Differential gene expression and developmental pathologies associated with persistent organic pollutants in sentinel fish in Troutman Lake, Sivuqaq, Alaska

Persistent organic pollutants (POPs) are lipophilic compounds that bioaccumulate in animals and biomagnify within food webs. Many POPs are endocrine disrupting compounds that impact vertebrate development. POPs accumulate in the Arctic via global distillation and thereby impact high trophic level vertebrates as well as people who live a subsistence lifestyle. The Arctic also contains thousands of point sources of pollution, such as formerly used defense (FUD) sites. Sivuqaq (St. Lawrence Island), Alaska was used by the U.S. military during the Cold War and FUD sites on the island remain point sources of POP contamination. We examined the effects of POP exposure on ninespine stickleback (Pungitius pungitius) collected from Troutman Lake in the village of Gambell as a model for human exposure and disease. During the Cold War, Troutman Lake was used as a dump site by the U.S. military. We found that PCB concentrations in stickleback exceeded the U.S. Environmental Protection Agency's guideline for unlimited consumption despite these fish being low trophic level organisms. We examined effects at three levels of biological organization: gene expression, endocrinology, and histomorphology. We found that ninespine stickleback from Troutman Lake exhibited suppressed gonadal development compared to threespine stickleback (Gasterosteus aculeatus) studied elsewhere. Troutman Lake stickleback also displayed two distinct hepatic phenotypes, one with lipid accumulation and one with glycogen-type vacuolation. We compared the transcriptomic profiles of these liver phenotypes using RNA sequencing and found significant upregulation of genes involved in ribosomal and metabolic pathways in the lipid accumulation group. Additionally, stickleback displaying liver lipid accumulation had significantly fewer thyroid follicles than the vacuolated phenotype. Our study and previous work highlight health concerns for people and wildlife due to pollution hotspots in the Arctic, and the need for health-protective remediation.

A fish with no sex: gonadal and adrenal functions partition between zebrafish NR5A1 co-orthologs

People with NR5A1 mutations experience testicular dysgenesis, ovotestes, or adrenal insufficiency, but we do not completely understand the origin of this phenotypic diversity. NR5A1 is expressed in gonadal soma precursor cells before expression of the sex-determining gene SRY. Many fish have two co-orthologs of NR5A1 that likely partitioned ancestral gene subfunctions between them. To explore ancestral roles of NR5A1, we knocked out nr5a1a and nr5a1b in zebrafish. Single-cell RNA-seq identified nr5a1a-expressing cells that co-expressed genes for steroid biosynthesis and the chemokine receptor Cxcl12a in 1-day postfertilization (dpf) embryos, as does the mammalian adrenal-gonadal (interrenal-gonadal) primordium. In 2dpf embryos, nr5a1a was expressed stronger in the interrenal-gonadal primordium than in the early hypothalamus but nr5a1b showed the reverse. Adult Leydig cells expressed both ohnologs and granulosa cells expressed nr5a1a stronger than nr5a1b. Mutants for nr5a1a lacked the interrenal, formed incompletely differentiated testes, had no Leydig cells, and grew far larger than normal fish. Mutants for nr5a1b formed a disorganized interrenal and their gonads completely disappeared. All homozygous mutant genotypes lacked secondary sex characteristics, including male breeding tubercles and female sex papillae, and had exceedingly low levels of estradiol, 11-ketotestosterone, and cortisol. RNA-seq showed that at 21dpf, some animals were developing as females and others were not, independent of nr5a1 genotype. By 35dpf, all mutant genotypes greatly under-expressed ovary-biased genes. Because adult nr5a1a mutants form gonads but lack an interrenal and conversely, adult nr5a1b mutants lack a gonad but have an interrenal, the adrenal, and gonadal functions of the ancestral nr5a1 gene partitioned between ohnologs after the teleost genome duplication, likely owing to reciprocal loss of ancestral tissue-specific regulatory elements. Identifying such elements could provide hints to otherwise unexplained cases of Differences in Sex Development.

A Hormone That Lost Its Receptor: Anti-Müllerian Hormone (AMH) in Zebrafish Gonad Development and Sex Determination

Fetal mammalian testes secrete Anti-Müllerian hormone (Amh), which inhibits female reproductive tract (Müllerian duct) development. Amh also derives from mature mammalian ovarian follicles, which marks oocyte reserve and characterizes polycystic ovarian syndrome. Zebrafish (Danio rerio) lacks Müllerian ducts and the Amh receptor gene amhr2 but, curiously, retains amh To discover the roles of Amh in the absence of Müllerian ducts and the ancestral receptor gene, we made amh null alleles in zebrafish. Results showed that normal amh prevents female-biased sex ratios. Adult male amh mutants had enormous testes, half of which contained immature oocytes, demonstrating that Amh regulates male germ cell accumulation and inhibits oocyte development or survival. Mutant males formed sperm ducts and some produced a few offspring. Young female mutants laid a few fertile eggs, so they also had functional sex ducts. Older amh mutants accumulated nonvitellogenic follicles in exceedingly large but sterile ovaries, showing that Amh helps control ovarian follicle maturation and proliferation. RNA-sequencing data partitioned juveniles at 21 days postfertilization (dpf) into two groups that each contained mutant and wild-type fish. Group21-1 upregulated ovary genes compared to Group21-2, which were likely developing as males. By 35 dpf, transcriptomes distinguished males from females and, within each sex, mutants from wild types. In adult mutants, ovaries greatly underexpressed granulosa and theca genes, and testes underexpressed Leydig cell genes. These results show that ancestral Amh functions included development of the gonadal soma in ovaries and testes and regulation of gamete proliferation and maturation. A major gap in our understanding is the identity of the gene encoding a zebrafish Amh receptor; we show here that the loss of amhr2 is associated with the breakpoint of a chromosome rearrangement shared among cyprinid fishes.

Eye Degeneration and Loss of otx5b Expression in the Cavefish Sinocyclocheilus tileihornes

Cave animals possess remarkable phenotypes associated with existence in their dark environments. The Chinese cavefish Sinocyclocheilus tileihornes shows substantial eye degeneration, a trait shared by most cave species. The extent to which independent evolution of troglomorphic traits uses convergent molecular genetic mechanisms is as yet unknown. We performed transcriptome-wide gene expression profiling in S. tileihornes eyes and compared results with those from the closely related surface species S. angustiporus and an independently derived congeneric cavefish, S. anophthalmus. In total, 52.85 million 100 bp long paired-end clean reads were generated for S. tileihornes, and we identified differentially expressed genes between the three possible pairs of species. Functional analysis of genes differentially expressed between S. tileihornes and S. angustiporus revealed that phototransduction (KEGG id: dre04744) was the most significantly enriched pathway, indicating the obvious differences in response to captured photons between the cavefish S. tileihornes and the surface species S. angustiporus. Analysis of key genes regulating eye development showed complete absence of otx5b (orthodenticle homolog 5) expression in S. tileihornes eyes, probably related to degradation of rods, but normal expression of crx (cone-rod homeobox). The enriched pathways and Otx5 are involved in phototransduction, photoreceptor formation, and regulation of photoreceptor-related gene expression. Unlike the S. tileihornes reported here, S. anophthalmus has reduced crx and otx5 expression. These results show that different species of cavefish within the same genus that independently evolved troglodyte characteristics can have different genetic mechanisms of eye degeneration.

A Search for Sex-Linked Loci in the Agamid Lizard, Calotes versicolor

The Indian garden lizard, Calotes versicolor, lacks cytologically recognizable sex chromosomes, and its mechanism of sex determination is unclear. We evaluated genotype-to-sex-phenotype association using RAD-seq in wild-caught males and females, 30 of each sex. Of 210,736 unique, 96-nt long RAD-tags, 48% contained polymorphisms, 23% of which were present in at least 40 of 60 individuals. Twenty one RAD-tags neared, but none achieved, the inclusion criteria for sex enrichment, as expected if C. versicolor lacks highly differentiated sex chromosomes. Three RAD-tags with alleles most strongly associated with sex tended to be heterozygous in females and to lack male-specific alleles, suggesting a ZW female/ZZ male system. Putative female alleles, however, were present in some males and lacking from some females, suggesting either recombination between these markers and the sex locus or sex reversal due to environmental or genetic factors. Paired-end, 250-nt reads from 1 male provided a fragmented draft genome assembly. Four sex-associated RAD-tags were identical to portions of 4 unique C. versicolor genomic contigs rather than linked to a single putative sex-linked region. The lack of strongly sex-linked loci coupled with weak evidence for temperature-associated sex determination intensifies the need for further investigation of the puzzling sex determination mechanism in C. versicolor.

Antarctic blackfin icefish genome reveals adaptations to extreme environments

Icefishes (suborder Notothenioidei; family Channichthyidae) are the only vertebrates that lack functional haemoglobin genes and red blood cells. Here, we report a high-quality genome assembly and linkage map for the Antarctic blackfin icefish Chaenocephalus aceratus, highlighting evolved genomic features for its unique physiology. Phylogenomic analysis revealed that Antarctic fish of the teleost suborder Notothenioidei, including icefishes, diverged from the stickleback lineage about 77 million years ago and subsequently evolved cold-adapted phenotypes as the Southern Ocean cooled to sub-zero temperatures. Our results show that genes involved in protection from ice damage, including genes encoding antifreeze glycoprotein and zona pellucida proteins, are highly expanded in the icefish genome. Furthermore, genes that encode enzymes that help to control cellular redox state, including members of the sod3 and nqo1 gene families, are expanded, probably as evolutionary adaptations to the relatively high concentration of oxygen dissolved in cold Antarctic waters. In contrast, some crucial regulators of circadian homeostasis (cry and per genes) are absent from the icefish genome, suggesting compromised control of biological rhythms in the polar light environment. The availability of the icefish genome sequence will accelerate our understanding of adaptation to extreme Antarctic environments.

Brain of the blind: transcriptomics of the golden-line cavefish brain

The genus Sinocyclocheilus (golden-line barbel) includes 25 species of cave-dwelling blind fish (cavefish) and more than 30 surface-dwelling species with normal vision. Cave environments are dark and generally nutrient-poor with few predators. Cavefish of several genera evolved convergent morphological adaptations in visual, pigmentation, brain, olfactory, and digestive systems. We compared brain morphology and gene expression patterns in a cavefish Sinocyclocheilus anophthalmus with those of a closely related surface-dwelling species S. angustiporus. Results showed that cavefish have a longer olfactory tract and a much smaller optic tectum than surface fish. Transcriptomics by RNA-seq revealed that many genes upregulated in cavefish are related to lysosomes and the degradation and metabolism of proteins, amino acids, and lipids. Genes downregulated in cavefish tended to involve "activation of gene expression in cholesterol biosynthesis" and cholesterol degradation in the brain. Genes encoding Srebfs (sterol regulatory element-binding transcription factors) and Srebf targets, including enzymes in cholesterol synthesis, were downregulated in cavefish brains compared with surface fish brains. The gene encoding Cyp46a1, which eliminates cholesterol from the brain, was also downregulated in cavefish brains, while the total level of cholesterol in the brain remained unchanged. Cavefish brains misexpressed several genes encoding proteins in the hypothalamus-pituitary axis, including Trh, Sst, Crh, Pomc, and Mc4r. These results suggest that the rate of lipid biosynthesis and breakdown may both be depressed in golden-line cavefish brains but that the lysosome recycling rate may be increased in cavefish; properties that might be related to differences in nutrient availability in caves.

Embryogenesis and early skeletogenesis in the antarctic bullhead notothen, Notothenia coriiceps

BACKGROUND

Environmental temperature influences rates of embryonic development, but a detailed staging series for vertebrate embryos developing in the subzero cold of Antarctic waters is not yet available from fertilization to hatching. Given projected warming of the Southern Ocean, it is imperative to establish a baseline to evaluate potential effects of changing climate on fish developmental dynamics.

RESULTS

We studied the Bullhead notothen (Notothenia coriiceps), a notothenioid fish inhabiting waters between -1.9 and +2 °C. In vitro fertilization produced embryos that progressed through cleavage, epiboly, gastrulation, segmentation, organogenesis, and hatching. We compared morphogenesis spatially and temporally to Zebrafish and medaka. Experimental animals hatched after about 6 months to early larval stages. To help understand skeletogenesis, we analyzed late embryos for expression of sox9 and runx2, which regulate chondrogenesis, osteogenesis, and eye development. Results revealed that, despite their prolonged developmental time course, N. coriiceps embryos developed similarly to those of other teleosts with large yolk cells.

CONCLUSIONS

Our studies set the stage for future molecular analyses of development in these extremophile fish. Results provide a foundation for understanding the impact of ocean warming on embryonic development and larval recruitment of notothenioid fish, which are key factors in the marine trophic system. Developmental Dynamics 245:1066-1080, 2016. © 2016 Wiley Periodicals, Inc.

Hoxb1b controls oriented cell division, cell shape and microtubule dynamics in neural tube morphogenesis

Hox genes are classically ascribed to function in patterning the anterior-posterior axis of bilaterian animals; however, their role in directing molecular mechanisms underlying morphogenesis at the cellular level remains largely unstudied. We unveil a non-classical role for the zebrafish hoxb1b gene, which shares ancestral functions with mammalian Hoxa1, in controlling progenitor cell shape and oriented cell division during zebrafish anterior hindbrain neural tube morphogenesis. This is likely distinct from its role in cell fate acquisition and segment boundary formation. We show that, without affecting major components of apico-basal or planar cell polarity, Hoxb1b regulates mitotic spindle rotation during the oriented neural keel symmetric mitoses that are required for normal neural tube lumen formation in the zebrafish. This function correlates with a non-cell-autonomous requirement for Hoxb1b in regulating microtubule plus-end dynamics in progenitor cells in interphase. We propose that Hox genes can influence global tissue morphogenesis by control of microtubule dynamics in individual cells in vivo.

Evolution of the eye transcriptome under constant darkness in Sinocyclocheilus cavefish

In adaptating to perpetual darkness, cave species gradually lose eyes and body pigmentation and evolve alternatives for exploring their environments. Although troglodyte features evolved independently many times in cavefish, we do not yet know whether independent evolution of these characters involves common genetic mechanisms. Surface-dwelling and many cave-dwelling species make the freshwater teleost genus Sinocyclocheilus an excellent model for studying the evolution of adaptations to life in constant darkness. We compared the mature retinal histology of surface and cave species in Sinocyclocheilus and found that adult cavefish showed a reduction in the number and length of photoreceptor cells. To identify genes and genetic pathways that evolved in constant darkness, we used RNA-seq to compare eyes of surface and cave species. De novo transcriptome assemblies were developed for both species, and contigs were annotated with gene ontology. Results from cave-dwelling Sinocyclocheilus revealed reduced transcription of phototransduction and other genes important for retinal function. In contrast to the blind Mexican tetra cavefish Astyanax mexicanus, our results on morphologies and gene expression suggest that evolved retinal reduction in cave-dwelling Sinocyclocheilus occurs in a lens-independent fashion by the reduced proliferation and downregulation of transcriptional factors shown to have direct roles in retinal development and maintenance, including cone-rod homeobox (crx) and Wnt pathway members. These results show that the independent evolution of retinal degeneration in cavefish can occur by different developmental genetic mechanisms.

Once weekly azithromycin in secondary prevention of rheumatic fever

Rheumatic fever and rheumatic heart disease (RHD) are still important problems in developing countries. Secondary prophylaxis which is the most cost-effective method in preventing recurrences of rheumatic fever is fraught with problems of drug compliance. The utility of 500 mg once weekly azithromycin (AZT), an orally effective long-acting antibiotic was evaluated against oral penicillin (phenoxy methyl penicillin 250 mg twice daily) in this study. Forty-eight consecutive patients (44% males, mean age 29.4 years) with established RHD were randomised into two groups-26 patients received AZT and 22 received oral penicillin. Patients were evaluated at randomisation, at 1 month, 3 months, and 6 months, clinically, serologically and by throat swab culture. End points were absence of streptococcal colonisation, infection or fever at the end of 6 months. During the study, 4 patients (15.4%) in the AZT group developed sore throat and fever, had positive throat culture and positive serology indicating streptococcal infection. None satisfied the criteria for rheumatic fever reactivation. None in the oral penicillin group developed streptococcal infection. In conclusion, weekly 500 mg of AZT is not effective in the prevention of streptococcal throat infection compared to oral penicillin therapy in adult patients with established RHD.

The role of stat1b in zebrafish hematopoiesis

STAT1 mediates response to interferons and regulates immunity, cell proliferation, apoptosis, and sensitivity of Fanconi Anemia cells to apoptosis after interferon signaling; the roles of STAT1 in embryos, however, are not understood. To explore embryonic functions of STAT1, we investigated stat1b, an unstudied zebrafish co-ortholog of human STAT1. Zebrafish stat1a encodes all five domains of the human STAT1-alpha splice form but, like the human STAT1-beta splice variant, stat1b lacks a complete transactivation domain; thus, two unlinked zebrafish paralogs encode protein forms translated from two splice variants of a single human gene, as expected by sub-functionalization after genome duplication. Phylogenetic and conserved synteny studies showed that stat1b and stat1a arose as duplicates in the teleost genome duplication (TGD) and clarified the evolutionary origin of STAT1, STAT2, STAT3, STAT4, STAT5A, STAT5B and STAT6 by tandem and genome duplication. RT-PCR revealed maternal expression of stat1a and stat1b. In situ hybridization detected stat1b but not stat1a expression in embryonic hematopoietic tissues. Morpholino knockdown of stat1b, but not stat1a, decreased expression of the myeloid and granulocyte markers spi and mpo and increased expression of the hematopoietic progenitor marker scl, the erythrocyte marker gata1, and hemoglobin. These results suggest that zebrafish Stat1b promotes myeloid development at the expense of erythroid development.

Percutaneous transmitral commissurotomy in juvenile mitral stenosis—comparison of long term results of Inoue balloon technique and metallic commissurotomy

OBJECTIVES

To compare the immediate and long term results of percutaneous mitral valvotomy using metallic commissurotome and Inoue balloon in juvenile mitral stenosis.

BACKGROUND

Inoue balloon technique for mitral commissurotomy (IBMC) is well established and carried out worldwide in the treatment of juvenile mitral stenosis. Percutaneous mitral metallic commissurotomy (PMMC) is reported to be a cheaper and effective alternative to balloon mitral commissurotomy.

METHODS

Thirty-three patients aged less than 20 years, who underwent PMMC, were compared with 33 age and sex matched control patients who underwent IBMC. Success of valvotomy, procedure related complications, and follow-up events of the two techniques were compared.

RESULTS

Basal echocardiographic and hemodynamic data were similar in both groups. Procedural success was similar in both groups, 31/33. Complications like cardiac tamponade and mitral regurgitation (requiring or not requiring mitral valve replacement) were similar in both groups. On follow-up of more than 3 years, both groups had comparable hemodynamic parameters and restenosis rates.

CONCLUSIONS

Both IBMC and PMMC are successful in providing relief from severe juvenile mitral stenosis in terms of gain in valve area and reduction in transmitral gradient. Both techniques have similar procedural success and complication rates. The long term follow-up results are comparable at follow-up of more than 3 years.

Comparison of percutaneous transmitral commissurotomy with Inoue balloon technique and metallic commissurotomy: immediate and short-term follow-up results of a randomized study

BACKGROUND

The Inoue balloon technique for mitral commissurotomy is well established and carried out worldwide. Metallic commissurotomy is reported to be a cheaper and effective alternative to balloon mitral commissurotomy.

METHODS

One hundred patients were randomized into 2 groups to undergo percutaneous transmitral commissurotomy (PTMC) by means of the Inoue balloon technique (IBMC, n = 49) or metallic commissurotomy (PMMC, n = 51). Patients were crossed over to the other technique when the initial technique was a failure. Success of valvotomy, procedure-related complications, and follow-up events of the 2 techniques were compared.

RESULTS

Basal echocardiographic and hemodynamic data were similar in both groups. Procedural success was similar in both groups: 45 of 49 procedures (91.8%) in the IBMC group, compared with 46 of 51 procedures (90.18%) in the PMMC group (P = 1.0). Crossover was also comparable, with 1 occurring in the IBMC group, compared with 3 in the PMMC group. Complications such as cardiac tamponade and mitral regurgitation (requiring or not requiring mitral valve replacement) were similar in both groups, with 3 complications in the IBMC group, compared with 4 complications in the PMMC group (P =.29). After a follow-up period of approximately 4 months, both groups had similar event rates and comparable hemodynamic parameters (P = not significant).

CONCLUSIONS

Both IBMC and PMMC are successful means of providing relief from severe mitral stenosis with a gain in valve area and reduction in transmitral gradient. Both techniques have similar procedural success, complication rates, and follow-up events.

Percutaneous coil closure of recanalised anomalous origin of left coronary artery from pulmonary artery

An asymptomatic boy underwent surgical correction of anomalous origin of left coronary artery from pulmonary artery (ALCAPA) with trans-pulmonary artery interruption and saphenous vein grafting to left anterior descending coronary artery. He developed a shunt through the re-canalised pulmonary artery end of the ALCAPA which was successfully embolised using a detachable PDA coil delivered into the left main coronary artery from the pulmonary artery.

Islet cell transplantation for insulin-dependant diabetes mellitus: perspectives from the present and prospects for the future

The long-term complications of insulin-dependant diabetes mellitus have become a major health care problem, and it is now clear that they arise from inadequate homeostatic control of blood glucose by injected replacement insulin. Transplantation of pancreatic islets is arguably the most logical approach to restoring metabolic homeostasis in people with diabetes. This review looks at the current status of human islet transplantation and the problems that remain. These include: (1) the limited supply of human islet tissue available for transplantation; (2) the adverse effects of current immunosuppressive protocols on diabetic patients; (3) the problems of primary nonfunction of the transplanted islets; (4) the rejection of islets; and (5) the recurrence of autoimmune diabetic disease. Some of the approaches that might solve these problems are then examined: (1) immune modulation to reduce or prevent immune attack by the recipient's immune system; (2) immunoisolation to prevent recognition of the islet graft; (3) induction of tolerance; (4) xenotransplantation using islets derived from animals; and (5) gene therapy.

Coronary artery ectasia: angiographic, clinical profile and follow-up

Out of 3200 coronary angiograms we reviewed, there were 144 cases of coronary ectasia--an incidence of 4.5 percent. Among these, 122 were associated with atherosclerotic coronary artery disease, i.e. coronary stenosis more than 50 percent (group A) and 22 not associated with coronary artery disease (group B). The patients in groups A and B were compared with age- and sex-matched patients (group C) (n=100) who had coronary artery disease alone without ectasia. The incidence of ectasia was not increased in patients with thoracoabdominal aortic aneurysm i.e. 2/154 (1.8%) or in patients with peripheral occlusive vascular disease i.e. 5/161 (3.1%). Ectasia was typed according to a modified version of the criteria proposed by Markis et al. Type II was the commonest, followed by type I, III and IV. Right coronary artery was the most commonly involved vessel by ectasia followed by left circumflex, left anterior descending artery and left main coronary artery. Diffuse ectasia was seen more frequently in right coronary artery and localised ectasia in left anterior descending artery. Patients in groups A and B had similar epidemiological characteristics, though more patients with ectasia alone (group B) had better left ventricular function and negative stress tests. The patients in group A had a similar incidence of previous myocardial infarction, coronary risk factor profile, treadmill exercise test status and severity of coronary artery disease when compared to group C. On a mean follow-up of 3+/-1.2 years, all the three groups had similar event rates.

Central pulmonary artery anatomy in right ventricular outflow tract obstructions

We reviewed the cine-angiograms of 190 patients with right ventricular outflow tract (RVOT) obstructions for size and anatomy of pulmonary arteries, patent ductus arteriosus (PDA) and major aorto pulmonary collateral arteries (MAPCAs). Patients were grouped into three, Tetralogy of Fallot (TOF) with pulmonary atresia (group 1, N=86), TOF with pulmonary stenosis (group 2, N=97) and 7 cases of pulmonary atresia with intact interventricular septum (group 3). Out of 86 patients in group 1, 49 had PDA alone, 30 had MAPCAs alone, six had both and one had none. In group 2, 31 patients had persistent PDA and one patient had MAPCAS and PDA. A discrete stenosis (DS) of pulmonary artery was seen significantly more in patients with RVOT obstructions associated with PDA compared to patients without PDA (67/84 vs. 5/96). Out of the 84 cases with ducti, 53 had stenosis of the pulmonary artery at the site of ductus insertion. Thus presence of PDA was an important factor in the development of DS. The likely cause of pulmonary artery stenosis in TOF with PDA may be the opposing flows through RVOT and PDA producing a watershed effect at the ductus-pulmonary artery junction. Diffuse hypoplasia of pulmonary arteries (DH) was seen more significantly in RVOT obstructions associated with MAPCAs, compared to other patient groups (19/36 vs. 14/87). These small pulmonary arteries had no discrete stenosis and this diffuse hypoplasia might be the result of inadequate blood flow during intrauterine life [Harikrishnan S, Tharakan J, Titus T, Bhat A, Sivasankaran S, Bimal F, Syam Sunder KR, James, KJ. Central pulmonary artery anatomy in right ventricular outflow tract obstructions. Indian Heart Journal 1997;49:624 (Abstract)[18]].

Saccular coronary aneurysms: angiographic and clinical profile and follow-up of 22 cases

Saccular coronary aneurysms are defined as aneurysms with the transverse dimension at least 1.5 times the longitudinal dimension. Out of 3,200 coronary angiograms reviewed, there were 22 patients (20 males) with saccular coronary aneurysms (totalling 25 aneurysms). The morphology of the aneurysms, the extent and severity of associated coronary lesions, the clinical profile and follow-up data of these patients were analysed. Aneurysms were located in left main coronary artery 3 (12%), left anterior descending coronary artery 13 (52%), right coronary artery 5 (20%) and left circumflex 4 (16%). There were 5 large aneurysms (> 15 mm in diameter) (1 in left main coronary artery, 2 each in right coronary artery and left anterior descending coronary artery) averaging 32 mm in size. Fifteen aneurysms had significant coronary artery stenosis located proximal to it, supporting the theory of post-stenotic dilatation as the aetiology of aneurysm formation. Two patients had associated muscle bridges distal to the aneurysm; 20 had atherosclerotic coronary artery disease and one had coronary artery ectasia. Five patients were lost to follow-up, which ranged from 1 year to 19 years (mean 5.3 +/- 4.1 years). No patient had history suggestive of rupture of the aneurysm on follow-up. Two patients had myocardial infarction in the territory of the vessel with the aneurysm. Rest of the patients were in NYHA class I/II. One large right coronary artery aneurysm was subjected to aneurysmectomy due to symptoms of tricuspid valve obstruction. One left main coronary artery aneurysm measuring 12 mm, on follow-up of 19 years increased in size to 45 mm, in addition the patient developed a right coronary artery aneurysm. Coronary risk factor profiles in the 20 patients with atherosclerotic coronary artery disease and aneurysms were similar to age- and sex-matched control population with atherosclerotic coronary artery disease without aneurysms.

Clinical and angiographic profile and follow-up of myocardial bridges: a study of 21 cases

Myocardial bridging describes an angiographic entity, which is any degree of systolic narrowing of a coronary artery observed in at least one angiographic projection. Among the cineangiograms of 3200 patients reviewed, there were 21 cases (19 males) of myocardial bridges--incidence of 0.6 percent. Of these, seven had hypertrophic cardiomyopathy, six had atherosclerotic coronary artery disease and remaining eight had no evidence of either. All 21 patients had myocardial bridges in proximal or mid left anterior descending coronary artery. In addition, one case of hypertrophic cardiomyopathy had whole posterior descending coronary artery under a myocardial bridge. Another case of hypertrophic cardiomyopathy had a short normal segment of 5 mm inside a long myocardial bridge of 35 mm (tandem myocardial bridges). The length of the bridges varied from 10 to 35 mm (mean 24.5 +/- 4.5 mm) and diameter stenosis during systole varied from 40-90 percent (mean 70 +/- 8%). Two patients had large saccular coronary aneurysms proximal to the muscle bridge. Four of the eight patients who had neither hypertrophic cardiomyopathy nor coronary artery disease presented with acute anterior wall myocardial infarction and three of them had regional wall motion abnormality of left descending territory. Of the six patients who had coronary artery disease, one had 60 percent left descending artery lesion and two had recanalized segments proximal to the bridge. Five of the above six patients had significant stenosis of other coronary vessels. Four patients were lost to follow-up (mean period 3.4 +/- 2 years). In the coronary artery disease group, one patient underwent coronary artery bypass graft surgery for 3-vessel disease including graft to left descending artery and one developed inferior wall myocardial infarction. The patients in the hypertrophic cardiomyopathy group and "no hypertrophic cardiomyopathy-no coronary artery disease" group were free of events at last follow-up. Long-term prognosis of isolated myocardial bridges appears to be excellent. Degree of systolic narrowing or length of myocardial bridge does not correlate with event rates on follow-up.

Percutaneous transvenous mitral commissurotomy using an Inoue balloon in children with rheumatic mitral stenosis

Percutaneous transvenous mitral commissurotomy (PTMC) using the Inoue technique was performed in 557 patients with rheumatic mitral stenosis. Of these, 107 were children aged 10-18 years (mean +/- SD 14.5 +/- 2.3). All patients were symptomatic New York Heart Association (NYHA) Class II (n = 78) and Class III (n = 29). All were in sinus rhythm. Following PTMC, the mitral valve area (MVA) increased from 0.73 +/- 0.18 to 1.7 +/- 0.53 cm2 (P < 0.001). There was a significant fall in mean transmitral gradient from 15.6 +/- 5.2 to 5.1 +/- 2.3 mmHg, and in mean pulmonary artery pressure from 41 +/- 15 to 28.4 +/- 10 (P < 0.001). Cardiac tamponade developed in one patient. One patient developed severe mitral regurgitation requiring emergency mitral valve replacement. Five patients (4.7%) developed moderate mitral regurgitation. There was no mortality or cerebral embolism in any of the children. Four patients (3.7%) had oximetry evidence of atrial septal defect. Mean mitral valve area and transmitral gradient at 14 months mean follow up was 1.68 +/- 0.4 cm2 and 6 +/- 3.5 mmHg, respectively, and were comparable to the immediate post-PTMC results. Two patients (1.8%) developed restenosis. The immediate haemodynamic results in children were compared to 450 adult patients who underwent PTMC in the same period. The outcome was similar in both groups. Children were found to have significantly higher pulmonary artery pressure compared to adults. We found that PTMC using an Inoue balloon is very effective and safe in children, and consider that it should be the procedure of choice for young patients with symptomatic rheumatic mitral stenosis.

Coronary artery fistula in children and adults: a review of 25 cases with long-term observations

We studied 25 patients with coronary artery fistula between 1976 and 1994. Age ranged from 1 to 58 years. Twelve patients were symptomatic; seven had dyspnoea, four had angina, one had palpitation and one had syncope. Coronary arteries in four. Coronary artery fistula drained into right ventricle in 11, right atrium in nine, pulmonary artery in four and left ventricle in two. The Qp/Qs ranged from 1.0 to 2.6 with a mean of 1.39 +/- 0.38. Five patients had associated cardiac anomalies. Two had atrial septal defects, one had patent ductus arteriosus, one had atresia of proximal right coronary artery and in one patient, the right coronary was arising from left coronary artery. Five patients underwent surgery without any operative mortality. Thirteen patients were followed-up medically for a mean period of 6.1 +/- 5.1 years. There were no complications related to coronary artery fistula during follow-up. In one patient coronary artery fistula closed spontaneously.

Bidirectional Glenn shunt: a step in the right direction

Bidirectional Glenn (BDG) shunt was carried out in 14 patients (age range 1.5-22 years; mean 9.3 years) for a variety of congenital cyanotic heart diseases with decreased pulmonary blood flow. Postoperative cardiac catheterisation was carried out in 10 patients including successful balloon angioplasty of the shunt and LPA in one patient. There was a significant improvement in oxygen saturation and a drop in haematocrit level at follow-up. Doppler echocardiography studies in 13 patients revealed functioning shunts in all cases with low velocity continuous flow. Thus BDG is a useful palliative procedure and could be undertaken as the first stage of total cavopulmonary connection in high-risk Fontan groups where biventricular repair is not feasible.

Clinical profile and natural history of Ebstein's anomaly of tricuspid valve

There were 63 patients of Ebstein's anomaly of tricuspid valve encountered from 1976 to 1991; 28 (44.4%) were male and 35 (55.6%) female. Their age at presentation ranged from 3 months to 51 years. Five (7.9%) patients were asymptomatic, 48 (76.2%) had class II-III exertional dyspnoea, palpitation or both. Thirty patients (47.6%) had cyanosis. Electrocardiogram showed paroxysmal atrial fibrillation in two, chronic atrial fibrillation in four (6.3%), paroxysmal supraventricular tachycardia in seven, atrial or ventricular ectopic beats in five (7.9%), 2:1 atrioventricular block in one (1.6%), complete atrioventricular block in two (3.2%) and type B WPW syndrome in nine patients (14.3%). Chest X-ray showed diminished vascularity in 22 (34.9%). Diagnosis was established by cardiac catheterization and or echocardiography. Atrialized right ventricular chamber was demonstrated in 51 (80.9%) by angiography and in 40 (63.5%) by electrophysiology. Patients were followed up for 1-172 months. Seventeen patients (26.9%) required surgery. Three patients (4.8%) died during medical follow-up, and five (7.9%) died following surgery. Survival probability for 46 medical patients was 88.9% at 172 months. Factors affecting survival were pulmonary blood flow, cyanosis, clubbing and systemic arterial oxygen saturation.

Prognosis for patients with Eisenmenger syndrome of various aetiology

The objective of this study was to determine the long-term survival pattern and variables affecting long-term survival and complications occurring during follow-up of patients with Eisenmenger syndrome. A retrospective study of patients diagnosed with Eisenmenger syndrome were followed up. A tertiary care centre was used and it provided superspeciality services in various disciplines. The subjects included 201 patients with Eisenmenger syndrome--diagnosed by a combination of echocardiography and a peripheral arterial oxygen saturation study and/or cardiac catheterisation with or without angiocardiography--worked up and followed up for variable duration over a period of 16 years from 1976 to 1992. One hundred nine patients were females and 92 were males--age of presentation varied from 3 months to 62 years (mean +/- standard deviation 19.23 +/- 12.62 years). A total of 12 different anatomic lesions were seen--the most common three being ventricular septal defect (33.33%), aterial septal defect (29.85%), and patent ductus arteriosus (14.23%). History, physical examination, chest skiagram and electrocardiogram established only the presence of pulmonary arterial hypertension except where differential cyanosis indicating ductus was discernible or the degree of splitting of second heart sound provided some clue to the level of shunt. Contrast echocardiography, completed in 25.4% established the level of shunt in all patients. In others the diagnosis was confirmed by cardiac catheterisation. Twenty patients died during a mean follow-up period of 54.6 +/- 54.47 months. Sudden cardiac deaths (30%), congestive heart failure (25%) and haemoptysis (15%) were the most predominant causes of death. Only one patient died during puerperium.(ABSTRACT TRUNCATED AT 250 WORDS)

Blade and balloon atrial septostomy for creation of an adequate interatrial communication

During a 7 year period from 1984 to 1991, 100 infants underwent either balloon atrial septostomy (BAS) (n = 92) or blade septostomy (BLS) (n = 8). The indication was complete transposition of the great arteries in all the patients. The mean age in the BAS group was 1.8 +/- 1.5 months while that in the infants requiring BLS due to a thick septum was 3.03 +/- 2.29 months. The degree of improvement in arterial oxygen saturation in both groups was satisfactory -27.16 +/- 14.06% in the BAS group vs 23.5 +/- 12.18% in the BLS group. There were no procedure related deaths in the BLS group, through only monoplane fluoroscopy was used in 6/8 patients. Three patients however died following balloon septostomy. We conclude that BLS is a safe and effective alternative to surgical septostomy when performed with due care. Two dimensional echocardiography during BAS enhances the speed and safety of the procedure and helps to identify patients who may require BLS due to a thick interatrial septum.

Primary pulmonary hypertension: natural history and prognostic factors

A retrospective cohort study was carried out in 61 patients (30 males, 31 females, age 24.6 +/- 11.8 years) with primary pulmonary hypertension diagnosed by strict clinical and hemodynamic criteria, to obtain an understanding of the natural history and prognostic markers. While 15 patients were alive, 46 patients (76%) had expired during the follow up period. Two, five and ten years survivals were 48%, 32% and 12% respectively. Median survival duration from time of diagnosis was 22 months. The survivors had significantly higher age of onset, cardiac index and significantly lower right atrial mean pressure, right ventricular end diastolic pressure, cardiothoracic ratio from chest rontgenogram and calculated pulmonary vascular resistance as compared to non survivors. While pulmonary artery systolic pressure was not significantly different, pulmonary artery diastolic and pulmonary artery mean pressures were significantly lower in survivors than in non-survivors. Lower New York Heart Association class, right atrial mean pressure < or = 7 mm Hg, right ventricular end diastolic pressure < or = 10 mmHg, cardiac index > 2.5 L/min/m2, pulmonary arterial oxygen saturation > 60%, were associated with significantly longer survival. The degree of pulmonary arterial hypertension had an indirect prognostic effect through the above parameters. Vasodilator therapy did not significantly alter the outcome of patients with primary pulmonary hypertension.

Thrombolytic therapy for prosthetic cardiac valve thrombosis

During 1992-93 12 patients (5 males, 7 females) with thrombosed prosthetic cardiac valves were treated with streptokinase on 13 occasions (one patient with prosthetic tricuspid valve had two thrombotic episodes). Their age ranged from 14 to 52 years (median 39). Two valves were in aortic position, six in mitral and four in tricuspid position. Eight were Bjork-Shiley prosthesis, three were Medtronic Hall valves and one was a St. Jude Valve. Timing of prosthetic valve thrombosis ranged from 3 months to 12 years after valve replacement surgery. Duration of symptoms due to valve thrombosis ranged from 1-4 months with tricuspid valve thrombosis and 1-14 days with left sided valve thrombosis. Five were in functional class II and four each were in functional class III and class IV. All patients were evaluated by echo Doppler and cine fluoroscopy. Loading dose of streptokinase was 2.5 lakh units in 4 patients and 1 lakh units in 9 patients. Maintenance infusion was at 1000 units/Kg/hour in 11 patients and 1 lakh units/hour in 2 patients. Duration of streptokinase infusion ranged from 3 hr to 38 hr. Thrombolytic therapy was successful (clinical, echo Doppler and fluoroscopy) in 12 out of 13 cases (92%). It was unsuccessful in a patient with valve at tricuspid position in whom infusion had to be stopped after 24 hour due to bleeding gums. One patient developed intracerebral bleed and expired. In conclusion streptokinase therapy is useful for prosthetic cardiac valve thrombosis.

Balloon pulmonary valvoplasty: factors determining short- and long-term results

Balloon pulmonary valvoplasty was performed in 139 patients (age 2-44 years) with pulmonary valve stenosis. The right ventricular peak systolic pressure decreased from 137.1 +/- 46.8 mmHg to 76 +/- 51.3 mmHg (P < 0.001) and the right ventricle to pulmonary artery peak systolic gradient decreased from 116.3 +/- 49 mmHg to 54.4 +/- 51.9 mmHg (p < 0.001). There was no significant change in systemic artery systolic pressure. The right ventricular peak systolic pressure to systemic artery systolic pressure ratio decreased from 1.13 +/- 0.41 to 0.63 +/- 0.42 (P < 0.001). Patients with incomplete immediate relief of obstruction (right ventricle to pulmonary artery peak systolic gradient > 35 mmHg) had higher pre-dilatation right ventricular peak systolic pressure (161.1 +/- 45.3 mmHg vs. 93.9 +/- 38.8 mmHg, P < 0.001) and higher right ventricular peak systolic pressure to systemic artery systolic pressure ratio (1.31 +/- 0.42 vs 0.98 +/- 0.33, P < 0.001) pre-dilatation and were older (17.2 +/- 8.6 years vs. 12.8 +/- 9.7 years, P < 0.01). The residual right ventricle to pulmonary artery peak systolic gradients in the majority of patients were infundibular, which regressed at follow up even in patients who did not receive long-term oral beta blockers. Follow up catheterisation in 79 patients after 13 +/- 8.7 months showed a further fall in right ventricular peak systolic-pressure (P < 0.001) and right ventricle-to-pulmonary artery peak systolic gradient (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon angioplasty for native coarctation of the aorta in children and adults: factors determining the outcome

Balloon angioplasty was performed in 46 patients (age 2-40 yr) with discrete native coarctation of aorta. Patients with associated patent ductus arteriosus, aberrant subclavian artery and aneurysms were excluded. The peak systolic gradient across the coarcted segment decreased from 52.1 +/- 18.5 mmHg to 18.6 +/- 14.8 mmHg (p less than 0.001), and the diameter of the coarcted segment increased from 3.6 +/- 1.7 mm/m2 to 9.1 +/- 3.2 mm/m2 (p less than 0.001). Follow-up haemodynamic and angiographic studies performed in 21 patients at 13.1 +/- 6.9 months after angioplasty, showed good results in 15 patients. Four patients undergoing haemodynamic study and 4 other patients undergoing noninvasive evaluation were graded as having bad results at follow-up. In 5 of these patients the poor results were due to primary failure of angioplasty in relieving the gradient, and three developed re-coarctation after initial fall in the trans-coarctation gradient. Four risk factors were identified on univariate analysis, which were associated with significantly larger residual gradients at follow-up: (1) size of isthmus/size of coarcted segment ratio less than 3.0; (2) size of post-coarctation descending aorta/size of isthmus ratio greater than 1.75; (3) size of coarcted segment after angioplasty/size of coarcted segment before angioplasty ratio less than 2.0; and (4) size of balloon/size of coarcted segment ratio less than 3.0. The presence of one or more risk factors was associated with bad late results. On multivariate analysis the ratio of balloon size/coarcted segment size was found to be the sole independent predictor of the late outcome (p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of severity of aortic stenosis by continuous wave Doppler echocardiography

Fifty consecutive patients with aortic stenosis were evaluated by continuous wave Doppler echocardiography for assessment of the transaortic gradient. The Doppler derived gradients were compared with the gradients measured at cardiac catheterisation. Excellent correlation was found between the Doppler and catheterisation findings for the maximum instantaneous gradient (r = 0.92) and the mean systolic gradient (r = 0.84). The maximum, midsystolic and late systolic Doppler gradients also showed a good correlation with the peak to peak catheter gradient. The maximum Doppler velocity however, showed overestimation of the peak to peak gradient in the presence of mild aortic stenosis (predictive accuracy 86%). The midsystolic Doppler velocity showed the highest predictive accuracy (94%) for the detection of severe aortic stenosis. No case of severe aortic stenosis was missed by Doppler using either the maximum or midsystolic Doppler velocity. These findings indicate that continuous wave Doppler ultrasound provides a reliable estimate of the gradient in patients with aortic stenosis.

Bilateral coronary arteriovenous fistulas

A 14-year-old girl with bilateral coronary arteriovenous fistulas (CAVFs) draining into the right ventricle (RV) is presented. Selective coronary angiography revealed involvement of both right and left coronary arteries in the fistulous formation, but communication into the RV was single.