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1.
Eye (Lond) ; 33(6): 948-952, 2019 06.
Article in English | MEDLINE | ID: mdl-30742028

ABSTRACT

OBJECTIVES: To report outcome data on the first 5000 consecutive cataract cases at a new paperless eye unit and benchmark against the Royal College of Ophthalmologists' National Ophthalmology Database (RCOphth NOD). METHODS: Using the in-built audit tool of the electronic medical records system, data from all cataract operations performed between 1 April 2014 and 13 January 2017 were compiled. RESULTS: Five thousand and eight cases were recorded of which the overall intra-operative complication rate was 2.4%, the most common being posterior capsular rupture-1.14%. Follow-up data on post-operative complications were recorded in 98.6% of cases. Pre- and post-operative visual acuities was measured in 98.0% of cases. In all, 40.8% of eyes achieved a visual acuity of 6/6 or better and 90.7% achieved 6/12 or better. CONCLUSIONS: A data set of >5000 consecutive cataract operations was obtained in this eye department. The recording of pre- and post-operative visual acuity in 98% of cases compare very favourably to the RCOphth NOD Audit Report 2017 where pre- and post-operative visual acuities were recorded in only 57.1% of operations. Despite this difference, the outcome measures from this unit and RCOphth NOD were very similar, validating the results of the RCOphth NOD audit reports. Significantly, when applying the RCOphth NOD audit criteria for measuring post-operative visual acuity, approximately 15% of cases were excluded from the data set, reducing the completeness of the data set. Paperless ophthalmology units are feasible in today's NHS and can produce near complete cataract data sets; this can ultimately lead to more comprehensive and reliable aggregate cataract outcome data.


Subject(s)
Cataract Extraction/statistics & numerical data , Electronic Health Records/organization & administration , Intraoperative Complications/epidemiology , Ophthalmology/statistics & numerical data , Postoperative Complications/epidemiology , Quality Improvement , Registries , Aged , Data Accuracy , Female , Follow-Up Studies , Humans , Incidence , Male , Retrospective Studies , United Kingdom/epidemiology , Visual Acuity
2.
Osteoporos Int ; 30(3): 611-620, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30456573

ABSTRACT

Chronic inflammation and protein energy wasting (PEW) syndrome are common in kidney transplant recipients (KTR). The presence of inflammation and PEW syndrome can directly affect bone resorption and bone formation, leading to bone loss and fractures. We showed PEW is independently associated with new clinically detected bone fractures in prevalent KTR. INTRODUCTION: Kidney transplant recipients (KTR) have a 4-fold higher risk of fracture compared to the general population. Chronic inflammation and PEW syndrome are common in KTR and are associated with poor outcomes. We hypothesized that the Malnutrition-Inflammation Score (MIS), a validated measure of PEW, is associated with higher risk of bone fractures in KTR. METHODS: This prospective cohort study included 839 prevalent KTR from a Central European academic center. MIS, a semiquantitative instrument of PEW, was calculated at the study entry. Self-reported history of fractures was recorded during the 2-year follow-up period. The association between MIS and bone fractures was examined in logistic regression analyses with adjustment for age, gender, eGFR, smoking habits, history of pre-transplant bone fractures, and acute rejection. RESULTS: Mean age was 51 ± 13 years, and 56% of patients were males with median (interquartile range) transplant vintage 69 (38-112) months, estimated glomerular filtration rate 55 ± 21 ml/min/1.73 m2, and calculated MIS 3 (2-4) at enrollment. Fifty-five (7%) patients experienced self-reported bone fractures during the 2-year follow-up period. Higher MIS score showed linear association with increased risk of fracture. Each one-point higher MIS was associated with 23% higher risk of bone fractures (odds ratio (OR) and 95% CI 1.23, 1.12-1.34), which remained significant after multivariable adjustments (OR 1.17, 95% CI 1.06-1.29). CONCLUSION: The MIS is independently associated with new clinically detected bone fractures in prevalent KTR.


Subject(s)
Inflammation/complications , Kidney Transplantation/adverse effects , Osteoporotic Fractures/etiology , Protein-Energy Malnutrition/complications , Adult , Aged , Female , Humans , Male , Middle Aged , Postoperative Complications/etiology , Prospective Studies , Risk Factors , Self Report , Severity of Illness Index
3.
Clin Transplant ; 28(11): 1271-8, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25159302

ABSTRACT

Clinically useful predictors of weight gain could be used to reduce the epidemic of post-kidney transplant obesity and resulting co-morbidities. The purpose of this study was to identify predictors of weight gain at 12 months following kidney transplant in a cohort of 96 recipients. Demographic, clinical, and environmental data were obtained at transplant and 12 months. Descriptive, correlational, and Bayesian network analysis were used to identify predictors. For the 52 (55.9%) recipients who gained weight, the average amount gained was 9.18 ± 6.59 kg. From the 15 baseline factors that met inclusion criteria, Bayesian network modeling identified four baseline predictors for weight gain: younger age, higher carbohydrate consumption, higher trunk fat percentage, and higher perception of mental health quality of life. Three are modifiable through either pre- or immediate post-transplant clinical intervention programs.


Subject(s)
Kidney Failure, Chronic/surgery , Kidney Transplantation/adverse effects , Obesity/etiology , Weight Gain , Adult , Age Factors , Aged , Body Mass Index , Cohort Studies , Feeding Behavior , Female , Humans , Male , Middle Aged , Quality of Life , Risk Factors , Young Adult
4.
Am J Transplant ; 8(11): 2243-51, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18808402

ABSTRACT

A consensus conference sponsored by the American Society of Transplant Surgeons (ASTS), American Society of Transplantation (AST), United Network for Organ Sharing (UNOS) and American Society of Nephrology (ASN) convened to examine simultaneous liver-kidney transplantation (SLK). Directors from the 25 largest liver transplant programs along with speakers with recognized expertise attended. The purposes of this conference were to propose indications for SLK, to establish a prospective data registry and, most importantly, to recommend standard listing criteria for these patients. Scientific registry of transplant recipients data, and single center data regarding chronic kidney disease (CKD) and acute kidney injury (AKI) in conjunction with liver failure as a basis for SLK was presented and discussed. The consensus was that Regional Review Boards (RRB) should determine listing for SLK, as with other MELD exceptions, with automatic approval for: (i) End-stage renal disease with cirrhosis and symptomatic portal hypertension or hepatic vein wedge pressure gradient >/= 10 mm Hg (ii) Liver failure and CKD with GFR /= 2.0 mg/dL and dialysis >/= 8 weeks (iv) Liver failure and CKD and biopsy demonstrating > 30% glomerulosclerosis or 30% fibrosis. The RRB would evaluate all other requests to determine appropriateness.


Subject(s)
Kidney Failure, Chronic/therapy , Kidney Transplantation/methods , Liver Diseases/therapy , Liver Transplantation/methods , Aged , Biopsy , Fibrosis/complications , Fibrosis/therapy , Gastroenterology/methods , Humans , Hypertension/complications , Hypertension/therapy , Middle Aged , Nephrology/methods , Registries , Treatment Outcome
5.
Clin Exp Dermatol ; 32(2): 191-6, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17342797

ABSTRACT

BACKGROUND: Hypotrichosis with juvenile macular dystrophy (HJMD) is a rare autosomal recessive disorder characterized by sparse and short hair, heralding progressive degeneration of the retinal pigment epithelium, which leads to blindness by the second decade of life. The disorder is caused by mutations in CDH3, a gene encoding P-cadherin, a major component of adherens junctions. Most HJMD cases reported to date have been shown to be caused by homozygous CDH3 mutations segregating in consanguineous families. AIM AND METHODS: To elucidate the genetic basis of HJMD in two nonconsanguineous families, we established the coding sequence of CDH3 in four patients and their healthy siblings. RESULTS: The four patients demonstrated markedly variable degrees of visual acuity impairment. Novel biallelic recessive mutations were identified in all affected individuals. One patient in the first family was found to carry two heterozygous mutations, IVS2 + 1G-->A and p.E504K; the other three patients in the second family were compound heterozygous for a missense mutation, p.H575R, and a nonsense mutation, p.R221X. CONCLUSION: This paper expands the spectrum of known mutations in CDH3 and points to the existence of clinical heterogeneity in this syndrome.


Subject(s)
Cadherins/genetics , Corneal Dystrophies, Hereditary/genetics , Hypotrichosis/genetics , Mutation, Missense/genetics , Adolescent , Child , DNA Mutational Analysis , Female , Heterozygote , Humans , Male , Molecular Sequence Data
6.
Plant Mol Biol ; 57(5): 645-57, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15988561

ABSTRACT

An aleurain-like protein, BoCP5, is up-regulated during harvest-induced senescence in broccoli floret and leaf tissue. BoCP5 is most closely related to an Arabidopsis protein (91%, AAF43041) and has 71% identity to barley aleurain (P05167). The mRNA for this gene accumulates within 6 h after harvest in broccoli florets, and its expression is reduced in tissue that has been held in senescence-delaying treatments (e.g. water, sucrose feeding, controlled atmosphere). The gene is also expressed in leaves during aging-related and harvest-induced senescence. Analysis of protein bands that cross-react with antibodies raised to the bacterial BoCP5 fusion protein, revealed prominent immunoreactive bands at ca. 26, 28, 31, and 38 kD in floret tissue. The 31 kD band was absent in protein extracts from leaf tissue. Agrobacterium-mediated transformation was used to produce transgenic broccoli plants with down-regulated BoCP5. A reduction in the postharvest expression of BoCP5 in floret tissue was achieved for four transgenic lines in the current study. In three of these lines postharvest floret senescence (yellowing) was delayed, and florets contained significantly greater chlorophyll levels during postharvest storage at 20 degrees C than wild-type plants. Line 4 showed the greatest down-regulation of BoCP5, and in this line postharvest protease activity remained at pre-harvest levels, and the yield of soluble proteins extracted from florets after harvest was significantly greater than that of wild-type tissue.


Subject(s)
Brassica/genetics , Cysteine Endopeptidases/genetics , Flowers/genetics , Amino Acid Sequence , Blotting, Western , Brassica/enzymology , Brassica/physiology , Cysteine Endopeptidases/metabolism , DNA, Antisense/genetics , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA, Complementary/isolation & purification , Flowers/enzymology , Flowers/physiology , Gene Expression Regulation, Developmental , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Molecular Sequence Data , Plants, Genetically Modified , RNA, Messenger/genetics , RNA, Messenger/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Time Factors
7.
Semin Dial ; 18(6): 550-7, 2005.
Article in English | MEDLINE | ID: mdl-16398720

ABSTRACT

Most recent randomized controlled trials (RCTs) have found that hemodialysis graft surveillance combined with preemptive correction of stenosis does not prolong graft survival. Nevertheless, such programs may be justified if they reduce other adverse outcomes or decrease the cost of care. This study tested this hypothesis by applying a secondary analysis to our original RCT. This study of 101 patients evaluated correction of stenosis based upon blood flow (Q) and stenosis surveillance. Patients were randomly assigned to control, flow, or stenosis groups, and were followed for up to 28 months. Q was measured monthly by ultrasound dilution; stenosis was measured quarterly by duplex ultrasound. Stenosis of 50% was corrected by percutaneous transluminal angioplasty (PTA) after referral for angiography. Referral criteria were: control group, clinical criteria; flow group, Q < 600 ml/min or clinical criteria; stenosis group, stenosis > 50% or clinical criteria. We compared access-related hospitalizations and cost of care, and use of central venous dialysis catheters (CVCs), among the three groups. Hospitalization rates were higher in the control and flow groups than in the stenosis group (0.50, 0.57, 0.18/patient-year, respectively [p < 0.01]), and hospitalization costs were lowest in the stenosis group (p = 0.026). The stenosis group had a trend toward lowest CVC rates (0.44, 0.32, 0.20/patient-year, respectively [p = 0.20]). The costs of care were higher in the control and flow groups than in the stenosis group (dollar 3727, dollar 4839, dollar 3306/patient-year, respectively [p = 0.015]). The costs of stenosis (dollar 142/patient-year) and Q (dollar 279/patient-year) measurements were minimal compared to the total cost of access-related care. In conclusion, stenosis surveillance by duplex ultrasound combined with preemptive correction yielded reduced hospitalization rates and costs, reduced total cost of access-related care, and a trend of reduced CVC rates. In contrast, flow surveillance did not yield a significant benefit. Stenosis surveillance provides important benefits that may justify application of such programs.


Subject(s)
Arteriovenous Shunt, Surgical , Graft Occlusion, Vascular/diagnostic imaging , Graft Occlusion, Vascular/economics , Hospital Costs , Renal Dialysis , Ultrasonography, Doppler, Duplex , Analysis of Variance , Angioplasty, Balloon , Costs and Cost Analysis , Double-Blind Method , Female , Graft Occlusion, Vascular/therapy , Graft Survival , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Poisson Distribution , Prospective Studies , Statistics, Nonparametric
8.
Kidney Int ; 64(1): 272-80, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12787419

ABSTRACT

BACKGROUND: It is widely accepted that hemodialysis graft surveillance combined with correction of stenosis reduces thrombosis and prolongs graft survival. Nevertheless, few randomized controlled trials have evaluated this approach. METHODS: In this randomized controlled trial, 101 patients were assigned to control, flow (Qa), or stenosis groups, and were followed for up to 28 months. All patients had monthly Qa measured by ultrasound dilution and quarterly percent stenosis measured by duplex ultrasound. Referral for angiography was based on the following criteria: (1) control group (N = 34), clinical criteria; (2) flow group (N = 32), Qa <600 mL/min or clinical criteria; and (3) stenosis group (N = 35), stenosis>50% or clinical criteria. Stenosis >or=50% during angiography was corrected by preemptive percutaneous transluminal angioplasty (PTA). RESULTS: The preemptive PTA rate in the control group (0.22/patient year) was two thirds the rate in the flow group (0.34/patient year), and was highest in the stenosis group (0.65/patient year, P < 0.01). The percentage of grafts that thrombosed was similar in the control (47%) and flow groups (53%), but reduced in the stenosis group (29%, P = 0.10). Two-year graft survival was similar in the control (62%), flow (60%), and stenosis groups (64%) (P = 0.89). CONCLUSION: Qa and stenosis surveillance were not associated with improved graft survival, although thrombosis was reduced in the stenosis group. The most important factors in this result may be that monthly Qa and quarterly stenosis measurements were not accurate or timely indicators of risk of thrombosis or progressive stenosis. This study does not support the concept that Qa or stenosis surveillance are superior to aggressive clinical monitoring.


Subject(s)
Blood Circulation , Blood Vessels/physiopathology , Blood Vessels/transplantation , Population Surveillance , Renal Dialysis , Thrombosis/prevention & control , Angioplasty, Balloon , Blood Vessels/diagnostic imaging , Case-Control Studies , Constriction, Pathologic , Female , Graft Survival , Humans , Male , Middle Aged , Ultrasonography, Doppler, Duplex
9.
Liver Transpl ; 7(8): 693-7, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11510013

ABSTRACT

Steroids have been 1 of the primary modes of immunosuppression since the inception of transplantation and have been credited with both the prevention and treatment of rejection. Steroids also have been held responsible for increased infections, posttransplantation diabetes, and recurrent hepatitis after orthotopic liver transplantation (OLT). The purpose of this ongoing prospective randomized trial is to eliminate steroid use in OLT through induction with rabbit antithymocyte globulin (RATG). This is the first report of a prospective randomized trial in OLT achieving complete absence of steroids. Seventy-one adult patients were prospectively randomized to administration of RATG or steroids. Thirty-six patients were randomized to the administration of RATG induction at a dose of 1.5 mg/kg intravenously (IV) beginning during the anhepatic phase. No steroids were administered. Patients were administered a second 1.5-mg/kg dose of RATG post-OLT day 1. Thirty-five patients were randomized to the administration of methylprednisolone, which had been our standard immunosuppressive protocol. These patients were administered methylprednisolone, 1,000 mg IV, initiated during the anhepatic phase and followed by steroid taper. Maintenance immunosuppression consisted of tacrolimus and mycophenolate, with or without prednisone. Three patients died in each group, for an overall survival rate of 91% in each group. One patient in each group required re-OLT, for a graft survival rate of 89% in each group. Seven patients administered RATG had biopsy-proven rejection (20.5%), all of whom were successfully treated by increasing tacrolimus doses. Eleven patients administered steroid had biopsy-proven rejection (32%), 7 (64%) of whom required additional steroids for treatment, whereas 4 patients (36%) were successfully treated by increasing tacrolimus doses. The incidence of rejection was not statistically significant; however, there was a significant difference in the incidence of steroid-requiring rejection (P =.01). The incidence of recurrent hepatitis C was 50% in RATG patients and 71% in steroid patients (P = not significant). The incidence and severity of infectious complications were slightly lower in RATG patients, accounted for by a greater incidence of cytomegalovirus (CMV) infection in the steroid patients. RATG induction enables complete avoidance of steroid use in OLT with a trend toward a lower rejection rate, decreased incidence of post-OLT diabetes and recurrent hepatitis C, and decreased CMV infection. This prospective randomized trial gives encouraging support that steroids can be safely eliminated in OLT.


Subject(s)
Antilymphocyte Serum/therapeutic use , Liver Transplantation , Animals , Antilymphocyte Serum/administration & dosage , Cytomegalovirus Infections/epidemiology , Drug Administration Schedule , Graft Rejection/epidemiology , Hepatitis C/epidemiology , Humans , Incidence , Methylprednisolone/therapeutic use , Postoperative Complications/epidemiology , Prospective Studies , Rabbits , Recurrence , Steroids/therapeutic use
11.
Clin Transplant ; 15 Suppl 6: 55-8, 2001.
Article in English | MEDLINE | ID: mdl-11903388

ABSTRACT

Here we describe a strategy for using livers from hepatitis B core antibody (anti-HBc) positive donors in anti-HBc negative recipients and report our preliminary results. Adult anti-HBc negative recipients were immunized against hepatitis B virus (HBV) prior to transplantation. Liver biopsies from anti-HBc positive, HBs Ag negative donors were performed at the time of procurement to rule out acute hepatitis or chronic liver disease. Donor serum and liver samples were collected for HBV DNA analysis by PCR. Recipients were given HBIG (10000 units, i.v.) during the anhepatic phase of transplantation. Patients were treated with lamivudine (150 mg) beginning on postoperative day (POD) 1. If HBV DNA was not detected in either donor liver or serum by PCR, recipient antiviral therapy was stopped. If donor liver and serum were positive for HBV DNA by PCR, the recipient was maintained on combination lamivudine and HBIG therapy. If HBV DNA was detected in donor liver but not in donor serum, the patient was managed on lamivudine therapy alone. Between February 1999 and June 2000, six anti-HBc negative recipients received liver transplants from anti-HBc positive donors. PCR analysis of serum from the six donors was negative for HBV DNA in each, while donor liver PCR analysis was positive in five of six for HBV DNA. Accordingly, all patients were given HBIG in the anhepatic phase of transplantation and five of six were maintained on daily lamivudine therapy. Follow-up periods have ranged from 2 to 18 months. There has been no emergence of de novo hepatitis B. Serial serum HBs Ag and HBV DNA assays have all proven negative. Moreover, while on lamivudine therapy, 2 patients now have undetectable HBV DNA in hepatic allograft biopsies by PCR analysis. Our strategy for using livers from anti-HBc donors has yielded promising initial results. De novo hepatitis B has not occurred and our data suggest residual hepatitis B virus may be eradicated in recipients maintained on lamivudine therapy.


Subject(s)
Hepatitis B/prevention & control , Hepatitis B/transmission , Liver Transplantation , Adult , Aged , Antiviral Agents/therapeutic use , DNA, Viral/analysis , Female , Hepatitis B Antibodies/metabolism , Hepatitis B Core Antigens , Hepatitis B Vaccines/administration & dosage , Humans , Lamivudine/therapeutic use , Male , Middle Aged , Polymerase Chain Reaction , Tissue Donors
13.
IEEE Trans Biomed Eng ; 47(7): 893-901, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10916260

ABSTRACT

Multielectrode arrays used to detect cellular activation have become so dense (electrodes per square millimeter) as to jeopardize the basic assumptions of activation mapping; namely, that electrodes are points adequately separated as to not interfere with the tissue or each other. This paper directly tests these assumptions for high-density electrode arrays. Using a finite element model with modified Fitzhugh-Nagumo kinetics, we represent electrodes as isopotential surfaces of varying widths and spacing ratio (SR) (center-to-center spacing divided by electrode width). We examine the signal strength and ability of a single electrode to detect activation due to a passing wavefront. We find that high-density arrays do not cause significant wavefront curvature or alter activation timing in the underlying tissue. Relationships between signal strength, cross talk, and array design are explained by the interaction of the propagating wavefront and induced sources on the isopotential electrodes. Sensitivity analysis shows that these results may be generalized to a wide range of physiologically relevant designs and applications. We conclude that electrode array designs in which electrode spacing greatly exceeds electrode diameter are overly conservative and that arrays with a SR of less than 2.0 may perform successfully in electrophysiological studies.


Subject(s)
Electrodes , Heart/physiology , Animals , Biomedical Engineering , Computer Simulation , Electrocardiography/instrumentation , Electrocardiography/statistics & numerical data , Heart Conduction System/physiology , Humans , Models, Cardiovascular
14.
J Appl Physiol (1985) ; 89(1): 251-8, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10904059

ABSTRACT

Little is known regarding the role of androgenic hormones in the maintenance of myosin heavy chain (MHC) composition of rodent masticatory muscles. Because the masseter is the principal jaw closer in rodents, we felt it was important to characterize the influence of androgenic hormones on the MHC composition of the masseter. To determine the extent of sexual dimorphism in the phenotype of masseter muscle fibers of adult (10-mo-old) C57 mice, we stained tissue sections with antibodies specific to type IIa and IIb MHC isoforms. Females contain twice as many fibers containing the IIa MHC as males, and males contain twice as many fibers containing the IIb MHC as females. There is a modest amount of regionalization of MHC phenotypes in the mouse masseter. The rostral portions of the masseter are composed mostly of type IIa fibers, whereas the midsuperficial and caudal regions contain mostly type IIb fibers. Using immunoblots, we showed that castration results in an increase in the expression of type IIa MHC fibers in males. Ovariectomy has no effect on the fiber type composition in females. We conclude that testosterone plays a role in the maintenance of MHC expression in the adult male mouse masseter.


Subject(s)
Masseter Muscle/metabolism , Myosin Heavy Chains/biosynthesis , Sex Characteristics , Age Factors , Animals , Antibody Specificity , Blotting, Western , Female , Immunohistochemistry , Male , Masseter Muscle/chemistry , Mice , Mice, Inbred C57BL , Myosin Heavy Chains/analysis , Myosin Heavy Chains/immunology , Orchiectomy , Ovariectomy
15.
Arch Oral Biol ; 45(8): 683-90, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10869480

ABSTRACT

To evaluate the role played by androgens in the development and maintenance of sex differences in the proportion of muscle fibres of different phenotypes, the effects of castration in adult (>6 months old) and in young adult (2-3 months old) male rabbits was examined. Immunohistochemical methods were used to evaluate the proportion of muscle fibres containing different myosin heavy-chain isoforms in 10 different neuromuscular compartments of the masseter. In young adult animals of both sexes, the proportion of fibres of different phenotypes in different compartments was not significantly different from that of normal adult females. In animals castrated as young adults, the development of adult male phenotype proportions was completely blocked in most compartments. In animals castrated as adults, proportions were not significantly different from those of the intact males. For most masseter compartments, androgens produced permanent changes in muscle fibre phenotype during a critical period of postnatal development. However, in the posterior deep compartment, androgen deprivation in young adults had no effect on phenotype proportions, but castration of adults resulted in a striking increase in the proportion of fibres containing the IIa myosin heavy-chain isoform.


Subject(s)
Aging/physiology , Androgens/physiology , Masseter Muscle/physiology , Sex Characteristics , Age Factors , Analysis of Variance , Androgens/deficiency , Animals , Female , Immunohistochemistry , Male , Masseter Muscle/innervation , Masseter Muscle/ultrastructure , Muscle Fibers, Skeletal/classification , Muscle Fibers, Skeletal/ultrastructure , Myosin Heavy Chains/analysis , Myosin Heavy Chains/classification , Neuromuscular Junction/ultrastructure , Orchiectomy , Phenotype , Protein Isoforms/analysis , Protein Isoforms/classification , Rabbits
16.
Phys Ther ; 80(2): 160-7, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10654062

ABSTRACT

BACKGROUND AND PURPOSE: The purpose of this study was to determine the effect of short-term, high doses of glucocorticoids on both body and diaphragm weights as well as contractile characteristics of the rat diaphragm. SUBJECTS: Adult, female Sprague-Dawley rats were divided into 2 groups: a control group (n=16) and a prednisolone group (n=16). METHODS: The prednisolone group received prednisolone at a dosage of 5 mg/kg, and the control group received sham saline injections for 5 days. Animals were weighed prior to and after completion of the drug injection period. At the completion of the drug injection period, the animals were sacrificed, and the diaphragm, soleus, and extensor digitorum longus muscles were removed and weighed. A small strip of the costal diaphragm was connected to a force transducer, and the following contractile characteristics were measured: maximal specific isometric tetanic tension, peak isometric twitch specific tension, one-half relaxation time, and time to peak tension. RESULTS: Both body and diaphragm weights decreased by 15% in the prednisolone group as compared with the control group. Maximal specific isometric tetanic tension was reduced 13% in the prednisolone group as compared with the control group. There was no difference in any twitch contractile characteristics between the 2 groups. CONCLUSION AND DISCUSSION: These data support the hypothesis that glucocorticoid treatment over a 5-day period results in a decrease in specific tension as well as diaphragm and body weight. These results may have implications for the treatment of patients receiving high doses of glucocorticoids for acute medical conditions.


Subject(s)
Diaphragm/drug effects , Glucocorticoids/pharmacology , Muscle Contraction/drug effects , Prednisolone/pharmacology , Animals , Body Weight , Female , Glucocorticoids/adverse effects , Muscular Atrophy/chemically induced , Organ Size , Rats , Rats, Sprague-Dawley
17.
Cells Tissues Organs ; 164(4): 179-91, 1999.
Article in English | MEDLINE | ID: mdl-10436326

ABSTRACT

The myosin heavy chain (MyHC) isoform composition of six adult (>7 months old) male and female rabbit masseter muscles was studied using seven monoclonal antibodies. In matched serial tissue sections, muscle fibers in 10 different neuromuscular compartments were analyzed. Nearly all fibers were found to express one of five phenotypes. They either contained one of four different slow/beta MyHC phenotypes (I(1)-I(4)), nearly all of which co-express cardiac alpha MyHC, or they contained type IIa MyHC. Very few fibers contained slow/beta or cardiac alpha MyHC only or both the alpha/slow/beta and IIa isoforms. Most, but not all, of the compartments studied contained similar proportions of fibers of the five major phenotypes, at least within sex. For 7 of the 10 compartments studied, significant sex differences in the proportion of I(1) and IIa fibers were found. Males contained more IIa fibers and fewer I(1) fibers than females. Fibers of the IIa phenotype were significantly larger than fibers of all of the other phenotypes and larger in males than females.


Subject(s)
Masseter Muscle/chemistry , Myosin Heavy Chains/analysis , Animals , Female , Immunoblotting , Immunohistochemistry , Male , Muscle Fibers, Skeletal/chemistry , Phenotype , Protein Isoforms/analysis , Rabbits , Rats , Sex Characteristics , Species Specificity
18.
Pacing Clin Electrophysiol ; 22(1 Pt 2): 158-64, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9990622

ABSTRACT

Optimizing lead placement in transvenous defibrillation remains central to the clinical aspects of the defibrillation procedure. Studies involving superior vena cava (SVC) return electrodes have found that left ventricular (LV) leads or septal positioning of the right ventricular (RV) lead minimizes the voltage defibrillation threshold (VDFT) in endocardial lead-->SVC defibrillation systems. However, similar studies have not been conducted for active-can configurations. The goal of this study was to determine the optimal lead position to minimize the VDFT for systems incorporating an active can. This study used a high resolution finite element model of a human torso that includes the fiber architecture of the ventricular myocardium to find the role of lead positioning in a transvenous LEAD-->can defibrillation electrode system. It was found that, among single lead systems, posterior positioning of leads in the right ventricle lowers VDFTs appreciably. Furthermore, a septal location of leads resulted in lower VDFTs than free-wall positioning. Increasing the number of leads, and thus the effective lead surface area in the right ventricle also resulted in lower VDFTs. However, the lead configuration that resulted in the lowest VDFTs is a combination of mid-cavity right ventricle lead and a mid-cavity left ventricle lead. The addition of a left ventricular lead resulted in a reduction in the size of the low gradient regions and a change of its location from the left ventricular free wall to the septal wall.


Subject(s)
Computer Simulation , Defibrillators, Implantable , Electric Countershock/instrumentation , Heart Ventricles/anatomy & histology , Models, Cardiovascular , Catheterization, Central Venous , Finite Element Analysis , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging/methods , Male , Reference Values , Tachycardia, Ventricular/diagnosis , Tachycardia, Ventricular/therapy , Thorax/anatomy & histology , Vena Cava, Superior/anatomy & histology , Ventricular Function
19.
IEEE Trans Biomed Eng ; 46(1): 26-34, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9919823

ABSTRACT

This study develops a three-dimensional finite element torso model with bidomain myocardium to simulate the transmembrane potential (TMP) of the heart induced by defibrillation fields. The inhomogeneities of the torso are modeled as eccentric spherical volumes with both the curvature and the rotation features of cardiac fibers incorporated in the myocardial region. The numerical computation of the finite element bidomain myocardial model is validated by a semianalytic solution. The simulations show that rotation of fiber orientation through the depth of the myocardial wall changes the pattern of polarization and decreases the amount of cardiac tissue polarized compared to the idealized analytic model with no fiber rotation incorporated. The TMP induced by transthoracic and transvenous defibrillation fields are calculated and visualized. The TMP is quantified by a continuous measure of the percentage of myocardial mass above a potential gradient threshold. Using this measure, the root mean square differences in TMP distribution produced by reversing the electrode polarity for anterior-posterior and transvenous electrode configurations are 13.6 and 28.6%, respectively. These results support the claim that a bidomain model of the heart predicts a change of defibrillation threshold with reversed electrode polarity.


Subject(s)
Electric Countershock , Heart/physiology , Membrane Potentials/physiology , Models, Cardiovascular , Computer Simulation , Electrophysiology , Finite Element Analysis , Humans , Mathematics , Neural Conduction/physiology
20.
Ochsner J ; 1(1): 27-32, 1999 Jan.
Article in English | MEDLINE | ID: mdl-21845116

ABSTRACT

Advances in the medical and surgical management of patients undergoing liver transplantation have made transplantation the method of choice for dealing with end-stage liver disease. With the availability of anti-viral agents such as interferon and ribavirin, pre and post transplant treatment of hepatitis C, the most common indication for liver transplantation, is now possible. The use of high dose hepatitis B immune globulin (HBIG) and lamivudine has decreased the incidence and severity of recurrence of hepatitis B after liver transplantation. Multimodal therapy including chemoembolization for hepatocellular carcinoma has made liver transplantation a viable option for selected patients with primary liver cancer. The development of more potent immunosuppressive agents has dramatically decreased the incidence of acute rejection, while the search for a solution to the problem of chronic rejection continues. Alcoholic liver disease remains a challenge for transplant physicians and surgeons; however, careful patient selection results in a relatively low rate of recidivism.Surgical advances in liver transplantation have focused on eliminating associated morbidity and mortality as well as expanding the donor pool. Veno-venous bypass (VVB) and T-tube stenting, which were once considered essential techniques in liver transplantation, are now only rarely, if ever, necessary. Operative time, blood product usage, and time to extubation, as well as intensive care unit stay, have all been significantly reduced by elimination of VVB without associated morbidity. Elimination of T-tube usage has also effectively decreased morbidity. Donor expansion has become critical as the need for liver transplants exceeds donor availability. Use of marginal donors, including older donors, donors with up to 40% fat content, and donors with high pressor requirements, has proven to be a safe and effective means of increasing the donor pool. In-situ splitting of donors is the most promising technical advance in liver transplantation. This technique, along with living-related liver transplantation, is very important for providing donors to the pediatric population where donor availability is even more limited.

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