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Biomedical subjects

C P Johnson

Publications and source records attributed to C P Johnson.

At least 19 recordsLinked to original sources

Endoscopic-guided trephination dacryocystorhinostomy (Hesham DCR): technique and pilot trial.

OBJECTIVES: (1) Test the feasibility and the safety of guided transnasal trephination in creating a nasolacrimal fistula. (2) Develop an appropriate lacrimal maintainer and test its value in modulating healing at the fistula site. DESIGN: Prospective, noncomparative interventional case series. PARTICIPANTS: Five cadavers and 19 patients. METHOD: A transcanalicular lacrimal probe penetrated the lacrimal fossa to guide the passage of a flexible trephine up the nose, which created the nasolacrimal communication. A special wide-caliber lacrimal maintainer was inserted along lacrimal tubes within the created passage. OUTCOME MEASURES: For cadaveric study, direct inspection after dissection of the facial flap was performed. For the clinical trial, subjective improvement in watery eye, dye testing, lacrimal probing, lacrimal irrigation, and endoscopic nasal examination. RESULTS: The technique resulted in the creation of a regular fistula of reproducible diameter into which a standard-shaped wide caliber maintainer could be inserted. Three months after removal of the maintainer and 6 months after surgery, a patent ostium was achieved in 17 of 18 (94%) patients who had a completed procedure. Relief of symptoms was achieved in 83%. CONCLUSIONS: Guided endoscopic dacryocystorhinostomy provides a simple and safe option for the treatment of nasolacrimal duct obstruction. The lacrimal maintainer is a useful device to achieve a large patent nasolacrimal communication.

Adult↗

An Islamic understanding of health care: what can it teach us?

Supporting the case for employment and use of non-Christian health care chaplains in the National Health Service (NHS), the Runnymede Trust (1997) states: The inclusiveness or otherwise of a society is seen particularly clearly in the provision which it makes for its members when they fall ill, and perhaps especially when they spend extended time in hospital. At this point of stress and distress in the lives of individuals and their families, are people helped to "maintain their own culture, traditions, language and values"? The Patient's Charter of 1991 requires that health care providers should ensure "respect for privacy, dignity and religious and cultural beliefs".... One way of helping to ensure that such respect is shown is through the appointment of hospital Chaplains.' Although the Patient's Charter (Department of Health 1991) and the subsequent NHS Management Executive document HSG (92)2 (Department of Health 1992) required provision for the religious needs of all patients, in reality, apart from a few exceptions, it led to the appointment of more Church of England Chaplains (Beckford and Gilliat, 1996). Recognizing this problem, Reid and Clarke (1998) indicated NHS Executive willingness to redraw these documents 'provided it comes in the form of a common agreed approach to all faith communities, on the status of chaplaincy and spiritual care in the NHS'.

Culture↗

Assessment tools: are they an effective approach to implementing spiritual health care within the NHS?

Over the last 25 years, many nursing and palliative care journals have carried articles on the subject of 'spiritual' health care. The following is a review of National Health Service (NHS) guidelines and the work of various writers who have contributed to the debate on 'spirit' and 'spiritual needs' from within sociology, palliative care and nursing studies. However, 'spiritual' in the current usage should not be confused with 'religious' and is part of an understanding of what is known as holistic nursing (Dossey et al. 1995). This paper will examine what is meant by 'spiritual' and religious needs and what is indicated by the words 'spiritual' and 'spirit'; and some of the implications for a health care team will be considered. The place of assessment tools in 'spiritual' health care, and the role of the NHS chaplain in the assessment and provision of 'spiritual' health care will be examined.

Holistic Nursing↗

Effects of intestinal transplantation on postprandial motility and regulation of intestinal transit.

BACKGROUND: The effects of intestinal transplantation on gut motility have not been completely defined. In this study we examine the effects of ileal transplantation on ileal smooth muscle contractility, together with gastroduodenal emptying, intestinal flow, and transit rates in a canine model of short-gut syndrome. METHODS: Animals (n = 22) were instrumented with strain gauge transducers, collection cannulae, and infusion catheters to assess motility, intestinal flow and transit rates, and gastroduodenal emptying. Ten animals served to define normal parameters. Six animals underwent a 70% resection of the proximal small intestine to serve as short-gut controls. Six animals underwent removal of a 100-cm segment of the ileum, with cold storage, and autotransplantation the following day combined with a 70% resection of proximal bowel. RESULTS: Transplant animals exhibited delayed gastroduodenal emptying, reduced intestinal flow rates, and postprandial phasic contractions that were similar to short-gut controls. However, transplant animals experienced rapid intestinal transit compared with short-gut controls (4.8 +/- 0.4 cm/min vs 2.0 +/- 0.3 cm/min; mean +/- SEM; P <.05). CONCLUSIONS: The transplanted intestine, even with 18 hours of cold storage, exhibits a relatively normal postprandial motor response. However, adaptive responses of the transplanted intestine, such as regulation of intestine transit, may be impaired by neuromuscular injury associated with denervation or ischemia.

Animals↗

Age related changes in the tunica media of the vertebral artery: implications for the assessment of vessels injured by trauma.

AIMS: To provide an illustrated, detailed semiquantitative analysis of the important degenerative changes along the length of the vertebral artery so that pathologists faced with investigating a fatal arterial injury can identify important pre-existing wall abnormalities. METHODS: Ten transverse annuli were taken along 34 vertebral arteries from 17 subjects and stained sections were prepared using haematoxylin and eosin and the picro-sirius red method. After routine microscopy, the elastic fibres, collagen, and smooth muscle nuclei in the tunica media were quantified using an eyepiece graticule. An estimate of the severity and extent of elastic tissue fragmentation, collagenous scarring, and intimal thickening/atheroma was then undertaken. RESULTS: Smooth muscle counts remained constant along the artery but collagen counts were higher and elastic counts substantially lower within the intracranial segment. Elastic fibre fragmentation was recognised in infancy and was moderately advanced by early adulthood but considerable collagenous scarring developed later in life. Some individuals demonstrated severe fragmentation and scarring before the age of 35 years. The degenerative changes were often focal and spared the intracranial segment almost completely. Atheroma increased with age but was rarely severe and appeared not to worsen appreciably beyond the age of 40 years. An unusual arrangement of the collagenous tissue was described within the upper cervical loops. CONCLUSION: Damaged vertebral arteries need to be sampled extensively to allow a proper histological assessment. The picro-sirius red method was successful in delineating the fine connective tissue structure of the wall and early degenerative changes. An understanding of the age and site specific changes should allow the pathologist to recognise important pre-existing abnormalities more easily.

Adolescent↗

Deficient iNOS in inflammatory bowel disease intestinal microvascular endothelial cells results in increased leukocyte adhesion.

Microvascular endothelial cells play a key role in inflammation by undergoing activation and recruiting circulating immune cells into tissues and foci of inflammation, an early and rate-limiting step in the inflammatory process. We have previously [Binion et al., Gastroenterology112:1898-1907, 1997] shown that human intestinal microvascular endothelial cells (HIMEC) isolated from surgically resected inflammatory bowel disease (IBD) patient tissue demonstrate significantly increased leukocyte binding in vitro compared to normal HIMEC. Our studies [Binion et al., Am. J. Physiol.275 (Gastrointest. Liver Physiol. 38):G592-G603, 1998] have also demonstrated that nitric oxide (NO) production by inducible nitric oxide synthase (iNOS) normally plays a key role in downregulating HIMEC activation and leukocyte adhesion. Using primary cultures of HIMEC derived from normal and IBD patient tissues, we sought to determine whether alterations in iNOS-derived NO production underlies leukocyte hyperadhesion in IBD. Both nonselective (N(G)-monomethyl-L-arginine) and specific (N-Iminoethyl-L-lysine) inhibitors of iNOS significantly increased leukocyte binding by normal HIMEC activated with cytokines and lipopolysaccharide (LPS), but had no effect on leukocyte adhesion by similarly activated IBD HIMEC. When compared to normal HIMEC, IBD endothelial cells had significantly decreased levels of iNOS mRNA, protein, and NO production following activation. Addition of exogenous NO by co-culture with normal HIMEC or by pharmacologic delivery with the long-acting NO donor detaNONOate restored a normal leukocyte binding pattern in the IBD HIMEC. These data suggest that loss of iNOS expression is a feature of chronically inflamed microvascular endothelial cells, which leads to enhanced leukocyte binding, potentially contributing to chronic, destructive inflammation in IBD.

Cell Adhesion↗

Practice parameter: screening and diagnosis of autism: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society [RETIRED].

Autism is a common disorder of childhood, affecting 1 in 500 children. Yet, it often remains unrecognized and undiagnosed until or after late preschool age because appropriate tools for routine developmental screening and screening specifically for autism have not been available. Early identification of children with autism and intensive, early intervention during the toddler and preschool years improves outcome for most young children with autism. This practice parameter reviews the available empirical evidence and gives specific recommendations for the identification of children with autism. This approach requires a dual process: 1) routine developmental surveillance and screening specifically for autism to be performed on all children to first identify those at risk for any type of atypical development, and to identify those specifically at risk for autism; and 2) to diagnose and evaluate autism, to differentiate autism from other developmental disorders.

Asperger Syndrome↗

A biomechanical study of the human vertebral artery with implications for fatal arterial injury.

We studied the biomechanical behaviour of ring and strip specimens from along the length of 18 vertebral arteries taken from 16 subjects aged 28-90 years, in order to consider some of the factors which may play a role in vertebral artery rupture. The method was chosen to allow a comparison between circumferential distension (ring samples) and longitudinal extension, (strip samples). The samples were extended between the jaws of a tensile testing apparatus until the specimen broke and a number of biomechanical parameters were derived. These were the percentage extension to break, the tensile strength, Young's modulus and the peak load. There were a number of important findings. The vertebral artery was shown to be susceptible to longitudinal stretching with a number of strip samples breaking when extended by as little as 16-20%. The tensile strength and load at peak of the strip specimens were correspondingly lower than for the ring samples. Marked intersubject variations were shown for all these parameters and prominent changes in behaviour occurred along the vertebral artery. This study indicates that the artery may be susceptible to head and neck movements which cause the vessel to stretch, and intersubject variations in behaviour may be one important explanation for the marked differences in outcome which appear to exist in subjects who suffer broadly similar head and neck insults.

Adult↗

Improved graft survival after renal transplantation in the United States, 1988 to 1996.

BACKGROUND: The introduction of cyclosporine has resulted in improvement in the short-term outcome of renal transplantation, but its effect on the long-term survival of kidney transplants is not known. METHODS: We analyzed the influence of demographic characteristics (age, sex, and race), transplant-related variables (living or cadaveric donor, panel-reactive antibody titer, extent of HLA matching, and cold-ischemia time), and post-transplantation variables (presence or absence of acute rejection, delayed graft function, and therapy with mycophenolate mofetil and tacrolimus) on graft survival for all 93,934 renal transplantations performed in the United States between 1988 and 1996. A regression analysis adjusted for these variables was used to estimate the risk of graft failure within the first year and more than one year after transplantation. RESULTS: From 1988 to 1996, the one-year survival rate for grafts from living donors increased from 88.8 to 93.9 percent, and the rate for cadaveric grafts increased from 75.7 to 87.7 percent. The half-life for grafts from living donors increased steadily from 12.7 to 21.6 years, and that for cadaveric grafts increased from 7.9 to 13.8 years. After censoring of data for patients who died with functioning grafts, the half-life for grafts from living donors increased from 16.9 years to 35.9 years, and that for cadaveric grafts increased from 11.0 years to 19.5 years. The average yearly reduction in the relative hazard of graft failure after one year was 4.2 percent for all recipients (P<0.001), 0.4 percent for those who had acute rejection (P=0.57), and 6.3 percent for those who did not have acute rejection (P<0.001). CONCLUSIONS: Since 1988, there has been a substantial increase in short-term and long-term survival of kidney grafts from both living and cadaveric donors.

Adult↗

Reduction of myocardial nitrosyl complex formation by a nitric oxide scavenger prolongs cardiac allograft survival.

Nitric oxide synthase (NOS) inhibitors have been shown to reduce NO but yield conflicting results on cardiac allograft survival. In this study, we provide an alternative approach specifically to examine the efficacy of a NO scavenger on nitrosyl complex formation and graft survival in a model of heterotopic cardiac transplantation. Efficacy was examined under both acute and chronic conditions (i.e., without or with immunosuppression, respectively). Electron paramagnetic resonance (EPR) spectroscopy of frozen myocardial tissue from untreated allografts showed progressive increases in nitrosylheme and nitrosomyoglobin before graft failure. These signals were not seen in either isografts or native hearts of allograft recipients. Both plasma nitrate plus nitrite and myocardial nitrosyl complex formation in cardiac allografts were significantly decreased in recipient animals treated with the NO scavenger, NOX-100, or by low-dose cyclosporine (CsA). Both interventions were nearly equivalent in significantly prolonging graft survival. The short-term combination treatment of both NOX-100 plus CsA completely eliminated myocardial nitrosyl complex formation and synergistically prolonged graft survival. Long-term combination drug treatment (days 0-100) followed by cessation of therapy resulted in permanent graft acceptance with no evidence for nitrosyl complex formation. These studies support a role of NO in cardiac allograft rejection. Furthermore, these studies indicate a potential therapeutic value of NO scavengers in preventing organ rejection.

Animals↗

Recurrent and de novo glomerular disease after renal transplantation: a report from Renal Allograft Disease Registry (RADR).

INTRODUCTION: Short-term and long-term results of renal transplantation have improved over the past 15 years. However, there has been no change in the prevalence of recurrent and de novo diseases. A retrospective study was initiated through the Renal Allograft Disease Registry, to evaluate the prevalence and impact of recurrent and de novo diseases after transplantation. MATERIALS AND METHODS: From October 1987 to December 1996, a total of 4913 renal transplants were performed on adults at the Medical College of Wisconsin, University of Cincinnati, University of California at San Francisco, University of Louisville, University of Washington, Seattle, and Washington University School of Medicine. The patients were followed for a minimum of 1 year. A total of 167 (3.4%) cases of recurrent and de novo disease were diagnosed by renal biopsy. These patients were compared with other patients who did not have recurrent and de novo disease (n=4746). There were more men (67.7% vs. 59.8%, P<0.035) and a higher number of re-transplants (17% vs. 11.5%, P<0.005) in the recurrent and de novo disease group. There was no difference in the rate of recurrent and de novo disease according to the transplant type (living related donor vs. cadaver, P=NS). Other demographic findings were not significantly different. Common forms of glomerulonephritis seen were focal segmental glomerulosclerosis (FSGS), 57; immunoglobulin A nephritis, 22; membranoproliferative glomerulonephritis (GN), 18; and membranous nephropathy, 16. Other diagnoses include: diabetic nephropathy, 19; immune complex GN, 12; crescentic GN (vasculitis), 6; hemolytic uremic syndrome-thrombotic thrombocytopenic purpura (HUS/TTP), 8; systemic lupus erythematosus, 3; Anti-glomerular basement membrane disease, 2; oxalosis, 2; and miscellaneous, 2. The diagnosis of recurrent and de novo disease was made after a mean period of 678 days after the transplant. During the follow-up period, there were significantly more graft failures in the recurrent disease group, 55% vs. 25%, P<0.001. The actuarial 1-, 2-, 3-, 4, and 5-year kidney survival rates for patients with recurrent and de novo disease was 86.5%, 78.5%, 65%, 47.7%, and 39.8%. The corresponding survival rates for patients without recurrent and de novo disease were 85.2%, 81.2%, 76.5%, 72%, and 67.6%, respectively (Log-rank test, P<0.0001). The median kidney survival rate for patients with and without recurrent and de novo disease was 1360 vs. 3382 days (P<0.0001). Multivariate analysis using the Cox proportional hazard model for graft failure was performed to identify various risk factors. Cadaveric transplants, prolonged cold ischemia time, elevated panel reactive antibody, and recurrent disease were identified as risk factors for allograft failure. The relative risk (95% confidence interval) for graft failure because of recurrent and de novo disease was 1.9 (1.57-2.40), P<0.0001. The relative risk for graft failure because of posttransplant FSGS was 2.25 (1.6-3.1), P<0.0001, for membranoprolifera. tive glomerulonephritis was 2.37 (1.3-4.2), P<0.003, and for HUS/TTP was 5.36 (2.2-12.9), P<0.0002. There was higher graft failure (64.9%) and shorter half-life (1244 days) in patients with recurrent FSGS. CONCLUSION: In conclusion, recurrent and de novo disease are associated with poorer long-term survival, and the relative risk of allograft loss is double. Significant impact on graft survival was seen with recurrent and de novo FSGS, membranoproliferative glomerulonephritis, and HUS/TTP.

Adult↗

Acute torsion of the renal transplant after combined kidney-pancreas transplant.

BACKGROUND: Surgical complications after combined kidney and pancreas transplantation are a major source of morbidity and mortality. Complications related to the pancreas occur with greater frequency as compared to renal complications. The occurrence in our practice of two cases of renal infarction resulting from torsion about the vascular pedicle led to our retrospective review of similar vascular complications after combined kidney and pancreas transplantation. METHODS: Charts were reviewed retrospectively, and two patients were identified who experienced torsion about the vascular pedicle of an intra-abdominally placed renal allograft. RESULTS: Two patients who had received combined intraperitoneal kidney and pancreas transplantation presented at 16 and 11 months after transplant, respectively, with abdominal pain and decreased urine output. One patient had radiological documentation of abnormal rotation before the graft loss; unfortunately, the significance of this finding was missed. Diagnosis was made in both patients at laparotomy, where the kidneys were infarcted secondary to torsion of the vascular pedicle. Both patients underwent transplant nephrectomy and subsequently received a successful second cadaveric renal transplant. CONCLUSIONS: The mechanism of this complication is a result of the intra-abdominal placement of the kidney, length of the vascular pedicle, excess ureteral length, and paucity of adhesions secondary to steroid administration. These factors contribute to abnormal mobility of the kidney. Technical modifications such as minimizing excess ureteral length and nephropexy may help to avoid this complication.

Adult↗

Inflammatory modulation of calcium-activated potassium channels in canine colonic circular smooth muscle cells.

BACKGROUND & AIMS: The characteristics of colonic circular smooth muscle slow waves are altered during inflammation. The aim of this study was to examine whether inflammation modulates the open-state probability of Ca2+-activated K+ (KCa) channels in these cells to contribute to these alterations. METHODS: The experiments were performed on freshly dissociated single smooth muscle cells from the canine colon using standard patch clamp methods. Inflammation was induced by mucosal exposure to ethanol and acetic acid. RESULTS: Inflammation decreased the open-state probability of large-conductance KCa (BK) channels in the cell-attached and excised inside-out configurations. The voltage sensitivity of the channels was also reduced during inflammation. Inflammation had no significant effect on the large, medium, and small conductances or the unitary current levels of channel openings. However, it decreased the maximum number of simultaneous channel openings. The channels were Ca2+-dependent and were blocked by tetraethylammonium and charybdotoxin in normal and inflamed cells. CONCLUSIONS: Inflammation decreases the open-state probability of BK channels. This may partially reverse the decrease in duration and amplitude of slow waves and depolarization of membrane potential seen in inflammation.

Animals↗

The screening and diagnosis of autistic spectrum disorders.

The Child Neurology Society and American Academy of Neurology recently proposed to formulate Practice Parameters for the Diagnosis and Evaluation of Autism for their memberships. This endeavor was expanded to include representatives from nine professional organizations and four parent organizations, with liaisons from the National Institutes of Health. This document was written by this multidisciplinary Consensus Panel after systematic analysis of over 2,500 relevant scientific articles in the literature. The Panel concluded that appropriate diagnosis of autism requires a dual-level approach: (a) routine developmental surveillance, and (b) diagnosis and evaluation of autism. Specific detailed recommendations for each level have been established in this document, which are intended to improve the rate of early suspicion and diagnosis of, and therefore early intervention for, autism.

Asperger Syndrome↗

Pre-transplant identification of risk factors that adversely affect length of stay and charges for renal transplantation.

BACKGROUND: In the current era of renal transplantation, increasing attention is being focused on resource utilization. The purpose of this study was to identify demographic, medical and immunologic risk factors that are associated with changes in length of stay (LOS) and charges for renal transplantation. METHOD: The study was a retrospective analysis of 311 consecutive renal transplants performed at a single institution. Univariate and multivariate analyses were used to examine relationships between risk factors, LOS, charges and post-operative complications. RESULTS: The following pre-transplant variables were found to be independently significant in predicting increased LOS and/or charges: African-American race, obesity for women, chronic obstructive pulmonary disease (COPD), presence of cardiac disease or previous stroke, pre-transplant dialysis time > or = 1 yr, a 10% increase in panel reactive antibody (PRA), cadaver donor and retransplantation. The analyses were performed with and without adjustment for key outcome variables such as delayed graft function (DGF) and use of induction antibody therapy. Increased LOS or charges for specific risk factors could be attributed to increased complication rates, including delayed graft function seen with various co-morbidities, or increased immunologic risk and more frequent use of induction antibody therapy. CONCLUSION: Analysis of linked financial and clinical databases can reveal demographic, medical and immunologic risk factors that correlate with LOS, charges and complications for renal transplantation. Efforts to establish quantitative relationships for various risk factors relative to resource utilization will become important in managed care and/or capitated healthcare delivery systems.

Adult↗

Renal transplantation for end-stage renal disease following bone marrow transplantation: a report of six cases, with and without immunosuppression.

UNLABELLED: BACKGROUND. Over 12000 bone marrow transplantations (BMT) are performed in the USA each year. This procedure is associated with significant morbidity including acute and chronic renal failure (CRF). CRF after BMT is usually secondary to radiation nephropathy and,or cyclosporine (CsA) toxicity. Survival on dialysis therapy for patients with radiation nephropathy is poor and renal transplantation may be a preferable form of renal-replacement therapy. METHODS: We report our experience with renal transplantation in 6 patients with end-stage renal disease (ESRD) following BMT: 4 as a result of radiation nephropathy; one secondary to hemolytic uremic syndrome; and 1 as a result of antitubular basement membrane nephritis. Ages at the time of BMT ranged from 26 to 40 yr. ESRD developed after a mean period of 94 months (range 42-140 months) after BMT. The kidney source was from a living donor in 5 patients, and a cadaveric donor (CAD) in 1 patient. In 3 recipients, the bone marrow and kidney were from the same donor. They are managed without any immunosuppressive therapy. The other 3 were initiated on triple therapy (prednisone, mycophenolate mofetil/azathioprine and cyclosporine/tacrolimus). RESULTS: These patients have been followed for up to 31 months (range 3-30 months) after kidney transplant, and 5 out of 6 are alive with functioning bone marrow and renal transplants. Their plasma creatinines range from 70 to 160 micromol/L (mean 97 micromol/L). One patient died following metastatic squamous cell cancer of the genital tract. CONCLUSIONS: 1) Renal transplant is a feasible alternative for patients with ESRD following BMT: 2) if bone marrow and kidney are from the same donor, the recipient requires little or no maintenance immunosuppression; 3) short-term results show good survival, but long-term follow-up is needed: 4) infections and malignancy post-renal transplantation were seen in recipients who needed immunosuppression; and 5) reduction in immunosuppression may be needed in such post-BMT patients who undergo kidney transplants.

Adult↗

American Academy of Pediatrics. Committee on Children With Disabilities. Care coordination: integrating health and related systems of care for children with special health care needs.

Care coordination is a process that links children with special health care needs and their families to services and resources in a coordinated effort to maximize the potential of the children and provide them with optimal health care. Care coordination often is complicated because there is no single entry point to multiple systems of care, and complex criteria determine the availability of funding and services among public and private payers. Economic and sociocultural barriers to coordination of care exist and affect families and health care professionals. In their important role of providing a medical home for all children, primary care pediatricians have a vital role in the process of care coordination, in concert with the family.

Case Management↗