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Biomedical subjects

K Sullivan

Publications and source records attributed to K Sullivan.

At least 55 records · Page 3Linked to original sources

Tissue-engineered human bioartificial muscles expressing a foreign recombinant protein for gene therapy.

Murine skeletal muscle cells transduced with foreign genes and tissue engineered in vitro into bioartificial muscles (BAMs) are capable of long-term delivery of soluble growth factors when implanted into syngeneic mice (Vandenburgh et al., 1996b). With the goal of developing a therapeutic cell-based protein delivery system for humans, similar genetic tissue-engineering techniques were designed for human skeletal muscle stem cells. Stem cell myoblasts were isolated, cloned, and expanded in vitro from biopsied healthy adult (mean age, 42 +/- 2 years), and elderly congestive heart failure patient (mean age, 76 +/- 1 years) skeletal muscle. Total cell yield varied widely between biopsies (50 to 672 per 100 mg of tissue, N = 10), but was not significantly different between the two patient groups. Percent myoblasts per biopsy (73 +/- 6%), number of myoblast doublings prior to senescence in vitro (37 +/- 2), and myoblast doubling time (27 +/- 1 hr) were also not significantly different between the two patient groups. Fusion kinetics of the myoblasts were similar for the two groups after 20-22 doublings (74 +/- 2% myoblast fusion) when the biopsy samples had been expanded to 1 to 2 billion muscle cells, a number acceptable for human gene therapy use. The myoblasts from the two groups could be equally transduced ex vivo with replication-deficient retroviral expression vectors to secrete 0.5 to 2 microg of a foreign protein (recombinant human growth hormone, rhGH)/10(6) cells/day, and tissue engineered into human BAMs containing parallel arrays of differentiated, postmitotic myofibers. This work suggests that autologous human skeletal myoblasts from a potential patient population can be isolated, genetically modified to secrete foreign proteins, and tissue engineered into implantable living protein secretory devices for therapeutic use.

Adult↗

Induction of Ca2+-activated K+ current and transient outward currents in human capillary endothelial cells.

Human capillary endothelial cells (HCEC) in normal media contain noninactivating outwardly rectifying chloride currents, TEA-sensitive delayed rectifier K+ currents and an inward rectifier K+ current. Two additional ionic currents are induced in HCEC when the media are allowed to become conditioned: A Ca2+-activated K+ current (BKCA) that is sensitive to iberiotoxin is induced in 23.5% of the cells, a transient 4-AP-sensitive K+ current (A current) is induced in 24.7% of the cells, and in 22.3% of the cells both the transient and BKCA currents are coinduced. The EC50 for Ca2+ activation of the BKCA current in HCEC from conditioned media is 213 nM. RNA message for BKCA (hSlo clone) is undetecable after PCR amplification in control cells but is seen in those from conditioned cells. The induction of BKCA current is not blocked by conditioning with inhibitors of nitric oxide synthase, cyclo-oxgenase or lypo-oxygenase pathways. Apparently the characteristics of human endothelial cells are highly malleable and can be easily modified by their local environment.

Calcium↗

Combined aromatase inhibitor and antiandrogen treatment decreases territorial aggression in a wild songbird during the nonbreeding season.

Male song sparrows (Melospiza melodia morphna) defend territories throughout the year in western Washington State. In the nonbreeding season (autumn and winter), aggression and song are robustly expressed but plasma testosterone (T) levels are basal. Also, castration does not decrease nonbreeding territoriality. In this field experiment, we asked whether nonbreeding aggression is independent of T. T can act via androgen receptors or T can be aromatized to 17beta-estradiol (E(2)) and act via estrogen receptors. We treated free-living nonbreeding birds with an aromatase inhibitor (ATD) and an androgen receptor antagonist (flutamide) in combination. We then challenged subjects with a live decoy and playback of tape-recorded songs. ATD+flutamide treatment decreased several aggressive behaviors. However, ATD+flutamide treatment did not affect body condition, suggesting that subjects were healthy and that foraging behavior was not reduced. As expected, ATD+flutamide treatment increased plasma T, probably by blocking negative feedback on luteinizing hormone. Surprisingly, ATD+flutamide treatment increased plasma E(2). Most other studies using aromatase inhibitors have not measured plasma E(2). However, it is possible that ATD+flutamide treatment decreased local E(2) levels in the brain but not in plasma. Finally, ATD+flutamide treatment increased plasma corticosterone, perhaps in response to increased plasma T or E(2). To our knowledge, these are the first data to suggest that nonbreeding territoriality is regulated by endogenous steroid hormones. Nongonadal production of sex steroids may support aggression in the nonbreeding season.

Aggression↗

Autologous haematopoietic stem cell transplants for autoimmune disease--feasibility and transplant-related mortality. Autoimmune Disease and Lymphoma Working Parties of the European Group for Blood and Marrow Transplantation, the European League Against Rheumatism and the International Stem Cell Project for Autoimmune Disease.

This ongoing multicentre prospective phase I/II trial enrolled 74 consecutive patients from 22 centres worldwide with severe autoimmune disease, 35 with rheumatological disorders, 31 with neurological, five with haematological and three with vasculitides. They were treated with autologous peripheral blood or bone marrow transplants according to predetermined criteria. Two patients died after mobilisation before transplant. Seventy-two patients were given 73 transplants, seven bone marrow, and 66 mobilised peripheral blood stem cell transplants. The graft was manipulated to remove T and/or B cells in 43 cases. All 73 transplants engrafted. Five patients died of transplant-related complications: two from bleeding, three from infections. Two patients died of progressive disease. The transplant-related mortality at 1 year of 9% (1-17%; 95% CI) is comparable to the transplant-related mortality of 6% (3-9%; 95% CI) in patients transplanted during the same period in Europe for non-Hodgkin's lymphoma in sensitive relapse (P = 0.39). Sixty patients are evaluable for response, 40 patients (65%) showed some improvement in their disease. Haematopoietic stem cell transplants are feasible for patients with severe refractory autoimmune disease. Transplant-related mortality is comparable to results in patients with non-Hodgkin's lymphoma in responsive relapse. Two-thirds of the patients show at least some response. These preliminary data are promising. Although associated with considerable risk, randomised trials comparing autologous stem cell transplants to conventional therapy are warranted.

Adolescent↗

The importance of information giving for patients newly diagnosed with cancer: a review of the literature.

The importance of information giving has been recognized and promoted in political, ethical and professional arenas and this has ultimately resulted in the publication of a vast amount of literature relating to the subject. This literature review considers the functions of patient information and the factors influencing information seeking for patients who have been diagnosed with cancer. Methods of providing information are discussed and the nurse's role in information giving is examined. A number of core problems are highlighted in relation to information giving. These problems, and possible reasons for them, are subsequently critically analysed. Finally, the literature relating to information needs of patients with cancer is evaluated and five key needs identified.

Humans↗

The utility of toxicologic analysis in children with suspected ingestions.

OBJECTIVE: To evaluate the usefulness of toxicologic studies on the management of children with suspected ingestions. DESIGN: Prospective, consecutive case series. SETTING: Two tertiary care children's hospital emergency departments. PATIENTS: All children < or =18 years of age presenting with a suspected ingestion. STUDY DESIGN: Pediatric emergency physicians completed a 14-point questionnaire on each identified patient that included demographics, signs, and symptoms, and if applicable, the extent of drug analysis performed. Pre-test and post-test utility values were determined by the ordering physician using an 11-point scale (0 = least valuable, 10 = most valuable). Physicians also assessed how positive or negative drug analyses affected patient management. RESULTS: Two hundred twenty patients met study criteria. Median age was 5 years, with males making up 53% of patients. Drug analysis was ordered in 72% (158/220) of cases, with 59% of these tests obtained for a history of ingestion and 27% obtained for altered mental status (AMS). The most common suspected ingestions were acetaminophen and cold preparations. Seventy-eight of 158 (49%) patients had positive toxicology tests, with 17 unsuspected findings. Patient management was affected in 53/158 (34%; 95% CI, 27-41%) cases. Unsuspected findings affecting management were found in only 4/158 (3%; 95% CI, 1-6%) cases. Significant differences in pre-test and post-test utility values occurred for serum assays (mean difference +0.4, P = 0.008), patients presenting with AMS (mean difference -0.8, P = 0.005), and patients having a negative drug test (mean difference -0.5, P = 0.003). Although negative drug analysis gave the physician reassurance in 39/80 (49%; 95% CI, 38-60%) cases, patient management was altered in only 8/80 (10%; 95% CI, 5-18%) cases. CONCLUSIONS: Seventy-two percent of children presenting with suspected drug ingestions had toxicologic analysis performed as part of their evaluation. Analysis was most valuable to physicians when evaluation of overdoses required serum drug levels. Qualitative urine drug screens provided minimal useful information. Unexpected findings on urine drug screening leading to changes in management were uncommon.

Adolescent↗

Detection of disabilities by schoolchildren: a pilot study in rural Pakistan.

An important consideration in planning services for disabled children is to establish the need, including the size of the potential beneficiary group. However, surveys are expensive and time consuming (especially surveys of disability, which has a low prevalence within the population), and can raise expectations of service for patients who are often very unsure about how to cope with their disabled child. The World Health Organization (WHO) has produced a series of survey tools which have been used to identify disabled children in settings where a service is planned. Zaman et al, produced the '10 Question Screen', a simple screening tool for use by community health staff to identify disabilities among children in the community. Both the WHO survey tools and the 10 Question Screen rely on trained primary health care (PHC) or community-based rehabilitation (CBR) staff. The small study reported here shows that schoolchildren are effective identifiers of disabled children within their home communities and may be a useful resource when there are no trained CBR or PHC workers to conduct surveys. Furthermore, the children's ability to identify within the five major disability groups was relatively robust when compared with medical diagnosis.

Child↗

Second-order belief attribution in Williams syndrome: intact or impaired?

Second-order mental state attribution in a group of children with Williams syndrome was investigated. The children were compared to age, IQ, and language-matched groups of children with Prader-Willi syndrome or nonspecific mental retardation. Participants were given two trials of a second-order reasoning task. No significant differences between the Williams syndrome and Prader-Willi or mentally retarded groups on any of the test questions were found. Results contrast with the view that individuals with Williams syndrome have an intact theory of mind and suggest that in their attributions of second-order mental states, children with Williams syndrome perform no better than do other groups of children with mental retardation.

Adolescent↗

Intubation and mechanical ventilation for COPD: development of an instrument to elicit patient preferences.

BACKGROUND: Whether to simply provide palliative care or to intubate and use mechanical ventilation (MV) in a patient with severe COPD in acute respiratory failure is a difficult decision. The outcome of MV cannot be accurately predicted. Some patients cannot be weaned from the ventilator; those who are weaned often return to chronic severe respiratory disability. It is important that patients participate in this decision, but assistance is required. To address these issues, we developed and pilot-tested an aid to assist patients with MV decisions. METHODS: A scenario-based decision aid was developed consisting of an audiocassette and a booklet describing intubation and MV and its possible outcomes. We used a probability tradeoff technique to elicit the patients' preferences and a decisional conflict scale to evaluate satisfaction. RESULTS: With the assistance of the decision aid, all patients (10 men and 10 women) reached a decision. Two men and all 10 women declined MV. Mean decisional conflict was low (2.2 of a possible 5; SD, 0.9). At 1 year, only two patients (11%) had changed their decision. The agreement between physicians and patients was 65%; between next-of-kin and patients, there was uniform disagreement. CONCLUSION: With the decision aid, stable decisions were made with satisfaction and confidence. Proxy decisions were incongruent, especially when made by family members. The strong gender effect should be further investigated. We suggest that the COPD decision aid be further tested in a community clinical setting.

Acute Disease↗

Thyroid volumes in US and Bangladeshi schoolchildren: comparison with European schoolchildren.

OBJECTIVE: The World Health Organization (WHO) recently adopted thyroid volume ultrasonography results from European schoolchildren as the international reference for assessing iodine deficiency disorders. Our objective was to describe thyroid volumes measured by ultrasonography in US and Bangladeshi schoolchildren and compare these with European schoolchildren. METHODS: Cross-sectional studies were performed in schoolchildren in the US (n=302) and Bangladesh (n=398). Data were collected on the following: thyroid size by palpation and ultrasonography; urinary iodine; age; sex; weight; and height. RESULTS: Applying the new WHO thyroid volume references to the Bangladeshi children resulted in prevalence estimates of enlarged thyroid of 26% based on body surface area (BSA) and 7% based on age. In contrast, in the US children, the prevalence estimates were less than 1% for each reference. In the US children, the best single predictor of thyroid volume was BSA (R2=0.32), followed by weight (R2=0.31). Using linear regression, upper normal limits (97th percentile) of thyroid volume from US children were calculated for BSA, weight and age, and were found to be lower than the corresponding references based on BSA and age from European schoolchildren. CONCLUSIONS: In areas with malnutrition, such as Bangladesh, the BSA reference should be preferred to the reference based on age. Results from the US children indicated that a thyroid volume reference based on weight alone would perform as well as the one based on BSA. European schoolchildren had larger thyroids than US children, perhaps due to a residual effect of iodine deficiency in the recent past in some areas in Europe.

Age Factors↗

Managed care plan performance since 1980: another look at 2 literature reviews.

OBJECTIVES: This article compares the quality of care provided by managed care plans (MCPs) and indemnity (or fee-for-service [FFS]) plans since 1980. METHODS: The 44 studies examined are the studies that Miller and Luft cited in their 1994 and 1997 reviews of the literature comparing MCPs with FFS plans. These studies are examined to determine how well they met Miller and Luft's selection criteria and, in addition, whether they controlled for differences in the breadth of insurance coverage. RESULTS: The 44 studies generated 57 observations. MCPs scored better than FFS plans on 10 of these, equally well on 25, and worse on 22. However, only 44 of these observations met the Miller-Luft criteria plus the coverage criterion. Four of these indicated that MCP care was better, 19 that MCP and FFS care were equivalent, and 21 that MCP care was worse. CONCLUSIONS: The small body of reliable studies comparing the quality of MCP care with that of FFS care indicates that the quality of care provided by MCPs tends to be equal or inferior to that provided by FFS plans.

Fee-for-Service Plans↗

The Philadelphia story: the 22q11.2 deletion: report on 250 patients.

A submicroscopic deletion of chromosome 22q11.2 has been identified in the majority of patients with the DiGeorge, velocardiofacial, and conotruncal anomaly face syndromes, and in some patients with the Opitz G/BBB and Cayler cardiofacial syndromes. We have been involved in the analysis of DiGeorge syndrome and related diagnoses since 1982 and have evaluated a large number of patients with the deletion. We describe our cohort of 250 patients whose clinical findings help to define the extremely variable phenotype associated with the 22q11.2 deletion and may assist clinicians in providing genetic counseling and guidelines for clinical management based on these findings.

Abnormalities, Multiple↗

Characterization of two avian reoviruses that exhibit strain-specific quantitative differences in their syncytium-inducing and pathogenic capabilities.

We previously proposed that the conservation of the nonessential syncytium-inducing phenotype among all reported avian reovirus (ARV) isolates may reflect a mechanism for enhanced virus dissemination in vivo, which in turn could contribute to the natural pathogenicity of ARV. Direct testing of this hypothesis has been hampered by the lack of available virus strains with defined differences in their fusion-inducing capability. We now report on the characterization of two ARV strains, ARV-176 and ARV-138, that exhibited strain-specific differences in their fusogenic properties, which correlated with their pathogenic potential in embryonated eggs. Moreover, both virus strains possessed similar replicative abilities in cell culture, suggesting that the weakly fusogenic ARV-138 virus is specifically inhibited in its syncytium-inducing ability. To test the use of these viruses for reassortant studies aimed at assessing the role of cell fusion in viral pathogenesis, a preliminary genetic analysis was undertaken using a monoreassortant that contained nine genome segments from the parental ARV-138 virus and the S1 genome segment from the highly fusogenic and pathogenic ARV-176 parental virus. The monoreassortant possessed the full fusogenic potential of the ARV-176 parental virus and displayed enhanced embryo pathogenicity, providing the first genetic evidence implicating the ARV S1 genome segment in both syncytium formation and viral pathogenesis.

Animals↗

Inflammatory bowel disease in African-American children living in Georgia.

We describe the clinical characteristics of inflammatory bowel disease (IBD) African-American compared with non-African-American children. We identified 172 children with IBD; forty-nine (29%) were African-American. Median symptom duration before IBD diagnosis in African-American children (6 months) was shorter than that of non-African-American children (10 months). The most frequent presenting symptom was hematochezia (ulcerative colitis) and abdominal pain (Crohn's disease) in both racial groups. The estimated incidence of Crohn's disease in African-Americans ranged from 7 per 100,000 to 12 per 100,000, whereas the observed incidence in those with ulcerative colitis was between 5 and 7 per 100,000 during the 10 years of the study. Our pilot study suggests that IBD may be more common in African-American children than previously reported. Prospective population-based studies would be useful to determine whether inheritable factors linked with ethnicity are associated with IBD.

Adolescent↗

Prediction of illness severity and outcome of children symptomatic following kerosene ingestion.

Kerosene pneumonitis is usually self-limiting and secondary infection is rare. Long-term studies in developed countries have produced conflicting results about complications. The position in developing countries, where children are exposed to adverse environmental and nutritional factors, is unknown. The aim of the present work was to determine whether there is an increase in respiratory or other illnesses following kerosene pneumonitis and whether these changes could be related to the severity of the initial lung damage. Fifty-seven children with clinical signs of pneumonitis were examined on admission and after overnight observation. Clinical signs were assessed for their usefulness for predicting severity. Cases and matched neighbourhood controls were seen every 2 weeks for 3 months. The time to predict most reliably the severity of short-term ill effects was 12-24 hours after the initial insult. There was no significant difference in respiratory symptoms during the 3-month follow-up in cases compared with controls. However, mild diarrhoea and fever were reported significantly more often in cases than in controls. Morbidity after clinical recovery was not shown to be a problem, irrespective of the severity of the acute event.

Case-Control Studies↗