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PubMed2001

Three-dimensional analysis of the local structure of Cu on TiO2(110) by in situ polarization-dependent total-reflection fluorescence XAFS.

Cu K-edge XAFS of Cu/TiO2(110) was measured by polarization-dependent total-reflection fluorescence XAFS technique. XAFS of [001], [110], and [110] directions were measured to elucidate the three dimensional structure of Cu species on the TiO2(110) surface prepared by the deposition of Cu(DPM)2 followed by reduction with H2. Simulation of the EXAFS functions as well as conventional curve fitting analysis revealed that plane Cu3,4 small clusters with similar structure to Cu(111) plane were formed by the reduction at 363 K. The small clusters converted into spherical metallic Cu particles by the reduction at 473 K.

Journal Article↗
PubMed2005

Fluorescence thiol modification assay: oxidatively modified proteins in Bacillus subtilis.

Oxidatively modified thiol groups of cysteine residues are known to modulate the activity of a growing number of proteins. In this study, we developed a fluorescence-based thiol modification assay and combined it with two-dimensional gel electrophoresis and mass spectrometry to monitor the in vivo thiol state of cytoplasmic proteins. For the Gram-positive model organism Bacillus subtilis our results show that protein thiols of growing cells are mainly present in the reduced state. Only a few proteins were found to be thiol-modified, e.g. enzymes that include oxidized thiols in their catalytic cycle. To detect proteins that are particularly sensitive to oxidative stress we exposed growing B. subtilis cells to diamide, hydrogen peroxide or to the superoxide generating agent paraquat. Diamide mediated a significant increase of oxidized thiols in a variety of metabolic enzymes, whereas treatment with paraquat affected only a few proteins. Exposure to hydrogen peroxide forced the oxidation especially of proteins with active site cysteines, e.g. of cysteine-based peroxidases and glutamine amidotransferase-like proteins. Moreover, high levels of hydrogen peroxide were observed to influence the isoelectric point of proteins of this group indicating the generation of irreversibly oxidated thiols. From the overlapping set of oxidatively modified proteins, also enzymes necessary for methionine biosynthesis were identified, e.g. cobalamin-independent methionine synthase MetE. Growth experiments revealed a methionine limitation after diamide and hydrogen peroxide stress, which suggests a thiol-oxidation-dependent inactivation of MetE. Finally, evidence is presented that the antibiotic nitrofurantoin mediates the formation of oxidized thiols in B. subtilis.

Bacillus subtilis↗
PubMedDate not supplied

Storage coefficient revisited: is purely vertical strain a good assumption?

The storage coefficient that is used ubiquitously today was first defined by the analytical work of Theis and Jacob over a half-century ago. Inherent within this definition is the restriction of purely vertical compression of the aquifer during a reduction in pressure. The assumption is revisited and quantitatively evaluated by comparing numerical results using both one- and three-dimensional strain models in the presence of three-dimensional flow. Results indicate that (1) calculated hydraulic head values are nearly identical for both models; (2) the release of water from storage in terms of volume strain is nearly identical for both models and that the location of maximum production moves outward from the well as a function of time; (3) the vertical strain components are markedly different with at least 50% of the total volume of water pumped originating from horizontal strain (and increasing to as much as 70%); and (4) for the one-dimensional strain model to yield the necessary quantity of water to the pumped well, the resulting vertical compaction (land subsidence) is as much as four times greater and vertical strain is as much as 60% greater than the three-dimensional strain model. Results indicate that small changes in porosity resulting from horizontal strain can yield extremely large quantities of water to the pumping well. This study suggests that the assumption of purely vertical strain used in the definition of the storage coefficient is not valid.

Elasticity↗
PubMed2006

Effect of decreased O2 supply on skeletal muscle oxygenation and O2 consumption during sepsis: role of heterogeneous capillary spacing and blood flow.

One of the main aspects of the initial phase of the septic inflammatory response to a bacterial infection is abnormal microvascular perfusion, including decreased functional capillary density (FCD) and increased blood flow heterogeneity. On the other hand, one of the most important phenomena observed in the later stages of sepsis is an increased dependence of tissue O(2) utilization on the convective O(2) supply. This "pathological supply dependency" is associated with organ failure and poor clinical outcomes. Here, a detailed theoretical model of capillary-to-tissue O(2) transport during sepsis is used to examine the origins of abnormal supply dependency. With use of three-dimensional arrays of capillaries with heterogeneous spacing and blood flow, steady-state O(2) transport is simulated numerically during reductions in the O(2) supply. Increased supply dependency is shown to occur in sepsis for hypoxic (decreased hemoglobin O(2) saturation) and stagnant (decreased blood flow) hypoxia. For stagnant hypoxia, a reduction in FCD with decreasing blood flow is necessary to obtain the observed increase in supply dependency. Our results imply that supply dependency observed under normal conditions does not have its origin at the level of individual capillaries. In sepsis, however, diffusion limitation and shunting of O(2) by individual capillaries occur to a degree that is dependent on the heterogeneity of septic injury and the arrangement of capillary networks. Thus heterogeneous stoppage of individual capillaries is a likely factor in pathological supply dependency.

Algorithms↗
PubMed2004

Alkylphosphocholines: a new therapeutic option in glaucoma filtration surgery.

PURPOSE: To investigate the effect of alkylphosphocholines (APCs) on human Tenon fibroblast (HTF) proliferation, migration, and cell-mediated collagen gel contraction. METHODS: HTFs were isolated from tissue samples of three patients obtained during surgery and cultured in DMEM and 10% fetal calf serum (FCS). HTFs (passage 3-6) were treated with one APC in different concentrations spanning the 50% inhibitory concentration (IC(50)), as determined previously. Inhibition of cell proliferation was assessed by the tetrazolium dye reduction assay. Migration was determined in chemoattractant chambers with fibronectin-coated polycarbonated membranes. For inhibition of contraction, three-dimensional collagen gels were seeded with HTFs, and the gel size was measured. Cell viability was determined by the trypan blue exclusion assay. For analysis of the mechanism of action, protein kinase C (PKC) activity was measured. RESULTS: The IC(50) varied between 7.0 and 10.5 microM for all APCs tested. At this concentration, all four APCs inhibited HTF migration and cell-mediated collagen gel contraction in the presence of serum. The inhibitory effects on HTF proliferation, migration, and contraction were observed at nontoxic concentrations. PKC activity was reduced to 50% of control level at the IC(50) of all APCs applied. CONCLUSIONS: APCs are effective inhibitors of HTF proliferation, migration, and cell-mediated contraction of collagen gels at nontoxic concentrations. Their mechanism of action seems to involve the inhibition of the PKC pathway.

Adult↗
PubMed2005

The proteomics of sickle cell disease: profiling of erythrocyte membrane proteins by 2D-DIGE and tandem mass spectrometry.

Quantitative changes in the red blood cell membrane proteome in sickle cell disease were analyzed using the two-dimensional fluorescence difference gel electrophoresis 2D-DIGE technique. From over 500 analyzed two-dimensional gel spots, we found 49 protein gel spots whose content in sickle cell membranes were changed by at least 2.5-fold as compared to control cells. In 38 cases we observed an increase and in 11 cases a decrease in content in the sickle cell membranes. The proteins of interest were identified by in-gel tryptic digestion followed by liquid chromatography in line with tandem mass spectrometry. From 38 analyzed gel spots, we identified 44 protein forms representing different modifications of 22 original protein sequences. The majority of the identified proteins fall into small groups of related proteins of the following five categories: actin accessory proteins--four proteins, components of lipid rafts--two proteins, scavengers of oxygen radicals--two proteins, protein repair participants--six proteins, and protein turnover components--three proteins. The number of proteins whose content in sickle RBC membrane is decreased is noticeably smaller, and most are either components of lipid rafts or actin accessory proteins. Elevated content of protein repair participants as well as oxygen radical scavengers may reflect the increased oxidative stress observed in sickle cells.

Anemia, Sickle Cell↗
PubMed1991

Volumetric atrophy of the amygdala in Alzheimer's disease: quantitative serial reconstruction.

The present study quantitatively assessed volumes of the amygdala and its subnuclei in autopsied cases of advanced Alzheimer's disease (AD) for comparison with age-matched controls. Amygdalar nuclei showed significant atrophy in AD with the exception of the paralaminar portion of the basal nucleus. The magnocellular regions of the amygdala showed proportionately greater size reductions as a fraction of total amygdala volume than did other areas. Computerized reconstruction of the amygdala provided three-dimensional views of a variety of structural alterations accompanying the volumetric declines with AD. The apparent selective vulnerability of the magnocellular amygdalar areas coincides with the loss of large nerve cells in AD.

Alzheimer Disease↗
PubMed2002

Three-dimensional morphometry of spinal cord injury following polyethylene glycol treatment.

We are developing a novel means of restoring function after severe acute spinal cord injury. This involves a brief application of polyethylene glycol (PEG) to the site of injury. In the companion paper, we have shown that a delayed application of PEG can produce strikingly significant physiological and behavioral recovery in 90-100 % of spinal-cord-injured guinea pigs. In the present paper, we used three-dimensional computer reconstructions of PEG-treated and sham-treated spinal cords to determine whether the pathological character of a 1-month-old injury is ameliorated by application of PEG. Using a novel isocontouring algorithm, we show that immediate PEG treatment and treatment delayed by up to 7 h post-injury statistically increased the volume of intact spinal parenchyma and reduced the amount of cystic cavitation. Furthermore, in PEG-treated animals, the lesion was more focal and less diffuse throughout the damaged segment of the spinal cord, so that control cords showed a significantly extended lesion surface area. This three-dimensional computer evaluation showed that the functional recovery produced by topical application of a hydrophilic polymer is accompanied by a reduction in spinal cord damage.

Administration, Topical↗
PubMedDate not supplied

Inhibition of tumor growth and angiogenesis by soluble EphB4.

EphB receptors and their ephrinB ligands play a key role in the formation of a regular vascular system. Recent studies have also shown the involvement of Eph/ephrin interactions in malignant tumor progression and angiogenesis. We have generated soluble monomeric EphB4 (sEphB4)-expressing A375 melanoma cells to study the effect of dominant negatively acting sEphB4 on tumor growth and angiogenesis. Soluble EphB4-expressing A375 tumors grown subcutaneously in nude mice show dramatically reduced tumor growth compared to control tumors. The proliferative capacity of sEphB4-expressing cells in monolayer culture is not altered. Yet, sEphB4-expressing A375 cells cannot establish proper cell-cell contacts in three-dimensional spheroids. However, sEphB4 transfectants have reduced proliferation and apoptosis rates when grown in three-dimensional culture in vitro or in subcutaneous tumors in vivo. Analysis of the vascular phenotype of the tumors revealed a reduction of intratumoral microvessel density in sEphB4-expressing tumors. Corresponding to these mouse experiments, a matched pair analysis of EphB4 and ephrinB2 expression in human colon carcinomas revealed significantly upregulated levels of EphB4 expression compared to adjacent normal tissue. Taken together, the data identify dual effects of sEphB4 on the tumor and the vascular compartment that collectively inhibit tumor growth.

Animals↗
PubMed1993

Magnetic resonance imaging and morphometric quantitation of cartilage histology after chronic infusion of interleukin 1 in rabbit knees.

Cartilage pathology in rabbit knees was monitored by noninvasive magnetic resonance imaging (MRI) and evaluated using morphometric histologic measurements. Infusion of rabbit knees with the cytokine interleukin 1 induces cartilage degradation and inflammation. A miniosmotic pump was implanted subcutaneously to deliver interleukin 1 through a polyethylene catheter inserted into the rabbit knee. Rabbit knees were imaged using MRI and prepared for histologic examination at 5 and 12 days after chronic infusion of interleukin 1. MRI obtained 0.7-mm sections for three-dimensional reconstruction of cartilage image. Cartilage deterioration near the site of infusion was visible on MRI. MRI measurements indicated a reduction in cartilage thickness. Histology revealed a loss of staining of cartilage matrix proteoglycan, synovial hypertrophy, and perichondral bone resorption. Morphometric analysis of cartilage histology indicated a reduction in both cellularity (chondrocytes/m mu 2 area) and cell to matrix area ratio. These observations suggest that a loss of proteoglycan, an early event in cartilage degeneration, can be detected by MRI.

Animals↗
PubMed1999

Antipeptide antibodies reveal interrelationships of MBP 200 and MBP 235: unique apoB-specific receptors for triglyceride-rich lipoproteins on human monocyte-macrophages.

Two human monocyte-macrophage (HMM) membrane binding proteins, (MBP) 200 and 235, are receptor candidates that bind to the apolipoprotein (apo)B-48 domain in triglyceride-rich lipoproteins for uptake independent of apoE. Microsequence analysis of the purified reduced MBP 200R characterized tryptic peptides of MBP 200R. A synthetic peptide mimicking a unique, unambiguous 10-residue sequence (AEGLMVTGGR) induced antipeptide antibodies that specifically recognized MBP 200, 235 and 200R, in 1- and 2-dimensional analyses, indicating 1) the ligand binding protein was sequenced and 2) MBP 200 and 235 yielded MBP 200R upon reduction. These antibodies identified the MBPs in human blood-borne, THP-1, U937 MMs, and endothelial cells (EC) but not in human fibroblasts or Chinese hamster ovary (CHO) cells. Fluorescence activated cell sorting (FACS) analysis located the MBPs on the MM surface as necessary for receptor function. The 10-residue, unambiguous MBP 200-derived sequence is unique, with no matches in extant protein databases. Antipeptide antibodies bind to the MBPs in reticuloendothelial cells that have this receptor activity, but not to proteins in cells that lack this receptor activity. These studies provide the first direct protein sequence and immunochemical data that a new, unique apoB receptor for triglyceride-rich lipoproteins exists in human monocytes, macrophages, and endothelial cells.

Amino Acid Sequence↗
PubMed2002

Usefulness of three-dimensional non-fluoroscopic mapping in the ablation of typical atrial flutter.

BACKGROUND: Catheter ablation of the cavo-tricuspid isthmus is rapidly becoming the first line of treatment in the management of atrial flutter. The standard procedure is usually performed under fluoroscopy guidance and relays on multisite endocardial recordings to assess the completeness of the isthmus conduction block. Despite the high rate of success there is, at follow-up, a considerable number of recurrences which could reflect the limitations of conventional assessment of conduction block across the isthmus. This new non-fluoroscopic mapping system allowing high density mapping along the entire length of the ablation line, could provide a more accurate way of verifying complete conduction block. The aim of the present study was to describe our overall results and long-term follow-up using a three-dimensional mapping system to guide radiofrequency ablation of typical atrial flutter. METHODS: A multipoint three-dimensional map of the cavo-tricuspid isthmus, septal and lateral atrial wall was performed in 87 patients prior to and following ablation for typical atrial flutter. Evidence of persisting gaps in the line of block was identified by visual inspection of the color-coded activation maps and these sites were re-ablated. The conduction sequence was also assessed with conventional bidirectional pacing and recording. The assess the reduction in fluoroscopy time, two groups of patients were compared: group A (14 patients) in whom the entire mapping-ablation procedure was guided by the three-dimensional system (Carto, Biosense-Webster, Diamond Bar, CA, USA) and group B (32 patients) in whom the same protocol was used but the procedure was guided by standard fluoroscopic imaging. RESULTS: Acute success was achieved in every patient. During bilateral isthmus pacing, the mean local activation time increased from 20.3 +/- 13.3 ms pre-ablation to 148.3 +/- 53.2 ms (p < 0.01) post-ablation with a mean difference of 120 +/- 31 ms. In 11 patients (9.2%) there was evidence of persisting conduction across the line of block despite evidence of reverse activation of the cavo-tricuspid isthmus by conventional pacing. A gap in the ablation line was identified and re-ablated. At a mean follow-up of 16.3 +/- 2.2 months, there were 5 (4.2%) recurrences of atrial flutter and 12 (10%) recurrences of isolated atrial fibrillation. Four of the 5 recurrences occurred in patients in whom ablation was guided by conventional fluoroscopy (group B). The fluoroscopy time was 4.2 +/- 1.5 min in group A and 27.2 +/- 8.2 min in group B (p < 0.001). CONCLUSIONS: Multipoint mapping of the ablation line following radiofrequency ablation of typical atrial flutter performed using the Carto system allows a more accurate assessment of the isthmus conduction block. This has the potential to reduce the recurrence rate to the level observed for other supraventricular tachycardias.

Atrial Flutter↗
PubMed2003

Radiation medicine innovations for the new millenium.

PURPOSE OF THE STUDY: To review technological advances in the field of radiation oncology in the management of benign and malignant diseases. BASIC PROCEDURES: We reviewed major advances in the field of radiation oncology in the past decade with special emphasis on reduction of treatment related toxicities, and technological improvements in planning and delivery of radiation. Modalities reviewed include computerized three-dimensional conformal treatment planning, stereotactic radiosurgery, intensity-modulated radiation therapy, ultrasound-guided transperineal permanent brachytherapy of the prostate, and high-dose rate brachytherapy. MAIN FINDINGS: There have been major technological advances as evidenced by a decrease in treatment-related toxicities and better target definition resulting in higher local control rates. PRINCIPAL CONCLUSIONS: Significant improvements in technique and equipment have firmly positioned radiotherapy as major artillery in the fight against both benign and malignant diseases.

Brachytherapy↗
PubMed1992

[Diagnostic goals in aortic dissection. Value of transthoracic and transesophageal echocardiography].

The combination of different ultrasound techniques like transthoracic, suprasternal, subcostal and transesophageal echocardiography have a high sensitivity and specificity in the diagnosis of aortic dissection. The limitation of this combined ultrasound technique is related to the visualization of the ascending part of the aortic arch which, cause of the interposition of the trachea, can not be visualized completely. The beginning or the end of a dissection in this part of the aorta may be misinterpreted. False negative results are rare. False positive results due to artefacts resulting from reverberations in an ectatic ascending aorta have to be taken into account. The most important diagnostic aims in acute or chronic aortic dissection can be described: 1. confirmation of the diagnosis by visualization of the intima membrane, 2. the differentiation of the true and false lumen depending on visualization of spontaneous echocardiographic contrast thrombus formation, slow or reduced reversed flow, systolic diameter reduction and signs of entry jet into the false lumen, 3. detection of intimal tear, demonstrating communication by two-dimensional or color Doppler echocardiography, 4. determination of the extent of the dissection with classification according to DeBakey type I, II and III or Stanford A and B with differentiation to communicating or non-communicating dissection, antegrade or retrograde dissection limited to the descending aorta or expanding to the ascending aorta, 5. detection of wall motion abnormalities as a sign of preexisting coronary artery disease or myocardial ischemia due to ostium occlusion by an intimal flap, coronary artery rupture or collapse of the true lumen during diastole, 6. detection and grading of aortic insufficiency, 7. detection of side branch involvement by suprasternal, subcostal and abdominal sonography, which will gain the information which side can be chosen for cannulation or catheterization at the femoral artery, 8. detection of pericardial pleural effusion and mediastinal hematoma as a sign of emergency as rupture can occur within minutes. Without surgical intervention have be performed. Based on these informations, surgery can be performed in all acute situations in type A dissection without further investigations. This decision is particularly important in patients with signs of emergency like pericardial or pleural effusion or mediastinal hematoma.

Aortic Dissection↗
PubMed1990

NMDA receptor agonist and antagonists alter retinal ganglion cell arbor structure in the developing frog retinotectal projection.

The development of sensory maps is thought to require an activity-dependent structural rearrangement of afferent terminal arbors within the CNS which recreates the topographic relations of sensory somata present in the periphery. In the frog retinotectal projection, activation of the NMDA receptor plays a role in this structural plasticity. Exposure of the optic tectum of tadpoles to NMDA receptor antagonists results in a rearrangement of retinal ganglion cell arbors so that their organization into a topographic projection and eye-specific stripes is disrupted (Cline et al., 1987; Cline and Constantine-Paton, 1989). Exposure of the optic tectum to the receptor agonist, NMDA, increases the eye-specific segregation of these arbors (Cline et al., 1987). We examined the projection of the supernumerary retina and the morphology of individual retinal afferent arbors of untreated, NMDA-treated, APV-treated, MK801-treated, and MK801/NMDA-treated 3-eyed tadpoles and young postmetamorphic frogs in an effort to understand how NMDA receptor activation is involved in the growth and ordering of retinal arbors. Treatments with MK801 in combination with NMDA resulted in a desegregation of eye-specific stripes, whereas treatments with MK801 or NMDA alone did not. As reported previously, APV treatment resulted in stripe desegregation without increasing the tangential area (measured from 2-dimensional drawings) of the terminal arbors. However, a detailed analysis revealed that the APV-treated tadpole arbors have 35% reduction in branch density (branch tips/area) compared to untreated 3-eyed tadpole arbors. We treated the optic tectum with a range of concentrations of NMDA prepared in the slow-release plastic Elvax. NMDA at 10(-4) M in Elvax was the optimal concentration to produce the sharpening of stripe borders. Exposure of the tectum to NMDA at 10(-6) M in Elvax produced no change in the stripe pattern, while 10(-2) M NMDA in Elvax resulted in beading of the arbors. At the optimal concentration NMDA treatment results in a 75% reduction in the number of axons crossing from a stripe to an interstripe zone. Drawings of individual HRP-labeled, NMDA-treated arbors demonstrate that they have fewer branch points and fewer branch tips. NMDA treatment reduced arbor density by approximately 50%. Arbors drawn from untreated postmetamorphic frogs have twice the branch density of arbors from untreated tadpoles. NMDA treatment in these animals reduced the branch density by 55%, comparable to the reduction seen in tadpole branch density. Our data support a specific hypothesis for NMDA receptor involvement in the activity-dependent structural refinement process within the developing retinotectal projection.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

[Hemodynamic evaluation of the prosthetic heart valves implanted in the aortic position].

In order to solve the problems of "valve-patient mismatch", hemodynamic problems with prosthetic heart valves implanted in the aortic position, and to clarify suitable size of the prostheses, in vivo hemodynamic studies and studies on the postoperative reduction of left ventricular (LV) hypertrophy were performed in 68 aortic valve replacement patients with various types of prosthetic valves. The pressure gradient across the valve (LV-Ao PG) and effective orifice area (EOA) were measured by perioperative pressure study and by continuous-wave Doppler echocardiography during the postoperative period. The postoperative reduction of LV hypertrophy was evaluated from the reductions of LV mass volume (LVM) on the M-mode echocardiogram, cross sectional area (CSA) on the two-dimensional echocardiogram, CTR on chest X-ray film and SV1 + RV5 on the electrocardiogram. A linear relationship was observed between cardiac output (CO) and LV-Ao PG in each type of prosthetic valve, and the slope of their correlation equation, showing the rate of increase in LV-Ao PG with the increase in CO, was steeper in the prosthesis with a smaller orifice area. The mean value of EOA-echo was 1.4 cm2 in the 19 mm St. Jude Medical valve, 1.6 cm2 in 21 mm Björk-Shiley (BS), 1.9 cm2 in 23 mm BS, 1.7 cm2 in 21 mm Medtronic Hall (MH) and 2.1 cm2 in 23 mm MH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Immediate postoperative results following conservative surgery of rheumatic mitral valve insufficiency in children].

The immediate post-operative results of conservative surgery were evaluated objectively in 31 children aged under 13 years referred to us for surgical correction of severe rheumatic mitral valve regurgitation. 16 patients had pure mitral regurgitation. In the others, lesions which required additional surgery were aortic regurgitation in 7 cases, tricuspid of the mitral valve and left ventricle was studied by two-dimensional TM-mode echocardiography. This examination was combined with a pulsed doppler study in search of a possible residual mitral regurgitation signal, with special attention to the depth at which it was recorded in the left atrium -- a semi-quantitative indication of the severity of residual leakage. Two mitral valve replacements were performed, and two early reoperations were needed for residual regurgitation developed between the 5th and 8th post-operative days. Three deaths occurred due to supra-systemic pulmonary arterial hypertension. The post-operative evaluation of mitral valvuloplasty results therefore involved 25 patients. In the absence of significant residual mitral regurgitation, two-dimensional echocardiography was inconclusive since the images obtained varied considerably according to the surgical procedures performed. There was a distinct reduction of end-diastolic diameters (43.5 +/- 5.9 versus 62.1 +/- 8.7 mm pre-operatively), reflecting the disappearance or marked decrease of the pre-operative ventricular volume overload consecutive to mitral regurgitation. The reduction of end-systolic diameters was also significant (31.2 +/- 6.7 mm versus 39.2 +/- 7.1 mm pre-operatively), though less pronounced than that of end-diastolic diameters, which explains the diminution observed in the percentage of fibre shortening, although the figures remained within normal limits (28.7 +/- 9.7 p. 100 versus 37.0 +/- 6.8 p. 100).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Surgical Procedures↗
PubMed1984

Clinical application of transvenous mitral commissurotomy by a new balloon catheter.

A new balloon catheter was developed which allows mitral commissurotomy without thoracotomy. The procedure has been successful in five of the six patients with mitral stenosis so treated. In the remaining patient, the procedure could not be performed because of technical difficulties. The balloon is reinforced with a nylon micromesh and its shape changes in three stages, depending on the extent of inflation. It is inserted from the saphenous vein into the mitral orifice transseptally, fixed across the mitral orifice with partial inflation, and finally inflated to full its extent, separating the fused commissures by its expansile force. After the procedure, catheterization revealed a significant reduction in the mean diastolic pressure gradient across the mitral valve without resultant mitral regurgitation in each patient. Two-dimensional echocardiograms showed a marked to moderate degree of dilatation of the mitral orifice in each patient. All five patients are well with remarkable clinical improvements 2 to 16 months after the procedure.

Adult↗