Endocytoscopic observation for esophageal squamous cell carcinoma: can biopsy histology be omitted?

We examined whether endocytoscopic observation of esophageal squamous cell carcinoma can replace the histologic examination of biopsy specimens. In a basic investigation, we examined 57 iodine-unstained areas in the resected specimens of the esophagus from 28 individuals. The endocytoscopic findings were graded from 0 to 3 in tandem with observations of the iodine staining. For endocytoscopic observation, we sprayed 1% methylene blue or toluidine blue as a vital dye on the surface of the esophageal mucosa, allowing 15-20 s for sufficient staining. One endoscopist observed the target lesions and decided their endocytoscopic type classification. Histological diagnoses were made by two pathologists who were unaware of the endoscopic findings. We then compared the endocytoscopic diagnosis and conventional histological diagnosis. In an in vivo investigation, we examined 71 lesions of esophageal squamous cell carcinoma. Two endoscopists diagnosed the type classification in consultation with a pathologist with regard to 'nuclear density,''nuclear abnormality,' and 'whether biopsy histology could have been omitted on the basis of endocytoscopic findings.' For the in vivo observation, we utilized XEC120U (higher magnification type [x1100]), XEC300F (lower magnification type [x450]), and XGIF-Q260EC1 (lower magnification type [x450]) instruments. In the basic investigation, among the 11 areas classified as Type 1, 10 (91%) were category 1 by the Vienna classification. Among the 39 lesions classified as Type 3, 36 (92%) were category 4 or 5. The sensitivity of endocytoscopy for malignant lesions (Vienna classification categories 4 and 5) was 94.7%, if Type 3 was considered malignant. The specificity was 84.2% according to the same criteria. In the in vivo observation, two endoscopists diagnosed more than 90% of esophageal squamous cell carcinomas as neoplasms using each type of endocytoscope. With regard to nuclear density, the pathologist considered it to be increased in 98% of cases with the XEC120U, in 94% with the XEC300F, and in 93% with the XGIF-Q260EC1. With regard to nuclear abnormality, the positivity rate was 90% with the XEC120U, 78% with the XEC300F, and 80% with the XGIF-Q260EC1. As to whether or not biopsy histology examination was considered necessary, the pathologist made a 'Yes' judgment for 84% of cases observed with the XEC120U, 66% with the XEC300F, and 67% with the XGIF-Q260EC1. Cancerous lesions diagnosed as Type 3 by both endoscopists using the XEC120U accounted for 46 (90.2%) of the 51 cases. Among these 46 cases, biopsy histology was considered unnecessary by the pathologist in 43 (93.5%). We believe that endocytoscopic observation has the potential to reduce the extent of histologic examination of biopsy specimens in cases corresponding to Types 1 and 3 of our classification.

The hydrocarbon-bearing clathrasil chibaite and its host-guest structure at low temperature.

The natural sII-type clathrasil chibaite [chemical formula SiO2·(M12,M16), where Mx denotes a guest mol-ecule] was investigated using single-crystal X-ray diffraction and Raman spectroscopy in the temperature range from 273 to 83 K. The O atoms of the structure at room temperature, which globally conforms to space group [V = 7348.9 (17) Å3, a = 19.4420 (15) Å], have anomalous anisotropic displacement parameters indicating a static or dynamic disorder. With decreasing temperature, the crystal structure shows a continuous symmetry-lowering transformation accompanied by twinning. The intensities of weak superstructure reflections increase as temperature decreases. A monoclinic twinned superstructure was derived at 100 K [A2/n, V = 7251.0 (17) Å3, a' = 23.7054 (2), b' = 13.6861 (11), c' = 23.7051 (2) Å, ß' = 109.47°]. The transformation matrix from the cubic to the monoclinic system is ai ' = (½ 1 ½ / ½ 0 -½ / ½ -1 ½). The A2/n host framework has Si-O bond lengths and Si-O-Si angles that are much closer to known values for stable silicate-framework structures compared with the averaged model. As suggested from band splitting observed in the Raman spectra, the [512]-type cages (one crystallographically unique in , four different in A2/n) entrap the hydro-carbon species (CH4, C2H6, C3H8, i-C4H10). The [51264]-type cage was found to be unique in both structure types. It contains the larger hydro-carbon mol-ecules C2H6, C3H8 and i-C4H10.

Clinical outcome after endoscopic mucosal resection for esophageal squamous cell carcinoma invading the muscularis mucosae--a multicenter retrospective cohort study.

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection (EMR) is now commonly indicated for esophageal squamous cell carcinoma (ESCC) within the lamina propria mucosa. However, EMR for ESCC that has invaded the muscularis mucosa is controversial because the risk of lymph node metastasis is not negligible. We conducted a multicenter retrospective cohort study to investigate the incidence of lymph node metastasis and survival after EMR for ESCC invading the muscularis mucosa. PATIENTS AND METHODS: A total of 104 patients with 111 lesions invading the muscularis mucosa, were retrospectively studied at eight institutes. No patients exhibited evidence of metastasis of lymph nodes or distant organs prior to EMR. Overall and cause-specific survival rates were calculated from the date of EMR to the date of death or the most recent follow-up visit. Survival curves were plotted according to the Kaplan-Meier method. RESULTS: In total, 86 patients (82.7%) who did not receive further treatment such as chemotherapy, irradiation therapy, chemoradiotherapy, or esophagectomy after EMR were followed up. Only two patients (1.9%) developed lymph node metastasis after EMR. With a median follow-up period of 43 months (range, 8-134 months), overall and cause-specific survival rates at 5 years after EMR were 79.5% and 95.0%, respectively. CONCLUSIONS: EMR for ESCC that invades the muscularis mucosa has curative potential as a minimally invasive treatment option.

Cloning of dnaK and dnaJ homologous genes from a purple non-sulfur bacterium Rhodopseudomonas species.

The dnaK and dnaJ genes were isolated as a cluster from a purple non-sulfur phototrophic bacterium, Rhodopseudomonas species No. 7 by a polymerase chain reaction (PCR) based method. The deduced products of dnaK (631 amino acids) and dnaJ (379 amino acids) were 67% and 56% identical to the respective Escherichia coli gene products. The functions of DnaK and DnaJ could be confirmed by complementation of the respective E. coli mutants.

Complete sequence and characterization of chick ventricular myosin heavy chain in the developing atria.

We isolated five complementary DNA (cDNA) clones, encoding the chick ventricular myosin heavy chain (MyHC) by reverse transcription polymerase chain reaction (RT-PCR). The entire cDNA consists of 5995 nucleotides with the 52 bp 5'-untranslated region and the 129 bp 3'-untranslated region. The complete cDNA encodes 1937 amino acids. Expression of the chick ventricular MyHC gene was also studied by Northern blot analysis. This gene continued to be strongly expressed in the ventricle during cardiac development. On the other hand, its expression was moderate in the early embryonic atria, and was down-regulated during development. In the adult atria, this gene was expressed at very low levels. To determine the localization of the ventricular MyHC protein, an immunohistochemical study was performed. The ventricular MyHC was present in early embryonic atrial myocytes. During development, the expression of this protein in the atrial myocytes was down-regulated, but continued to be present in the atrial conduction system. Our results indicate that the ventricular MyHC appears in the primary atrial myocardium and is then localized in the conduction cells of the atria.

Novel mechanism associated with an inherited cardiac arrhythmia: defective protein trafficking by the mutant HERG (G601S) potassium channel.

BACKGROUND: The congenital long-QT syndrome (LQTS) is an inherited disorder characterized by a prolonged cardiac action potential and a QT interval that leads to arrhythmia. Mutations in the human ether-a-go-go-related gene (HERG), which encodes the rapidly activating component of the delayed rectifier current (IKr), cause chromosome 7-linked LQTS (LQT2). Studies of mutant HERG channels in heterologous systems indicate that the mechanisms mediating LQT2 are varied and include mutant subunits that form channels with altered kinetic properties or nonfunctional mutant subunits. We recently reported a novel missense mutation of HERG (G601S) in an LQTS family that we have characterized in the present work. METHODS AND RESULTS: To elucidate the electrophysiological properties of the G601S mutant channels, we expressed these channels in mammalian cells and Xenopus oocytes. The G601S mutant produced less current than wild-type channels but exhibited no change in kinetic properties or dominant-negative suppression when coexpressed with wild-type subunits. To examine the cellular trafficking of mutant HERG channel subunits, enhanced green fluorescent protein tagging and Western blot analyses were performed. These showed deficient protein trafficking of the G601S mutant to the plasma membrane. CONCLUSIONS: Our results from both the Xenopus oocyte and HEK293 cell expression systems and green fluorescent protein tagging and Western blot analyses support the conclusion that the G601S mutant is a hypomorphic mutation, resulting in a reduced current amplitude. Thus, it represents a novel mechanism underlying LQT2.

Truncus arteriosus communis associated with chromosome 22q11 deletion.

OBJECTIVES: The purpose of this study was to clarify characteristics of truncus arteriosus communis associated with chromosome 22q11 deletion (del 22q11). BACKGROUND: DiGeorge syndrome and conotruncal anomaly face syndrome are associated with del 22q11 (hemizygosity). In 30% of cases, truncus arteriosus communis is associated with the deletion. METHODS: Fifteen consecutive patients with truncus arteriosus communis were checked for 22q11 with fluorescent in situ hybridization using an N25 probe (Oncor). Cardiovascular anomalies were studied with cardiac catheterization, cineangiography and echocardiography. RESULTS: Five patients had del 22q11. Two had a rare type of truncus arteriosus: type A3 of Van Praagh and Van Praagh with major aortopulmonary collateral arteries and pulmonary ostial stenosis. The other three had type A1 truncus arteriosus and pulmonary artery stenosis. One of them had major aortopulmonary collateral arteries. Ten patients with truncus arteriosus had no del 22q11. The types of truncus arteriosus in these 10 patients were type A1 in 7, type A2 in 2 and type A3 with closed ductus in 1. None of nine patients with type 1 or type 2 truncus arteriosus had pulmonary stenosis. CONCLUSIONS: In truncus arteriosus communis, the rare type A3 with major aortopulmonary collateral arteries and pulmonary ostial stenosis and type A1 with pulmonary artery stenosis are associated with del 22q11.

Tetralogy of Fallot with pulmonary atresia associated with chromosome 22q11 deletion.

OBJECTIVES: The purpose of this study was to clarify characteristics of tetralogy of Fallot and pulmonary atresia associated with chromosome 22q11 deletion. BACKGROUND: DiGeorge syndrome and conotruncal anomaly facies syndrome are associated with chromosome 22q11 deletion (hemizygosity). Associated cardiac anomalies include tetralogy of Fallot, truncus arteriosus and interrupted aortic arch. METHODS: Twenty-three patients with tetralogy of Fallot and pulmonary atresia were proved to have chromosome 22q11 deletion with fluorescent in situ hybridization using N25 probe (Oncor). Cardiovascular anomalies were compared with those in 26 patients with tetralogy of Fallot and pulmonary atresia without the deletion. Cardiovascular anomalies were studied with cardiac catheterization, cineangiography and echocardiography. RESULTS: In patients with 22q11 deletion, additional anomalies of the aortic arch, ductus arteriosus and pulmonary artery were more common as follows: right aortic arch (70% with deletion vs. 23% without deletion), high aortic arch reaching third rib (43% vs. 15%), aberrant left subclavian artery (35% vs. 0%), absent ductus arteriosus (83% vs. 46%), major aortopulmonary collateral arteries (91% vs. 50%), absent confluent central pulmonary arteries (48% vs. 4%). CONCLUSIONS: In patients with tetralogy of Fallot and pulmonary atresia, additional anomalies of the aortic arch, ductus arteriosus and pulmonary arteries are more common in patients with than in those without the 22q11 deletion.

Long-term effect of angiotensin-converting enzyme inhibitor in volume overloaded heart during growth: a controlled pilot study.

OBJECTIVES: This study examined whether long-term therapy with an angiotensin-converting enzyme (ACE) inhibitor reduces excessive increases in left ventricular (LV) mass as well as volume in growing children with aortic regurgitation or mitral regurgitation. BACKGROUND: The ACE inhibitor reduces volume overload and LV hypertrophy in adults with aortic or mitral regurgitation. METHODS: This study included 24 patients whose ages ranged from 0.3 to 16 years at entry to the study. On echocardiography, we measured LV size, systolic function and mass. After obtaining baseline data, patients were allocated into two groups. Twelve patients were given an ACE inhibitor (ACE inhibitor group), and 12 patients were not (control group). Echo parameters were again assessed after an average 3.4 years of follow-up. RESULTS: Left ventricular parameters at baseline in the two groups were similar. The Z value of LV end-diastolic dimensions decreased from +0.82 +/- 0.55 to +0.57 +/- 0.58 in the ACE inhibitor group, whereas it increased from +0.73 +/- 0.85 to +1.14 +/- 1.04 in the control group (mean change -0.25 +/- 0.33 for the ACE inhibitor group vs. +0.42 +/- 0.48 for the control group, p = 0.0007). The mass normalized to growth also reduced from 221 +/- 93% to 149 +/- 44% of normal in the ACE inhibitor group and increased from 167 +/- 46% to 204 +/-59% of normal in the control group (mean change -72 +/- 89% of normal for the ACE inhibitor group vs. +37 +/- 35% of normal for the control group, p = 0.0007). CONCLUSIONS: Long-term treatment with ACE inhibitors is effective in reducing not only LV volume overload but also LV hypertrophy in the hearts of growing children with LV volume overload.

Balloon angioplasty for postoperative pulmonary artery stenosis in transposition of the great arteries.

OBJECTIVES: This study was designed to assess the success rate and determinants of success or failure of balloon angioplasty for postoperative pulmonary stenosis in patients with transposition of the great arteries. BACKGROUND: Previous reports have suggested that pulmonary stenosis that develops after the arterial switch operation is not likely to be dilated. METHODS: Twenty-eight patients with transposition of the great arteries underwent 39 balloon angioplasty procedures after the arterial switch operation. The mean age at dilation was 4.5 +/- 2.2 years (range 0.7 to 9.8), and the interval between operation and balloon dilation was 3.6 +/- 1.8 years. The criterion of successful dilation was a > or = 50% increase in predilation diameter or a > or = 50% decrease in predilation pressure gradient. If the right ventricular/aortic pressure ratio decreased by > or = 0.2, so that the ratio became < 0.68, reoperation was thought to be not indicated. RESULTS: The success rate of balloon angioplasty for pulmonary artery stenosis was 51% (20 of 39 dilations). The mean age at dilation in the group with successful dilation (3.6 years) was significantly younger than that in the group with unsuccessful dilation (5.4 years). The interval between operation and dilation in the successful dilation group (2.4 years) was significantly less than that in the unsuccessful dilation group (4.6 years). In 13 patients who underwent balloon angioplasty < 3.5 years after operation, balloon dilation was successful in 92%. The balloon/artery ratio was significantly greater in the successful than in the unsuccessful dilation group. A right ventricular/aortic pressure ratio > or = 0.68 was observed in 20 patients, and reoperation was not indicated in 10 patients (50%). There was no death, but one pulmonary artery rupture that did not require surgical intervention occurred. Aneurysmal dilation of the pulmonary artery was observed in three patients. CONCLUSIONS: These data indicate that although the success rate of balloon angioplasty for pulmonary artery stenosis after the arterial switch operation is low (approximately 50%), balloon angioplasty can be the first therapeutic choice owing to the low complication rate and the potential benefit of the procedure. The success rate can be high if angioplasty is performed < 3.5 years after operation and a balloon of adequate size is used.

Inhibition of outflow cushion mesenchyme formation in retinoic acid-induced complete transposition of the great arteries.

OBJECTIVE: Endocardial cushion tissue formation, the primordia of valves and septa, is a critical event in cardiac morphogenesis. Maternally administrated all-trans retinoic acid is known to induce complete transposition of the great arteries (TGA) in the mouse embryo. To address the mechanisms of TGA, the effect of retinoic acid on cushion tissue formation was examined. METHODS: Using a three-dimensional collagen gel culture model, we performed various types of endothelial-mesenchymal transformation assays of co-cultured endocardium with myocardium obtained from 9.5-day mouse embryonic hearts. In vivo immunohistochemical detections of extracellular matrices, fibronectin and type I collagen, were also performed. RESULTS: Endothelial-to-mesenchymal transformation at the onset of cushion tissue formation was suppressed in the outflow tract of embryos exposed to retinoic acid in culture. This inhibitory effect of retinoic acid was spatially restricted to the outflow tract and reversed by treatment with embryonic myocardial conditioned medium enriched in extracellular inductive molecules. Mesenchyme formation in the outflow tract was inhibited at a lower concentration of retinoic acid (10(-10) mol/l) than that which inhibited the atrio-ventricular canal (10(-7) mol/l) in culture. The fibronectin and type I collagen depositions in pre-migratory outflow tract cardiac jelly in retinoic acid-treated embryonic heart were reduced compared to those in the control. CONCLUSIONS: Exogenously applied retinoic acid inhibits outflow tract cushion mesenchyme formation in the embryonic heart with TGA. It is suggested that retinoic acid inhibits the expression of extracellular matrices and inductive molecules synthesized by myocardium in the outflow tract.

Molecular characterization of a novel atrial-specific myosin heavy-chain gene expressed in the chick embryo.

A 1.2 kb fragment of a myosin heavy-chain (MHC) gene was isolated from the complementary DNA (cDNA) library derived from embryonic day 15 (E15), Hamburger and Hamilton (H.H) stage 41 chick embryonic ventricle, using a fragment of human beta-cardiac MHC cDNA as a probe. DNA sequence analysis determined that the gene (CCSV2) encoded the amino acid sequence of the rod portion (part of S2 and light meromyosin) of the chick atrial-specific MHC gene. The nucleotide sequence of CCSV2 was slightly different (90% homologous) from a previously reported atrial-specific MHC (AMHC1) expressed in chick embryo. Northern blot analysis, with the CCSV2 fragment (1.2 kb) used as a probe, showed that the gene is expressed intensively in the developing chick atrial muscle, but weakly in the ventricle and pectoralis muscle. S1-nuclease mapping analysis, with CCSV2 used as a probe, demonstrated a fully protected fragment in the atrium and ventricle. In this study, no intensive signal of a partially protected fragment was detected in the atrium. On the other hand, not only a fully protected fragment, but also four partially protected fragments were observed in the pectoralis muscle. Whole-mount in situ hybridization was performed in developing chick heart at H.H. stages 19, 21 and 30. The hybridization signal was intensive in the primitive atrium (H.H. stages 19 and 21) and in the atrial appendages derived from the primitive atrium (H.H. stage 30). Weak signals were detected in the primitive ventricle (H.H. stages 19 and 21), the ventricle (H.H. stage 30) and in the somites (H.H. stages 19 and 21).(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of four myosin heavy chain genes in developing blood vessels and other smooth muscle organs in rabbits.

At least two smooth muscle myosin heavy chain (MHC) isoforms (SM1, SM2) and two non-muscle MHC isoforms (NMA, NMB) have been detected in smooth muscles. We used the S-1 nuclease mapping procedure to study the expression of these four types of MHC mRNAs in various rabbit blood vessels, such as the aorta (Ao), pulmonary artery (PA), inferior vena cava (IVC) and ductus arteriosus (DA), and in various rabbit tissues and organs. The results demonstrated that in the blood vessels, the four types of MHC mRNA were expressed during all developmental stages in Ao and PA and that SM2 expression appeared to increase dramatically after birth. Compared to the other fetal vessels, the fetal DA contained considerably higher amounts of the four types of MHC mRNAs. SM2 was more prevalent than SM1 in the esophagus, stomach, small intestine and urinary bladder, which are often stretched and show vigorous contractile activity. SM2 expression in a smooth muscle cell appears to correlate well with the contractile ability and/or activity of the cell. Our data show that among the four types of MHC mRNAs, the expression of SM2 MHC mRNA shows great variation among different organs, blood vessel types and stages of development of Ao and PA.

Aortic valve prolapse and aortic regurgitation associated with subpulmonic ventricular septal defect.

The natural development of aortic valve deformity was studied in 315 patients with subpulmonic ventricular septal defect. The patients with early development of aortic regurgitation had a pulmonary-to-systemic flow ratio of > 1.5, normal right ventricular pressure, and severe aortic regurgitation.

Characteristics and natural history of abnormal atrial rhythms in left isomerism.

The object of this study is to document variation in atrial pacemaker rate and P-wave axis, and to clarify the natural history of abnormally slow atrial rhythms in left isomerism. Standard 15-lead electrocardiograms of 50 patients with left isomerism were retrospectively studied. On the average, 9 electrocardiograms covering 7 years for each patient were available. For comparison, atrial rhythms in patients with right isomerism and in those with situs solitus and 5 representative congenital cardiac conditions were studied with the same study protocol. In left isomerism, atrial rhythm with constantly normal P-wave axis was exceptional and the presence of atrial rhythm with abnormal P-wave axis was the rule. The most frequent abnormal mean frontal P-wave axis was between -30 and -90 degrees, recorded in 70%. Slow atrial rates below the second percentile were observed in 50%, either transiently and recurrently (in 40%), or persistently (in 10%), and were associated with junctional escape in 42%. The number of patients with slow atrial rate increased with age. In right isomerism, multiple atrial rhythms were also frequent, but slow atrial rhythms was present in only 4%. Multiple atrial rhythms or bradycardia associated with junctional escape were rare in the group of patients with congenital heart disease and situs solitus. It is concluded that multiplicity and progressive slowing of the atrial rhythm are characteristic in patients with left isomerism.

Further evidence suggesting a limited role of digitalis in infants with circulatory congestion secondary to large ventricular septal defect.

In infants with a large ventricular septal defect, the acute hemodynamic effect of intravenous digitalis varies depending on baseline systemic and pulmonary resistance. Digitalis may act adversely by increasing pulmonary blood flow with an elevation in left atrial pressure in severely congested infants with ventricular septal defects.

Cardiac anomalies associated with a chromosome 22q11 deletion in patients with conotruncal anomaly face syndrome.

Among 114 cardiac patients with conotruncal anomaly face syndrome and DiGeorge syndrome, 100 patients were found to have a chromosome 22q11 deletion. Those with the deletion included 73 patients with tetralogy of Fallot, 12 with ventricular septal defect, 5 with aortic arch anomalies without intracardiac anomaly, 4 with interrupted aortic arch, 2 with double-outlet right ventricle, 2 with truncus arteriosus, 1 with complete transposition, and 1 with atrial septal defect.

Comparison of three-dimensional contrast-enhanced magnetic resonance angiography and axial radiographic angiography for diagnosing congenital stenoses in small pulmonary arteries.

Accuracy of 3-dimensional contrast-enhanced magnetic resonance angiography (MRA) in diagnosing morphology of the branch pulmonary artery (PA) was evaluated in 73 patients (aged 7.2 +/- 6.4 years [mean +/- SD]) with various congenital heart diseases. The presence or absence of localized stenosis of branch PAs, PA diameter, and Nakata's PA index were determined on MRA and axial radiographic angiography, and the results were compared. Sensitivity, specificity, and overall accuracy in detecting branch PA stenoses were 92.7%, 96.2%, and 95.2%, respectively. Correlations between axial radiographic angiography and MRA were excellent in measuring PA diameter (r = 0.956, SEE = 1.49 mm, n = 139) as well as PA index (r = 0.839, SEE = 48.9, n = 37); both p < 0.0001. Bland-Altman plots showed a mean difference +/- SD for PA diameter of 0.17 +/- 1.51 mm and for PA index of 8.5 +/- 50.1. When the main right and left PAs were taken as the first generation, the most distal branches visible on MRA were the 4.7 +/- 0.7 generation with breath-holding (n = 23) and the 3.7 +/- 0.5 without breath-holding (n = 50), respectively (p < 0.0001). Both intra- and interobserver variabilities of MRA measurements were few (9.5 +/- 11.6% and 13.5 +/- 15.0%, respectively, n = 139). In conclusion, 3-dimensional contrast-enhanced MRA enables us to document branch PA morphology clearly in infants and adult patients with congenital cardiovascular defects.

Scintigraphic monitoring of coronary artery occlusion due to Kawasaki disease.

Noninvasive monitoring of the process of coronary occlusion will probably aid in determining the timing of therapeutic interventions for Kawasaki disease. A pair study of coronary angiography and thallium scintigraphy after dipyridamole infusion-single-photon emission computed tomography with dipyridamole infusion (Dp-SPECT) was repeated at least twice at intervals of several years in 29 patients, and these findings were compared and analyzed in a chronologic manner. The current study demonstrated that angiographic stenosis was more severe, with an increase in the severity of the perfusion defect. Positive rates determined by Dp-SPECT increased with increasing severity of stenosis on angiography. Angiographic findings from the first to the second serial study that showed worsening, no change and improvement were correctly diagnosed from scintigraphic changes in 94% of coronary arterial lesions. About half of the arteries with progression in stenotic severity could be found before complete occlusion by scintigraphic monitoring. It is concluded that Dp-SPECT can be used as a noninvasive monitor of the occurrence and progression of coronary stenoses due to Kawasaki disease.

Phenotypic discordance in monozygotic twins with 22q11.2 deletion.

We report on male monozygotic twins with 22q11.2 deletion and discordant phenotypes. The twins had twin-to-twin transfusion syndrome. Twin 1, the smaller of the pair, had Tetralogy of Fallot, a characteristic facial appearance, swallowing dysfunction, anal atresia, short stature, and mental retardation, whereas twin 2 had a characteristic facial appearance but no other signs of the 22q11 deletion syndrome. Fluorescence in situ hybridization analysis showed a microdeletion on chromosome 22q11.2 in both twins. Zygosity analysis gave a probability of monozygosity greater than 99.999%. These observations indicate that environmental factors or postzygotic events play a role in the phenotypic variability in the twins.