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1.
Clin Radiol ; 76(4): 262-272, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33375984

ABSTRACT

Immune checkpoint inhibitors (ICIs), a form of immunotherapy, are increasingly used for a variety of malignancies and have been linked to numerous treatment-related side effects known as immune-related adverse events (irAEs). IrAEs can affect multiple organ systems and are important to recognise in order to avoid misinterpretation as progressive tumour and to ensure appropriate management. In this pictorial review, we will briefly discuss radiological response criteria of immunotherapy and describe the imaging appearances of the wide spectrum of these ICI-associated toxicities.


Subject(s)
Immune Checkpoint Inhibitors/adverse effects , Neoplasms/diagnostic imaging , Neoplasms/drug therapy , Adrenal Gland Diseases/diagnostic imaging , Adrenal Gland Diseases/etiology , Colitis/diagnostic imaging , Colitis/etiology , Encephalitis/diagnostic imaging , Encephalitis/etiology , Hepatitis/diagnostic imaging , Hepatitis/etiology , Humans , Myocarditis/diagnostic imaging , Myocarditis/etiology , Pancreatitis/diagnostic imaging , Pancreatitis/etiology , Pericarditis/diagnostic imaging , Pericarditis/etiology , Pneumonia/diagnostic imaging , Pneumonia/etiology , Sarcoidosis/diagnostic imaging , Sarcoidosis/etiology , Thyroiditis/diagnostic imaging , Thyroiditis/etiology
3.
Int J Oral Maxillofac Surg ; 47(12): 1534-1540, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29789198

ABSTRACT

A new surgical technique of intra-tumoural ligation for the treatment of low-flow vascular malformations in the head and neck region is proposed. Ninety patients with diffuse low-flow vascular malformations diagnosed clinically and/or radiologically were treated surgically with the corset suturing technique. All patient records and clinical photographs were reviewed retrospectively. Significant clinical results were obtained: a reduction of the turnout tumour mass and a return of the regional facial outline was evident within 4 weeks after surgery. Recurrence of the lesion (seen in 10 patients) and transient facial nerve palsy (seen in seven patients) were the main complications. All incisions were placed within the junction lines of cosmetic subunits and skin tension lines of the head and neck. The advantages of this technique over the widely used and popular Popescu technique are discussed. Also, the indications, disadvantages, operative technique, and complications are described. In conclusion, corset suturing was found to be a simple, aesthetic, and cost-effective method of treating diffuse low-flow vascular malformations of the head and neck.


Subject(s)
Head/blood supply , Neck/blood supply , Suture Techniques , Vascular Malformations/surgery , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Vascular Malformations/diagnostic imaging
4.
Dis Esophagus ; 30(3): 1-5, 2017 03 01.
Article in English | MEDLINE | ID: mdl-28184470

ABSTRACT

Barrett's esophagus is a well-recognized risk factor for esophageal adenocarcinoma. The natural history of Barrett's esophagus classified as 'indefinite for dysplasia' (IND) is poorly characterized. The aim of this study is to characterize the natural history of IND by determining the rate of neoplastic progression and identifying risk factors for progression. Patients from the University of Pennsylvania Health System pathology database and Barrett's esophagus registry with a diagnosis of IND between 2000 and 2014 were identified. Exclusion criteria included: (1) prior diagnosis of low-grade dysplasia (LGD), high-grade dysplasia (HGD), or esophageal adenocarcinoma (EAC); (2) presence of LGD, HGD, or EAC at the time of diagnosis of IND; and (3) lack of follow-up endoscopy after diagnosis. Patients with neoplastic progression were classified as having either prevalent disease (LGD, HGD, or EAC on surveillance biopsy within 12 months of IND diagnosis) or incident disease (LGD, HGD, or EAC on surveillance biopsy >12 months after IND diagnosis). One hundred six patients were eligible for analysis. Of 87 patients with follow-up endoscopy and biopsies within 1 year of IND diagnosis, 7 (8%) had prevalent disease (2 LGD, 4 HGD, 1 EAC). The prevalence of LGD was 2.3%, HGD was 4.6%, and EAC was 1.1%. Importantly, four of the seven prevalent (2 LGD, 2 HGD) cases were found to have dysplasia within 6 months of IND diagnosis. No demographic or endoscopic characteristics studied were associated with prevalent disease. Of the 106 IND patients, there were 66 patients without prevalent dysplasia with >1-year follow-up. Three (4.5%) progressed (1 to LGD after 12 months, 2 to HGD after 16.5 and 28 months), yielding an incidence rate for any dysplasia of 1.4 cases/100 person-years and HGD/EAC of 0.9/100 person-years. Risk factors for incident disease were smoking (p = 0.02) and Barrett's esophagus segment length (p = 0.03). IND is associated with considerable risk of prevalent dysplasia, especially within the first 6 months after diagnosis. However, the incidence of HGD/EAC is low and similar to previous studies of IND. These data suggest that IND patients should have repeat endoscopy within 6 months with careful surveillance protocols. Longer BE length and smoking history may help predict which patients are more likely to develop dysplasia, and therefore identify patients who may warrant even closer monitoring.


Subject(s)
Adenocarcinoma/parasitology , Barrett Esophagus/pathology , Cell Transformation, Neoplastic/pathology , Esophageal Neoplasms/pathology , Registries , Academic Medical Centers , Adenocarcinoma/physiopathology , Adenocarcinoma/surgery , Aged , Barrett Esophagus/physiopathology , Barrett Esophagus/surgery , Biopsy, Needle , Disease Progression , Disease-Free Survival , Esophageal Neoplasms/mortality , Esophageal Neoplasms/parasitology , Esophageal Neoplasms/physiopathology , Esophageal Neoplasms/surgery , Esophagectomy/methods , Esophagectomy/mortality , Female , Follow-Up Studies , Humans , Immunohistochemistry , Male , Middle Aged , Precancerous Conditions/pathology , Proportional Hazards Models , Retrospective Studies , Risk Assessment , Statistics, Nonparametric , Survival Analysis
5.
J West Afr Coll Surg ; 6(1): 100-107, 2016.
Article in English | MEDLINE | ID: mdl-28344940

ABSTRACT

BACKGROUND: Rhinoorbito-cerebral mucormycosis is an uncommon and acute fungal infection which runs a fulminant course. Uncontrolled diabetes mellitus is the most common predisposing factor. AIM: To assess the outcome of a poorly controlled diabetic with Rhinoorbito-cerebral mucormycosis using a multi-modality management. METHODOLOGY: We report a case of a 57-year old male who presented to us with proptosis and total external ophthalmoplegia diagnosed with rhino-orbito-cerebral mucormycosis. Patient was started on conventional intravenous amphotericin B to which he developed systemic toxicity. As an alternative, a combination therapy of oral posacanazole along with peribulbar amphotericin B injections for a more localised effect was initiated. RESULTS: He had a favourable outcome with dramatic improvement in vision and marginal recovery of extra ocular movements within 20 days of initiation of combination therapy. CONCLUSION: Rhinoorbito-cerebral mucormycosis is a major diagnostic dilemma with quick progression and a high mortality. Prompt medical management with a multi-modality approach can save the patient from orbital exenteration.

6.
J Neurosci Res ; 87(15): 3403-14, 2009 Nov 15.
Article in English | MEDLINE | ID: mdl-19224580

ABSTRACT

The galactolipids galactocerebroside and sulfatide have been implicated in oligodendrocyte (OL) development and myelin formation. Much of the early evidence for myelin galactolipid function has been derived from antibody and chemical perturbation of OLs in vitro. To determine the role of these lipids in vivo, we previously characterized mice lacking galactocerebroside and sulfatide and observed abundant, unstable myelin and an increased number of OLs. We have also reported that mice incapable of synthesizing sulfatide (CST-null) while maintaining normal levels of galactocerebroside generate relatively stable myelin with unstable paranodes. Additionally, Hirahara et al. (2004; Glia 45:269-277) reported that these CST-null mice also contain an increased number of OLs in the forebrain, medulla, and cerebellum at 7 days of age. Here, we further the findings of Hirahara et al. by demonstrating that the number of OLs in the CST-null mice is also increased in the spinal cord and that this elevated OL population is maintained through, at least, 7 months of age. Moreover, we show that the enhanced OL population is accompanied by increased proliferation and decreased apoptosis of oligodendrocytic-lineage cells. Finally, through ultrastructural analysis, we show that the CST-null OLs exhibit decreased morphological complexity, a feature that may result in decreased OL competition and increased OL survival.


Subject(s)
Cell Proliferation , Myelin Sheath/metabolism , Nerve Fibers, Myelinated/metabolism , Oligodendroglia/metabolism , Sulfoglycosphingolipids/metabolism , Sulfotransferases/genetics , Aging/genetics , Aging/metabolism , Animals , Apoptosis/genetics , Cell Count , Cell Differentiation/genetics , Cell Lineage/genetics , Cell Survival/genetics , Disease Models, Animal , Gene Expression Regulation/genetics , Hereditary Central Nervous System Demyelinating Diseases/genetics , Hereditary Central Nervous System Demyelinating Diseases/metabolism , Hereditary Central Nervous System Demyelinating Diseases/physiopathology , Mice , Mice, Knockout , Nerve Fibers, Myelinated/ultrastructure , Oligodendroglia/pathology , Spinal Cord/metabolism , Spinal Cord/pathology , Spinal Cord/physiopathology , Stem Cells/metabolism , Stem Cells/pathology , Up-Regulation/genetics
7.
Indian J Nephrol ; 19(3): 119-21, 2009 Jul.
Article in English | MEDLINE | ID: mdl-20436733

ABSTRACT

Historically HIV positive patients were considered a contraindication for renal transplant. After the year 1996, with the introduction of HAART the retropositive patients live longer and therefore end stage organ disease is now an increasingly important cause of mortality and morbidity in these patients. Here we report our experience for the first time in India. A forty nine year old hypertensive female from Africa who was diagnosed chronic kidney disease and retropositive status, progressed to end stage renal disease and underwent live related renal transplant at our centre.

8.
Transplant Proc ; 39(3): 711-3, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17445578

ABSTRACT

The Indian Transplant Registry has been made possible due to the efforts of the Indian Society of Organ Transplantation (ISOT) over the past 5 years. The ISOT is about 20 years old and has more than 450 members related to multiorgan transplants with elected officers. It is in its first phase of development and is now available on the Web at www.transplantindia.com. The objective of developing this registry is to be able to view, collate, and audit the national data for all transplants in the country. In the first phase, "fast track" data are being captured with essential details of the program along with the yearly number of transplantations performed, the sex ratio, and type of transplantation. Over 10 major institutions have submitted their data to the registry. In the second phase, over 20 fields would be captured; all member institutions would be encouraged to enter data prospectively. In the third phase, audit of the data would be possible. The members of the ISOT have been supportive and enthusiastic about the registry as reflected in their data submission to date.


Subject(s)
Organ Transplantation/statistics & numerical data , Heart Transplantation/statistics & numerical data , Humans , India , Internet , Kidney Transplantation/statistics & numerical data , Liver Transplantation/statistics & numerical data , Organ Transplantation/trends , Registries
9.
Transplant Proc ; 39(3): 714-8, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17445579

ABSTRACT

Tamil Nadu has been at the forefront of medical care in the country. It was the first state in the country that started a living kidney transplant program. It is also the first state to successfully start the cadaver programme after the passing of the "Transplantation of Human Organ Act" of 1994 and in the last 5 years has formed a network between hospitals for organ sharing. From the year 2000 to 2006 an organ sharing network was started in Tamil Nadu and the facilitator of this programme has been a non-government organization called MOHAN (acronym for Multi Organ Harvesting Aid Network) Foundation. The organs shared during the period number over 460 organs in two regions (both Tamil Nadu and Hyderabad). In Tamil Nadu the shared organs have included 166 Kidneys, 24 livers, 6 hearts, and 180 eyes. In 2003 sharing network was initiated by MOHAN in Hyderabad and to some extent the Tamil Nadu model was duplicated. with some success and 96 cadaver organs have been transplanted in the last 3 years. There are many advantages of organ sharing including the cost economics. At present there is a large pool of brain dead patients who could become potential organ donors in the major cities in India. Their organs are not being utilized for various support logistics. A multi-pronged strategy is required for the long term success of this program. These years in Tamil Nadu have been the years of learning, un-learning and relearning and the program today has matured slowly into what can perhaps be evolved as an Indian model. In all these years there have been various difficulties in its implementation and some of the key elements for the success of the program is the need to educate our own medical fraternity and seek their cooperation. The program requires trained counselors to be able to work in the intensive cares. The government's support is pivotal if this program to provide benefit to the common man. MOHAN Foundation has accumulated considerable experience to be able to evolve a model to take this program to the national level and more so as it recently has been granted 100% tax exemption on all donations to form a countrywide network for organ sharing.


Subject(s)
Organ Transplantation/statistics & numerical data , Tissue Donors/statistics & numerical data , Tissue and Organ Procurement/organization & administration , Cadaver , Corneal Transplantation/statistics & numerical data , Heart Transplantation/statistics & numerical data , Humans , India , Kidney Transplantation/statistics & numerical data , Liver Transplantation/statistics & numerical data , Organ Transplantation/psychology , Public Opinion , Tissue and Organ Harvesting/methods , Tissue and Organ Procurement/statistics & numerical data
10.
J Assoc Physicians India ; 54: 241-3, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16800353

ABSTRACT

This study analyses the pre-disposing factors, diagnostic modalities, therapeutic options and prognostic factors involved in 7 subjects with renal abscess. Most often they presented with high fever and flank pain. USG and CT were used to establish the diagnosis. Urine culture yielded organisms in five cases and hence empirical antibiotic therapy for Gram-negative organism was offered. Complicated abscess in our series carried high mortality especially in immuno suppressed and cachectic patients.


Subject(s)
Abscess , Kidney Diseases , Abscess/diagnosis , Abscess/etiology , Abscess/therapy , Adolescent , Adult , Female , Humans , Immune System Diseases/complications , Kidney Diseases/diagnosis , Kidney Diseases/etiology , Kidney Diseases/therapy , Kidney Failure, Chronic/complications , Kidney Glomerulus/pathology , Male , Middle Aged , Renal Artery Obstruction/complications , Urinary Tract Infections/complications
11.
Glia ; 53(4): 372-81, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16288467

ABSTRACT

Galactocerebroside (GalC) and sulfatide are abundant myelin lipids. In mice incapable of synthesizing these lipids, myelin is thin and regionally unstable and exhibits several subtle structural abnormalities. Although galactolipid-null mice have been beneficial in the analysis of galactolipid function, it has not been possible to differentiate between the functions of GalC and sulfatide with these mice alone. In the present work, we have analyzed a murine model that forms normal levels of GalC but is incapable of synthesizing sulfatide. By comparing a plethora of morphological features between the galactolipid-null and the sulfatide-null mice, we have begun to differentiate between the specific functions of these closely related lipids. The most striking difference between these two mutants is the reduction of myelin developmental abnormalities (e.g., redundant and uncompacted myelin sheaths) in young adult sulfatide-null mice as compared with the galactolipid-null animals. Although sulfatide appears to play a limited role in myelin development, this lipid is essential for myelin maintenance, as the prevalence of redundant, uncompacted, and degenerating myelin sheaths as well as deteriorating nodal/paranodal structure is increased significantly in aged sulfatide-null mice as compared with littermate wildtype mice. Finally, we show that the role played by sulfatide in CNS maintenance is not limited to the myelin sheath, as axonal caliber and circularity are normal in young adult mutant mice but are significantly altered in aged sulfatide-null animals.


Subject(s)
Axons/physiology , Central Nervous System/cytology , Myelin Sheath/physiology , Sulfoglycosphingolipids/pharmacology , Aging/physiology , Algorithms , Animals , Axons/ultrastructure , Central Nervous System/growth & development , Central Nervous System/ultrastructure , Galactosylceramides/genetics , Galactosylceramides/metabolism , Immunohistochemistry , Mice , Mice, Knockout , Microscopy, Electron , Myelin Sheath/ultrastructure , Reverse Transcriptase Polymerase Chain Reaction , Sulfotransferases/metabolism
12.
Am J Physiol Heart Circ Physiol ; 289(1): H114-30, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15961371

ABSTRACT

A new dynamic model of left ventricular (LV) pressure-volume relationships in beating heart was developed by mathematically linking chamber pressure-volume dynamics with cardiac muscle force-length dynamics. The dynamic LV model accounted for >80% of the measured variation in pressure caused by small-amplitude volume perturbation in an otherwise isovolumically beating, isolated rat heart. The dynamic LV model produced good fits to pressure responses to volume perturbations, but there existed some systematic features in the residual errors of the fits. The issue was whether these residual errors would be damaging to an application where the dynamic LV model was used with LV pressure and volume measurements to estimate myocardial contractile parameters. Good agreement among myocardial parameters responsible for response magnitude was found between those derived by geometric transformations of parameters of the dynamic LV model estimated in beating heart and those found by direct measurement in constantly activated, isolated muscle fibers. Good agreement was also found among myocardial kinetic parameters estimated in each of the two preparations. Thus the small systematic residual errors from fitting the LV model to the dynamic pressure-volume measurements do not interfere with use of the dynamic LV model to estimate contractile parameters of myocardium. Dynamic contractile behavior of cardiac muscle can now be obtained from a beating heart by judicious application of the dynamic LV model to information-rich pressure and volume signals. This provides for the first time a bridge between the dynamics of cardiac muscle function and the dynamics of heart function and allows a beating heart to be used in studies where the relevance of myofilament contractile behavior to cardiovascular system function may be investigated.


Subject(s)
Blood Pressure , Blood Volume , Models, Cardiovascular , Myocardial Contraction , Ventricular Function, Left , Animals , Kinetics , Male , Muscle Fibers, Skeletal/physiology , Papillary Muscles/physiology , Rats , Temperature
13.
Pharmacol Biochem Behav ; 75(3): 529-36, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12895670

ABSTRACT

The present investigation was aimed at determining the spectrum of activity of the methanolic extract of Clitoria ternatea (CT) on the CNS. The CT was studied for its effect on cognitive behavior, anxiety, depression, stress and convulsions induced by pentylenetetrazol (PTZ) and maximum electroshock (MES). To explain these effects, the effect of CT was also studied on behavior mediated by dopamine (DA), noradrenaline, serotonin and acetylcholine. The extract decreased time required to occupy the central platform (transfer latency, TL) in the elevated plus maze (EPM) and increased discrimination index in the object recognition test, indicating nootropic activity. The extract was more active in the object recognition test than in the EPM. The extract increased occupancy in the open arm of EPM by 160% and in the lit box of the light/dark exploration test by 157%, indicating its anxiolytic activity. It decreased the duration of immobility in tail suspension test (suggesting its antidepressant activity), reduced stress-induced ulcers and reduced the convulsing action of PTZ and MES. The extract exhibited tendency to reduce the intensity of behavior mediated via serotonin and acetylcholine. The effect on DA- and noradrenaline-mediated behavior was not significant. In conclusion, the extract was found to possess nootropic, anxiolytic, antidepressant, anticonvulsant and antistress activity. Further studies are necessary to isolate the active principle responsible for the activities and to understand its mode of action.


Subject(s)
Central Nervous System Agents/therapeutic use , Clitoria , Mental Disorders/drug therapy , Plant Components, Aerial , Animals , Catalepsy/chemically induced , Catalepsy/drug therapy , Central Nervous System Agents/isolation & purification , Central Nervous System Agents/pharmacology , Hypothermia/chemically induced , Hypothermia/drug therapy , Male , Mental Disorders/chemically induced , Mice , Mice, Inbred BALB C , Phytotherapy/methods , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Rats , Rats, Wistar , Seizures/chemically induced , Seizures/drug therapy
15.
J Assoc Physicians India ; 51: 919-20, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14710985

ABSTRACT

A 38 years insulin-dependent diabetic male, with nephropathy on antituberculous treatment presented with painless frank hematuria followed by anuria for a day which was associated with fever. Ultrasonogram of the abdomen showed bilateral hydroureteronephrosis. Necrotic papillae were retrieved after ureteroscopy which on histopathological examination and culture showed Candida albicans. This was successfully treated with fluconazole and ureteroscopic removal of necrotic papillae.


Subject(s)
Anuria/etiology , Candidiasis/complications , Kidney Papillary Necrosis/etiology , Adult , Antifungal Agents/therapeutic use , Candidiasis/drug therapy , Diabetes Mellitus, Type 1/complications , Fluconazole/therapeutic use , Humans , Kidney Papillary Necrosis/pathology , Male
16.
Circulation ; 104(4): 473-9, 2001 Jul 24.
Article in English | MEDLINE | ID: mdl-11468212

ABSTRACT

BACKGROUND: Paclitaxel can inhibit vascular smooth muscle proliferation in vitro, and early studies suggest that paclitaxel may be useful in preventing restenosis. Early and late intimal growth and local vascular pathological changes associated with paclitaxel delivered via stents have not been fully explored. METHODS AND RESULTS: Localized drug delivery was accomplished with balloon-expandable stainless steel stents coated with a cross-linked biodegradable polymer, chondroitin sulfate and gelatin (CSG), containing various doses of paclitaxel. CSG-coated stents with paclitaxel (42.0, 20.2, 8.6, or 1.5 microgram of paclitaxel per stent), CSG-coated stents without paclitaxel, and uncoated stents (without paclitaxel or CSG) were deployed in the iliac arteries of New Zealand White rabbits, which were killed 28 days after implant. Mean neointimal thickness at stent strut sites was reduced 49% (P<0.0003) and 36% (P<0.007) with stents containing 42.0 and 20.2 microgram of paclitaxel per stent, respectively, versus CSG-coated stents without paclitaxel. However, histological findings suggested incomplete healing in the higher-dose (42.0 and 20.2 microgram) paclitaxel-containing stents consisting of persistent intimal fibrin deposition, intraintimal hemorrhage, and increased intimal and adventitial inflammation. Stents coated with CSG alone (without paclitaxel) had similar neointimal growth as uncoated stents. In a separate group of rabbits killed at 90 days, neointimal growth was no longer suppressed by CSG-coated stents containing 42.0 or 21.0 microgram of paclitaxel CONCLUSIONS: CSG coating appears to be a promising medium for localized drug delivery. Paclitaxel polymer-coated stents reduce neointima formation but are associated with evidence of incomplete healing at 28 days. However, neointimal suppression was not maintained at 90 days.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Drug Delivery Systems/methods , Paclitaxel/pharmacology , Stents , Angiogenesis Inhibitors/pharmacokinetics , Animals , Cell Division/drug effects , Chondroitin Sulfates , Dose-Response Relationship, Drug , Fibrin/drug effects , Fibrin/metabolism , Gelatin , Hemorrhage/chemically induced , Hemorrhage/pathology , Iliac Artery/drug effects , Iliac Artery/metabolism , Iliac Artery/pathology , Inflammation/chemically induced , Inflammation/pathology , Male , Paclitaxel/blood , Paclitaxel/pharmacokinetics , Polymers , Rabbits , Time Factors , Tunica Intima/drug effects , Tunica Intima/metabolism , Tunica Intima/pathology
17.
J Appl Physiol (1985) ; 90(6): 2427-38, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11356810

ABSTRACT

Smooth muscle relaxation is expected to yield beneficial effects on hydraulic impedance properties of large vessels. We investigated the effects of intravenous diltiazem infusion on aortic wall stiffness and local hydraulic impedance properties. In seven anesthetized, closed-chest dogs, instantaneous cross-sectional area and pressure of the descending thoracic aorta were measured using transesophageal echocardiography combined with acoustic quantification and a micromanometer, respectively. Data were acquired during a vena caval balloon inflation, both at the control condition and with diltiazem infusion. At the operating point, diltiazem reduced blood pressure in all dogs but did not alter aortic dimensions or wall stiffness. Over the observed pressure range, aortic area-pressure relationships were linear. Whereas diltiazem affected the slope of this relationship variably (no change in 3 dogs, increase in 1 dog, decrease in 3 dogs), the zero-pressure area intercept was significantly increased in every case such that higher area was observed at any given pressure. When comparisons were made at a common level of wall stress, wall stiffness was either increased or unchanged during diltiazem infusion. In contrast, diltiazem decreased wall stiffness in every case when comparisons were made at a common level of aortic midwall radius. Aortic characteristic impedance and pulse wave velocity, components of left ventricular hydraulic load that are determined by aortic elastic and geometric properties, were affected variably. A comparison of wall stiffness at matched wall stress appears inappropriate for assessing changes in smooth muscle tone. Because of the competing effects of changes in vessel diameter and wall stiffness, smooth muscle relaxation is not necessarily accompanied by the expected beneficial changes in local aortic hydraulic impedance. These results can be reconciled by recognizing that components other than vascular smooth muscle (e.g., elastin, collagen) contribute to aortic wall stiffness.


Subject(s)
Aorta, Thoracic/physiology , Muscle, Smooth, Vascular/physiology , Vascular Resistance/physiology , Algorithms , Animals , Aorta, Thoracic/diagnostic imaging , Aorta, Thoracic/drug effects , Calcium Channel Blockers/pharmacology , Diltiazem/pharmacology , Dogs , Elasticity , Manometry , Models, Biological , Muscle Relaxation/drug effects , Muscle Relaxation/physiology , Muscle Tonus/drug effects , Muscle Tonus/physiology , Muscle, Smooth, Vascular/diagnostic imaging , Muscle, Smooth, Vascular/drug effects , Ultrasonography , Vascular Resistance/drug effects , Vasodilator Agents/pharmacology
18.
Circulation ; 103(14): 1912-9, 2001 Apr 10.
Article in English | MEDLINE | ID: mdl-11294812

ABSTRACT

BACKGROUND: Three-month studies of stent-delivered brachytherapy in the rabbit model show reduced neointimal growth. However, intimal healing is delayed, raising the possibility that intimal inhibition is merely delayed rather than prevented. The purpose of this study was to explore the long-term histological changes after placement of beta-emitting radioactive stents in normal rabbit iliac arteries. METHODS AND RESULTS: Three-millimeter beta-emitting (32)P stents (6, 24, and 48 microCi) were placed in normal rabbit iliac arteries with nonradioactive stents as controls. Animals were euthanatized at 6 and 12 months, and histological assessment, morphometry, and analysis of endothelialization were performed. Morphometric measurements demonstrated a >50% reduction in intimal growth and percent lumen stenosis within 24- and 48-microCi stents versus control nonradioactive stents at both 6 and 12 months. However, the 24- and 48-microCi stents also showed delayed healing of the intimal surface, characterized by persistent fibrin thrombus with nonconfluent areas of matrix, incomplete endothelialization, and increased intimal cellular proliferation. Stent edge stenosis was present at 12 months in the 24- and 48-microCi stent groups, characterized by both intimal thickening and negative arterial remodeling. CONCLUSIONS: Inhibition of intimal growth is maintained 6 and 12 months after (32)P beta-emitting stent placement. However, delayed arterial healing, incomplete endothelialization, and edge effects are present.


Subject(s)
Iliac Artery/radiation effects , Stents , Animals , Arteriosclerosis/pathology , Cell Division/radiation effects , Endothelium, Vascular/pathology , Endothelium, Vascular/radiation effects , Endothelium, Vascular/ultrastructure , Fibrin/metabolism , Fibrin/radiation effects , Iliac Artery/pathology , Male , Microscopy, Electron, Scanning , Phosphorus Radioisotopes/pharmacology , Rabbits , Time Factors , Tunica Intima/metabolism , Tunica Intima/pathology , Tunica Intima/radiation effects
19.
Am J Physiol Heart Circ Physiol ; 280(5): H1954-62, 2001 May.
Article in English | MEDLINE | ID: mdl-11299194

ABSTRACT

Genetically modified mice have created the need for accurate noninvasive left ventricular mass (LVM) measurements. Recent technical advances provide two-dimensional images adequate for LVM calculation using the area-length method, which in humans is more accurate than M-mode methods. We compared the standard M-mode and area-length methods in mice over a wide range of LV sizes and weights (62-210 mg). Ninety-one CD-1 mice (38 normal, 44 aortic banded, and 9 inherited dilated cardiomyopathy) were imaged transthoracically (15 MHz linear transducer, 120 Hz). Compared with necropsy weights, area-length measurements showed higher correlation than the M-mode method (r = 0.92 vs. 0.81), increased accuracy (bias +/- SD: 1.4 +/- 27.1% vs. 36.7 +/- 51.6%), and improved reproducibility. There was no significant difference between end-systolic and end-diastolic estimates. The truncated ellipsoid estimation produced results similar in accuracy to the area-length method. Whereas current echocardiographic technology can accurately and reproducibly estimate LVM with the two-dimensional, area-length formula in a variety of mouse models, additional technological improvements, rather than refinement of geometric models, will likely improve the accuracy of this methodology.


Subject(s)
Echocardiography/standards , Hypertrophy, Left Ventricular/diagnostic imaging , Hypertrophy, Left Ventricular/pathology , Myocardium/pathology , Animals , Aorta , Cardiomyopathy, Dilated/diagnostic imaging , Cardiomyopathy, Dilated/pathology , Chronic Disease , Disease Models, Animal , Echocardiography/methods , Echocardiography/statistics & numerical data , Female , Heart Ventricles/pathology , Male , Mice , Mice, Inbred Strains , Mice, Transgenic , Observer Variation , Reproducibility of Results
20.
J Am Soc Echocardiogr ; 14(3): 209-18, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11241017

ABSTRACT

OBJECTIVE: CREB(A133) transgenic mice that express a dominant negative CREB transcription factor in cardiomyocytes develop a dilated cardiomyopathy that is anatomically, physiologically, and clinically similar to human idiopathic dilated cardiomyopathy. The goals of this study were to quantitate left ventricular (LV) contractility and measure cardiac reserve in CREB(A133) mice by using the relation of end-systolic wall stress to the velocity of fiber shortening. METHODS: A total of 37 adult CD-1 mice (including both nontransgenic and CREB(A133) transgenic mice) were studied with simultaneously acquired high-fidelity instantaneous aortic pressures and 2-dimensionally targeted M-mode echocardiograms. RESULTS: CREB(A133) mice displayed significantly lower values of LV fiber shortening velocities over a wide range of afterloads, and they displayed smaller dobutamine-induced shifts from baseline contractility relations. Counterbalancing effects of differences in LV geometry and aortic pressures resulted in comparable levels of LV wall stress during ejection in both groups. CONCLUSION: These results demonstrate directly that CREB(A133) mice display reduced LV contractility at baseline and decreased cardiac reserve.


Subject(s)
Cardiomyopathy, Dilated/physiopathology , Ventricular Function, Left/physiology , Animals , Cardiomyopathy, Dilated/complications , Disease Models, Animal , Echocardiography , Gene Expression Regulation , Heart Failure/etiology , Heart Failure/physiopathology , Mice , Mice, Transgenic , Regression Analysis
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