categories; fewer than one fourth took sole responsibility. Reliance on nonphysician health care providers was evident for all categories; in some cases, up to half of the respondents would allow therapists to take over these decisions, and a small but significant percentage of physicians would entrust DME prescription decisions to vendors alone. CONCLUSIONS: Our findings indicate that many practicing pediatricians and those in training may be unwilling to assume sole responsibility in prescribing and managing therapies and DME for CWSN. Although the number who would rely on consultation with specialists is somewhat reassuring, we found that a significant percentage would turn to nonphysician health care providers and even vendors to make these decisions in some cases, raising liability implications, conflict-of-interest issues, and quality-of-care issues. To protect themselves and their patients from fraud and inappropriate prescriptions and medical management, pediatricians must become increasingly conscientious about complying with American Medical Association guidelines and federal and state laws regarding initiation and supervision of therapies and DME. We offer some recommendations that may help to address this problem.

Child↗

PubMed2000

Cardiopulmonary morbidity as a complication of severe preeclampsia HELLP syndrome.

OBJECTIVE: To profile the types and frequencies of cardiopulmonary morbidity encountered in patients with severe preeclampsia with or without hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome). STUDY DESIGN: We initiated a retrospective study of 979 patients with severe preeclampsia with and without HELLP syndrome. Types of cardiopulmonary morbidity were analyzed among the three classes of HELLP syndrome and severe preeclampsia without HELLP syndrome. RESULTS: Cardiopulmonary morbidity occurred in 7.6% of study patients. As a group, patients with cardiopulmonary complications were more likely to have cesareans (11% vs 6%, p = 0.019) earlier in gestation (1366 +/- 700 gm birth weight versus 1734 +/- 892 gm birth weight, p = 0.021), with higher peak postpartum blood pressures (< 0.001) and with more abnormal laboratory values indicative of multisystem disease, compared with patients without this complication. Patients with cardiopulmonary complications required almost twice as long to achieve diuresis as comparison patients (22 +/- 23 hours versus 12 +/- 11 hours, p < 0.001). CONCLUSION: The probability of cardiopulmonary complications increases significantly when patients develop class 1 HELLP syndrome. Of all cardiopulmonary complications, acute lung injury/acute respiratory distress syndrome is most specific to class 1 HELLP syndrome. Transient renal dysfunction is closely related to cardiopulmonary morbidity.

Cesarean Section↗

PubMed2000

A prospective, randomized, controlled trial of high and low maintenance doses of magnesium sulfate for acute tocolysis.

OBJECTIVE: This study was undertaken to compare a high-dose protocol for magnesium sulfate tocolytic therapy with a low-dose regimen with respect to time needed to achieve tocolysis. STUDY DESIGN: Patients between 24 and 34 weeks' gestation with preterm labor were included. Patients with ruptured membranes or nonreassuring fetal assessments were excluded. Gravid women received a 4-g loading dose of magnesium sulfate and were prospectively randomly assigned to receive a maintenance dose of 2 or 5 g/h. RESULTS: The median times to tocolysis were 120 minutes (semi-interquartile range, 30 minutes) in the low-dose group and 90 minutes (semi-interquartile range, 28 minutes) in the high-dose group (P <.001). CONCLUSION: Patients treated with a higher maintenance dose of magnesium sulfate had a higher frequency of side effects; however, tocolysis was achieved more rapidly and they required shorter admissions to the labor and delivery unit without increased maternal or neonatal morbidity.

Adult↗

PubMed2000

Training of pediatricians in care of physical disabilities in children with special health needs: results of a two-state survey of practicing pediatricians and national resident training programs.

OBJECTIVE: One goal of the American Academy of Pediatrics' Future of Pediatric Education II Project is to establish guidelines in training physicians to care for children with special health care needs (CWSN). Assessment of current practices in prescribing therapies and devices is necessary to meet this goal. Although much has been written about CWSN, there is a paucity of literature describing pediatricians' preparedness in prescribing such therapies and devices to children with physical disabilities. In an effort to assess physician preparedness, we surveyed pediatric residents nationwide and practicing pediatricians from 2 states, 1 urban and 1 rural. METHODS. A questionnaire aimed at identifying areas of concern regarding preparedness of physicians in practice and in training was prepared and mailed to prospective participants in Ohio and Mississippi. After follow-up mailings to nonresponders, approximately 59% responded. Summary statistics were reported as proportions with 95% confidence intervals. RESULTS: Among those polled, >70% reported no training in prescribing certain durable medical equipment and over 50% reported no training in prescribing certain therapies. In addition, at least 20% reported no training in treating some of the more common childhood physical disabilities. Nearly three fourths of the respondents indicated that they did not believe that they were adequately prepared to take an active role in prescribing therapies and durable medical equipment. Fewer respondents believed that they should be the sole providers of these therapies and durable medical equipment. CONCLUSIONS: The results of the survey indicate a lack of specific training and physician confidence in prescribing therapies and devices to CWSN, establishing the necessity of expanding training programs to better ensure quality health care for special needs children. Although additional ongoing research is necessary to fully evaluate the preparedness of physicians in caring for CWSN, this survey does help to identify areas of physician training that require improvement to provide quality health care for CWSN.

Child↗

PubMed2000

Increasing maternal weight: a risk factor for preeclampsia/eclampsia but apparently not for HELLP syndrome.

BACKGROUND: Maternal obesity is a risk factor for severe preeclampsia. We sought to ascertain whether a similar relationship exists between maternal weight and HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) as an atypical form of severe preeclampsia. METHODS: In this retrospective investigation, 434 patients with HELLP syndrome were assigned to one of four study groups according to maternal weight and were analyzed in relation to selected maternal and perinatal data reflective of disease severity. RESULTS: We found no significant associations between maternal weight and parameters of HELLP syndrome severity, race, delivery mode, gestational age, or perinatal outcome. Significantly associated with increasing maternal weight were maternal age, parity, admission mean arterial pressure, peak peripartum systolic blood pressures, concurrent essential hypertension, and the interval between admission and delivery. Inversely associated were eclampsia and the interval between delivery and discharge. CONCLUSIONS: Severity and complications attendant with HELLP syndrome appear unrelated to maternal weight. Paradoxically, eclampsia occurs most commonly in the lighter gravida with HELLP syndrome.

Adult↗

PubMed2000

Leukocytosis is proportional to HELLP syndrome severity: evidence for an inflammatory form of preeclampsia.

BACKGROUND: We investigated the possibility that HELLP syndrome is in part a systemic inflammatory response. METHODS: We evaluated total white blood cell (WBC) counts of all patients with severe preeclampsia with and without HELLP syndrome admitted to our hospital between 1995 and 1997. Patients were grouped by diagnosis and timing of platelet nadir. Analysis of variance and regression analysis were used for data analysis. RESULTS: Of 177 patients, 91 had HELLP syndrome, and 86 had severe preeclampsia alone. The WBC counts were significantly higher in patients with HELLP syndrome (12.5 +/- .442 x 10(9)/L) than in patients with severe preeclampsia (10.3 +/- .288 x 10(9)/L). Regression analysis showed that platelet counts varied inversely with WBC counts. Also, patients with class I HELLP syndrome had significantly higher WBC counts than patients with other classes of HELLP syndrome. CONCLUSION: The finding of an association between increasing leukocytosis and worsening thrombocytopenia early in the course of HELLP syndrome supports the hypothesis that it may represent an inflammatory process.

Analysis of Variance↗

PubMed1999

The spectrum of severe preeclampsia: comparative analysis by HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome classification.

OBJECTIVE: This study was undertaken to explore the spectrum of maternal disease with a triple classification system of HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome and compare these classes with severe preeclampsia without HELLP syndrome. STUDY DESIGN: In this retrospective analytic study the pregnancies of 777 patients with class 1, 2, or 3 HELLP syndrome were compared and contrasted with those of 193 women with severe preeclampsia but without HELLP syndrome. RESULTS: Eclampsia, epigastric pain, nausea and vomiting, significant proteinuria, major maternal morbidity, and stillbirth increased as HELLP syndrome worsened from class 3 to class 1. In contrast, headache and diastolic hypertension were more common among the significantly heavier patients with severe preeclampsia without HELLP syndrome. Approximately half of pregnancies complicated by class 1 HELLP syndrome exhibited significant maternal morbidity, compared with only 11% of those complicated by severe preeclampsia without HELLP syndrome. Although a significant trend was apparent in increasing levels of lactate dehydrogenase, aspartate aminotransferase, and uric acid as HELLP syndrome worsened, there was considerable variation within groups. CONCLUSION: Laboratory and clinical indices of disease severity in patients with severe preeclampsia or eclampsia generally were highest with class 1 HELLP syndrome and were lowest when HELLP syndrome was absent. Class 3 HELLP syndrome is considered a clinically significant transitional group.

Aspartate Aminotransferases↗

PubMed1999

Early risk assessment of severe preeclampsia: admission battery of symptoms and laboratory tests to predict likelihood of subsequent significant maternal morbidity.

OBJECTIVE: This study was undertaken to investigate the utility of an admission battery of findings and laboratory data in the discrimination of patients with severe preeclampsia with or without HELLP (hemolysis, elevated liver enzyme levels, and low platelet count) syndrome at high risk for development of significant maternal morbidity. STUDY DESIGN: The clinical and laboratory findings at hospital admission for 970 patients with severe preeclampsia with or without HELLP syndrome were studied retrospectively to develop parameters associated with low, moderate, and high risks for the subsequent development of significant maternal morbidity involving the hematologic and coagulation, cardiopulmonary, and hepatorenal systems. RESULTS: Nausea and vomiting and epigastric pain are independent risk factors for complicated severe preeclampsia. Results of a panel of tests with values including lactate dehydrogenase level >1400 IU/L, aspartate aminotransferase level >150 IU/L, alanine aminotransferase level >100 IU/L, uric acid level >7.8 mg/dL, serum creatinine level >1.0 mg/dL, and 4+ urinary protein by dipstick can be used to discriminate the patient at high risk for significant maternal morbidity. Concentrations of lactate dehydrogenase, aspartate aminotransferase, and uric acid above these cut points have the strongest predictive value and are risk additive with worsening thrombocytopenia. CONCLUSION: The presence of nausea and vomiting, epigastric pain, or both in association with admission laboratory values that are in excess of the cutoffs for lactate dehydrogenase, aspartate aminotransferase, and uric acid concentrations or for all 6 tests is predictive of high risk of morbidity for the patient with severe preeclampsia. These factors are independent of and additive with the rising maternal risk associated with decreasing platelet count.

Alanine Transaminase↗

PubMed1999

Second-trimester uterine evacuation: A comparison of intra-amniotic (15S)-15-methyl-prostaglandin F2alpha and intravaginal misoprostol.

OBJECTIVE: Our purpose was to compare the efficacy, safety, and adverse effects of intra-amniotically administered (15S)-15-methyl-prostaglandin F(2alpha) and intravaginally administered misoprostol for second-trimester uterine evacuation. STUDY DESIGN: Fifty-one patients were randomly assigned to receive either a single 2.5-mg intra-amniotic injection of (15S)-15-methyl-prostaglandin F(2)(alpha) (n = 26) or two 200-microg intravaginal doses of misoprostol (n = 25) at 12-hour intervals. The primary outcome measured was evacuation of the uterus within 24 hours. RESULTS: The mean time from initiation of termination to uterine evacuation was less in the prostaglandin group than in the misoprostol group (17.5 +/- 8.6 hours vs 22.3 +/- 12.5 hours), but this was not statistically significant (P >.05). The rate of successful fetal evacuation at 24 hours was significantly higher in the prostaglandin group than in the misoprostol group (88% vs 60%, P =.02). The complete-abortion rate and the incidence of adverse effects were similar in both groups. CONCLUSION: The use of an intra-amniotic injection of (15S)-15-methyl-prostaglandin F(2alpha) for midtrimester pregnancy termination is safe and is associated with a greater number of successful uterine evacuations within 24 hours, without an increase in adverse effects, than intravaginal administration of misoprostol.

Abortifacient Agents, Nonsteroidal↗

PubMed1999

Oral nicardipine versus intravenous magnesium sulfate for the treatment of preterm labor.

OBJECTIVE: The aim of this study was to compare the efficacy and safety of oral nicardipine in acute therapy for preterm labor with those of parenteral magnesium sulfate. STUDY DESIGN: Patients between 24 and 34 weeks' gestation with documented preterm labor were randomly assigned to receive oral nicardipine (n = 57) or intravenous magnesium sulfate (n = 65) as initial tocolytic therapy. Patients in the nicardipine group received a 40-mg loading dose and then 20 mg every 2 hours as needed to stop contractions (total 80 mg). Patients in the magnesium sulfate group received a 6-g bolus followed by 2 to 4 g/h to provide uterine quiescence. Patients could be switched to another tocolytic regimen if they continued to have contractions after 6 hours of therapy. The main outcome variables examined were time to uterine quiescence, time gained in utero, recurrence of preterm labor, failure of tocolysis, and pertinent maternal and neonatal outcomes. RESULTS: There were no significant differences in maternal demographic characteristics between the groups. Among patients who responded with uterine quiescence within 6 hours, there was a significant decrease in the time to uterine quiescence in the nicardipine group (P <.01). Patients in the magnesium sulfate group were more likely to have recurrence of preterm labor necessitating further tocolytic attempts (P =.048). The patients in the magnesium sulfate group had more adverse side effects, mainly nausea and vomiting (P =.004). There were no differences in birth weight, estimated gestational age at delivery, or neonatal complications between the 2 groups. CONCLUSIONS: Oral nicardipine is an effective, safe, and well-tolerated tocolytic agent. In this prospective clinical trial patients randomly assigned to receive oral nicardipine had arrest of preterm labor more rapidly than did those randomly assigned to receive parenteral magnesium sulfate. Patients who received magnesium sulfate were more likely to have adverse medication effects and recurrent preterm labor.

Administration, Oral↗

PubMed1999

Preeclampsia-associated hepatic hemorrhage and rupture: mode of management related to maternal and perinatal outcome.

This article is a critical review of the obstetric literature concerning preeclampsia-associated hepatic hemorrhage to develop guidelines conducive to optimal maternal and perinatal outcomes. An English literature search was performed for reports of hepatic hemorrhage or hepatic rupture in pregnancy during 1960 to 1997. Data were analyzed by Statmost packages using ANOVA, Chi-square, and Fisher's exact tests. One hundred forty-one patients with hepatic rupture/hemorrhage were reported. The three most common presenting findings were epigastric pain, hypertension, and shock. With rare exception, patients had evidence of preeclampsia. Diagnosis was elusive and most frequently accomplished at laparotomy. When utilized, ultrasound and computed tomography (CT) were helpful diagnostic modalities. Maternal survival was highest in the arterial embolization treatment group. Maternal and perinatal survival improved considerably during the study interval. Route of delivery did not seem to impact survival rates. It was concluded that the application of ultrasound and CT for diagnosis and the use of hepatic artery embolization for treatment of hepatic hemorrhage/rupture seem to be beneficial management options for this rare event.

Antibodies, Monoclonal↗

PubMed1998

Individually determined postpartum magnesium sulfate therapy with clinical parameters to safely and cost-effectively shorten treatment for pre-eclampsia.

OBJECTIVE: The purpose of this study was to investigate the safety of treating pre-eclampsia with magnesium sulfate, with clinical determinants used for drug discontinuation. STUDY DESIGN: One hundred sixty-eight patients were enrolled. After delivery, women with mild pre-eclampsia received a minimum of 6 hours of intravenous magnesium sulfate, whereas women with severe pre-eclampsia received a minimum of 12 hours. Magnesium sulfate was discontinued in the absence of clinical symptoms associated with spontaneous diuresis, minimal protein by urinary dipstick, and satisfaction of predetermined blood pressure criteria. RESULTS: Patients with mild pre-eclampsia required significantly less magnesium sulfate (mean 9.5 +/- 4.2 hours) than did those with severe pre-eclampsia alone (mean 16 +/- 5.9 hours); pre-eclampsia superimposed on chronic hypertension (mean 16 +/- 5.8 hours); or hemolysis, elevated liver enzyme, and low platelet count syndrome (mean 20 +/- 6.7 hours). With this protocol there was no eclampsia, and recovery room time was reduced by 50%. CONCLUSION: Individual determination of postpartum magnesium sulfate therapy for pre-eclampsia appears to be a safe approach that carries minimal risk of eclampsia.

Adolescent↗

PubMed1998

Cervical ripening: a randomized comparison between intravaginal misoprostol and an intracervical balloon catheter combined with intravaginal dinoprostone.

OBJECTIVES: Our purpose was to compare the efficacy of intravaginal misoprostol and intracervical Foley catheter/intravaginal dinoprostone for cervical ripening. STUDY DESIGN: Patients admitted for induction of labor were randomized to receive intravaginal misoprostol 25 microg every 4 hours or intracervical Foley catheter/intravaginal dinoprostone 4 mg every 4 hours. Patients not entering active labor and having ruptured membranes or arrest of dilatation received intravenous oxytocin. RESULTS: Sixty-five patients received Foley catheter/dinoprostone gel and 62 patients received misoprostol. The mean time until cervical ripening was less in the catheter/gel group (7.5 +/- 3.4 vs 12.0 +/- 5.9 hours, p < 0.01). The mean time until vaginal delivery was less in the catheter/gel group (17.4 +/- 6.9 vs 21.2 +/- 7.5 hours, p = 0.004). Among vaginal deliveries, more patients in the catheter/gel group delivered within 24 hours (90% vs 69%, p = 0.013). CONCLUSIONS: Intracervical Foley catheter/intravaginal dinoprostone was associated with more rapid cervical ripening, shorter induction to vaginal delivery interval, and greater number of vaginal deliveries within 24 hours.

Administration, Intravaginal↗

PubMed1998

Hypothesis testing and confidence interval construction in 2 x 2 tables of correlated proportions.

The 2 x 2 table is an invaluable tool for displaying bivariate binary data. It is easy to find examples of correlated binary response in biopharmaceutical experiments and clinical research and analysis of these data is a current research topic. The most common hypothesis tested for 2 x 2 tables of correlated proportions is that of homogeneity of the marginal proportions or, equivalently, the hypothesis of table symmetry. The 2 x 2 table of correlated proportions is rich with information and we present a survey of some of the analyses relevant for these data. Using asymptotic theory, we develop estimators of relevant parameters and associated test statistics that are of interest. We discuss interval estimation using arguments proposed by Quesenberry and Hurst (1) and Goodman (2). These interval estimators do not rely on estimation of the covariance matrix and are not necessarily equivalent to those obtained using modified chi-square statistics.

Analysis of Variance↗

PubMed1998

On the singularity of the covariance matrix for estimates of multinomial proportions.

It is well known that the covariance matrix for the multinomial distribution is singular and, therefore, does not have a unique inverse. If, however, any row and corresponding column are removed, the reduced matrix is nonsingular and the unique inverse has a closed form. We elucidate some of the properties of the multinomial covariance matrix and its reduced forms. We state and prove a theorem that gives insight into the singularity and its removal. Based on these results, we establish that the covariance matrix for the multinomial distribution is positive semidefinite and that the reduced matrix is positive definite. In addition, we show that the determinant of the reduced matrix is invariant to the particular row and column that are removed. Goodness-of-fit statistics, including Pearson's chi-square, and justification of the degrees of freedom follow from the multivariate central limit theorem once the singularity is removed.

Analysis of Variance↗