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Biomedical subjects

C A Sullivan

Publications and source records attributed to C A Sullivan.

At least 19 recordsLinked to original sources
PubMed2004

Effects of the herbicide hexazinone on nutrient cycling in a low-pH blueberry soil.

The herbicide hexazinone was applied as the commercial formulation Velpar L at field-rate (FR) concentrations of FR (14.77 microg ai g(-1)), FRx5 (73.85 microg ai g(-1)), FRx10 (147.70 microg ai g(-1)), FRx50 (738.50 microg ai g(-1)), and FRx100 (1477.00 microg ai g(-1)) to acidic soil, pH 4.12, taken from a lowbush blueberry field. Hexazinone was tested for inhibitory effects on various transformations of the nitrogen cycle and soil respiration. Nitrogen fixation was unaffected by hexazinone levels up to FRx100 following a 4-week incubation period. Ammonification was initially inhibited by all levels of hexazinone, but after 4 weeks, ammonification in all treatment systems was equal to or greater than the control. Nitrification was more sensitive to hexazinone; however, application at a field-rate level caused no inhibition. Inhibitory effects were noted above FR after a 2-month endpoint analysis and above FRx5 after a 6-month endpoint analysis. Hexazinone concentrations up to and including FRx100 stimulated denitrification. Soil respiration was also stimulated over a 3-week period when applied at a level up to 100 times the recommended field rate. In general, it was found that when applied at the recommended field application rate, hexazinone does not adversely affect the nitrogen cycle or soil respiration in acidic lowbush blueberry soils.

Agriculture↗
PubMed2003

The sharing of water between society and ecosystems: from conflict to catchment-based co-management.

Human uses of freshwater resources are increasing rapidly as the world population rises. As this happens, less water is left to support aquatic and associated ecosystems. To minimize future human water shortages and undesirable environmental impacts, more equitable sharing of water resources between society and nature is required. This will require physical quantities and social values to be placed on both human and aquatic ecosystem requirements. Current water valuation systems are dominated by economic values and this paper illustrates new quantification and valuation methods that take more account of human well-being and environmental impacts. The key to the effective implementation of these more equitable water allocation methods is the use of catchment-based integrated water resources management. This holistic framework makes it possible for human and ecosystem water requirements and the interactions between them to be better understood. This knowledge provides the foundation for incorporating relevant social factors so that water policies and laws can be developed to make best use of limited water resources. Catchment-based co-management can therefore help to ensure more effective sharing of water between people and nature.

Conservation of Natural Resources↗
PubMed2001

Etiology and treatment of achalasia in the pediatric age group.

Achalasia in children bears many similarities to the disorder in adults, both in terms of clinical features and in terms of the approach to therapy. Pharmacologic management is of limited temporary benefit until more definitive therapy is undertaken. Intrasphincteric injections of botulinum toxin provides safe but short-term relief from symptoms. Based on our review of the safety and effectiveness of pneumatic dilation, we advocate this procedure as the primary form of definitive therapy for achalasia in children. In patients who do not achieve satisfactory results from a series of graduated pneumatic dilations, Heller myotomy provides safe and effective surgical treatment.

Adolescent↗
PubMed2000

Tongue replantation in an animal model.

Although the tongue is not a vital organ in sustaining life, it may be a vital organ in sustaining the will to live in many people. As carcinoma of the tongue represents the majority of the 30,000 oral cavity cancers diagnosed per year in the United States, many patients face the potential consequences of resection of part or all of the tongue for cure. To date, reconstructive options do not restore optimal tongue function including articulation, swallowing, taste, or sensation. With the ultimate goal of improving tongue reconstruction, we report on a successfully performed autograft transplantation of the tongue in an animal model. Before undertaking allograft transplantation of the tongue, an autograft tongue transplant would be attempted to identify the feasibility of such a procedure and to determine the similarity of an animal model with human techniques. The dog's neck, tongue, and oral anatomy represent an excellent animal model for tongue reconstruction. This procedure can be performed successfully in an animal model. The only previously published replantation of the tongue involved the reattachment of the anterior portion of a human tongue after physical trauma. To our knowledge, the enclosed report represents the first successful total excision and replantation of the tongue in either a human or animal model.

Anastomosis, Surgical↗
PubMed2000

Prenatal diagnosis of total arhinia.

Complete or total arhinia, in which there is absence of the soft tissue of the nose, is extremely rare. The embryological origin of the defect is thought to be maldevelopment of the paired nasal placodes. Available neonatal case descriptions have reported the frequent coexistence of other facial anomalies. This report is the first to describe the antenatal diagnosis of total arhinia confirmed after delivery. Sonographic views of the fetal profile, showing an absence of the nose led to consideration of the diagnosis.

Adult↗
PubMed1999

Complications of rhytidectomy in an otolaryngology training program.

OBJECTIVES/HYPOTHESIS: Complications of rhytidectomy have been widely reported in the literature. This study examines the incidence of complications after rhytidectomy in the hands of chief residents under appropriate attending supervision in an otolaryngology-head and neck surgery training program. MATERIALS AND METHODS: The charts of 96 consecutive SMAS rhytidectomy patients were retrospectively reviewed. Patients were selected for surgery from a clinic designed exclusively for cosmetic facial surgery patients. This clinic was run by the otolaryngology chief resident and was supervised by an attending staff surgeon. Most patients elected local anesthesia and sedation administered by the surgical team. Submental liposuction was performed followed by SMAS plication rhytidectomy. RESULTS: Follow-up ranged from 1 to 60 months. Complications included expanding hematoma (1%), temporary facial nerve weakness (3%), pretragal/mastoid skin slough (4.2%), permanent ear numbness (1%), hypertrophic scar (3.1%), wound infection (1%), and dissatisfaction with result (4%). There were no cases of permanent facial nerve injury. CONCLUSION: These complication rates compare favorably with reported rates of larger studies over the past 30 years. These data support the conclusion that rhytidectomy can be performed safely by otolaryngology residents with little morbidity and good patient satisfaction.

Aged↗
PubMed1998

Sonographic evaluation of the uterine cervix.

Ultrasonographic evaluation of the uterine cervix has been shown to help predict patients who may be at an increased risk for preterm delivery. The use of ultrasound in at-risk patients may improve the selection of those needing obstetric intervention, which therefore, may improve outcome and lower overall health care costs. Cervical competence, once thought to be a categorical variable, should now be thought of as a continuous variable, as the shortest cervical lengths are found in those women with a history of very early preterm delivery (> 24 weeks). Adjunctive tests, such as fetal fibronectin Bishop scoring and bacterial vaginosis may help to improve the accuracy of prediction of preterm birth; therefore a multifaceted risk approach to preterm birth is suggested in this article.

Cervix Uteri↗
PubMed1998

Dose-related tissue effects of the CO2 and noncontact Nd:YAG lasers in the canine glottis.

OBJECTIVES: The CO2 laser is the standard for control of recurrent respiratory papillomatosis because of its predictable action on laryngeal tissue. The noncontact neodymium:yttrium aluminum garnet (Nd:YAG) 1064-nm laser is generally not used in the larynx owing to the lack of data on its tissue effects, and its potential lack of safety in the larynx. Combined Nd:YAG and CO2 laser treatments have been used safely in the tracheobronchial tree to eradicate recurrent respiratory papillomas. The objectives of this study were to describe and evaluate a method for applying the noncontact Nd:YAG laser to the larynx, to compare the tissue effects of the Nd:YAG, CO2, and combined Nd:YAG and CO2 lasers in the canine larynx, and to extrapolate canine tissue data to the human. METHODS: The CO2, Nd:YAG, and combined Nd:YAG/CO2 lasers were applied to the glottis in four mongrel dogs. Laryngectomy was performed and the tissue was examined histologically. The nature and degree of tissue injury were analyzed relative to laser type and energy data. RESULTS: In the canine larynx, the CO2 laser vaporized the surface epithelium and caused varying degrees of edema and necrosis of the lamina propria. The Nd:YAG laser did not cause ulceration but did show a greater degree of thermal damage to the lamina propria. Combined Nd:YAG/CO2 applications resulted in separation of the perimysial fibers from the muscle fibers of the vocalis muscle. CONCLUSION: These findings suggest that the noncontact Nd:YAG laser can be applied in a controlled fashion to the canine larynx at appropriate power densities. Anatomical differences between human and canine larynges are considered. Extrapolation to humans is proposed.

Animals↗
PubMed1998

Cesarean delivery for the second twin in the vertex-vertex presentation: operative indications and predictability.

BACKGROUND: The incidence of second twin delivery by cesarean section and whether obstetric parameters are predictive should be studied. METHODS: In this retrospective study, all vertex-vertex twin deliveries during a 48-month period were reviewed. RESULTS: During the study period, 106 sets of vertex-vertex twins were identified. In 68 pairs, both were delivered vaginally (group 1), and 21 pairs were born via cesarean section. In the 17 pairs in group 2, the first infant was delivered vaginally and the second by cesarean section because of fetal distress in 6 cases (35%), cord prolapse in 6 (35%), abnormal/unstable lie in 4 (23%), and abruptio placenta in 1 case (6%). The only maternal factor associated with abdominal delivery for twin B was greater maternal age. When cesarean delivery was required for twin B, a longer interval between deliveries and a lower Apgar score were noted. CONCLUSION: Cesarean birth of twin B is a more common clinical event than previously reported but is not easily predicted by obstetric parameters.

Apgar Score↗
PubMed1997

Cytokine regulation of host defense against parasitic gastrointestinal nematodes: lessons from studies with rodent models.

Studies with rodents infected with Trichinella spiralis, Heligmosomoides polygyrus, Nippostronglyus brasiliensis, and Trichuris muris have provided considerable information about immune mechanisms that protect against parasitic gastrointestinal nematodes. Four generalizations can be made: 1. CD4+ T cells are critical for host protection; 2. IL-12 and IFN-gamma inhibit protective immunity; 3. IL-4 can: (a) be required for host protection, (b) limit severity of infection, or (c) induce redundant protective mechanisms; and 4. Some cytokines that are stereotypically produced in response to gastrointestinal nematode infections fail to enhance host protection against some of the parasites that elicit their production. Host protection is redundant at two levels: 1. IL-4 has multiple effects on the immune system and on gut physiology (discussed in this review), more than one of which may protect against a particular parasite; and 2. IL-4 is often only one of multiple stimuli that can induce protection. Hosts may have evolved the ability to recognize features that characterize parasitic gastrointestinal nematodes as a class as triggers for a stereotypic cytokine response, but not the ability to distinguish features of individual parasites as stimuli for more specific protective cytokine responses. As a result, hosts deploy a set of defense mechanisms against these parasites that together control infection by most members of that class, even though a specific defense mechanism may not be required to defend against a particular parasite and may even damage a host infected with that parasite.

Animals↗
PubMed1996

A pilot study of intravenous ondansetron for hyperemesis gravidarum.

OBJECTIVE: We attempted to determine whether the antiemetic ondansetron would be more effective than promethazine in treating hyperemesis gravidarum. STUDY DESIGN: Patients with hyperemesis gravidarum who required hospital admission were randomized to receive either intravenous ondansetron (n = 15) or intravenous promethazine (n = 15) in a double-blind manner. Severity of disease was determined by electrolyte status, weight loss, ketonuria, and prior use of outpatient antiemetics. Outcome variables included degree of nausea, weight gain during treatment, days of hospitalization, and number of medication doses. RESULTS: In this preliminary investigation ondansetron offered no advantage when compared with promethazine in the relief of nausea, weight gain, days of hospitalization (4.5 +/- 2.3 vs 4.5 +/- 1.5), and total doses of medication per hospitalization (2.1 +/- 1.2 vs 1.9 +/- 1.3). CONCLUSION: This preliminary trial of ondansetron demonstrated no benefit over promethazine in patients hospitalized for hyperemesis gravidarum.

Adult↗
PubMed1996

Gastroesophageal reflux: a common exacerbating factor in adult asthma.

There is a unique yet common relationship between gastroesophageal reflux (GER) and asthma. This paper's discussion covers the lower esophageal sphincter (LES) and other components that form the anti-reflux barrier and how the barrier can be breached. There are three predominant theories on the asthma/GER connection; (1) the inhalation of microaspirate into the lungs causes an inflammatory response, (2) a vagally mediated reflex pathway occurring when acid is present in the esophagus, and (3) a combination of the first two theories. Available diagnostic tests for GER include the "gold standard," the 24-hour ambulatory pH monitor. Adult asthmatic patients with GER can present with atypical symptoms such as worsening nocturnal asthma or hoarseness and not have a single classic symptom like heartburn. Treatment is implemented in a step-wise approach first using education to introduce conservative anti-reflux measures, progressing to pharmacotherapy (acid suppressive agents and promotility agents) and finally surgical correction like the Nissen fundoplication to create a competent anti-reflux barrier, thus achieving improved asthma management.

Adult↗
PubMed1996

Combining medical and mechanical methods of cervical ripening. Does it increase the likelihood of successful induction of labor?

OBJECTIVE: To determine if combining two commonly used methods or cervical ripening (intracervical prostaglandin E2 [Pge2] gel and Foley balloon catheter) would result in a higher number of successful inductions and fewer cesarean sections when compared to PGE2 gel alone. STUDY DESIGN: Seventy-eight patients with unfavorable cervixes eligible for induction of labor were prospectively randomized to receive either one dose (0.5 mg) of PGE2 gel followed by insertion of a 24-French Foley catheter (group 1, 41 patients) or two doses of 0.5 mg of intracervical gel (group 2, 37 patients). Outcome parameters included change in Bishop score, number of failed inductions, rate of cesarean section, rate of uterine hyperstimulation and postpartum infection. RESULTS: Patients in group 1 had a significant increase in posttreatment Bishop scores (7.26 +/- 2.0 SD vs. 4.82 +/- 1.8 P = .0001) and fewer failed inductions (0 vs. 6, P = .009) when compared to patients in group 2. Abdominal delivery rates, uterine hyperstimulation and infections complications were not different between the two groups. CONCLUSION: The combination of the Foley balloon and prostaglandin gel significantly improved the Bishop score and led to fewer failed inductions, although it did not increase the vaginal delivery rate.

Adult↗
PubMed1995

Incidence of adverse cardiopulmonary effects with low-dose continuous terbutaline infusion.

OBJECTIVE: Our purpose was to determine the incidence of adverse cardiovascular effects of terbutaline sulfate when administered as a continuous subcutaneous infusion in women with arrested preterm labor. STUDY DESIGN: Over a 6-year period records from 8709 women prescribed this therapy for preterm labor that had previously been arrested with other intravenous tocolytics were reviewed. These women were assessed daily for cardiovascular complaints and tolerance of the medication, while either in the hospital or at the home (by telephone). The main outcomes studied were the occurrence of pulmonary edema, sustained cardiac arrhythmias, chest pain, or myocardial ischemia. Any maternal death regardless of cause was also reviewed. RESULTS: Of the 8709 subjects, 47 (0.54%) had one or more cardiopulmonary problems. Pulmonary edema developed in 28 patients (0.32%) while receiving continuous subcutaneous infusion of terbutaline, 5 at home and 23 in the hospital. Of the total, 17 women were being treated concurrently with large amounts of intravenous fluids and one to three other tocolytic agents. In the 11 remaining subjects, 4 were diagnosed with pregnancy-induced hypertension and/or multiple gestation. Nineteen patients experienced other adverse cardiovascular effects, including electrocardiogram changes, irregular heart rate, chest pain, or shortness of breath. CONCLUSIONS: Continuous terbutaline infusion for women with stabilized preterm labor is associated with much fewer adverse effects than previous literature regarding intravenous beta-adrenergic agonist therapy would suggest.

Adrenergic beta-Agonists↗
PubMed1995

Corticosteroid-induced arrest of HELLP syndrome progression in a marginally-viable pregnancy.

Corticosteroid therapy in preterm pregnancy complicated by severe pre-eclampsia as HELLP syndrome temporarily stabilizes the HELLP syndrome. One such patient complicated by extreme prematurity was treated with long-term high-dose corticosteroid therapy. The HELLP syndrome was temporarily stabilized and additional in utero fetal maturation was gained.

Adrenal Cortex Hormones↗
PubMed1995

Management of the obstetric patient with thrombocytopenia.

Thrombocytopenia that complicates pregnancy can occur secondary to known maternal disease processes or may arise again during, and as a result of, gestation. A combination of maternal history, clinical presentation, and laboratory investigation usually leads the obstetrician to the proper diagnosis of the condition and, when necessary, dictates appropriate fetal intervention. Although the differential diagnosis of thrombocytopenia can be a frustrating and difficult exercise, especially in an emergent intrapartum environment, clinical persistence coupled with hematology consultation when appropriate usually will reward the provider and patient with the best chance to achieve optimal maternal-fetal outcome.

Clinical Protocols↗
PubMed1995

Emergent management of the patient in preterm labor.

Clinicians who treat PTL should realize that side effects rarely occur when tocolytic medications are properly used. The beneficial effects of tocolytic therapy vastly outweigh the risks associated with their use for the prolongation of gestation. Even a short extension of in utero life for a few days or weeks can significantly and positively affect neonatal survival and long-term outcome. Although the opponents of tocolytic therapy argue that no reduction in the PTB rate has occurred since their introduction, this argument does not consider that the large majority of PTBs are not eligible for tocolytic intervention. If patients with clear indications for tocolysis could be compared with those that were not treated (which most studies have not done), a substantial beneficial effect of tocolytic administration probably would be demonstrated. Based on available data, we consider MgSO4 and terbutaline to be first-line tocolytics. Magnesium is used more often because of its lower side-effect profile. Indomethacin and nifedipine should be reserved for difficult or refractory preterm labor, and should only be used for intervals of < or = 48 hours. We have attempted to present a method of decision analysis which should be followed for every patient who is admitted to the obstetric care unit for a presumptive diagnosis of premature labor. We realize that many of the issues included here are controversial, however, we hope that by developing a decision tree (see Fig. 1), a more complete management scheme will be created and lead to improved care of the patient undergoing premature labor.

Adrenergic beta-Agonists↗