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Biomedical subjects

C Campbell

Publications and source records attributed to C Campbell.

At least 181 records · Page 10Linked to original sources
PubMed1995

The relationship between interferon-gamma and keratinocyte alloantigen expression after burn injury.

BACKGROUND: Cultured keratinocyte (CK) and cadaveric skin allografts have prolonged survival in patients with massive thermal injury. It is unclear if this delayed rejection is due to impaired host responsiveness or decreased graft immunogenicity. Although burn injury has been shown to decrease parameters of allograft response, no studies have examined the effect of burn injury on alloantigen expression. This study investigated the effect of burn size on class II antigen expression in CK allografts as well as on tissue levels of interferon-gamma (IFN-gamma), the principle regulator of alloantigen expression. METHODS: Anesthetized CBA mice (n = 64) received a 0%, 20% partial-thickness (PT), 20% full-thickness (FT), or 40% FT contact burn. Forty-eight hours later, wounds were partially excised and covered with CK allografts from C57BL/6 donors. Five days after burn injury, grafts were analyzed for donor-specific class II antigen. Protein expression was determined by Western immunoblotting and quantified with video densitometry. Wound, serum, and unburned skin levels of IFN-gamma were determined by enzyme-linked immunosorbent assay. Groups were compared by Fisher's analysis of variance. RESULTS: As burn size increased, class II antigen expression decreased (p < 0.001). This corresponded with decreased wound and skin levels of IFN-gamma after 40% burn (p < 0.05); however, wound IFN-gamma was significantly elevated after 20% PT and FT burns (p < 0.01). Serum IFN-gamma increased as burn size increased (p < 0.01). CONCLUSIONS: Burn injury decreases the antigenicity of CK allografts, which partly explains delayed allograft rejection after burn injury. Although wound IFN-gamma increases after minor thermal injury, the profound decrease in wound and skin IFN-gamma after a major burn corresponds with diminished class II antigen expression. The decreased availability of IFN-gamma after major thermal injury provides a mechanism for limited allograft tolerance.

Animals↗
PubMed1995

Polymicrobial sepsis following trauma inhibits interleukin-10 secretion and lymphocyte proliferation.

Immune competence declines following major injury, and predisposes the trauma patient to infection. Interleukin-10 (IL-10), although an immunosuppressive cytokine, is also important in the initiation of immune responses. This study investigated alterations in IL-10 and immune function associated with polymicrobial sepsis following trauma using murine femur fracture (FFx) and cecal ligation/puncture (CLP) models. Mice were randomized to Normal, FFx, Alcohol and FFx (EtOH + FFx), CLP, FFx + CLP, and EtOH + FFx + CLP. Polymicrobial sepsis was induced by performing CLP 4 days after FFx, and animals were killed 14 days later; immune function was assessed by in vitro splenocyte cultures. Lymphocyte proliferative responses were significantly suppressed in FFx and CLP animals. Splenocyte IL-10 production was significantly reduced in FFx and CLP animals, with concurrent increases in nitrite and tumor necrosis factor release. This study documents that trauma induces alterations in the inflammatory cytokine cascade that affect the immune response to subsequent septic challenges.

Animals↗
PubMed1995

In situ expression of the early growth response gene-1 during murine nephrogenesis.

WT1 maps to chromosome 11p13 and encodes a deoxyribonucleic acid (DNA) binding protein whose expression is necessary for normal urogenital development. The WT1 protein binds to some of the same DNA sequences as the early growth response gene-1 (EGR-1) protein, the latter being an immediate-early gene product that activates or represses transcription in a promoter and cell-specific manner. Transient transfection experiments have shown that WT1 can repress EGR-1 activated transcription from the EGR-1 promoter. To determine if WT1 is likely to be a physiologically important repressor of EGR-1 we performed ribonucleic acid (RNA) in situ hybridization of EGR-1 on sequential sagittal sections of murine embryos before and throughout nephrogenesis, and compared the results to our previous study of WT1 expression during murine embryogenesis. Prior to embryological day 9.5 WT1 messenger RNA expression is absent in the embryo proper but is expressed in the maternal uterus. With the initiation of organogenesis on embryological day 10.5 WT1 messenger RNA localizes within the pronephric and mesonephric tissues. By embryological day 11.5 the nephrogenic cord, urogenital ridge and metanephric tissue have WT1 hybridization signals and increasingly centripetal expression of WT1 in the kidney correlates with differentiation from embryological days 11.5 to 16.5. In contrast to previous reports of the tissue restricted expression of WT1, EGR-1 expression by in situ hybridization was apparent in all 3 germ layers and their derivatives throughout embryogenesis. Down-regulation of EGR-1 expression occurred in the maternal uterus as well as the metanephric blastema and its derivatives during renal development. This observation defines a spatial and temporal window during which WT1 competition for EGR-1 DNA binding sites may be involved in regulating EGR-1 expression.

Animals↗
PubMed1995

Superimposition of PET images using 18F-fluorodeoxyglucose with magnetic resonance images in patients with pancreatic carcinoma.

Six patients with histologically proven adenocarcinoma of the pancreas were studied using 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) using positron emission tomography (PET), and magnetic resonance imaging (MRI). In all six cases there was avid accumulation of 18F-FDG within the pancreatic tumour and clear visualization of the tumour on the MRI images. Delineation of the tumours was aided by superimposition of the images from the two imaging methods, which was achieved by using a system of surface markers.

Adenocarcinoma↗
PubMed1995

Up-regulation of p21WAF1/CIP1 in psoriasis and after the application of irritants and tape stripping.

p21WAF1/CIP1 is a nucleoprotein that was initially characterized by its ability to be regulated transcriptionally by p53 and by its ability to mediate growth arrest by binding to cyclin-dependent kinases. Although p21WAF1/CIP1 is thought to mediate the effects of p53 in causing growth arrest, p21WAF1/CIP1 is also regulated in a p53-independent manner, e.g., during terminal differentiation of some cell lines. Growth factors including epidermal growth factor also induce p21WAF1/CIP1 through p53-independent pathways. Because the epidermal growth factor signaling pathway is abnormal in psoriatic epidermis, we studied p21WAF1/CIP1 expression, using in situ hybridization and immunohistochemistry, in psoriasis. Both p21WAF1/CIP1 mRNA and protein were significantly elevated in untreated psoriatic plaques compared with uninvolved psoriatic skin (p < 0.0001), with the up-regulation of p21WAF1/CIP1 being predominantly suprabasal. This increase was accompanied by a small increase in p53 protein expression of uncertain significance. Furthermore, p21WAF1/CIP1 expression was induced in skin after sellotape stripping and by the application of agents, such as dithranol, that are capable of inducing hyperproliferation. The pattern of p21WAF1/CIP1 expression observed is consistent with a role in induction and maintenance of differentiation. Our experiments, however, cannot determine whether the abnormalities of p21WAF1/CIP1 epidermal expression in psoriasis and after insult are independent of changes in p53 expression.

Anthralin↗
PubMed1995

The target switch algorithm: a constructive learning procedure for feed-forward neural networks.

We propose an efficient procedure for constructing and training a feed-forward neural network. The network can perform binary classification for binary or analogue input data. We show that the procedure can also be used to construct feedforward neural networks with binary-valued weights. Neural networks with binary-valued weights are potentially straightforward to implement using microelectronic or optical devices and they can also exhibit good generalization.

Algorithms↗
PubMed1995

Autonomic failure, depression and anxiety in Parkinson's disease.

BACKGROUND: The study tested the hypothesis that subjects with Parkinson's disease (PD) have more autonomic complaints and more attenuation of autonomic reflexes than controls, and that both clusters of variables are related to the presence of anxiety and depression. METHOD: Thirty-two subjects and 32 healthy controls matched by age and sex were prospectively compared on psychiatric, cognitive and autonomic tests. RESULTS: 'Autonomic' symptoms: were more frequent in PD patients than in healthy controls; were not related to age or changes in autonomic reflexes; were significantly associated with depression and anxiety (medication was not relevant to the association); and did not correlate with motor symptoms. CONCLUSIONS: The diagnosis of anxiety and depression in some PD subjects is likely to be a behavioural phenocopy caused by autonomic failure. This explains why antidepressant medication is often unhelpful in PD subjects diagnosed as depressed.

Aged↗
PubMed1995

Inner-city hospitals: a call for research.

Inner-city hospitals serve as safety nets for poor and underserved populations. They cope with serious issues of uncompensated care, aging facilities, and inadequate reimbursement. Yet, little research exists on their needs and problems. The authors argue that research on inner-city institutions is necessary to obtain "policy" attention, legitimize demand for resources, reframe inner-city health issues as a delivery problem, and gain insights on better ways to manage inner-city hospitals. They provide data-based illustrations of future research questions related to issues of inefficiency, overstaffing, case severity, and facility renovation that can contribute to better policymaking on inner-city hospitals. The authors recognize systemic barriers to research including the unpopularity of access issues, lack of data, and absence of input from practitioners working in inner-city institutions. To remove such barriers, they suggest creation of a representative forum, original databases, increased linkage with research and policy agencies, and increased cooperation between inner-city professionals and researchers.

Catchment Area, Health↗
PubMed1995

Are PRO discharge screens associated with postdischarge adverse outcomes?

OBJECTIVE: We evaluate whether patient outcomes may be affected by possible errors in care at discharge as assessed by Peer Review Organizations (PROs). DATA SOURCES/STUDY SETTING: The three data sources for the study were (1) the generic screen results of a 3 percent random sample of Medicare beneficiaries age 65 years or older who were admitted to California hospitals between 1 July 1987 and 30 June 1988 (n = 20,136 patients); (2) the 1987 and 1988 California Medicare Provided Analysis and Review (MEDPAR) data files; and (3) the American Hospital Association (AHA) 1988 Annual Survey of Hospitals. STUDY DESIGN: Multivariate logistic regression analysis was used to evaluate the association between the results of generic discharge administered by the PROs and two patient outcomes: mortality and readmission within 30 days. The analysis was adjusted for other patient characteristics recorded on the uniform discharge abstract. PRINCIPAL FINDINGS: Four discharge screens indicated an increased risk of an adverse outcome-absence of documentation of discharge planning, elevated temperature, abnormal pulse, and unaddressed abnormal test results at discharge. The other three discharge screens examined-abnormal blood pressure, IV fluids or drugs, and wound drainage before discharge-were unrelated to postdischarge adverse outcomes. CONCLUSIONS: Generic discharge screens based on inadequate discharge planning, abnormal pulse, increased temperature, or unaddressed abnormal tests may be important indicators of substandard care. Other discharge screens apparently do not detect errors in care associated with major consequences for patients.

Aged↗
PubMed1995

Trends in managed care contracting among U.S. hospitals.

This article describes the changing profile of hospitals initiating managed care contracts as of 1992. Based on statistical tests, early contractors rank higher on profitability, case mix, bed size, affiliation, and urban location. In contrast, recent and noncontractors are predominantly rural, freestanding hospitals with low case mix, low profitability, high subacute services, and government ownership. A number of lessons for the future are drawn and a stage-by-stage approach to studying managed care issues is proposed.

Academic Medical Centers↗
PubMed1994

Nitric oxide inhibition normalizes splenocyte interleukin-10 synthesis in murine thermal injury.

OBJECTIVE: To examine the effect of nitric oxide inhibition on cytokine production and immunologic function in a murine thermal-injury and an alcohol (ETOH)-ingestion model. DESIGN: Randomized controlled experiment. SETTING: University surgical research laboratory. ANIMALS: Forty male Balb/C mice. INTERVENTIONS: Animals were randomized to four groups: normal saline solution-sham (NS-sham), ETOH-sham, NS-burn, and ETOH-burn. Animals received 20% ETOH or NS daily for 14 days by gavage. A 20% full-thickness burn was induced 4 hours after the last dose of ETOH or NS was administered. Animals were killed 4 days after the burn was induced. MAIN OUTCOME MEASURES: Splenocytes were harvested and stimulated with the mitogens lipopolysaccharide or concanavalin A. These mitogen-stimulated splenocyte cultures had the addition of exogenous N-monomethyl-L-arginine (2.5 or 10 micrograms/mL), a nitric oxide synthase inhibitor. Splenocyte production of interleukin-10 (IL-10), interferon-gamma, nitrite, and prostaglandin E2 were measured, and lymphocyte proliferative response was examined. RESULTS: Interleukin-10 and interferon-gamma production were significantly suppressed in thermal injury, and lymphocyte proliferative response was markedly reduced. Exogenous N-monomethyl-L-arginine normalized splenocyte IL-10 production in a dose-dependent manner in NS-burn and ETOH-burn groups, improved lymphocyte proliferative response, and significantly decreased splenocyte nitrite production. Interferon-gamma release was not up-regulated by N-monomethyl-L-arginine. CONCLUSIONS: Thermal injury is associated with a suppression of splenocyte IL-10 production and lymphocyte proliferative response. Inhibition of nitric oxide synthesis normalized IL-10 production and significantly improved splenocyte proliferative response. These data suggest that nitric oxide is an important modulator of cytokine regulation and immunologic function in thermal injury, thereby ultimately influencing host defense.

Alcoholism↗
PubMed1994

Chromosome 9 allele loss occurs in both basal and squamous cell carcinomas of the skin.

Linkage studies of kindreds with the nevoid basal cell carcinoma syndrome and the high frequency of chromosome 9 allele loss in sporadic basal cell carcinomas indicate that chromosome 9 may contain tumor suppressor genes important in the development of sporadic and familial basal cell carcinomas. The recent mapping of the Ferguson-Smith syndrome, which predisposes affected individuals to the development of multiple lesions histologically indistinguishable from squamous cell carcinomas, suggests that tumor suppressor genes on 9q may also be important in the development of squamous cell neoplasms of the skin. Fifty-four non-melanoma skin cancers (24 basal cell carcinomas, 14 squamous cell carcinomas, and 16 cases of Bowen's disease) were examined for loss of heterozygosity on chromosome 9. Allelic loss at one or more loci on chromosome 9 was observed in 14 of 24 basal cell carcinomas, four of 14 squamous cell carcinomas, and three of 16 cases of Bowen's disease. Allelic deletion of one or more 9q markers was seen in 14 basal cell carcinomas, three squamous cell carcinomas, and three cases of Bowen's disease. Five basal cell carcinomas had interstitial deletions and in one the breakpoint mapped within the nevoid basal cell carcinoma syndrome locus. 9p loss occurred in three of nine informative squamous cell carcinomas. Allelic deletion of 9p markers was not seen in 19 basal cell carcinomas and seven cases of Bowen's disease. These findings suggest that chromosome 9 contains one or more tumor suppressor genes important in the development of both basal and squamous cell carcinomas of the skin.

Alleles↗
PubMed1994

Dissociation of erythema and p53 protein expression in human skin following UVB irradiation, and induction of p53 protein and mRNA following application of skin irritants.

The mechanisms mediating the varied effects of ultraviolet radiation (UVR) on human skin are unclear, although a relationship between erythema and DNA damage is suggested by photosensitivity in xeroderma pigmentosum. Increased p53 expression in response to UVR is thought to reflect direct DNA damage, but recent evidence indicates that UVR also activates membrane and cytosolic signal transduction pathways. In this study, we have investigated the relationship between erythema and p53 induction following UVB and whether this p53 response is specific to UVR. p53 protein expression was determined by immunocytochemistry using the monoclonal antibody DO7, and p53 mRNA expression was examined by non-isotopic in situ hybridization. Incremental doses of UVB were administered to the lower back of eight subjects. Immunostaining revealed that p53 positive nuclei were significantly increased 8 h after suberythemogenic doses of UVB (79 +/- 12), compared to normal unirradiated skin (8 +/- 6, p < 0.0005), but no change in p53 mRNA was seen. Higher UVB doses, which resulted in moderate erythema, resulted in a similar or greater induction of p53 protein. Indomethacin (1% w/v), applied immediately after UVB irradiation, significantly inhibited UVB erythema at 8 h in six subjects (p < 0.005), but did not reduce p53 immunostaining. Dithranol (1 microgram/microliter, n = 8), sodium dodecylsulphate (5%, n = 4), and retinoic acid (0.5%, n = 4), applied for 48 h, caused erythema, significantly increased p53 protein levels (p < 0.05), and also increased p53 mRNA. Our results show that in human skin, UVB-induced p53 elevation can be dissociated from erythema and skin irritants can also induce p53 protein. The induction of p53 mRNA by irritants but not UVR suggests different mechanisms of action.

Adult↗
PubMed1994

Calculation method for retinal irradiance from extended sources.

A method is given for calculating retinal irradiance from an extended source, whether the source is focused on the retina or not. Both the refractive state of the eye and the source distance from the eye are taken into consideration. Examples for emmetropic and ametropic eyes are given.

Humans↗
PubMed1994

Mycetoma caused by Nocardia transvalensis.

Nocardia transvalensis can be a rare cause of actinomycotic mycetoma. A 40 year old man presented with his right arm showing multiple discharging sinuses, which had been present for four years. N transvalensis was isolated from a biopsy specimen. No other underlying disease was detected. The patient was successfully managed with surgical excision of the lesion and treatment with co-trimoxazole. This is the first case of N transvalensis infection to be reported from the Indian subcontinent as far as is known.

Adult↗
PubMed1994

Ondansetron prevents postoperative nausea and vomiting in women outpatients.

Three doses of intravenous (i.v.) ondansetron, 1 mg, 4 mg, and 8 mg, were compared to placebo for their antiemetic effect and safety. The drugs or placebo were administered in a double-blind manner, prophylactically to 589 women undergoing elective outpatient surgical procedures under nitrous oxide opioid-based general endotracheal anesthesia. In the postanesthesia care unit, the number of emetic episodes, periodic assessments of nausea severity using an 11-point scale (0 = no nausea; 10 = worst nausea), vital signs, and adverse events were collected by an independent observer for 2 h. Upon discharge, identical information, with the exception of vital signs, was collected from the patients' diary and via phone call. One pre- and two poststudy blood specimens for hematology and chemistries were evaluated. During the initial 2 h, patients receiving any dose of ondansetron had significantly better complete response rates (no emesis) than those receiving placebo. Over the 24-h study period, patients who received either 4 mg or 8 mg ondansetron continued to have significantly greater complete response rates. Adverse events were minor, and ondansetron-treated patients had profiles similar to those of the placebo. Heart rate, blood pressure, respiratory rate, and laboratory safety variables were not different among the groups. Ondansetron did not prolong awakening time. This study indicates that ondansetron is a safe and effective prophylactic antiemetic for women who have outpatient surgery under nitrous oxide opioid-based general anesthesia.

Adolescent↗