Posttransplant diffuse large B-cell lymphoma of "lymphomatoid granulomatosis" type

The exact relationship between lymphomatoid granulomatosis (LyG) and posttransplant lymphoproliferative disorders (PTLDs) is not clear. Both are observed in immunodeficient patients and are Epstein-Barr virus driven. These disorders are, however, considered distinct based upon the immune response elicited; LyG is T-cell rich while PTLDs are T-cell poor. We describe a case of LyG-type diffuse large B-cell lymphoma (DLBCL) in a lung transplant recipient. The unusual features include rare occurrence of LyG in a posttransplant setting, systemic involvement by LyG variant of DLBCL in a solid organ transplant recipient, paucity of T-cells in this LyG type lymphoma, and subcutaneous panniculitic pattern in a B-cell lymphoproliferative disorder. This first report of systemic LyG variant of DLBCL in a posttransplant setting has features suggesting similarities and overlap between LyG and PTLD.

Catheter ablation of left free wall accessory pathway in a patient with inferior vena cava interruption

Access to the right side of the heart for diagnostic and interventional procedures is usually obtained via the femoral vein and inferior vena cava. Anatomic variations or obstruction of the inferior vena cava can make this access difficult. In such cases, alternative routes to the right side of the heart such as the azygos vein and the superior vena cava can be used.

Ten-year experience with the arterial switch operation

BACKGROUND

Arterial level repair is considered the most appropriate procedure for transposition of the great arteries. This report describes our experience with the arterial switch operation over the past decade.

METHODS AND RESULTS

From January 1991 to January 2001, a total of 299 patients underwent an arterial switch operation for transposition of the great arteries or double-outlet right ventricle. Group I (n=169, 56.5%) comprised patients with transposition of the great arteries in whom the ventricular septum was essentially intact. Group II patients (n=130, 43.5%) had transposition of the great arteries with an additional significant ventricular septal defect or had double-outlet right ventricle with a subpulmonic ventricular septal defect. Of the total, 245 (82%) were males and 54 (18%) were females. In group I, the ages ranged from 2 days to 18 years (median 19 days) and weight ranged from 1.7 to 68 kg (median 2.5 kg). In group II, the ages ranged from 4 days to 4 years (median 90 days) and weight ranged from 2.5 to 17 kg (median 4 kg). Fifteen percent of the patients (25/169) in group I and 30% of the patients (39/130) in group II had features of bacteriologic infection. Arterial switch operation was performed on standard lines. In group I, 141 patients (83.4%) had a primary arterial switch operation while 28 (16.6%) underwent a rapid two-stage repair. Twenty-three patients required concomitant relief of associated anatomic left ventricular outflow tract obstruction. Operative mortality was 8.8% (15/169) in group I and 33% (44/130) in group II with an overall mortality of 19% (59/299). The major causes of operative mortality included pulmonary arterial hypertensive crisis (n=21), sepsis and related complications (n=16), and left ventricular failure (n=8). Coexisting arch anomalies, longer cross-clamp time, late presentation, and preoperative bacteriologic infections were incremental risk factors. Follow-up ranged from 1 to 10 years and was 87% complete. On follow-up, 91% of the patients were asymptomatic and off all medications. There were 3 late deaths and 5 patients required reoperation.

CONCLUSIONS

Excellent long-term results are obtained in operative survivors following the arterial switch operation. However. operative mortality remains a concern in our set-up.

Usefulness of an inexpensive, Paracheck test in detecting asymptomatic infectious reservoir of plasmodium falciparum during dry season in an inaccessible terrain in central India

OBJECTIVES

The performance of a new indigenous rapid diagnostic test, Paracheck Pf was evaluated in detection of Plasmodium falciparum in asymptomatic children in remote forest villages of Mandla district, central India to determine the lower limits of sensitivity and specificity of rapid test.

METHODS

A finger prick blood sample was collected to prepare blood smear and for testing with the Paracheck test. The blood smears were read by an experienced technician blinded to the Paracheck results. The figures for specificity, sensitivity, accuracy and predictive values were calculated using microscopy as gold standard.

RESULTS

The new diagnostic test had a sensitivity of 94% and a specificity of 89%. The positive and negative predictive values were 71% and 98%, respectively. The J -index was 0.83%.

CONCLUSION

The rapid test was found to be very easy to perform and the result could be read reliably by field workers. The field evaluation with this new inexpensive test, ($0.65/test) indicates that it could be used as an epidemiological tool in the management of malaria particularly in areas where microscopy is not operationally feasible to attain the goal of the roll back malaria initiative.

Conformational dynamics of photoexcited conjugated molecules

Time-dependent photoexcitation and optical spectroscopy of pi-conjugated molecules is described using a new method for the simulation of excited state molecular dynamics in extended molecular systems with sizes up to hundreds of atoms. Applications are made to poly(p-phenylene vinylene) oligomers. Our analysis shows self-trapping of excitations on about six repeat units in the course of photoexcitation relaxation, identifies specific slow (torsion) and fast (bond-stretch) nuclear motions strongly coupled to the electronic degrees of freedom, and predicts spectroscopic signatures of molecular conformations.

Achilles tendinopathy: some aspects of basic science and clinical management

Achilles tendinopathy is prevalent and potentially incapacitating in athletes involved in running sports. It is a degenerative, not an inflammatory, condition. Most patients respond to conservative measures if the condition is recognised early. Surgery usually involves removal of adhesions and degenerated areas and decompression of the tendon by tenotomy or measures that influence the local circulation.

Omphalocele: clinical review and surgical experience using dura patch grafts

Over a period of 15 years we surgically treated 50 cases of omphaloceles. The pathology occurred more frequently in boys (n = 30) than in girls (n = 20). The mean birth weight was 2995 g and mean gestational age was 38 weeks. Four infants (8%) were delivered vaginally and the rest (92%) by cesarian section. Eleven infants (22%) underwent primary closure, but in 20 infants (40%) with larger defects a primary closure of the skin was possible; however, a single solvent-dried dura graft implant was employed for the fascia enlargement. The remaining 19 infants (38%) had extremely large defects, and optimal closure of the defect required a two layered graft implantation. Twenty-five infants (50%) had associated anomalies, the majority being congenital cardiac anomalies. Five patients (10%) required secondary laparotomies due to bowel associated complications. Four patients (8%) experienced non-bowel-associated complications. The average postoperative mechanical ventilation required was for a period of 3.2 days and the average hospital stay was 45.7 days. The overall mortality rate was 8% (n = 4) and was largely due to severe congenital heart anomalies. Solvent-dried dura was successfully employed in the management of the larger defects with no major complications; only one patient (2%) had a local abscess around the area of the implant and was managed conservatively. Our experience favors the employment of solvent-dried dura graft implants for the repair of large omphaloceles. The solvent-dried dura grafts are biomaterials that promote rapid scar formation and integration with the adjacent skin tissue and do not produce any foreign body reactions at the site of implantation.

Efficient computation of the structural phase behavior of block copolymers

A numerical implementation of self-consistent mean-field theory for the structural phase behavior of block copolymers is proposed. Our scheme does not require a priori assumptions of the underlying mesoscopic symmetries. The method potentially enables us to characterize, with high accuracy, the structural phase diagram of block copolymers with significant architectural complexity. We illustrate the method by applying it to a triblock copolymer system.

Study of trace element correlations with drought tolerance in different sorghum genotypes using energy-dispersive X-ray fluorescence technique

Drought-tolerant and drought-susceptible genotypes of sorghum (Sorghum bicolor L. Monech) were analyzed by the energy-dispersive X-ray fluorescence (EDXRF) technique to study the correlation of trace elements with drought-tolerance capacities. Samples prepared from mature seeds, young seedlings, and old plants were analyzed using a 109Cd radioisotope source and a Si(Li) semiconductor detector of resolution 170 eV for 5.9-keV MnKalpha X-rays. Elements such as K, Fe, Cu, Zn, Rb and Sr and Y were found to be present in varying concentrations in different samples. The trace element profile studied in the seeds of 11 genotypes and in seedlings (young and old) of 4 sorghum genotypes showed considerable variation. The genotype Arfa Gadamak (AG) showed a distinct presence of a high level of Zn in its young seedling. It was observed that in most of the genotypes (seeds), K and Fe concentrations were more in the tolerant genotype as compared to the susceptible type. The concentration of Fe decreased with maturity in the tolerant group and it increased with maturity in the susceptible group.

Management of cardiomyopathy resulting from incessant supraventricular tachycardia in infants and children

BACKGROUND

Radiofrequency ablation is considered to be the treatment of choice in patients with ventricular dysfunction related to incessant supraventricular tachycardia. However, reservations regarding its use in infants and children prompted us to try alternative strategies for this group.

METHODS AND RESULTS

Eight children (age range: 1 day to 10 years) were diagnosed to have tachycardia-related ventricular dysfunction in the past 6 years. They presented with symptoms of palpitation, dyspnea and/or generalized swelling over the body of 3 months to 2 years'duration. The cardiothoracic ratio at presentation was 64% (52%-70%) and ejection fraction was 22.2% (15%-45%). In 7 patients tachycardia was diagnosed to be ectopic atrial and in 1 it was permanent junctional reciprocating tachycardia. Six of these children were managed with intravenous/oral amiodarone in combination with digoxin (3) and/or propranolol (2). In one child addition of amiodarone to digoxin and propranolol led to polymorphic ventricular tachycardia, and amiodarone was withdrawn. Only one child underwent radiofrequency ablation as the first choice because regular follow-up was not possible due to logistic reasons. Sinus rhythm with normalization of ventricular function was achieved in 6 of the 7 children treated medically. One child continued to have frequent episodes of tachycardia and underwent successful radiofrequency ablation of a high right atrial ectopic focus. Two out of the 6 patients on amiodarone could be managed with only digoxin and propranolol after their ventricular function had returned to normal. A third patient relapsed on stopping amiodarone and underwent successful radiofrequency ablation of a left atrial ectopic tachycardia.

CONCLUSIONS

Short-term amiodarone in combination with digoxin/propranolol is a safe and effective treatment strategy for infants/children with tachycardiomyopathy. Control of tachycardia is achieved in the majority, leading to recovery of ventricular function. This approach may avoid unnecessary ablations in children or at least postpone it till the procedure would be safer.

Expression of Bcl-x, Bcl-2, Bax, and Bak in endarterectomy and atherectomy specimens

The regulation of apoptosis in atherosclerosis is not completely defined. The aim of this study was to determine the expression of Bcl-2, Bcl-x, Bax, and Bak in relation to apoptosis in advanced atherosclerotic lesions. In atherectomy (15), endarterectomy (10), and control non-atherosclerotic segments of renal (2) and of coronary and carotid (5) arteries, the extent of apoptosis was determined using TdT dUTP nick end labelling (TUNEL) and nuclear morphology (karyorrhexis/pyknosis) and expression of apoptosis regulators by immunohistochemistry and western blot analysis on paraffin-embedded material. In all specimens, the atherosclerotic involvement was advanced: grade V (n=18) and grade VI (n=7). The apoptotic index was high (mean 30%) in advanced lesions compared with controls (<2%) and smooth muscle cells (SMCs) were the predominant cell type undergoing apoptosis. In all TUNEL-positive apoptotic cells, Bax and Bak were present, while Bcl-x was absent. Bcl-2 was absent in a majority of these cells, but occasional TUNEL-positive cells expressed Bcl-2. In non-apoptotic cells, Bcl-x was present and western blot detected only the long isoform, Bcl-xL, from the plaques. In conclusion, increased Bax and Bak coupled with lack/paucity of Bcl-2 and Bcl-xL are associated with SMC apoptosis in advanced lesions. Bcl-xL in non-apoptotic cells appears to contribute to prolonged cell survival.

Nucleation in systems with elastic forces

Systems with long-range interactions when quenched into a metastable state near the pseudospinodal exhibit nucleation processes that differ from classical nucleation seen near the coexistence curve. In systems with long-range elastic forces the description of the nucleation process can be quite subtle due to the presence of bulk and surface elastic compatibility constraints. We analyze the nucleation process in a simple 2D model with elastic forces and show that the nucleation process generates critical droplets with a different structure than the stable phase. This has implications for nucleation in many crystal-crystal transitions, specifically martensites and shape memory alloys, and for the structure of the final state.

Modulation of ovarian function in female dogs immunized with bovine luteinizing hormone receptor

Adult female dogs were immunized with 0.5 mg bovine luteinizing hormone receptor (LH-R) encapsulated in a silastic subdermal implant and subsequently with four intramuscular booster injections of 0.1 mg LH-R each. Circulating LH-R antibody was detected in the sera 3 weeks post-implant. The appearance of LH-R antibody was associated with a decline in the serum progesterone concentrations to a range of 0-0.5 ng/ml until day 365 in the immunized dogs in comparison with a range of 5-10 ng in the control animals, suggesting a lack of ovulation and corpus luteum function in immunized dogs. The immunized dogs did not show signs of 'standing heat' and failed to ovulate when induced by LH-RH challenge. Serum oestradiol levels, however, remained in the range of 30-40 pg/ml in both the immunized and the control dogs. With the decline in the antibody titres, the hormonal profile and vaginal cytology returned to a fertile state and the dogs exhibited signs of 'standing heat', as well as vaginal bleeding. Dogs immunized with LH-R did not show any serious metabolic, local or systemic adverse effects. The hypothalamic--pituitary gonadal axis remained intact as indicated by little difference in pituitary LH levels between control and immunized animals, and by the release of LH by LH-RH challenge. These studies demonstrate that active immunization of female dogs with LH-R could immunomodulate ovarian function to cause a reversible state of infertility. It may be postulated that, due to extensive interspecies homology, a recombinant LH receptor-based immunocontraceptive vaccine may also be effective in other vertebrates.

Effects of competing short- and long-range dispersive interactions on discrete breathers

The discrete nonlinear Schrödinger equation with competing short-range and long-range interactions is considered in spatial dimensions d> or =2. This model equation is derived for a situation of two linearly coupled excitations (independently of dimension), and we analytically and numerically study its properties in 2+1 dimensions. We analyze theoretically and demonstrate numerically the dependence of the discrete breather solutions on the amplitude and range of the interactions. We find that complete suppression of the existence thresholds obtained recently for short-range interactions can be achieved beyond a critical value of the amplitude or of the range of the long-range kernel. For supercritical values of the corresponding parameters, staggered branches of solutions are obtained both in theory as well as in the numerical experiment.

Total anomalous pulmonary venous connection: surgical experience in Indians

BACKGROUND

We report a retrospective analysis of the demographic. morphological and clinical profiles of patients along with results of operative repair for total anomalous pulmonary venous connection.

METHODS AND RESULTS

In the last 15 years, 248 patients (168 boys, 80 girls) underwent repair for total anomalous pulmonary venous connection. Their ages ranged from I day to 24 years (median 8 months) and 145 of them were < or = 1 year of age. The patients' weight ranged from 2 to 52 kg (median 5 kg). About 70% of patients (n = 174) were less than the 50th percentile of predicted weight for age and sex. The anomalous connection was supracardiac in 134 (54%), cardiac in 80 (32.2%), infracardiac in 9 (3.6%) and mixed in 25 (10.1%) patients. Fifty (20.2%) patients had obstructed drainage and 76 patients (30.2%) had moderate or severe pulmonary arterial hypertension. Forty-five patients (18.1%) had to be operated upon on an emergency basis. All the patients were operated upon using moderately hypothermic cardiopulmonary bypass. In 114 patients, circulatory arrest was used. There were 45 (19.1%) in-hospital deaths. The major causes of early death were pulmonary arterial hypertensive crisis in 19 (7.7%) and low cardiac output syndrome in 17 (6.9%) patients. Age < or = 1 year (odds ratio 2.16; 95% confidence interval: 1.22-3.82, p=0.008), severe pulmonary arterial hypertension (odds ratio 5.86; 95% confidence interval: 2-17, p=0.001), and need for emergency surgery (odds ratio 3.65; 95% confidence interval: 1.59-8.38, p=0.002) were independent risk factors for early death. Follow-up ranged from 1 to 180 months (median 48 months). There were 4 lake deaths. Actuarial survival at 12 years was 92.6% +/- 2.8%.

CONCLUSIONS

In Indian circumstances, mortality continues to be high in infants with total anomalous pulmonary venous connection. Severe pulmonary arterial hypertension appears to be the most important predictor of operative mortality. Severe malnutrition, delayed diagnosis and late referrals possibly contribute to the high mortality.

The Leishmania genome project: new insights into gene organization and function

The sequencing of Leishmania major Friedlin chromosome 1 (Chr1), Chr3, and Chr4 has been completed. and several other chromosomes are well underway. The complete genome sequence should be available by 2003. Over 1,000 full-length new genes have been identified, with the majority (approximately 75%) having unknown function. Many of these may be Leishmania (or kinetoplastid) specific. Most interestingly, the genes are organized into large (> 100-500 kb) polycistronic clusters of adjacent genes on the same DNA strand. Chr1 contains two such clusters organized in a "divergent" manner, i.e., the mRNAs for the two sets of genes are both transcribed towards the telomeres. Nuclear run-on analysis suggests that transcription is initiated in both directions within the "divergent" region. Chr3 and Chr4 contain two "convergent" clusters, with a single "divergent" gene at one telomere of Chr3. Sequence analysis of several genes from the LD1 region of Chr35 indicates a high degree of sequence conservation between L. major and L. donovani/L. infantum within protein-coding open reading frames (ORFs), with a lower degree of conservation within the non-coding regions. Immunization of mice with recombinant antigen from two of these genes, BTI (formerly ORFG) and ORFF, results in significant reduction in parasite burden following Leishmania challenge. Recombinant ORFF antigen shows promise as a serodiagnostic. We have also developed a tetracycline-regulated promoter system, which allows us to modulate gene expression in Leishmania.

Physical growth assessment in adolescence

OBJECTIVE

To describe ponderosity indices body mass index--"BMI" and ponderal index "PI" and skin fold thicknesses (triceps, biceps, subscapular and suprailiac) for affluent Indian school going adolescents.

DESIGN

Cross sectional.

METHODS

Measurements were recorded in healthy affluent school going adolescents in public schools of 12 cities in India (boys=11,863 and girls 7,694). Means and percentiles of ponderosity indices and skinfold thicknesses at yearly intervals were derived for each sex and related to sexual maturity.

RESULTS

BMI, PI and skin fold thickness (SFT) were higher in girls. There was lower variability of these parameters with sexual maturity rating (breast/genital development stages) as compared to age, suggesting use of these indices in relation to sexual maturity for assessment of adolescent growth.

CONCLUSION

Pediatricians and endocrinologists can use these indices for assessment of thinness and obesity, in adolescent Indian children, in relation to sexual maturity for the age.

Efficient antitumor immunity derived from maturation of dendritic cells that had phagocytosed apoptotic/necrotic tumor cells

Dendritic cells (DCs) that acquired antigen from apoptotic tumor cells are able to induce major histocompatibility complex (MHC) class I-restricted cytotoxic T lymphocytes and antitumor immunity. In the present study, we investigated the efficiency of antitumor immunity derived from DCs that had phagocytosed apoptotic/necrotic BL6-10 melanoma cells compared with that of DCs pulsed with the tumor mTRP2 peptide. Our data showed that phagocytosis of apoptotic/necrotic tumor cells resulted in maturation of DCs with up-regulated expression of proinflammatory cytokines [interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha, interferon-gamma and granulocyte-macrophage colony-stimulating factor], chemokines (MIP-1alpha, MIP-1beta and MIP-2), the CC chemokine receptor CCR7 and the cell surface molecules (MHC class II, CD11b, CD40 and CD86), and down-regulated expression of the CC chemokine receptors CCR2 and CCR5. These mature DCs displayed enhanced migration toward the CC chemokine MIP-3beta in a chemotaxis assay in vitro and to the regional lymph nodes in an animal model in vivo. Our data also showed that vaccination with DCs that had phagocytosed apoptotic/necrotic BL6-10 cells was able to (i) more strongly stimulate allogeneic T-cell proliferation in vitro, (ii) induce an in vivo Th1-type immune response leading to more efficient tumor-specific cytotoxic CD8(+) T-cell-mediated immunity and (iii) eradicate lung metastases in all 6 vaccinated mice compared with mice vaccinated with DCs pulsed with the tumor mTRP2 peptide, in which lung metastases were reduced (mean number of 16 per mouse) but not completely eradicated. Therefore, DCs that had phagocytosed apoptotic/necrotic tumor cells appear to offer new strategies in DC cancer vaccines.

Interaction between sine-Gordon breathers

Using the exact breather lattice solution of the sine-Gordon equation, we obtain the asymptotic interaction between two breathers. We identify the exponential dependence of the interaction on the breather separation as well as its power-law dependence on the breather frequency. Numerical simulation of the breather lattice demonstrates its instability. However, stabilization of such structures is found to be feasible through ac driving and damping. Finally, other limits of the original periodic solution are traced, obtaining the leading-order terms in the interaction between "pseudosphere" solutions and kink-antikink pairs.

Three-dimensional elastic compatibility and varieties of twins in martensites

We model a cubic-to-tetragonal martensitic transition by a Ginzburg-Landau free energy in the symmetric strain tensor. We show in three dimensions (3D) that solving the St. Venant compatibility relations for strain, treated as independent field equations, generates three anisotropic long-range potentials between the two order parameter components. These potentials encode 3D discrete symmetries, express the energetics of lattice integrity, and determine 3D textures. Simulation predictions include twins with temperature-varying orientation, helical twins, competing metastable states, and compatibility-induced elastic frustration. Our approach also applies to improper ferroelastics.