A rare nonsense variant of the X-gene in a paediatric patient with severe peripheral pulmonary stenosis

Background

Most cases of peripheral pulmonary stenosis (PPS) associated with William's syndrome are usually very mild or resolve spontaneously. However, we encountered a paediatric case of William's syndrome (WS) with severe PPS. In this case, we investigate whether the patient's genetic background was responsible for the severity of the PPS.

Case presentation

Shortly after birth, the male patient was suspected as WS because of his peculiar facial appearance and PPS. Fluorescence in situ hybridization identified microdeletion in the 7q11.23 region, and he had a confirmed diagnosis of WS. PPS became worsened subsequently, and a cardiac catheterization was performed at the age of 7 years. Due to severe multiple PPS, the right ventricular pressure exceeded the left ventricular pressure. At the age of 12, he had haemoptysis, which required ventilatory management. A pseudoaneurysm of the right pulmonary artery was identified and a right middle lobectomy was performed.

Methods and results

First, we performed multiplex ligation-dependent probe amplification and whole exome sequencing, considering the possibility of homozygous mutations in the region responsible for WS (7q11.23) or a larger deletion of this region in the patient. The deletion was confirmed to be a heterozygous deletion with a typical range for WS. Therefore, we hypothesized that the causative gene of severe PPS may exist separately from the region responsible for WS. After reviewing the result of the whole exome sequencing, we identified a rare nonsense variant of the “X”-gene as the disease-causing gene. The X-gene is involved in the suppression of vascular smooth muscle cell proliferation and the generation of pulmonary arteriolar dilator “Y”. The X-gene has been reported as a disease-causing gene in patients with pulmonary arterial hypertension. Based on these previous reports, we assumed that the X gene variant could be a cause of PPS; therefore, we performed functional analysis. We first introduced a mutant X-gene construct into human pulmonary arterial endothelial cells (hPAECs) and human pulmonary arterial smooth muscle cells and found that the mutant significantly reduced the production of Y compared to the wild-type X-gene. When transfected into hPAECs, the mutant X gene significantly increased cell proliferation compared to the wild-type X-gene. The hPAECs also showed reduced caspase 3/7 activity and reduced apoptosis compared to wild-type X-gene transfected cells. In the patient's own lung pathology specimens, irregular fibrous thickening of the intima of the intrapulmonary arteries was observed, which supported the results of the functional analysis.

Conclusion

Our study showed that an X-gene variant could lead to reduced Y production in the pulmonary arteries, abnormal proliferation of hPAECs, and the development of severe PPS. As Y-replenishing drugs are already in clinical use, the results may lead to the development of medical treatments for severe PPS.

Funding Acknowledgement

Type of funding sources: None.

Association of the Jun dimerization protein 2 gene with intracranial aneurysms in Japanese and Korean cohorts as compared to a Dutch cohort

In a previous study a linkage region for association to IA patients was found on chromosome 14q22. In this study, we report the findings of a positional candidate gene, Jun dimerization Protein 2 (JDP2), and single nucleotide polymorphisms (SNP) of that gene that are associated with intracranial aneurysms in different ethnic populations. We screened the linkage region around chromosome 14q22 and narrowed it down to JDP2. We then genotyped case and control groups of three different ethnic populations: 403 Japanese intracranial aneurysm (IA) cases and 412 controls, 181 Korean IA cases and 181 controls, 379 Dutch cases and 642 Dutch controls. Genotyping was performed using polymerase chain reaction and direct sequencing technology. The allele distribution of three SNPs (two intronic: rs741846; P=0.0041 and rs175646; P=0.0014, and one in the untranslated region: rs8215; P=0.019) and their genotype distribution showed significant association in the Japanese IA patients. The allelic and genotypic frequency of one intronic SNP (rs175646; P=0.0135 and P=0.0137, respectively) and the genotypic frequency for the SNP in the UTR region (rs8215; P=0.049) was also significantly different between cases and controls of the Korean cohort. There was no difference in allelic or genotypic frequencies in the Dutch population. These SNPs in JDP2 are associated with intracranial aneurysms, suggesting that variation in or near JDP2 play a role in susceptibility to IAs in East Asian populations.

Participation of elderly patients in registration trials for oncology drug applications in Japan

BACKGROUND

The objective of this study was to evaluate the age-based enrollment of cancer patients into registration trials of new drug applications or expanding the indications for use.

MATERIALS AND METHODS

The data from 234 registration trials in Japan and overseas of 43 drugs, which were reviewed by the Pharmaceuticals and Medical Devices Agency and approved by the Ministry of Health, Labour and Welfare in Japan between 1999 and 2008, were retrospectively analyzed according to the age distribution of enrolled patients. The age distribution of the Japanese cancer population was derived from Cancer Statistics in Japan 2003 and Annual Report on Health, Labour and Welfare 2003-2004.

RESULTS

In the Japanese cancer population, the estimated median age of cancer patients is 70 years, and 66% of cancer patients are aged 65 years or more. The estimated median age of cancer patients in all registration trials conducted in Japan was 59 years, whereas it was 55 years in the registration trials conducted overseas. The proportion of patients aged 65 years or more enrolled in registration trials conducted in Japan was 35%; this number was 28% in registration trials conducted overseas.

CONCLUSION

Elderly patients are underrepresented in oncology registration trials in Japan.

[Intrathecal baclofen therapy for spastic paraparesis due to aortic dissecting aneurysm; recent progress in treatment strategy]

A 48-year-old man suffered from acute dissection of thoracic aortic aneurysm which eventually led to replacement of the ascending aorta with a tube graft. During this clinical course, circulatory failure in intercostal artery resulted in spinal cord infarction followed by moto-sensory disturbance below Th7 dermatomic area. Seven months later, spasticity with pain in both lower extremities became conspicuous that was uncontrollable by any oral medication. Eventually the patient underwent the implantation of continuous infusion pump for intrathecal baclofen therapy (ITB). The clinical condition was remarkably improved and now has been well controlled. ITB, authorized by Japanese Ministry of Health Labour and Welfare in 2006, has notable therapeutic effects on spasticity derived from any sort of central nervous disorder. More promotive enlightenment if ITB is indispensable for enhancement of its medical benefit in Japan.

Relative contributions of myeloperoxidase and NADPH-oxidase to the early host defense against pulmonary infections with Candida albicans and Aspergillus fumigatus

Generation of oxidative products by phagocytic cells is known to be an important host defense mechanism directed toward killing of invading microorganisms. The importance of two major oxidant-producing enzymes, myeloperoxidase (MPO) and NADPH-oxidase, in in vivo fungicidal action was directly compared in genetically engineered mice. Both MPO-deficient (MPO-/-) and NADPH-oxidase-deficient (X-linked chronic granulomatous disease [X-CGD]) mice showed increased susceptibility to pulmonary infections with Candida albicans and Aspergillus fumigatus compared with normal mice, and the X-CGD mice exhibited shorter survivals than MPO-/- mice. This increased mortality of X-CGD mice was associated with a 10- to 100-fold increased outgrowth of the fungi in their organs during the first 6 days. These results suggest that superoxide (O2-) produced by NADPH-oxidase is more important than hypochlorous acid (HOCl) produced by MPO, although both oxidative products obviously contribute to the host defense against pulmonary infection with those fungi. We also observed that MPO-/-/X-CGD double knockout mice showed comparable levels of susceptibility to the X-CGD mice against C. albicans and A. funigatus, indicating that MPO is unable to play a role in host defense in the absence of NADPH-oxidase. This strongly suggests that hydrogen peroxide, the precursor of HOCl, is solely derived from O2- produced by NADPH-oxidase.

Differential host susceptibility to pulmonary infections with bacteria and fungi in mice deficient in myeloperoxidase

Myeloperoxidase (MPO), which is located within neutrophils capable of producing hypochlorous acid, is active in vitro against bacteria and fungi. However, MPO-deficient persons are usually healthy. To define the in vivo contribution of MPO to early host defense against pulmonary infections, MPO-deficient and control mice were intranasally infected with various fungi and bacteria, and the number of residual microorganisms in lungs was compared 48 h later. MPO-deficient mice showed severely reduced cytotoxicity to Candida albicans, Candida tropicalis, Trichosporon asahii, and Pseudomonas aeruginosa. However, the mutant mice showed a slight but significantly delayed clearance of Aspergillus fumigatus and Klebsiella pneumoniae and had comparable levels of resistance to the wild type against Candida glabrata, Cryptococcus neoformans, Staphylococcus aureus, and Streptococcus pneumoniae. These results suggest that the MPO-dependent oxidative system is important for host defense against fungi and bacteria, although the effect varies by pathogen species.

Stresgenin B, an inhibitor of heat-induced heat shock protein gene expression, produced by Streptomyces sp. AS-9

Stresgenin B was isolated as an inhibitor of heat-induced heat shock protein (HSP) gene expression from a culture broth of Streptomyces sp. AS-9 by silica gel chromatography and HPLC. The molecular formula of the novel compound was determined as C11H13NO5 by high resolution FAB-MS analysis, and the structure was determined by UV, 1H NMR, 13C NMR, HMQC, HMBC, and NOESY spectra. Stresgenin B inhibited heat-induced luciferase reporter-gene expression directed by the human hsp70B promoter in Chinese hamster ovary (CHO) cells at concentrations lower than the concentrations for inhibition of dexamethasone-induced luciferase reporter-gene expression directed by the mouse mammary tumor virus (MMTV)-LTR promoter. The inhibition of heat-induced reporter gene expression was evident even when cells were exposed to stresgenin B only during heat stress treatment. Moreover, the compound inhibited heat-induced syntheses of hsp72/73, hsp90, and hsp110 and thereby suppressed the induction of thermotolerance. Stresgenin B showed moderate cytotoxic activities against several neoplastic cell lines and also showed antibacterial activities against Micrococcus luteus, Bacillus subtilis and Staphylococcus aureus strains.

Suppression of thermotolerance development through cycloheximide-induced negative control of stress protein gene expression

Expression of a luciferase reporter gene by Chinese hamster ovary cells under the control of the human heat shock protein (hsp) 70 gene promoter was suppressed by incubation at 37 degrees C after treatment with cycloheximide (CHX) during 42 degrees C heat shock exposure. The CHX-induced suppression of hsp gene expression induced no development of thermotolerance. However, 42 degrees C heat shock treatment without CHX followed by CHX inhibition of protein synthesis during recovery incubation at 37 degrees C induced thermotolerance expression by inducing enhanced synthesis of hsps including hsp70 in subsequent heat challenge incubation at 43 degrees C. The results demonstrated a direct correlation between suppression (induction) of stress protein gene expression and non-expression (expression) of thermotolerance. Kinetic analysis showed that the CHX suppression of hsp gene induction was greater than the CHX inhibition of protein synthesis, and that it depended on the severity of heat stress: it decreased with increasing heat stress doses. Moreover, prior feeding of the proline analog L-azetidine 2-carboxylic acid abrogated the CHX-induced suppression of hsp gene expression. In addition, CHX treatment during heat cell-killing at 43 degrees C induced protection of cells. These results were well explained by the proposed model of negative or positive control of stress protein gene expression depending on the level of free hsp70, which may be modulated by both the rate of protein synthesis and the severity of heat stress.

Stress dose-dependent suppression of heat shock protein gene expression by inhibiting protein synthesis during heat shock treatment

When a clone of Chinese hamster ovary (CHO) cells transfected with a plasmid containing a luciferase reporter gene under the control of the human heat shock protein (hsp) 70 gene promoter was treated with cycloheximide during heat exposure at 42 and 43 degrees C for 15 to 100 minutes and then incubated at 37 degrees C after removal of cycloheximide, reporter gene expression was suppressed by the protein synthesis inhibitor only at small heat shock doses (i.e., heat shock of less than 40 minutes at 42 degrees C and 15 minutes at 43 degrees C). A similar stress dose-dependent suppression of reporter gene expression by cycloheximide was also demonstrated by treatment with sodium arsenite at 37 degrees C. However, dexamethasone-dependent reporter gene expression in a different CHO clone was not inhibited after the inducer treatment for different times in the presence of cycloheximide. In addition, synthesis of most cellular proteins (except for hsp) was not affected after heat shock treatment with cycloheximide. The results suggested that the cycloheximide inhibition of gene expression is specific to hsp gene expression induced by limited stress doses. Furthermore, a prior 42 degrees C heat shock treatment for 30 minutes induced a decreased responsiveness (tolerance) to a second 42 degrees C heat treatment for hsp gene expression, but tolerance did not develop in cells exposed to the first heat shock in the presence of cycloheximide. These results confirm previous findings that induction of hsp gene expression by stress is balanced by the severity of stress and rate of protein synthesis. They also support the proposed model of autoregulation of hsp gene expression by levels of free hsp70.

Effects of light stimulation on the activity of the autonomic nerves in anesthetized rats

The existence of the retino-hypothalamic pathway suggests that light stimulation may influence the activity of the autonomic outflows. Efferent activities of the pancreatic, hepatic, and gastric branches of the vagus nerve and those of pancreatic, hepatic, splenic, adrenal, and renal branch of the splanchnic nerve were recorded. Light stimulation with 2000 1x for 10 min to the left eye increased the splanchnic (sympathetic) outflows and suppressed the vagal outflows. The effects lasted for several hours. The minimal effective stimulation was 20 1x for 1 min or 200 1x for 0.1 min. These responses were observed in the light period as well as dark period. However, in the suprachiasmatic nucleus (SCN) lesioned rat, the changes in autonomic outflows following light stimulation were absent. The observations suggest that light stimulation modulates visceral functions through changes in the autonomic nervous system activities via the SCN.

Purification and characterization of aseanostatins: actinomycete-derived fatty acid inhibitors to myeloperoxidase release from human polymorphonuclear leukocytes

We found inhibitors, designated aseanostatins P1 and P5, against myeloperoxidase (MPO) release from human polymorphonuclear leukocytes (PMN). Aseanostatins were extracted from an actinomycete isolated in Thailand and purified by a series of column chromatography of charcoal and silica gel, and HPLC. Physico-chemical characterization by gas liquid chromatography and GC-MS indicated that aseanostatins were fatty acids. The active forms of aseanostatins were recovered by hydrolyzing their methyl esters after HPLC. Two components P1 and P5 with the IC50 of 0.96 and 0.54 microgram/ml to the MPO release were obtained as pure forms, indicating aseanostatin P5 was higher activity than aseanostatin P1. The component P1 was identical with 12-methyltridecanoic acid and P5 was indistinguishable to 12-methyltetradecanoic acid (ante-i-15:0). Aseanostatin P5 (1 microgram/ml) did not inhibit beta-glucuronidase release, but O2- production a little. It has no effect on chemotaxis of PMN to fMet-Leu-Phe (10(-8)M), PMN adhesion or phosphorylation of a 64-kD protein in the PMN cell-lysate system.

Excision of papillary endocardial tumor

We report the eighth case of surgical removal of a papillary endocardial tumor. The surgical approach was aided by intraoperative two-dimensional echocardiography. The tumor was attached to the chorda tendinea of the mitral valve and was successfully removed via a left atrial approach.

Characterization and localization of plasmid functions involved in pock formation and pock resistance of plasmid pSK3 of Streptomyces kasugaensis MB273

Deletion derivatives and recombinants of the plasmid pSK3, which is a cointegrate of pSK1 and pSK2 in Streptomyces kasugaensis, were constructed and analysed for their ability to transfer and 'pock' on strains carrying pSK1 or pSK2. Various deletions in the pSK1 and/or pSK2 regions of pSK3 were grouped into nine classes on the basis of their pock-forming ability and pock resistance. Analysis of these deletions and insertions provided tentative locations of DNA regions for two pock-resistance determinants (Por1 and Por2), two pock-forming determinants (Poc1 and Poc2) consisting of plasmid transfer and spread determinants (Tra/Spr), and two replication determinants (Rep1 and Rep2) corresponding to the pSK1 and pSK2 regions of pSK3. In particular, the Por2 function in the pSK2 region was determined to be located in a 1.35 kb segment.

Characterization of a natural cointegrate of the pock-forming plasmids pSK1 and pSK2 of Streptomyces kasugaensis MB273

Strains carrying only one species of pock-forming plasmid, designated as pSK3, were isolated from two different derivative strains of Streptomyces kasugaensis MB273 which contained three species of plasmids, pSK1, pSK2 and pSK3. Single and double digestion of pSK3 with seven restriction endonucleases yielded fragments identical with those of pSK3 and assignable to those obtained from pSK1 and pSK2. In particular, digestion with BglII alone or in combination with other restriction endonucleases afforded the same size fragments as those of pSK1 and pSK2. Strains containing pSK3 induced pocks on lawns of strains carrying pSK1 or pSK2 and resisted pock formation by the latter strains. Therefore, it was concluded that pSK3 was a pSK3 derivative with elevated pock-forming ability and represented a composite plasmid consisting of two elements, pSK1 and pSK2, without any loss of their plasmid functions. Deletion derivative plasmids constructed from the BglII fragments of pSK3 provided evidence supporting the above conclusion. Pock formation by a pSK3-containing strain against strains carrying pSK1, or pSK2 or no plasmid accompanied the transfer of pSK3 from the former to the latter. Segregation of pSK1 and pSK2 from pSK3 was observed in mycelium from pocks caused by pSK3-containing strains and on subculture of pSK3-containing strains.

Ventricular septal defect associated with aortic regurgitation

The effectiveness of aortic valvuloplasty and the indications for aortic valve replacement were examined in 76 patients with ventricular septal defect associated with aortic regurgitation. Results of this study indicate aortic regurgitation is associated with rapid deterioration and that aortic valvuloplasty should be performed as soon as aortic regurgitation is detected. The data also suggest that aortoplasty is indicated if aortic valvuloplasty alone is inadequate for coaptation of the aortic cusps with thickening.

[Intraoperative autotransfusion in aortic aneurysm operations combined with temporary external shunt]

Intraoperative autotransfusion was done in nine patients who underwent major vascular surgery for thoracic aortic aneurysms including one total abdominal aneurysm using temporal external shunt. After general heparinization (1mg/kg), shed blood was collected by Sorenson Autotransfusion System with local heparinization. After confirming ACT longer than 300-400 second, 425-3700 ml, averaged 1804 ml, of shed blood was reinfused to the patients by gravity flow. The reinfusion rate of shed blood was 43.1 +/- 15.8%. There were no deaths and no complications referable to autotransfusion. Although mild hemolysis was observed immediately after surgery, plasma free hemoglobin level returned to normal in the first operative day and no renal failure occurred. The volume of bleeding after surgery was not differed from that of control. Microembolism was not evident clinically. We concluded that intraoperative autotransfusion is safe and useful procedure in major vascular surgery if proper anticoagulation is done.

Late pathological changes of Carpentier-Edwards porcine bioprostheses in the mitral position

Eighty-nine patients received mitral valve replacement with Carpentier-Edwards porcine bioprostheses between 1975 and 1983. Eighty-three patients (93.3%) were followed up after the operation; early death (within one month of operation) occurred in 6 patients and late death in 2 patients. After the operation, 64 survivors (85.3%), who did not require reoperation, exhibited improved symptoms according to the NYHA functional class. Of the 6 patients (6.7%) who required reoperation, 5 patients underwent reoperation 50 to 85 months after the implantation. Pathologically, all the removed valves showed degeneration of collagen and elastic fibers, no host endothelialization and mild to moderate infiltration of inflammatory cells. Thrombus in the left atrium was detected in one case. Destruction of the cusps was seen in three cases and calcification of the cusps developed in three cases. In general, the Carpentier-Edwards porcine bioprosthesis provided good clinical improvement over the periods studied. However, morphological changes of the bioprosthetic valve, such as destruction collagen and elastic fiber, and inflammatory cell infiltration of the cusps, seems to occur more frequently with the passage of time. We therefore suggest that patients with this prosthesis should be followed carefully, particularly at late intervals after implantation.

Endocardial excision versus encircling endocardial ventriculotomy. A comparison of effects on ventricular structure and function

Although endocardial excision and encircling endocardial ventriculotomy are being performed in patients with extensive triple-vessel disease and compromised ventricular function, long-term effects of the operative intervention on structure and function of the left ventricle have not been determined. These procedures were performed in healthy dogs in three groups: control (ventriculotomy alone), endocardial excision, and encircling endocardial ventriculotomy (five dogs per group). Six weeks later, through a left thoracotomy, an arterial line, left atrial line, and Swan-Ganz catheter were inserted. Cardiac output measurements permitted calculation of left ventricular stroke work index, and gated nuclear ventriculograms permitted calculation of left ventricular volume indices. Myocardial performance (stroke work index/end-diastolic volume index relation), systolic elastance (systolic blood pressure/end-systolic volume index relation) and diastolic pressure-volume relationship (left atrial pressure/end-diastolic volume index relation) were determined from volume loading studies. In the endocardial excision group, the left atrial pressures were increased at similar end-diastolic volumes (p less than 0.05 by performance and systolic elastance were similar in the three groups. On completion of hemodynamic studies, the hearts were excised. Gross and light microscopic examination showed that the inner layer of myocardium was scarred in the area of intervention after both endocardial excision and encircling endocardial ventriculotomy. In neither group was there significant morphologic change elsewhere in the myocardium. Both endocardial excision and encircling endocardial ventriculotomy have little effect on long-term structure and function when performed in healthy canine hearts.

Crystal structure at 2.6 A resolution of the complex of subtilisin BPN' with streptomyces subtilisin inhibitor

The crystal structure of the complex of a bacterial alkaline serine proteinase, subtilisin BPN', with its proteinaceous inhibitor SSI (Streptomyces subtilisin inhibitor) was solved at 2.6 A resolution. Compared with other similar complexes involving serine proteinases of the trypsin family, the present structure is unique in several respects. (1) In addition to the usual antiparallel beta-sheet involving the P1, P2 and P3 residues of the inhibitor, the P4, P5 and P6 residues form an antiparallel beta-sheet with a previously unnoticed chain segment (residues 102 through 104, which was named the S4-6 site) of subtilisin BPN'. (2) The S4-6 site does not exist in serine proteinases of the trypsin family, whether of mammalian or microbial origin. (3) Global induced-fit movement seems to occur on SSI: a channel-like structure in SSI where hydrophobic side-chains are sandwiched between two lobes becomes about 2 A wider upon complexing with subtilisin. (4) The complex is most probably a Michaelis complex, as in most of the other complexes. (5) The main role of the "secondary contact region" of SSI seems to be to support the reactive site loop ("primary contact region"). Steric homology of the two contact regions between the inhibitors of the SSI family and the pancreatic secretory trypsin inhibitor-ovomucoid inhibitor family is so high that it seems to indicate divergent evolutionary processes and to support the general notion as to the relationship of prokaryotic and eukaryotic genes put forward by Doolittle (1978).

Plasmids of Streptomyces kasugaensis MB273: their pock formation, their dispensable endonuclease cleavage sites for pock formation, and transformation of S. kasugaensis MB273 by them

Plasmid-free strains of Streptomyces kasugaensis MB273 were isolated. In mating experiments S. kasugaensis MB273 was found to cause a lethal zygosis (pock) phenotype in a plasmid-free host. The pock-forming plasmids were identified as either pSK1* or pSK2* on the basis of their endonuclease cleavage-sites. The strain carrying pSK1* was found to induce pocks on the strain bearing pSK2*, and vice versa. The endonuclease cleavage-sites in pSK1* and pSK2* that were nonessential for pock formation were determined in deletion or insertion derivatives. The single sites for Bcl I and Sal I in pSK1* and for Bgl II in pSK2*, respectively, could be useful for DNA cloning without destroying pock-forming ability. Protoplasts of S. kasugaensis MB273-derivatives prepared in stationary phase of mycelial growth were competent for transformation, however, regeneration frequencies decreased during this phase.

[Surgical treatment of infective endocarditis in childhood--report of 3 cases]

This is the case report of 3 surgical patients with infective endocarditis in childhood. Case 1: A 8 year-old boy was admitted with high fever and congestive heart failure. Aureus staphylococci were identified by blood culture. Echocardiogram showed a vegetating mass on the posterior mitral leaflet. This patient was cured by emergency mitral valve replacement during the active phase of infection. Case 2: A 3 year-old girl was admitted with infective endocarditis related to VSD. Viridans streptococci were identified by blood culture. Echocardiogram showed a vegetating mass on the septal tricuspid leaflet. After successful antibiotic therapy, this patient underwent the closure of VSD and tricuspid valvuloplasty. Case 3: A 7 year-old boy was admitted with infective endocarditis related to VSD. Aureus staphylococci were identified with blood culture. Echocardiogram showed a vegetating mass on the anterior tricuspid leaflet and moderate tricuspid regurgitation. After successful antibiotic therapy, this patient underwent the closure of VSD and tricuspid valvuloplasty. We believe that echocardiography plays an important role in the diagnosis and management of infective endocarditis and that tricuspid valvuloplasty is the method of first choice in treatment of the patient with regional tricuspid infective endocarditis.

Surgical treatment of double-outlet left ventricle in situs inversus [I,D,D]

A case of double-outlet left ventricle [I,D,D] with a subaortic ventricular septal defect and pulmonary stenosis is reported. The diagnosis was made at operation and was reconfirmed postoperatively by two-dimensional echocardiography. Repair was achieved by patch closure of the ventricular septal defect and enlargement of the functional right ventricular outflow tract using a valved patch. The postoperative course was uneventful except for a transient complete heart block. To our knowledge, this represents the second instance of surgical treatment of double-outlet left ventricle [I,D,D] reported in the literature.

Questionable role of glucose-insulin in cardioplegic solution

To evaluate the myocardial protective effect of glucose-insulin (GI) in a cold cardioplegic solution, we compared the effect of a solution not containing GI (solution I) with that of an identical solution containing GI (solution II) under cardiopulmonary bypass in mongrel dogs. After 120 minutes of ischemic arrest, defibrillation was necessary to restore cardiac activity in 12.5% of the solution I group and 42.8% of the solution II group, respectively. No distinct intergroup differences were noted in recovery of left ventricular function, oxygen and lactate extraction of the myocardium during the post-arrest period, the myocardial ultrastructure, and myocardial ATP levels. Although creatine phosphate was less well preserved, glucose-6-phosphate and lactate were more accumulated in the solution II group than in the solution I group. Thus, significant advantages of substrate enhancement by addition of GI to cold cardioplegic solution were not found in spite of multidose cardioplegia and presence of noncoronary collateral blood flow.