Search PubMed⌕ Search

Biomedical subjects

M Hull

Publications and source records attributed to M Hull.

49 records · Page 3Linked to original sources
PubMed1983

Ischemic bowel: the protective effect of free-radical anion scavengers.

Recent data indicates that the free-radical anion superoxide (O2-), an unstable cytotoxic form of oxygen, is implicated in the pathogenesis of ischemic bowel following reperfusion after low flow states. This report evaluates the effect of free radical scavengers on survival in an animal model with bowel ischemia. At laparotomy, the superior mesenteric artery (SMA) of 79 weanling rats (90 g) was occluded for one minute and released. Animals were divided into three experimental groups: group I acted as controls (n = 41), group II, received thiopental 5 mg/kg IV (n = 19), group III, received methohexital 2.5 mg/kg IV (n = 19). At one week animals were evaluated for mortality, mean survival time, evidence of bowel necrosis or perforation, and bowel appearance on scanning electron microscopy (EM). Mortality was 63.5% (26/41) in group I, 19 had necrotic bowel and 7 had gross perforation; 31.6% in group II (6/19) (p less than .05 versus control), with one necrotic bowel and 5 perforations; and 57.9% in group III (11/19) where 7 had necrotic bowel and 4 had perforations (p NS v control). Survival time (mean +/- SD in days) post SMA occlusion was 3.2 +/- 1.9 for group I; 4.0 +/- 1.7 for group II; and 2.5 +/- 2.0 for group III. EM showed mucosal destruction worsened by the duration of reperfusion, decreased by thiopental but not by methohexital. Thiopental, a free radical anion scavenger was cytoprotective in this animal model, as it decreased mortality and the incidence of bowel necrosis and perforation. These data support the thesis that following low flow states bowel ischemia may be related to a reperfusion injury due to the release of toxic free radical anions.

Animals↗
PubMed1983

Neonatal apnea, xanthines, and necrotizing enterocolitis.

This study evaluates the relationship of xanthine treatment of premature apnea and NEC in a bowel ischemia model. The superior mesenteric artery was occluded for 1.0 minute in 82 wheanling rats. Group I (n = 41) were untreated controls. Group II (n = 21) received aminophylline (AMPH) 40 mg/kg I.P., 4 hr and immediately prior to clamping. Animals were evaluated for bowel infarction, perforation, and mortality at 7 days. In 20 additional rats (10 per group) bowel was evaluated by scanning electron microscopy (EM) at timed intervals (5 and 30 min). Ischemic bowel occurred in 25 of 41 (60%) controls (18 (43%) with necrosis; 7 (17%) with perforations) and 19 of 21 (90%) rats with AMPH (15 (70%) had necrosis; 4 (19%) perforations). Mortality was 60% (controls) and 90% (AMPH) respectively (p less than .05). On EM, AMPH enhanced bacterial overgrowth however actual mucosal damage appeared similar. Following ischemia, AMPH has an adverse effect on the bowel. Use of AMPH in prematures at risk for NEC is questioned.

Aminophylline↗
PubMed1981

Leiomyosarcoma of the skin and subcutaneous tissue.

Leiomyosarcomas arising in the skin and subcutaneous tissue are rare tumors, and diagnosis usually is made by microscopic examination of the lesion. These lesions typically appear as a single, smooth nodule in the skin but may also occur as multiple nodules with varying surface changes. After local excision, these lesions recur in a large proportion of patients. However, metastatic spread that leads to death seems to occur only in patients with the subcutaneous variety of the tumor. Three patients had varied clinical appearances of leiomyosarcomas. In one case, which was available for long-term evaluation, no recurrence was noted six years after surgical excision of a single lesion.

Aged↗
PubMed1977

Life-threatening swelling after mandibular vestibuloplasty.

This case report illustrates the potential for severe hemorrhage which authors have alluded to in articles on the vestibuloplasty procedure. The surgeon must be prepared to deal not only with the hemorrhage, but also with the sudden and possible life-threatening swelling that may accompany the bleeding.

Angioedema↗
PubMedDate not supplied

FETAX interlaboratory validation study: phase III--Part 1 testing.

The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a 96-h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published, along with a companion atlas that aids in embryo staging and identifying malformations. As part of the ASTM process, a three-phase interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FETAX. Seven different participants collaborated in the study. In Phase I, FETAX proved to be more repeatable and reliable than many bioassays. However, some excessive variation was observed in a few laboratories. An initial lack of assay experience by some technicians caused variation. Phase II showed far less intra- and interlaboratory variability than Phase I. Non-teratogens showed the most consistent results, while more variability was observed for the two teratogens tested. Interlaboratory coefficient of variation values for all endpoints ranged from 7.3 to 54.7. Phase III--Part 1, using coded samples and test concentration ranges selected by each laboratory, showed results similar to Phase I. Analysis of the causes of variation suggested that some technicians judged some embryos to be malformed while others consistently judged similar embryos as normal. Concentration ranges tested by some of the laboratories varied greatly and a new protocol for selecting concentrations for initial testing was written to reduce variation from this source. Testing to date suggests that FETAX is as repeatable and reliable as other standard bioassays.

Aminopropionitrile↗
PubMedDate not supplied

Phase III interlaboratory study of FETAX. Part 3. FETAX validation using 12 compounds with and without an exogenous metabolic activation system.

FETAX (Frog Embryo Teratogenesis Assay-Xenopus) is a 96-h whole-embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published, along with a companion atlas that helps in embryo staging and in identifying malformations. As part of the ASTM process, an interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FETAX and to evaluate the potential teratogenic hazard of 12 compounds. Three different laboratories participated in the study. All three participating laboratories had extensive experience with the assay. FETAX intralaboratory and interlaboratory variability, as judged by coefficients of variation, were very low. Potential teratogenic hazard was evaluated using two major criteria from FETAX experiments employing metabolic activation systems (MAS). These were the teratogenic index TI (TI = 96-h lc(50)/96-h ec(50) (malformation)) and the minimum concentration that inhibits growth (MCIG). A compound was considered teratogenic by this criterion when the MCIG was significantly different from controls at concentrations below the 30% level of the MAS 96-h lc(50). Based on the results of this and other studies, a decision table was constructed in order to evaluate additional studies. Severity of malformations caused, especially near the MAS 96-h ec(50) (malformation), were also evaluated. Four compounds were non-teratogenic but two compounds were clearly teratogenic. The remaining six compounds were ranked as equivocal teratogens. The results were discussed in light of the difficulty of producing an adequate decision table. FETAX proved to yield repeatable and reliable data as long as care was taken during range-finding and technicians were adequately trained. The MAS was essential in using FETAX to predict developmental hazard in mammals, and still requires further development.

Acetates↗
PubMedDate not supplied

Flight crew physical fitness: a baseline analysis.

INTRODUCTION: The purpose of this pilot study was to determine whether flight crew personnel are physically fit in comparison to published standards for the average American adult. SETTING: The study group consisted of pilots, paramedics and nurses in two similarly configured and geographically located rotor-wing air medical transport programs. METHODS: A physical fitness assessment of flight crew members was conducted. The results were compared with published standards for average adult males and females (AVG). Percentage of fat in body composition (FM%), aerobic fitness (VO2MAX), muscular endurance (ME), muscular strength (MS) and flexibility (FL) measurements were obtained using accepted testing methods. RESULTS: The study population consisted of 29 male and 21 female individuals. The following were their mean scores. Males averaged: pFAT = 19% (AVG = 20.0%); VO2MAX = 41.0 (AVG = 42.5); ME = 37.0 (AVG = 28.5); MS = 125.0 (AVG = 86.5); FL = 5.2 (AVG = 1.4); Females averaged: pFAT = 28.0% (AVG = 26.5%); VO2MAX (AVG = 34.0); ME = 27.0 (AVG = 21.0); MS = 83.0 (AVG = 76.5); FL = 4.5 (AVG = 3.4). CONCLUSION: These baseline data suggest the study population of air medical flight crew was physically fit compared to the average American adult.

Adult↗
PubMedDate not supplied

Inflammation and Alzheimer's disease.

Inflammation clearly occurs in pathologically vulnerable regions of the Alzheimer's disease (AD) brain, and it does so with the full complexity of local peripheral inflammatory responses. In the periphery, degenerating tissue and the deposition of highly insoluble abnormal materials are classical stimulants of inflammation. Likewise, in the AD brain damaged neurons and neurites and highly insoluble amyloid beta peptide deposits and neurofibrillary tangles provide obvious stimuli for inflammation. Because these stimuli are discrete, microlocalized, and present from early preclinical to terminal stages of AD, local upregulation of complement, cytokines, acute phase reactants, and other inflammatory mediators is also discrete, microlocalized, and chronic. Cumulated over many years, direct and bystander damage from AD inflammatory mechanisms is likely to significantly exacerbate the very pathogenic processes that gave rise to it. Thus, animal models and clinical studies, although still in their infancy, strongly suggest that AD inflammation significantly contributes to AD pathogenesis. By better understanding AD inflammatory and immunoregulatory processes, it should be possible to develop anti-inflammatory approaches that may not cure AD but will likely help slow the progression or delay the onset of this devastating disorder.

Alzheimer Disease↗
PubMedDate not supplied

Elevated plasma neopterin levels in Alzheimer disease.

We assessed plasma neopterin level as a marker of inflammation in Alzheimer disease (AD). Plasma neopterin levels were higher in 51 patients with AD (9.3 +/- 5.9 ng/mL) than in 38 age-matched control subjects (6.3 +/- 2.6 ng/ml, p = 0.002). There was no correlation between neopterin levels and Mini-Mental State Examination score or duration of disease; there was a weak association between neopterin level and age (r = 0.26, p = 0.02). Although measurement of plasma neopterin levels is not useful for diagnosis, this assay may provide guidance for the development of anti-inflammatory treatment strategies for AD.

Aged↗
PubMedDate not supplied

Struggling with paradoxes: the process of spiritual development in women with cancer.

PURPOSE/OBJECTIVES: To examine the process of spiritual development in women diagnosed with cancer within five years of initial treatment. DESIGN: Exploratory, qualitative. SETTING: Outpatients in the mid-central and southwestern United States. SAMPLE: 10 Caucasian women, ages 45-70, who completed initial treatment, were not undergoing treatment for recurrence, and were within five years of diagnosis for breast or ovarian cancer or non-Hodgkin's lymphoma. METHODS: Data collected during two semistructured interviews, coded and analyzed using grounded theory techniques. Frame of reference--symbolic interactionism. MAIN RESEARCH VARIABLES: Developmental processes of spirituality; responses to diagnosis, treatment, and survival of cancer. FINDINGS: Diagnosis of cancer threatened the meaning of the women's lives, resulting in a sense of disintegration. This problem was resolved through the basic social psychological process of Struggling With Paradoxes, a three-phase process of Deciphering the Meaning of Cancer for Me, Recognizing Human Limitations, and Learning to Live with Uncertainty. In phase I, the paradoxes focused on the possibility of death, distress, vulnerability, and maintaining connection. In phase II, the paradoxes involved confronting death, asking difficult questions, and letting go of ultimate control of their lives. In phase III, the paradoxes centered on uncertainty, redefining meaning, and identifying spiritual growth. Reintegration occurred over time, although when threatened by the possibility of recurrence, disintegration resurfaced for a time. CONCLUSIONS: Findings emphasize not only the importance of spirituality, but also that spiritual experience is individualized and developmental in nature. Spiritual growth occurs over time following the diagnosis of cancer and is not necessarily related to age. IMPLICATIONS FOR NURSING PRACTICE: Spiritual concerns may be painful for patients to address; spiritual caregiving requires an acknowledgment of need by the woman with cancer and a caring, sensitive caregiver. Nurses should be aware of the phases of spiritual development so that interventions can be designed to address individual needs that may vary over time.

Adaptation, Psychological↗