Uncommon iatrogenic pneumothorax.
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Adult↗
Biomedical subjects
K B Gupta
Publications and source records attributed to K B Gupta.
Mechanics of the single left ventricle: a study in ventricular-ventricular interaction II.
BACKGROUND: Left ventricular (LV) effects on right ventricular (RV) function are well known. Less is understood about the effect of the RV on systemic LV mechanics. To determine this interaction, we compared systemic LVs with and without an RV mechanically coupled to them. METHODS AND RESULTS: MR myocardial tagging was used to examine 18 subjects with systemic LVs: 10 with functional single LVs (SLV) and 8 normal subjects (NL). Tracking the systolic motion of the intersecting stripes were used to determine regional twist and radial motion. Finite strain analysis was applied to derive principal strains at the atrioventricular valve (AVV) and apical short-axis levels and in 4 anatomic wall regions. Similar E1 (circumferential shortening) strain and heterogeneity of strain were noted between SLV and NL except in the septal wall. At the septal wall, NL displayed greater absolute strain (AVV=-0.16+/-0.02, apex=-0.17+/-0.02) and less heterogeneity of strain than SLV (AVV= -0.12+/-0.02, apex=-0.13+/-0.02). Similar E2 (wall thickening) strain and heterogeneity of strain were also noted between SLV and NL except again at the septal wall. At the septal wall, SLV displayed greater absolute E2 strain (AVV=0.17+/-0.08, apex=0.19+/-0.09) and less heterogeneity of strain than NL (AVV=0.07+/-0.07, apex=0.05+/-0.05). SLV twisted significantly less counterclockwise than NL in 6 of 8 wall regions and actually twisted clockwise at the AVV lateral wall. Although there was no significant difference between groups in radial wall motion, the septal and inferior walls of SLV demonstrated significantly less radial motion compared with other SLV walls. CONCLUSIONS: A major influence of the RV on systemic LV strain and radial motion occurs in the septal wall, whereas absence of the RV causes marked differences in LV twist. These findings may yield clues to the long-term functioning of the SLV and be useful in determining strategies for RV augmentation of LV function.
Adolescent↗
State-related changes in upper airway caliber and surrounding soft-tissue structures in normal subjects.
State-dependent changes in upper airway caliber were studied with magnetic resonance imaging (MRI) techniques. We hypothesized that changes in airway caliber during sleep in normal subjects would result from positional and dimensional changes in upper airway soft-tissue structures, including the lateral pharyngeal walls, tongue, and soft palate. We used MRI to study 15 normal subjects during wakefulness and sleep. Sleep was facilitated by one night of sleep deprivation prior to MRI. During sleep, the volume of the retropalatal (RP) airway was reduced by 19% (p = 0.03). The volume of the retroglossal (RG) airway was not significantly reduced during sleep, suggesting that the RP region may be more likely to collapse. The mean minimal cross-sectional airway area was reduced by 228% (p = 0.004) in the RP and by 22% (p = 0.02) in the RG region during sleep as compared with values in anatomically matched axial images during wakefulness. Airway anteroposterior (AP) and lateral dimensions were also significantly reduced in the RP region. Airway narrowing in the RP region was associated with a 7% increase in thickness of the lateral pharyngeal walls (p = 0.04). In nine subjects, sagittal data showed significant posterior displacement of the soft palate during sleep as compared with wakefulness. Multiple linear regression analyses indicated that reduction in the RP airway area during sleep resulted from posterior movement of the soft palate, thickening of the lateral pharyngeal walls, and an increase in tongue oblique distance. We conclude that the lateral pharyngeal walls play an important role in upper airway narrowing during sleep in normal subjects.
Adult↗
Genital neoplasm in the elderly women of Himachal Pradesh: 6-year study.
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Adenoma↗
Adolescent pregnancy: a high risk group.
In a retrospective study the obstetric behaviour and outcome in 80 teenage pregnancies (< or = 19 years of age) were compared to a control group (n = 80) of women (20-30 years) of same parity. There were 32 booked cases (40%) in study group and 45 (56.2%) in control group (p < 0.05). The overall teenage pregnancy was 3.2%. Majority of patients were 18 years (27.5%) and 19 years (65.0%) in study group and most of them (87.5%) were primiparas. Of all cases 27.5% were grouped under Kuppuswamy classification III in assessing socio-economic status. Anaemia (27.5%), intra-uterine growth retardation (27.5%) and hypertension (15%) were mostly found as complications in study group as compared to controls (11.2%, 8.7% and 8.7% respectively). The incidence of forceps delivery was higher (17.4%) in the study group as compared to controls (6.2%). Stillbirth rate was 1.25% and there was no maternal mortality.
Adolescent↗
Dynamic three-dimensional imaging of the mitral valve and left ventricle by rapid sonomicrometry array localization.
OBJECTIVES: The first objective was to develop a quantitative method for tracking the three-dimensional geometry of the mitral valve. The second was to determine the complex interrelationships of various components of the mitral valve in vivo. METHODS AND RESULTS: Sixteen sonomicrometry transducers were placed around the mitral vale anulus, at the tips and bases of both papillary muscles, at the ventricular apex, across the ventricular epicardial short axis, and on the anterior chest wall before and during cardiopulmonary bypass in eight anesthetized sheep. Animals were studied later on 17 occasions. Reproducibility of derived chord lengths and three-dimensional coordinates from sonomicrometry array localization, longevity of transducer signals, and the dynamics of the mitral valve and left ventricle were studied. Reproducibility of distance measurements averages 1.6%; Procrustes analysis of three-dimensional arrays of coordinate locations predicts an average error of 2.2 mm. Duration of serial sonomicrometry array localization signals ranges between 60 and 151 days (mean 114 days). Sonomicrometry array localization demonstrates the saddle-shaped mitral anulus, its minimal orifice area immediately before end-diastole, and uneven, apical descent during systole. Papillary muscles shorten only 3.0 to 3.5 mm. Sonomicrometry array localization demonstrates nonuniform torsion of papillary muscle transducers around a longitudinal axis and shows rotation of papillary muscular bases toward each other during systole. CONCLUSION: Tagging of ventricular structures in experimental animals by sonomicrometry array localization images is highly reproducible and suitable for serial observations. In sheep the method provides unique, quantitative information regarding the interrelationship of mitral valvular and left ventricular structures throughout the cardiac cycle.
Animals↗
Upper airway and soft tissue structural changes induced by CPAP in normal subjects.
Nasal continuous positive airway pressure (CPAP) is the treatment of choice for adults with obstructive sleep apnea. CPAP is known to increase upper airway size; however, the direct effects of CPAP on soft tissue structures surrounding the upper airway are less well understood. Magnetic resonance imaging was used to study the effect of incremental levels (0, 5, 10, and 15 cm H2O) of CPAP on the upper airway and surrounding soft tissue structures in 10 normal subjects. Progressive increases in CPAP resulted in the following major findings: (1) airway volume and airway area (measured at several different locations [midregion, minimal, maximal]) within the retropalatal and retroglossal regions increased; (2) lateral airway dimensional changes were greater than anterior-posterior changes; (3) lateral upper airway soft tissue structural changes were significantly greater than anterior-posterior changes; (4) lateral pharyngeal wall thickness decreased and the distance between the lateral parapharyngeal fat pads increased. An inverse relationship was demonstrated between CPAP level and pharyngeal wall thickness; (5) minimal changes were noted in the soft palate and tongue. These data suggest that the lateral pharyngeal walls are more "compliant" than the soft palate and tongue. This investigation provides further evidence that the lateral pharyngeal walls play an important role in mediating upper airway caliber.
Adult↗
Perinatal outcome in pregnancy induced hypertension.
Perinatal outcome and the factors affecting it were studied in 140 pregnant women with hypertension. Perinatal mortality rate (PNM) was 140/1000 and the stillbirth rate was 8.7%. In severe hypertension PNM was 52.3% and all perinatal deaths were 8.7%, when the serum uric acid level were more than 4.5 mg%.
Birth Weight↗
A study of ectopic pregnancy and high risk factors in Himachal Pradesh.
Although the total number of pregnancies have declined over the past decade, the rate of ectopic pregnancies has increased dramatically. Incidence was maximum in 26-30 years of age group (37.6%) and in para 2 (32.9%). Pain was the commonest symptom (91.7%) followed by bleeding per vaginum (71.7%) and amenorrhoea (41.4%). High risk factors were present in 67% of cases (57 out of 85 cases, 7 patients had 2 high risk factors).
Adult↗
Pathogenesis of acute ischemic mitral regurgitation in three dimensions.
Changes in the geometric and intravalvular relationships between subunits of the ovine mitral valve were measured before and after acute posterior wall myocardial infarction in three dimensions by means of sonomicrometry array localization. In 13 sheep, nine sonomicrometer transducers were attached around the mitral anulus and to the tip and base of each papillary muscle. Five additional transducers were placed on the epicardium. Snares were placed around three branches of the circumflex coronary artery. One to 2 weeks later, echocardiograms, dimension measurements, and left ventricular pressures were obtained before and after the coronary arteries were occluded. Data were obtained from seven sheep. Coronary occlusion infarcted 32% of the posterior left ventricle and produced 2 to 3+ mitral regurgitation by Doppler color flow mapping. Multidimensional scaling of dimension measurements obtained from sonomicrometry transducers produced three-dimensional spatial coordinates of each transducer location throughout the cardiac cycle before and after infarction and onset of mitral regurgitation. After posterior infarction, the mitral anulus enlarges asymmetrically along the posterior anulus, and the tip of the posterior papillary muscle moves 1.5 +/- 0.3 mm closer to the posterior commissure at end-systole. The posterior papillary muscle also elongates 1.9 +/- 0.3 mm at end-systole. The left ventricle enlarges asymmetrically and ventricular torsion along the long axis changes. The development of postinfarction mitral regurgitation appears to be the consequence of multiple small changes in ventricular shape and contractile deformation and in the spatial relationship of mitral valvular subunits.
Animals↗
Use of sonomicrometry and multidimensional scaling to determine the three-dimensional coordinates of multiple cardiac locations: feasibility and initial implementation.
We describe a new method which uses sonomicrometry and the statistical technique of multidimensional scaling (MDS) to measure the three-dimensional (3-D) coordinates of multiple cardiac locations. We refer to this new method as sonomicrometry array localization (SAL). The new method differs from standard sonomicrometry in that each piezoelectric transducer element is used as both transmitter and receiver and the set of intertransducer element distances is measured. MDS calculates the 3-D coordinates of each sonomicrometry transducer element from the set of intertransducer element distances. The feasibility of this new method was tested with mathematical simulations which demonstrated the ability of MDS to compensate for signal error and missing intertransducer element distances. We describe the design elements of a modified digitally controlled sonomicrometer in which a single transducer element can sequentially broadcast to as many as eight receiver elements. That design is used to validate SAL in a water bath and in ex vivo and living hearts. Correlation with caliper measurement in the water bath (y int. = 3.91 +/- 3.36 mm, slope = 1.04 +/- 0.05, r2 = 0.969 +/- 0.027) and with radiography in ex vivo (y int. = -0.87 +/- 0.92 mm, slope = 0.97 +/- 0.02, r2 = 0.960 +/- 0.023) and in vivo hearts (y int. = 2.98 +/- 2.59 mm, slope = 1.01 +/- 0.06, r2 = 0.953 +/- 0.031) was excellent. Sonomicrometry array localization is able to accurately measure the 3-D coordinates of multiple cardiac locations. It can potentially measure myocardial deformation and remodeling after ischemic or valvular injury.
Algorithms↗
Pulmonary thromboembolism: recent developments in diagnosis with CT and MR imaging.
Recent technical advances in computed tomography (CT; helical and electron beam) and magnetic resonance (MR) imaging have spurred a renewed interest in these modalities for the diagnosis of acute and chronic pulmonary embolism (PE). These techniques can enable accurate clot detection down to segmental pulmonary arteries, with CT currently allowing more accuracy than that with MR imaging. Ongoing technical advances, particularly in MR angiography, will likely increase diagnostic accuracy. Inability to reliably detect subsegmental acute emboli may not prove to be a clinically significant limitation if lung imaging is coupled with evaluation for deep venous thrombosis. MR imaging can potentially accomplish this within a single examination. Incorporation of CT and MR imaging into diagnostic algorithms for suspected PE can be cost-effective. Evaluation of these new modalities should be based on patient outcome, not solely on clot detectability. Well-designed clinical trials are warranted before CT and MR imaging can be used routinely in the diagnosis of acute PE.
Acute Disease↗
Regional wall motion and strain analysis across stages of Fontan reconstruction by magnetic resonance tagging.
To determine whether systolic regional wall deformation and motion, which may be used as an index of mechanical function, change with surgical intervention in patients with a functional single ventricle, a noninvasive magnetic resonance tagging technique was used to examine 33 such patients at all stages of Fontan reconstruction. The systolic motion of the intersection points was tracked to determine regional twist and radial shortening. Finite strain analysis was applied to the grid lines, and principal E1 strains were derived. The results were as follows. 1) Fontan and prebidirectional cavopulmonary anastomosis (hemiFontan) groups had the highest compressive strains, and regional heterogeneity of strain was least in the Fontan group. 2) Fontan patients had endocardial/epicardial strain different from the other surgical subgroups as well as the normal left ventricle, while the pre- and post-hemiFontan groups had basal/apical short-axis strain different from Fontan patients and normal subjects. 3) Functional single left ventricles had a different strain distribution across wall regions and surgical subgroup from functional single right ventricles. 4) Contrary to the normal human adult studied by the same method, which twists uniformly counterclockwise, 31 of 33 single ventricles, regardless of ventricular morphology or surgical subgroup, twisted counterclockwise in one region, clockwise in another, and met at a "transition zone" of no twist, which had the highest strains of all regions. 5) Radial contraction was greatest in the superior walls and least at the inferior walls of single-ventricle patients regardless of morphology. In the Fontan group, the inferior walls moved paradoxically. In conclusion, markedly different strain characteristics are noted at each stage of Fontan reconstruction, across various wall regions, and between ventricular morphological groups. Differences in regional wall motion were demonstrated in functional single ventricles throughout Fontan reconstruction regardless of morphology, and differences in associated strains and radial contraction were noted across various wall regions and surgical subgroups. These may play an important role in the energetics of the heart and the long-term viability of the single ventricle.
Child↗
Upper airway and soft tissue anatomy in normal subjects and patients with sleep-disordered breathing. Significance of the lateral pharyngeal walls.
The geometry and caliber of the upper airway in apneic patients differs from those in normal subjects. The apneic airway is smaller and is narrowed laterally. Examination of the soft tissue structures surrounding the upper airway can lead to an understanding of these apneic airway dimensional changes. Magnetic resonance imaging was utilized to study the upper airway and surrounding soft tissue structures in 21 normal subjects, 21 snorer/mild apneic subjects, and 26 patients with obstructive sleep apnea. The major findings of this investigation in the 68 subjects were as follows: (1) minimum airway area was significantly smaller in apneic compared with normal subjects and occurred in the retropalatal region; (2) airway narrowing in apneic patients was predominantly in the lateral dimension; there was no significant difference in the anterior-posterior (AP) airway dimension between subject groups; and (3) distance between the rami of the mandible was equal between subject groups, and thus the narrowing of the lateral dimension was not explained by differences in bony structure; (4) lateral airway narrowing was explained predominantly by larger pharyngeal walls in apneic patients (the parapharyngeal fat pads were not closer together as one would expect if the airway walls were compressed by fat); and (5) fat pad size at the level of the minimum airway was not greater in apneic than normal subjects. At the minimum airway area, thickness of the lateral pharyngeal muscular walls rather than enlargement of the parapharyngeal fat pads was the predominant anatomic factor causing airway narrowing in apneic subjects.
Adult↗
Epidermal growth factor (EGF) receptor carboxy-terminal domains are required for EGF-induced glucose transport in transgenic 3T3-L1 adipocytes.
Insulin-stimulated glucose transport in adipocytes is mediated by the insulin receptor. To ascertain whether a related receptor could also trigger this response, the epidermal growth factor (EGF) receptor (EGFR) was introduced into adipocytes. 3T3-L1 fibroblasts were infected by a retroviral construct encoding either the full-length (WT) or a carboxy-terminal truncated (c'973) human EGFR; truncation of the amino acids distal to 973 removes all autophosphorylation motifs. After selection and conversion to adipocytes, the level of EGFR expression was retained in infectant adipocytes (150,000 and 250,000/cell, respectively), but not in the parental 3T3-L1 adipocytes (< 5000/cell). WT and c'973 EGFR exhibited ligand-dependent tyrosine kinase activity and stimulated mitogen-activated protein kinase activity equivalently; neither phosphorylated insulin receptor substrate-1. WT EGFR, but not c'973 EGFR, underwent ligand-induced autophosphorylation. EGF did not stimulate tyrosine phosphorylation of the insulin receptor or insulin receptor substrate-1. EGF had a minimal effect on glucose transport by parental 3T3-L1 adipocytes. Glucose transport in the WT EGFR adipocytes was stimulated equivalently by insulin and EGF; exposure to insulin and EGF in combination did not result in augmented transport. Glucose transport in the c'973 EGFR adipocytes was stimulated by insulin, but not by EGF. GLUT4 was translocated to the plasma membrane to a similar extent in response to insulin or EGF in the WT EGFR adipocytes; only insulin caused a significant GLUT4 translocation in the parental or c'973 EGFR adipocytes. These data suggest that the insulin and EGF signaling pathways that lead to glucose transport converge in these adipocytes down-stream of the insulin receptor, and that activation of this pathway requires signaling motifs in the carboxy-terminus of the EGFR. This model system represents a novel approach with which to dissect signal transduction pathways in terminally differentiated adipocytes.
3T3 Cells↗
Unusual presentation of ectopic pregnancy.
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Adult↗
Changes in passive mechanical stiffness of myocardial tissue with aneurysm formation.
BACKGROUND: Myocardium undergoes complex cellular and histochemical alterations after acute myocardial infarction. These structural changes directly affect the mechanical stiffness of infarcted and remote myocardia. Previous investigations of infarct stiffness have been limited to uniaxial testing, which does not provide a unique description of the tissue's three-dimensional material properties. This study describes the first serial measurements of biaxial mechanical properties of sheep myocardium after anteroapical infarction. METHODS AND RESULTS: Anteroapical infarctions of 23.7 +/- 2.5% of the left ventricular mass were produced by coronary arterial ligation in sheep. Biaxial force-extension measurements were made on freshly excised squares (6.45 cm2) of remote, noninfarcted, and infarcted myocardia before and 4 hours, 1 week, 2 weeks, and 6 weeks after ligation. Adjacent myocardial samples were assayed for hydroxyproline content. Force-extension data and a derived constitutive equation were used to describe stresses and strains and material properties of each sample. In sheep, anteroapical infarctions evolve into thin left ventricular aneurysms that consist of predominantly fibrous tissue with disrupted groups of muscle cells encased in scar. In the infarct, Cauchy stresses at 15% extensions (control stresses: circumferential, sigma C, 19.4 +/- 3.3 g/cm2; longitudinal, sigma L, 54.8 +/- 34.8 g/cm2) increase within 4 hours, peak at 1 to 2 weeks (sigma C, 338.5 +/- 143.6 g/cm2; sigma L, 310.7 +/- 45.9 g/cm2), and then decrease 6 weeks after infarction (sigma C, 115 +/- 47.2 g/cm2; sigma L, 53.2 +/-28.9 g/cm2). Stresses in the remote myocardium follow a similar time course but to a lesser extent than the infarcted region. Hydroxyproline content, a measure of collagen content, does not correlate with infarct stiffness but progressively increases to 69.7 +/- 7.6 micrograms/mg after 6 weeks. Stress-extension curves demonstrate directional anisotropy of both infarcted and remote myocardia. CONCLUSIONS: The findings indicate that infarcted myocardium becomes more stiff during the first 1 to 2 weeks after anteroapical infarction and then more compliant. The infarct also exhibits directional anisotropy. These observations underscore the importance of ventricular material properties during the remodeling process after acute myocardial infarction and may partially explain the progressive left ventricular dilatation and functional deterioration that occur in some patients after anteroapical infarction.
Animals↗
Gynaecological neoplasms in postmenopausal women of Himachal Pradesh.
A controlled prospective study was conducted on 300 postmenopausal women attending the Kamla Nehru Hospital from November, 1990 to August, 1992. The incidence of gynaecological neoplasms was 31.3% in both the study group (300 postmenopausal women) and the control group (300 premenopausal women). The incidence of malignant neoplasms was 24.6% in study group and 8.6% in control group. This difference was highly significant (p < 0.001). Carcinoma cervix (16%) was the commonest gynaecological malignancy followed by ovarian cancer (6%). The incidence of benign neoplasms was lower in the study group (6.6%) as compared to the control (22.6%).
Female↗