Ntsr1 contributes to pulmonary hypertension by enhancing endoplasmic reticulum stress via JAK2-STAT3-Thbs1 signaling

Pulmonary hypertension (PH) is a severe clinical syndrome with pulmonary vascular remodeling and poor long-term prognosis. Neurotensin receptor 1 (Ntsr1), serve as one of the G protein-coupled receptors (GPCRs), implicates in various biological processes, but the potential effects of Ntsr1 in PH development are unclear. The Sugen/Hypoxia (SuHx) or monocrotaline (MCT) induced rat PH model was used in our study and the PH rats showed aggravated pulmonary artery remodeling and increased right ventricular systolic pressure (RVSP). Our results revealed that Ntsr1 induced endoplasmic reticulum (ER) stress response via ATF6 activation contributed to the development of PH. Moreover, RNA-sequencing (RNA-seq) and phosphoproteomics were performed and the Ntsr1-JAK2-STAT3-thrombospondin 1 (Thbs1)-ATF6 signaling was distinguished as the key pathway. In vitro, pulmonary artery smooth muscle cells (PASMCs) under hypoxia condition showed enhanced proliferation and migration properties, which could be inhibited by Ntsr1 knockdown, JAK2 inhibitor (Fedratinib) treatment, STAT3 inhibitior (Stattic) treatment, Thbs1 knockdown or ATF6 knockdown. In addition, adeno-associated virus 1 (AAV1) were used to knockdown the expression of Ntsr1, Thbs1 or ATF6 in rats and reversed the phenotype of PH. In summary, our results reveal that Ntsr1-JAK2-STAT3-Thbs1 pathway can induce enhanced ER stress via ATF6 activation and increased PASMC proliferation and migration capacities, which can be mechanism of the pulmonary artery remodeling and PH. Targeting Ntsr1 might be a novel therapeutic strategy to ameliorate PH.

Impact of stage-specific limb function exercises guided by a self-management education model on arteriovenous fistula maturation status

BACKGROUND

The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula (AVF). However, due to the lack of a unified exercise standard in China, many patients have insufficient awareness of the importance of AVF, leading to poor effectiveness of limb function exercise. The self-management education model can effectively promote patients to take proactive health-related actions. This study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in factors such as the maturity of AVF.

AIM

To assess the impact of stage-specific limb function exercises, directed by a self-management education model, on the maturation status of AVFs.

METHODS

This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan Province, China. Patients were randomly divided into an observation group and a control group using a random number table method. The observation group underwent tailored stage-specific limb function exercises, informed by a self-management education model which took into account the unique features of AVF at various stages, in conjunction with routine care. Conversely, the control group was given standard limb function exercises along with routine care. The assessment involves the maturity of AVFs post-intervention, postoperative complications, and the self-management level of the fistula in both groups patients. Analyses were conducted using SPSS version 23.0. Count data were represented by frequency and percentage and subjected to chi-square test comparisons. Measurement data adhering to a normal distribution were presented as mean ± SD. The independent samples t-test was utilized for inter-group comparisons, while the paired t-test was used for intra-group comparisons. For measurement data not fitting a normal distribution, the median and interquartile range were presented and analyzed using the Wilcoxon rank sum test.

RESULTS

At the 8-wk postoperative mark, the observation group demonstrated significantly higher scores in AVF symptom recognition, symptom prevention, and self-management compared to the control group (P < 0.05). However, the variance in symptom management scores between the observation and control groups lacked statistical significance (P > 0.05). At 4 wk after the operation, the observation group displayed a superior vessel diameter and depth from the skin of the drainage vessels in comparison to the control group (P < 0.05). While the observation group did manifest elevated blood flow rates in the drainage vessels relative to the control group, this distinction was not statistically significant (P > 0.05). By the 8-wk postoperative interval, the observation group outperformed the control group with notable enhancements in blood flow rates, vessel diameter, and depth from the skin of drainage vessels (P < 0.01). Seven days following the procedure, the observation group manifested significantly diminished limb swelling and an overall reduced complication rate in contrast to the control group (P < 0.05). The evaluation of infection, thrombosis, embolism, arterial aneurysm stenosis, and incision bleeding showed no notable differences between the two groups (P > 0.05). By the 4-wk postoperative juncture, complications between the observation and control groups were statistically indistinguishable (P > 0.05).

CONCLUSION

Stage-specific limb function exercises, under the guidance of a self-management education model, amplify the capacity of AVF patients to discern and prevent symptoms. Additionally, they expedite AVF maturation and mitigate postoperative limb edema, underscoring their efficacy as a valuable method for the care and upkeep of AVF in hemodialysis patients.

Zbtb16 increases susceptibility of atrial fibrillation in type 2 diabetic mice via Txnip-Trx2 signaling

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia, and recent epidemiological studies suggested type 2 diabetes mellitus (T2DM) is an independent risk factor for the development of AF. Zinc finger and BTB (broad-complex, tram-track and bric-a-brac) domain containing 16 (Zbtb16) serve as transcriptional factors to regulate many biological processes. However, the potential effects of Zbtb16 in AF under T2DM condition remain unclear. Here, we reported that db/db mice displayed higher AF vulnerability and Zbtb16 was identified as the most significantly enriched gene by RNA sequencing (RNA-seq) analysis in atrium. In addition, thioredoxin interacting protein (Txnip) was distinguished as the key downstream gene of Zbtb16 by Cleavage Under Targets and Tagmentation (CUT&Tag) assay. Mechanistically, increased Txnip combined with thioredoxin 2 (Trx2) in mitochondrion induced excess reactive oxygen species (ROS) release, calcium/calmodulin-dependent protein kinase II (CaMKII) overactivation, and spontaneous Ca2+ waves (SCWs) occurrence, which could be inhibited through atrial-specific knockdown (KD) of Zbtb16 or Txnip by adeno-associated virus 9 (AAV9) or Mito-TEMPO treatment. High glucose (HG)-treated HL-1 cells were used to mimic the setting of diabetic in vitro. Zbtb16-Txnip-Trx2 signaling-induced excess ROS release and CaMKII activation were also verified in HL-1 cells under HG condition. Furthermore, atrial-specific Zbtb16 or Txnip-KD reduced incidence and duration of AF in db/db mice. Altogether, we demonstrated that interrupting Zbtb16-Txnip-Trx2 signaling in atrium could decrease AF susceptibility via reducing ROS release and CaMKII activation in the setting of T2DM.

Higher Sodium Channel Excitability in Cardiac Purkinje Fibers: Implications for Multifocal Ectopic Purkinje-Related Premature Contractions

BACKGROUND

Multifocal ectopic Purkinje-related premature contractions (MEPPCs) are associated with SCN5A variants. However, it is not well understood why Purkinje fibers, but not ventricular myocardium, play a predominant role in arrhythmogenesis.

OBJECTIVES

This study sought to explore the underlying mechanisms of MEPPC.

METHODS

Whole-cell patch-clamp and molecular biology techniques were used in the present study.

RESULTS

Clinical data from one patient with R814W variant showed MEPPC syndrome, which is well responsive to amiodarone. Compared with canine ventricular myocytes, Purkinje cells (PCs) had significantly larger sodium current (INa), leftward shift of INa activation and inactivation curves, suggesting higher sodium channel excitability in PCs. Real-time polymerase chain reaction and Western blot analysis showed that the mRNA and protein expression of NaVβ1 and NaVβ3 was higher in canine Purkinje fibers than in ventricular myocardium. INa in heterologous Chinese hamster ovary cell expression system co-expressing NaV1.5 and NaVβ1/NaVβ3 exhibited similar biophysical properties of INa in PCs. R814W variant shifted INa activation in a hyperdepolarized direction, caused a larger window current, and generated an outward-gating pore current at depolarized voltages. Coexpression of NaVβ1/NaVβ3 with Nav1.5-R814W further left-shifted INa activation and caused an even larger window current and gating pore current, suggesting higher susceptibility of Purkinje fibers to R814W variant. Amiodarone inhibited INa, shifted its inactivation to more negative voltages, and significantly decreased the window current.

CONCLUSIONS

A higher expression of β1 and β3 subunits contributes to higher sodium channel excitability in cardiac Purkinje fibers, making them more susceptible to MEPPC.

Loss-of-function CFTR p.G970D missense mutation might cause congenital bilateral absence of the vas deferens and be associated with impaired spermatogenesis

Congenital bilateral absence of the vas deferens (CBAVD) is observed in 1%-2% of males presenting with infertility and is clearly associated with cystic fibrosis transmembrane conductance regulator (CFTR) mutations. CFTR is one of the most well-known genes related to male fertility. The frequency of CFTR mutations or impaired CFTR expression is increased in men with nonobstructive azoospermia (NOA). CFTR mutations are highly polymorphic and have established ethnic specificity. Compared with F508Del in Caucasians, the p.G970D mutation is reported to be the most frequent CFTR mutation in Chinese patients with cystic fibrosis. However, whether p.G970D participates in male infertility remains unknown. Herein, a loss-of-function CFTR p.G970D missense mutation was identified in a patient with CBAVD and NOA. Subsequent retrospective analysis of 122 Chinese patients with CBAVD showed that the mutation is a common pathogenic mutation (4.1%, 5/122), excluding polymorphic sites. Furthermore, we generated model cell lines derived from mouse testes harboring the homozygous Cftr p.G965D mutation equivalent to the CFTR variant in patients. The Cftr p.G965D mutation may be lethal in spermatogonial stem cells and spermatogonia and affect the proliferation of spermatocytes and Sertoli cells. In spermatocyte GC-2(spd)ts (GC2) Cftr p.G965D cells, RNA splicing variants were detected and CFTR expression decreased, which may contribute to the phenotypes associated with impaired spermatogenesis. Thus, this study indicated that the CFTR p.G970D missense mutation might be a pathogenic mutation for CBAVD in Chinese males and associated with impaired spermatogenesis by affecting the proliferation of germ cells.

Antibacterial surfaces: Strategies and applications

Antibacterial surfaces are surfaces that can resist bacteria, relying on the nature of the material itself. It is significant for safe food and water, human health, and industrial equipment. Biofilm is the main form of bacterial contamination on the material surface. Preventing the formation of biofilm is an efficient way to develop antibacterial surfaces. The strategy for constructing the antibacterial surface is divided into bacteria repelling and bacteria killing based on the formation of the biofilm. Material surface wettability, adhesion, and steric hindrance determine bacteria repelling performance. Bacteria should be killed by surface chemistry or physical structures when they are attached to a material surface irreversibly. Killing approaches are usually in the light of the cell membrane of bacteria. This review summarizes the fabrication methods and applications of antibacterial surfaces from the view of the treatment of the material surfaces. We also present several crucial points for developing long-term stability, no drug resistance, broad-spectrum, and even programable antibacterial surfaces.

Clinical observation of mineralized collagen bone grafting after curettage of benign bone tumors

Curettage of benign bone tumor is a common cause for bone defect. For such bone defect repair, autogenous bone, allogeneic bone and traditional artificial bone graft substitutes have many disadvantages. In recent years, a biomimetic mineralized collagen (MC) with similar composition and microstructures to the natural bone matrix was developed and used for treating various bone defects. In this work, a retrospective study analyzed clinical outcomes of patients treated with curettage of benign bone tumors and bone grafting with MC, in comparison to another group treated with the same surgical method and autogenous bone. Lane–Sandhu X-ray score of the autogenous bone group was superior to the MC group at 1 month after the operation, but the two groups had no statistical difference at 6 and 12 months. The MC group was better in Musculoskeletal Tumor Society scoring at 1 and 6 months after the operation, and the two groups had no statistical difference at 12 month. Therefore, the MC performed not as good as autogenous bone in early stage of bone healing but achieved comparable outcomes in long-term follow-ups. Moreover, the MC has advantages in function recovery and avoided potential complications induced by harvesting autogenous bone.

Protective role of silibinin against myocardial ischemia/reperfusion injury-induced cardiac dysfunction

Silibinin is a traditional medicine and utilized for liver protection with antioxidant, anti-inflammation and anti-apoptosis properties. However, its role in myocardial I/R injury and the mechanism involved is currently unknown. In the present study, Silibinin treatment improves cardiac function and limits infarct size, and subsequently inhibits fibrotic remodeling in mice with myocardial I/R injury. Mechanistically, silibinin reduces cardiomyocytes apoptosis, attenuates mitochondrial impairment and endoplasmic reticulum (ER) stress, alleviates ROS generation, neutrophil infiltration and cytokines release. Consistently, silibinin prevents H9C2 cells from hypoxia/reperfusion-induced cell death, oxidative stress and inflammation in vitro. Furthermore, H9C2 cells treated with silibinin blocks NF-κB signaling activation by inhibiting IKKα phosphorylation, IκBα degradation and p65 NF-κB nuclear translocation during hypoxia/ reperfusion. In addition, silibinin plus BAY 11-7082 (a selected NF-κB inhibitor) do not provide incremental benefits in improving myocytes apoptosis, oxidative stress and inflammation in comparison with NF-κB signaling inhibition only. Thus, silibinin-mediated cardioprotection in myocardial I/R injury is associated with decreased apoptosis, oxidative stress and inflammatory response through deactivation of NF-κB pathway.

Macrophages facilitate post myocardial infarction arrhythmias: roles of gap junction and KCa3.1

Effective therapeutic targets against post-myocardial infarction (MI) arrhythmias remain to be discovered. We aimed to investigate the role of macrophages in post-MI arrhythmias.

Methods: Mononuclear cell accumulation, macrophage polarization from M0 to M1 subset, and gap junction formation were analyzed in MI patients and MI mice by flow cytometry, immunofluorescence and patch clamping. Differentially expressed genes were identified by RNA sequencing. Macrophages and cardiomyocytes were cocultured in vitro, and the effects of gap junction and KCa3.1 on electrophysiological properties were assessed by patch clamping. The effects of KCa3.1 inhibition on post-MI arrhythmias were assessed by intracardiac stimulation and ambulatory electrocardiograms in vivo.

Results: Percentage of pro-inflammatory mononuclear cells were significantly elevated in patients with post-MI arrhythmias compared with MI patients without arrhythmias and healthy controls (p<0.001). Macrophages formed gap junction with cardiomyocytes in MI border zones of MI patient and mice, and pro-inflammatory macrophages were significantly increased 3 days post-MI (p<0.001). RNA sequencing identified Kcnn4 as the most differentially expressed gene encoding ion channel, and the upregulation is mainly attributed to macrophage accumulation and polarization into pro-inflammatory subset. In vitro coculture experiments demonstrated that connection with M0 macrophages via gap junction slightly shortened the action potential durations (APDs) of cardiomyocytes. However, the APD90 of cardiomyocytes connected with M1 macrophages were significantly prolonged (p<0.001), which were effectively attenuated by gap junction inhibition (p=0.002), KCa3.1 inhibition (p=0.008), KCa3.1 silencing (p<0.001) and store-operated Ca²⁺ channel inhibition (p=0.005). In vivo results demonstrated that KCa3.1 inhibition significantly decreased the QTc durations (p=0.031), intracardiac stimulation-induced ventricular arrhythmia durations (p=0.050) and incidence of premature ventricular contractions (p=0.030) in MI mice.

Conclusion: Macrophage polarization leads to APD heterogeneity and post-MI arrhythmias via gap junction and KCa3.1 activation. The results provide evidences of a novel mechanism of post-MI heterogeneous repolarization and arrhythmias, rendering macrophages and KCa3.1 to be potential therapeutic targets.

The transient receptor potential melastatin 4 channel inhibitor 9-phenanthrol modulates cardiac sodium channel

BACKGROUND AND PURPOSE

9-Phenanthrol, known as a specific inhibitor of the transient receptor potential melastatin 4 (TRMP4) channel, has been shown to modulate cardiac electrical activity and exert antiarrhythmic effects. However, its pharmacological effects remain to be fully explored. Here, we tested the hypothesis that cardiac sodium current inhibition contributes to the cardioprotective effect of 9-phenanthrol.

EXPERIMENTAL APPROACH

Single ventricular myocytes (VMs) and Purkinje cells (PCs) were enzymatically isolated from rabbits. Arterially perfused rabbit wedge preparations were also used, and transmural electrocardiogram and endocardial action potentials (APs) were simultaneously recorded. Wild-type and mutated human recombinant SCN5A were expressed in HEK293 cells. Anemonia toxin II (ATX-II) was used to amplify the late sodium current (I_NaL ) and induce arrhythmias. Whole-cell patch clamp technique was used to record APs and ionic currents.

KEY RESULTS

9-Phenanthrol (10-50 μM) stabilized ventricular repolarization and abolished arrhythmias induced by ATX-II in both isolated VMs, PCs and wedge preparations. Further study revealed that 9-phenanthrol modulated the gating properties of cardiac sodium channels and dose-dependently inhibited I_NaL and peak sodium current (I_NaP ) in VMs with an IC₅₀ of 18 and 71.5 μM respectively. Its ability to inhibit I_NaL was further confirmed in PCs and HEK293 cells expressing SCN5A mutations.

CONCLUSIONS AND IMPLICATIONS

Our results indicate that 9-phenanthrol modulates the gating properties of cardiac sodium channels and inhibits I_NaL and I_NaP , which may contribute to its antiarrhythmic and cardioprotective effects.

[Current progress in single sperm cryopreservation]

Sperm cryopreservation has been widely used in assisted reproduction, but conventional techniques are not suitable for the cryopreservation of small numbers of sperm. The application of the single sperm cryopreservation technique has significantly improved the clinical treatment of cryptozoospermia and non-obstructive azoospermia. Ever since Cohen et al first developed the method of single sperm cryopreservation in 1997, constant efforts have been made to develop the carriers for this technique. In this review, we mainly discuss the existing methods and clinical outcomes of single sperm cryopreservation.

Crucial Role of ROCK2-Mediated Phosphorylation and Upregulation of FHOD3 in the Pathogenesis of Angiotensin II-Induced Cardiac Hypertrophy

Cardiac hypertrophy is characterized by increased myofibrillogenesis. Angiotensin II (Ang-II) is an essential mediator of the pressure overload-induced cardiac hypertrophy in part through RhoA/ROCK (small GTPase/Rho-associated coiled-coil containing protein kinase) pathway. FHOD3 (formin homology 2 domain containing 3), a cardiac-restricted member of diaphanous-related formins, is crucial in regulating myofibrillogenesis in cardiomyocytes. FHOD3 maintains inactive through autoinhibition by an intramolecular interaction between its C- and N-terminal domains. Phosphorylation of the 3 highly conserved residues (1406S, 1412S, and 1416T) within the C terminus (CT) of FHOD3 by ROCK1 is sufficient for its activation. However, it is unclear whether ROCK-mediated FHOD3 activation plays a role in the pathogenesis of Ang-II-induced cardiac hypertrophy. In this study, we detected increases in FHOD3 expression and phosphorylation in cardiomyocytes from Ang-II-induced rat cardiac hypertrophy models. Valsartan attenuated such increases. In cultured neonate rat cardiomyocytes, overexpression of phosphor-mimetic mutant FHOD3-DDD, but not wild-type FHOD3, resulted in myofibrillogenesis and cardiomyocyte hypertrophy. Expression of a phosphor-resistant mutant FHOD3-AAA completely abolished myofibrillogenesis and attenuated Ang-II-induced cardiomyocyte hypertrophy. Pretreatment of neonate rat cardiomyocytes with ROCK inhibitor Y27632 reduced Ang-II-induced FHOD3 activation and upregulation, suggesting the involvement of ROCK activities. Silencing of ROCK2, but not ROCK1, in neonate rat cardiomyocytes, significantly lessened Ang-II-induced cardiomyocyte hypertrophy. ROCK2 can directly phosphorylate FHOD3 at both 1412S and 1416T in vitro and is more potent than ROCK1. Both kinases failed to phosphorylate 1406S. Coexpression of FHOD3 with constitutively active ROCK2 induced more stress fiber formation than that with constitutively active ROCK1. Collectively, our results demonstrated the importance of ROCK2 regulated FHOD3 expression and activation in Ang-II-induced myofibrillogenesis, thus provided a novel mechanism for the pathogenesis of Ang-II-induced cardiac hypertrophy.

Role of adenosine-guided pulmonary vein isolation in patients undergoing catheter ablation for atrial fibrillation: a meta-analysis

AIMS

Adenosine had been reported to unmask dormant conduction and thus identify pulmonary vein at risk of reconnection. However, the role of adjunctive adenosine infusion after pulmonary vein isolation (PVI) on long-term arrhythmia-free survival was still contentious. The purpose of the present meta-analysis was to assess the association of adenosine testing with long-term ablation success in patients with atrial fibrillation (AF) (i.e. freedom from AF recurrence).

METHODS AND RESULTS

We systematically searched the electronic databases and finally included 10 studies, with 1771 patients undergoing adenosine-guided PVI and 1787 patients undergoing conventional PVI. In comparison to conventional PVI alone, adenosine-guided PVI improved the arrhythmia-free survival by 17% during a median follow-up of 12 months [relative risk (RR): 1.17; 95% confidence interval (CI): 1.07 to 1.27; P = 0.014]. Patients undergoing adenosine-guided PVI had similar fluoroscopy time to those who undergoing conventional PVI [weighted mean difference (WMD): 1.76; 95% CI: -5.66 to 9.17; P = 0.64], despite longer procedure time (WMD: 20.6; 95% CI: 0.70 to 40.50; P = 0.042).

CONCLUSION

From the available data of clinical studies, adenosine-guided PVI was associated with an increased arrhythmia-free survival when compared with conventional PVI in patients undergoing catheter ablation for AF.

Larger rate dependence of late sodium current in cardiac Purkinje cells: A potential link to arrhythmogenesis

BACKGROUND

Purkinje cells (PCs) have a steeper rate dependence of repolarization and are more susceptible to arrhythmic activity than do ventricular myocytes (VMs). Late sodium current (I_NaL) is rate dependent and contributes to rate dependence of repolarization.

OBJECTIVE

This study sought to test our hypothesis that PCs have a larger rate dependence of I_NaL, contributing to their steeper rate dependence of repolarization and higher susceptibility to arrhythmic activity, than do VMs.

METHODS

I_NaL was recorded in isolated rabbit PCs and VMs with the whole-cell patch clamp technique. Action potential was examined using the microelectrode technique.

RESULTS

Compared with VMs, PCs exhibited a significantly larger rate dependence of I_NaL with a larger I_NaL to basic cycle length (BCL) slope. Moreover, PCs had a larger rate dependence of I_NaL decay and slower recovery kinetics. Interestingly, the larger rate dependence of I_NaL matched to a steeper rate dependence of action potential duration (APD) in PCs. The I_NaL blocker tetrodotoxin significantly blunted, while the I_NaL enhancer anemone toxin (ATX-II) significantly increased, the rate dependence of I_NaL and APD in PCs and VMs. In the presence of ATX-II, the rate dependence of I_NaL in PCs was markedly larger than that in VMs, causing a much steeper rate dependence of APD in PCs. Accordingly, PCs exhibited greater rate-dependent electrical instability and were more prone to ATX-II-induced early afterdepolarizations, which were completely inhibited by the I_NaL inhibitor ranolazine.

CONCLUSION

PCs have a significantly larger rate dependence of I_NaL than do VMs because of distinctive I_NaL decay and recovery kinetics, which contributes to their larger rate adaptation, and simultaneously predisposes them to a higher risk of arrhythmogenesis.

Semaphorin 3a transfection into the left stellate ganglion reduces susceptibility to ventricular arrhythmias after myocardial infarction in rats

AIMS

Myocardial infarction (MI) induces neural remodelling of the left stellate ganglion (LSG), which may contribute to ischaemia-induced arrhythmias. The neural chemorepellent Semaphorin 3a (Sema3a) has been identified as a negative regulator of sympathetic innervation in the LSG and heart. We previously reported that overexpression of Sema3a in the border zone could reduce the arrhythmogenic effects of cardiac sympathetic hyperinnervation post-MI. This study investigated whether Sema3a overexpression within the LSG confers an antiarrhythmic effect after MI through decreasing extra- and intra-cardiac neural remodelling.

METHODS AND RESULTS

Sprague-Dawley rats were subjected to MI, and randomly allocated to intra-LSG microinjection of either phosphate-buffered saline (PBS), adenovirus encoding green fluorescent protein (AdGFP), or adenovirus encoding Sema3a (AdSema3a). Sham-operated rats served as controls. Two weeks after infarction, MI-induced nerve sprouting and sympathetic hyperinnervation in the LSG and myocardium were significantly attenuated by intra-LSG injection with AdSema3a, as assessed by immunohistochemistry and western blot analysis of growth-associated protein 43 and tyrosine hydroxylase. This was also confirmed by sympathetic nerve function changes assessed by cardiac norepinephrine content. Additionally, intra-LSG injection with AdSema3a alleviated MI-induced accumulation of dephosphorylated connexin 43 in the infarct border zone. Furthermore, Sema3a overexpression in the LSG reduced the incidence of inducible ventricular tachyarrhythmia by programmed electrical stimulation post-MI, and arrhythmia scores were significantly lower in the AdSema3a group than in the PBS and AdGFP groups.

CONCLUSION

Semaphorin 3a overexpression in the LSG ameliorates the inducibility of ventricular arrhythmias after MI, mainly through attenuation of neural remodelling within the cardiac-neuraxis.

Effect of berberine on acetylcholine-induced atrial fibrillation in rabbit

The purpose of this study was to test the efficacy of Berberine (Ber) on atrial fibrillation (AF) induced by acetylcholine (ACh) and explore its underlying mechanisms of action. In vivo electrophysiology experiments were performed in adult anesthetized rabbits. Single atrial myocytes were isolated from rabbit hearts and action potentials recorded using patch clamp techniques. AF was induced by rapid atrial burst pacing during intravenous (IV) ACh infusion alone or with IV Ber. Compared to the Baseline, IV Ber (2 mg/kg) prolonged the RR interval and effective refractory period (195 ± 10 vs. 215 ± 11 msec; 80 ± 4 vs. 85 ± 5 msec, respectively; both P<0.05). The induced rate of sustained 1 min AF was lower during ACh infusion with Ber than during ACh infusion alone (4/10 vs. 30/35, P<0.01). The termination rate of ACh-induced AF was higher with IV Ber (1 mg/kg) than with IV saline (sustained 1 min AF: 6/8 vs. 6/20, sustained 10 min AF: 8/10 vs. 1/6, both P<0.05). ACh perfusion significantly shortened the action potential duration (APD) of isolated atrial myocytes (APD50: 152 ± 13 vs. 81 ± 10 msec; APD90: 256 ± 19 vs. 132 ± 13 msec, both P<0.01). Application of Ber reversed the APD shortening induced by ACh (APD50: 81 ± 10 vs. 134 ± 15 msec; APD90: 132 ± 13 vs: 213 ± 17 msec, both P<0.01). We conclude that Ber suppresses ACh-induced AF in the rabbit by increasing atrial effective refractory period and prolonging the APD of atrial myocytes.

Hallermann-Streiff syndrome associated with small cerebellum, endocrinopathy and increased chromosomal breakage

Hallermann-Streiff syndrome (HSS) is a rare clinic entity of unknown aetiology. Further clinical and metabolic-genetic evaluations are indicated. A 2-mo-old female baby presented with ocular abnormalities and severe failure to thrive since birth. The clinical features were compatible with the diagnosis of HSS. Further imaging, metabolic and cytogenetic examinations were performed. Features characteristic of HSS were dyscephaly with mandibular and nasal cartilage hypoplasia, microphthalmia, bilateral cataracts with congenital glaucoma, natal teeth and proportionate dwarfism. Rare anomalies such as choanal atresia and small cerebellum, very low insulin-like growth factor I level, hypothyroidism, generalized organic aciduria were also noticed. An increased chromosomal breakage rate is suggestive of the existence of some DNA repair defects in HSS patients.

CONCLUSION

The associated anomalies in this patient may broaden the clinical spectrum of HSS. Underlying conditions of organic aciduria, growth factor deficiency and impaired DNA repair are likely to contribute to the progeria-like facies, congenital cataracts and growth failure.

Can physicians' admission evaluation of patients' status help to identify patients requiring social work interventions?

OBJECTIVE

To evaluate the utility of these physicians' initial clinical assessments in identifying patients admitted from their homes who subsequently require social work intervention for discharge planning.

DESIGN

Retrospective chart review of discharge disposition correlated with a prospective physician evaluation of patients.

SETTING

An academic medical center.

PARTICIPANTS

Consecutive patients, (2,571) men and women, admitted at the New York Hospital between July 1, 1997 and October 31, 1997.

MEASUREMENT

Prospective evaluation of clinical status, functional status, illness severity and stability by physicians within 24 hours of admission.

RESULTS

Older patients, sicker and less functional, have higher needs for social work intervention (P < 0.001). New nursing home placement patients were older and had worse function (P < 0.001). Total cost of hospitalization and length of stay were predicted by discharge disposition.

CONCLUSION

Early discharge intervention has often been targeted as a potential mechanism to lower hospitalization cost and reduce length of stay. Age and physician evaluation of functional status at admission may provide early identification of those who require social work assistance.

Autoimmune thyroiditis in children with Turner syndrome

PURPOSE

To determine the frequency of autoimmune thyroiditis (AIT) and the risk of development of thyroid dysfunction in children with Turner syndrome.

METHODS

From 1988 to 1998, 77 children with Turner syndrome were prospectively followed up at National Taiwan University Hospital. The mean (+/- standard deviation) age of these patients was 10.0 +/- 4.7 years at diagnosis of Turner syndrome and 17.4 +/- 5.2 years at the end of the present study. Antithyroglobulin antibody, antimicrosomal antibody, and thyroid function were assessed once every 6 months during the study period.

RESULTS

Thyroid autoantibodies were detected in 21 of the 77 (27%) patients. The mean age at the detection of thyroid autoantibodies was 12.2 +/- 5.2 years. The cumulative frequency of AIT at 10 years after diagnosis of Turner syndrome was 36%. Both patients with a ring X chromosome developed AIT. Three of the 21 patients (14%) with AIT developed thyroid dysfunction. One patient developed hypothyroidism at the time of the detection of thyroid autoantibody. Two other patients were noted to have hyperthyroidism 0.5 and 2.5 years, after the detection of thyroid autoantibodies, respectively.

CONCLUSIONS

Our data demonstrated a high frequency of AIT in Taiwanese children with Turner syndrome. Some of these patients later developed thyroid dysfunction. Hence, this study has confirmed that regular follow-up assessment of thyroid autoantibody and thyroid function in Taiwanese children with Turner syndrome regardless of their age is necessary for timely diagnosis of thyroid dysfunction and administration of appropriate treatment.

Renal malformations in children with Turner's syndrome

Between 1988 and 1999, renal sonography and intravenous urography were performed to detect renal malformations in 54 patients with Turner's syndrome (TS). The mean age of these patients at diagnosis of TS was 9.2 +/- 4.6 years. Renal malformations were detected in 21 patients by intravenous urography and there was no significant difference in the frequency of renal malformations among different karyotype groups. Horseshoe kidney was the most common renal malformation, followed by duplex kidney. Fifteen of 21 renal malformations were not detected by renal sonography. We conclude that these TS patients had a high frequency of renal malformations, and that the detection rate of horseshoe kidney and duplex kidney by renal sonography was not satisfactory. Although renal sonography alone can be used to detect more severe renal malformations that may need further management, it may underestimate the frequency of renal malformation in children with TS.

Alstrom syndrome with hepatic dysfunction: report of one case

Alstrom syndrome is a rare autosomal recessive disorder associated with early childhood retinopathy, progressive sensorineural hearing loss, truncal obesity, and acanthosis nigricans. We report a 10-year-old boy with Alstrom syndrome presenting with general malaise and abnormal liver function for 1 year. In addition to the above mentioned features, he also had hyperglycemia and hyperinsulinemia. The mechanism responsible for the persistent elevation of liver enzymes could not be identified. To the best of our knowledge, this is the first-reported case of Alstrom syndrome with hepatic dysfunction in Taiwan.

Growth of bifidobacteria in soymilk and their survival in the fermented soymilk drink during storage

Growth of Bifidobacterium infantis CCRC 14633 and B. longum B6, in soymilk was investigated in the present study. It was found that soymilk could support the growth of both organisms tested. B. infantis grew better than B. longum in soymilk. Supplementation of bifitose (isomaltooligosccharie), glucose, lactose or galactose to soymilk increased the growth of B. infantis and B. longum as determined after 48 h of fermentation. On the other hand, addition of yeast extract, peptone, tryptone, casitone or N-Z-Case plus to soymilk enabled B. infantis to reach its maximum population in a shorter cultivation time of 24 h. Acid production by B. longum and B. infantis in soymilk was mainly non-growth associated, while in the yeast extract-supplemented soymilk, acid produced by B. infantis was found to be growth-associated. Populations of B. longum reduced more than did B. infantis in the prepared fermented soymilk drink during storage period. Viable population of both test organisms reduced less in the fermented drink held at 5 degrees C than at 25 degrees C. After a 10-day storage at 5 degrees C, viable B. infantis and B. longum reduced by 0.44 and 3.18 log CFU/ml, respectively, in the fermented drink. Addition of sucrose to the fermented drink resulted in an increased reduction of viable bifidobacteria during the storage period. This phenomenon was most prominent with B. infantis in the fermented drink held at 25 degrees C.

Metabolic disorders mimicking Reye's syndrome

BACKGROUND

Several metabolic disorders such as encephalopathy and hepatic dysfunction have been described as Reye's-like syndrome because they present with similar clinical manifestations that mimic Reye's syndrome. We performed a retrospective study to explore the underlying metabolic etiologies of Reye's-like syndrome in patients treated at National Taiwan University Hospital.

METHODS

From January 1991 to June 1998, 19 children with a syndrome fitting the Reye's-like syndrome description were identified for study. Urine organic acid analysis, plasma amino acid analysis, liver pathology, and skin fibroblast enzyme assays were studied during the acute stage of illness.

RESULTS

The etiologies of patients' syndromes included urea cycle disorders (n = 7), glycogen storage disease type Ia (4), primary carnitine deficiency (2), hereditary fructose intolerance (1), methylmalonic acidemia (2), and 3-hydroxy-3-methylglutaric acidemia (1). Fatty acid oxidation defects were suspected in the remaining two cases.

CONCLUSIONS

A significant number of patients who present with Reye's-like syndrome have an underlying inherited metabolic disorder. In patients with Reye's-like syndrome, an accurate diagnosis is essential to ensure normal growth and development and to prevent recurrence of the condition.

Congenital contractural arachnodactyly (Beals syndrome)

Congenital contractural arachnodactyly (CCA, Beals syndrome) is an autosomal dominant disorder that is phenotypically similar to Marfan syndrome. CCA is characterized by arachnodactyly, dolichostenomelia, scoliosis, multiple congenital contractures and abnormalities of the external ears. We report here 28 patients with CCA, in whom a wide range of phenotypic expression is observed. These individuals usually have abnormally formed ears, limited extension of fingers and toes, arachnodactyly, clinodactyly, delay of developmental milestones and psychomotor retardation. Limited extensions of elbows, knees and hips are not constant features. With time, those affected individuals experience spontaneous improvement of their contractures but the kyphosis, unlike the joint contractures, tends to be progressive. No ocular problems were found in all patients, but congenital heart defects were detected in 32.2% of them. Atrial septal defect and ventricular septal defect are common components in our patients. Within the only one family with two multiply affected siblings there is little phenotypic variation between the patients.

Protective effects of sodium tanshinone IIA sulphonate against adriamycin-induced lipid peroxidation in mice hearts in vivo and in vitro

Protective effects of sodium tanshinone IIA sulphonate against adriamycin-induced lipid peroxidation were investigated. Data showed that treatment with sodium tanshinone IIA sulphonate could prevent mice from decrease in body weight caused by adriamycin. It was found that myocardial lipid peroxidation in sodium tanshinone IIA sulphonate-treated mice was lower compared with that in adriamycin-treated ones. The activities of some endogenous antioxidant enzymes, such as superoxide dismutase, glutathione peroxidase and catalase, were higher in the sodium tanshinone IIA sulphonate group than that in the adriamycin group. In vitro experiments showed that sodium tanshinone IIA sulphonate could inhibit adriamycin-induced mitochondrial lipid peroxidation and swelling. Sodium tanshinone IIA sulphonate could scavenge adriamycin semiquinone free radical in heart homogenate dose-dependently. Thus, protective effects of sodium tanshinone IIA sulphonate may not only be related to its antioxidant activity but also to its regulation of antioxidant enzyme activities in the heart.

Oral-facial-digital syndrome with Y-shaped fourth metacarpals and endocardial cushion defect

We report on a boy with pseudo-cleft of the upper lip, cleft palate, bifid uvula, lobulated tongue, hypoplasia of the epiglottis, both preaxial and central polydactyly of the hands (Y-shaped fourth metacarpals), bilateral preaxial polydactyly of the feet, postaxial polydactyly of the left foot, hearing impairment, and congenital heart disease with endocardial cushion defect. These clinical manifestations resembled oral-facial-digital syndrome type II (OFDS II, Mohr syndrome) or type VI (Váradi syndrome), associated with an atrioventricular canal. Clinical variability of OFDS II has been observed repeatedly. To the best of our knowledge, this is the first reported case of OFDS II with Y-shaped fourth metacarpals. In addition to Y-shaped fourth metacarpals, Mohr syndrome plus atrioventricular canal and hypoplasia of the epiglottis may represent an additional subgroup of OFDS.

Study of human Y chromosome polymorphism in Taiwan

The Y chromosome is one of the human chromosomes carrying significant amount of constitutive heterochromatin. To investigate the prevalence of Y chromosome polymorphism and its clinical significance in Taiwan, we analyzed the Y chromosome among 6,286 unrelated males by G-banding and, if necessary, fluorescence in situ hybridization studies. The prevalence of the Y chromosome variants were: large Y (Yq+) 3.6%, pericentric inverted Y [inv(Y)] 0.27%, and small Y (Yq-) 0.59%, respectively. More than 99% of those variants were from their biological fathers. The incidence of the Y polymorphisms was similar in three groups: children with mental retardation, other chromosomal aberrations or multiple congenital anomalies, and normal controls. The Yq12 heterochromatin region may contribute to the variation in Y chromosome length. The prevalence of inv(Y) and Yq+ was higher than those in the white population. Our results conclude that there are no indications that Yq+, inv(Y) and Yq- are connected with any deviations in intelligence or with an increased risk of physical malformations or other chromosomal disorders, which is of great help for genetic counseling.

Detection of KAL-1 gene deletion with fluorescence in situ hybridization

We investigated the molecular cytogenetic status of two unrelated boys and their family members because they had features consistent with Kallmann syndrome but normal karyotypes. The first patient was a 6-year-old boy who suffered from ichthyosis, bilateral cryptorchidism, hyposmia, and neurologic disorders including mirror movements of the hands and nystagmus. Mild to moderate mental retardation was also noted in this boy, his mother, and maternal grandmother. Fluorescence in situ hybridization (FISH) study using probes for Kallmann (KAL), steroid sulfatase, and ocular albinism type 1 all showed nullisomy on Xp22.3 in this patient, and hemizygosity in his older sister, mother, and maternal grandmother. The second patient was a 1-year-old boy who had micropenis, cryptorchidism, and hypoplastic scrotum since birth. Family study disclosed a 28-year-old maternal uncle with cryptorchidism, lack of secondary sexual characteristics, and anosmia. FISH showed only the KAL gene deletion. Polymerase chain reaction analysis also showed an absence of the KAL-1 sequence. FISH is a useful tool for the detection of KAL-1 deletion in people with normal karyotypes but features consistent with Kallmann syndrome.

Corneal opacity and congenital glaucoma associated with massive heparan sulfaturia: report of one case

A four month-old male infant was noted to have had severe corneal opacity since birth. Buphthalmos, increased intraocular pressure and corneal opacity with neovascularization were noted during physical examination. There was neither dysmorphic face nor hirsutism and the liver and spleen were impalpable. In addition, hypotonia, poor head control, and absence of Moro and grasping reflexes were also noted. There was no evidence of congenital infection by TORCH study. Tests of both urine and plasma amino acids were within normal limits. However, excessive urinary excretion of heparan sulfate was detected by thin-layer chromatography. Corneal transplantation was performed at 6 months old. Histopathological examination of the corneal button showed homogeneous thickening of Bowmen's membrane and intracytoplasmic pinkish substances in corneal stroma. The Alcian blue stain was positive, which was consistent with mucopolysaccharidosis of cornea. The manifestation of this case may be a clinical variant of Sanfilippo's syndrome (Mucopolysaccharidosis type III).

FISH analysis in both classical and atypical cases of Williams-Beuren syndrome

Williams-Beuren syndrome (WBS) is a rare neurodevelopmental disorder, characterized by distinct facial changes, growth deficiency, mental retardation, supravalvular aortic stenosis (SVAS)/peripheral pulmonary stenosis, and associated at times with infantile hypercalcemia. A pilot study has been carried out to assess the reliability of the detection of hemizygosity at the elastin locus by fluorescence in situ hybridization (FISH) analysis as a diagnostic test in both classical and atypical WBS. Eight subjects with classical WBS and four others in whom a diagnosis could not be confirmed on clinical criteria alone were enrolled. In the classical WBS group, five (5/8) had a visible interstitial 7q11.22-11.23 deletion detected by high-resolution banding, and all (8/8) had a submicroscopic deletion of the elastin locus on chromosome 7 by FISH analysis. In the atypical WBS group, only one (1/4) had elastin deletion. The other three, with isolated SVAS, had normal development and minimal signs of WBS. Furthermore, the patients with microscopic 7q11.22-11.23 deletion have more associated features of WBS than those without visible interstitial deletions by high-resolution banding. These results, therefore, emphasize the importance of a combined high-resolution and molecular cytogenetic (i.e., FISH) approach to diagnosis and suggest that the degree to which microscopic/submicroscopic deletions of chromosome 7 extending in beyond the elastin locus may explain some of the phenotypical variability found in WBS.

An epidemiological and aetiological study of children with intellectual disability in Taiwan

A large-scale cytogenetic study of the causes of intellectual disability (ID) in children from special schools and institutions was made in Taiwan between 1991 and 1996. The screening methods and the identification of subjects with ID consisted of both clinical evaluation (i.e. photographs, questionnaires on family, pre-, peri- and postnatal history, and hospital records, including IQ) and further laboratory studies for diagnosis (i.e. standard chromosome analysis, and if indicated, high-resolution banding, cytogenetic fragile-X study or molecular techniques). A total of 11,892 patients were enrolled in this study. After excluding the acquired causes of ID, such as infections and the sequelae of brain insults, or the well-known single-gene disorders and other multifactorial diseases, 4372 (36.8%) cumulative cases were recruited for karyotyping studies according to their phenotypes and medical records. Abnormal karyotypes were noted in 1889 children (43.2% of all selected children). Thus, the overall incidence of chromosomal aberrations in subjects with ID was estimated as 15.9%. Down's syndrome, the most common cause of ID, accounted for 82.4% of all patients with abnormal karyotypes. The causes of ID were considered to be prenatal in 55.2% (n = 6564) of cases, perinatal in 9.5% (n = 1130), postnatal in 3.3% (n = 392) and unknown in 32.0% (n = 3805) of cases. Two large groups were classified: (1) serious ID (37%), including profound, severe and moderate categories; and (2) mild ID (63%). The causes (pre-, peri- and postnatal, and unknown) in these two populations were: 70%, 10.5%, 5.4% and 14.1%, and 46.5%, 8.9%, 2.1% and 42.5%, respectively. Genetic causes accounted for 38.5% (n = 4578) of all cases in this study, including 1557 with Down's syndrome, 233 with fragile-X syndrome, 199 with other various chromosomal abnormalities (i.e. unbalanced translocation, supernumerary markers and structural rearrangements), 238 with a defined or presumed single-gene defect, and 98 with a recognized contiguous gene syndrome (Prader-Willi, 56; Angelman, 34; Williams, 5; and Kallmann, 3); 2120 cases had familial ID. Multiple anomalies of undefined pattern, but without chromosomal aberration, infantile autism, ID of normal phenotype or family history, were of the other categories. Patients with a single-gene disorder or chromosomal aberration, especially those with unbalanced translocated or rearranged chromosomes, had genetic counselling and family studies. Pre-screening with photographs and questionnaires may give a better costbenefit than blind mass cytogenetic studies for each individual with ID.

Jacobsen distal 11q deletion syndrome with a myelodysplastic change of hemopoietic cells

We describe a male infant with unusual facial appearance, relative pancytopenia, bilateral simian creases, and an accessory nipple. Cytogenetic analysis showed deletion of the long arm of chromosome 11 [46,XY,del(11)(pter-->q23.2:)]. Bone-marrow study showed a myelodysplastic change of hemopoietic cells compatible with peripheral blood findings. Pachygyria of the temporal and frontal lobes was demonstrated by magnetic resonance image (MRI) of the brain. We present our findings in order to contribute to the information on 11q23 deletion.

Unusual features in children with inv dup(15) supernumerary marker: a study of genotype-phenotype correlation in Taiwan

Recent molecular cytogenetic studies have elucidated the origin and nature of extra structurally abnormal chromosomes (ESACs) or small supernumerary chromosomes, which are often associated with developmental delay and malformations. We studied the prevalence of inv dup(15) in a nationwide screening programme for mentally retarded children in Taiwan and tried to correlate the genotype and phenotype in those patients. Fluorescence in situ hybridization (FISH) analysis using D15Z, D15Z1, and the cosmids from the Prader-Willi/Angelman syndrome chromosome region (PW/ASCR) was performed on 54 patients (0.45%) with ESACs from 11893 probands within a 5-year period. Of them, inv dup(15) was confirmed in 25 children (46.3%) by FISH analysis. The PW/ASCR probes were used to clarify the size and DNA composition of the markers. Patients with inv dup(15) chromosomes, containing only the heterochromatin or little euchromatin of the proximal 15q (i.e., pter-->q11:q11-->pter) may have a rather mild or nearly normal phenotype (group 1). Only one patient had some features suggestive of Angelman syndrome, but was considered to be a result of deleted (15)(q12) in the chromosome 15 homologue. Additional copies within D15S11 through GABRB3 (15q11.2-13) resulted in an abnormal phenotype which involved mental and developmental delay but was different from the classical phenotype of PW/AS (groups 2, 3). Signs of autistic behavior did occur in each group. FISH combined with microsatellite analyses showed that the marker was often of maternal origin in de novo cases (n = 12, 86%), or inherited from the mother in only one familial case. Down-inv dup(15) was mentioned in two cases. Unusual features including diaphragmatic eventration, hyperlaxity of joints, arachnodactyly, brain atrophy, epilepsy (particularly infantile spasm), ataxia, genital abnormalities, and cleft lip/palate were noted in those patients. This observation expands the range of phenotypic expression associated with this relatively common ESAC.

CONCLUSION

Marked phenotypic diversities exist in children with inv dup(15), dependent upon the size or genetic composition of the markers, degree of mosaicism, parental origin and familial occurrence or not. Patients with a larger inv dup(15) marker chromosome including the PW/ASCR may have a higher risk of abnormalities, but not the typical Prade-Willi/Angelman syndrome phenotype.

Partial DiGeorge anomaly associated with 10p deletion

We report a girl with partial DiGeorge anomaly associated with a distal chromosome 10p deletion. The initial manifestation was hypocalcemia convulsion at the age of 14 days. The patient was small for her gestational age and showed symptoms of poor feeding and inspiratory stridor. Facial dysmorphisms included a cupped ear, hypertelorism downslanted and short palpebral fissures frontal bossing, anteverted nostrils, a flat nasal bridge, and micrognathia. Developmental delay was also noted. Hypoplasia of the thymus was detected by ultrasound examination, but results of immunologic studies were all normal at 6 weeks of age. The echocardiogram, brain ultrasound, electroencephalogram, and magnetic resonance images of the brain were normal, but brainstem auditory evoked potentials showed bilateral sensorineural hearing loss. Chromosomal analysis showed 16, XX, del(10)(p12.3); the parents had normal karyotypes. After treatment with vitamin D, calcium gluconate, and magnesium sulfate, the patient's serum calcium and magnesium levels were within normal limits. She was discharged and received regular follow-up at our clinic for physical therapy and to ensure adequate supply of divalent cations. Complex partial seizure was noted at the age of 1 year and was controlled with carbamazepine. To our knowledge, this is the first Taiwanese reported to have partial DiGeorge anomaly associated with 10p deletion. We recommend that standard karyotyping should be performed in children suspected to have this anomaly.

CATCH 22: deletion of locus 22q11 in velocardiofacial syndrome, DiGeorge anomaly, and nonsyndromic conotruncal defects

DiGeorge anomaly (DGA) and velocardiofacial syndrome (VCFS) are frequently associated with monosomy of chromosomal subband 22q11. It is not clear whether individuals who present with only some of the features (e.g., isolated hypoparathyroidism or conotruncal defects) of these conditions also have the same deletion. In a prospective study of 30 children from 1994 to 1996, we used both high-resolution banding and fluorescence in situ hybridization (FISH) to assess the deletion status of children with a wide range of DGA-like or VCFS-like clinical features. Microdeletion of the chromosomal subband 22q11.22 was detected in 17 children by high-resolution banding and in two additional children with conotruncal defect (CTD) who had submicroscopic deletions proved by FISH analyses. Of the patients with microscopical deletion (n = 17), only six had classical DGA (n = 4) or VCFS (n = 2) phenotypes. The other 11 had various forms of congenital heart defects as the only presenting signs of deletion. One patient with DGA stigmata had another chromosomal aberration of monosomy 10p13. Only 10 patients were found to have neither cytogenetic nor molecular abnormalities. Therefore, it appeared that the majority, if not all, of the DGA and VCFS patients with the 22q11 deletion were identifiable using FISH with the single N25 (D22S75) probe. It would also be advisable that children with isolated CTD should be carefully examined to detect the other morphologic abnormalities of DGA and VCFS, or CATCH 22 (cardiac defects, abnormal facies, thymic hypoplasia/aplasia, cleft palate, hypocalcemia, and 22q11 deletion). Once these abnormalities are found, a molecular cytogenetic analysis for the so-called 22q11 region is indicated. Because of other associated chromosomal findings, routine or high-resolution cytogenetic analysis should be performed on patients with suspected CATCH 22.

Tricho-rhino-phalangeal syndrome type II associated with epiglottic aplasia and congenital nephrotic syndrome

A male neonate with tricho-rhino-phalangeal syndrome type II (Langer-Giedion syndrome) and interstitial deletion of chromosome 8 with karyotype 46, XY, del (8) (q24.11-->q24.13) is reported. In addition to hypotrichosis of the scalp hair, abnormally bulbous nose and redundant skin, which are usually found in this syndrome, aplasia of the epiglottis and non-Finnish type congenital nephrotic syndrome were also present. He died of renal failure and respiratory failure at 11 days of age. Electron microscopy of renal necropsy showed foot process loss, focal thickening and splitting of the glomerular basement membrane and mesangial expansion. These have never been reported and could be new associations in this disease that may serve to support the concept of contiguous gene syndrome in patients with tricho-rhino-phalangeal syndrome.

Optimization of walking in children

Previous work demonstrated that adults naturally adopt a walking frequency to optimize physiological cost, symmetry, and stability. Furthermore, the optimal frequency is predictable using the force-driven harmonic oscillator (FDHO) model. However, no studies have established the developmental processes of optimization in children. Thus, the purposes of this study were to examine the predictability of the preferred stride frequency (PSF) and optimization features of 3- to 12-yr-old children using the FDHO model. Forty-five children and nine adults were measured for anthropometric data to calculate the predicted frequency. They later walked at three frequencies (PSF, PSF +25%, and PSF -25%) at a constant speed on a treadmill. The results indicated that the FDHO model was accurate in predicting the preferred frequency of children (prediction error < 0.07 s). We identified three stages of learning in the development of optimization: an early manifestation of sensitivity to resonant frequency, the subsequent development of ability to modulate walking frequency, and the final establishment of an adult optimization form at age seven. Our findings suggest that walking development may be determined by the dynamic cooperation of physiological, neural, and musculoskeletal systems with respect to the environmental context.