Assessment of left ventricular function long term after arterial switch operation for transposition of the great arteries by dobutamine stress echocardiography

OBJECTIVES

To use dobutamine stress echocardiography to determine left ventricular (LV) function and wall motion of children long term after arterial switch operation (ASO) for transposition of the great arteries.

DESIGN AND PATIENTS

31 patients (24 boys) with ASO performed at a mean (SD) of 15.5 (4.3) days of life were studied at an age of 9.4 (2.0) years. All had normal coronary angiographic findings. LV echocardiographic indexes, including fractional shortening, ejection fraction, rate corrected velocity of circumferential fibre shortening (VCFc), and wall stress, as well as LV wall motion abnormalities were determined at rest and under dobutamine stress. The results were compared with those of 20 healthy age matched control participants.

SETTING

Tertiary paediatric cardiac centre.

RESULTS

Fractional shortening, ejection fraction, and VCFc were significantly lower in patients than in controls at rest (all with p < 0.001). Stress-velocity index detected impaired LV contractility in 19 (61%) patients at rest. An older age at operation (p = 0.01), longer bypass (p = 0.01) and circulatory arrest times (p = 0.045), and an unusual coronary artery pattern (p = 0.059) were associated with impaired resting LV contractility. Dobutamine stress echocardiography unmasked wall motion abnormalities in 23 (74%) patients. Exercise myocardial perfusion scan, performed in 22 patients, showed reversible myocardial perfusion defects in 17. These defects corresponded to segments of hypokinesia as detected by dobutamine stress echocardiography.

CONCLUSION

A significant proportion of children, albeit asymptomatic, had impaired baseline LV contractility and reversible myocardial perfusion defects and mild wall motion abnormalities on stress after ASO.

Application of Overexcitation Model Induced by Penicillin Sodium in the Study of Inhibitory Effect of Sedative-Hypnotic Drugs

Excessive release of glutamate can cause many nervous system disorders. It has been reported that when a high dose of penicillin sodium is administered into the rat's brain, epilepsy, accompanied with glutamate elevation, will result. In this experiment, a low dose of penicillin sodium (1000 kIU/l) was microinjected into the rat's lateral ventricle to set up an overexcitation model, in which the concentration of ipsilateral hippocampal glutamate was monitored in vivo. by microdialysis-HPLC method as an indicator of the rat's excitatory state. Influences of sedative-hypnotic drugs on this model were verified by coadministration of diazepam or phenobarbital with Na-PCN intracerebroventricularly. In models, hippocampal glutamate concentration was elevated to 307% compared with its baseline level (p < 0.05), and this increase of glutamate was inhibited completely when different doses of diazepam or phenobarbital were administered (p < 0.05). The sedative effect of jujuboside A and trifluoperazine were then studied with this model. Jujuboside A (JuA) 0.1 g/l also reduced the glutamate level significantly (p < 0.05). Calmodulin antagonist trifluoperazine showed similar inhibitory effect as JuA, which may indicate that the effect of JuA is correlated with its anticalmodulin action. This model can be used to investigate the inhibitory effect of central nervous system drugs.

Local atomic structures of palladium nanowire

In this paper, investigation of the structure of palladium nanowire has been performed by using genetic algorithm simulation based on the molecular dynamics. Our calculation employs a well-fitted, tight-binding many-body potential for Pd atoms. Some local atomic structures and defects in nanowires have been reported. The melting behavior of palladium nanowire has also been investigated. An interesting result is that the diffusion of the central atoms results in the beginning of the melting. The moving central atoms build up a monostrand atomic chain during the melting process. The single atomic chain is very stable which can exist in a wide temperature region (800-950 K). The formation of the single atomic chain causes some new defects in the nanowire. And the new defects result in the decrease of the thermal stability of the nanowire. Interestingly, the liquid from the nanowire melting has a supercooled feature because the splitting of the second peak of pair correlation function is observed. The curves of the internal energy and the local cluster are used to monitor the phase transition. The melting of the nanowire is not only due to the single atomic diffusion, but also the diffusion of the local clusters.

The single nucleotide polymorphisms of the chicken myostatin gene are associated with skeletal muscle and adipose growth

Myostatin, a new member of the TGF-beta superfamily, is predominantly expressed in skeletal muscle cells and functions as a negative regulator of skeletal muscle growth in animals. Recently, we have reported three single nucleotide polymorphisms (SNPs) in the chicken myostatin gene. Herein, we investigate the association of those SNPs with the production traits in a F2 chicken line derived from Broilers crossing to Silky with the least square analysis. The results show that the BB and AA genotypes are strongly associated with abdominal fat weight (AFW), abdominal fat percentage (AFP), and birth weight (BW) (P < 0.05). Breast muscle percentage (BMP) of the AA type is higher than that of the AB type. The breast muscle weight and breast muscle percentages of F2 individuals have significant difference between CC and DD genotypes (P< 0.05). Breast muscle weight (BMW) of EF birds is higher than that of EE birds (P< 0.05). In this report, we present the first genetic evidence to show that chicken myostatin not only plays an important role in controlling skeletal muscle growth and differentiation, but also may be involved in regulation of adipose growth in chicken.

Efficient synthesis and photodynamic activity of porphyrin-saccharide conjugates: targeting and incapacitating cancer cells

Since the role of saccharides in cell recognition, metabolism, and cell labeling is well-established, the conjugation of saccharides to drugs is an active area of research. Thus, one goal in the use of saccharide-drug conjugates is to impart a greater specificity toward a given cell type or other targets. Although widely used to treat some cancers and age related macular degeneration, the drugs used in photodynamic therapy (PDT) display poor chemical selectivity toward the intended targets, and uptake by cells most likely arises from passive, diffusional processes. Instead, the specific irradiation of the target tissues, and the formation of the toxic species in situ, are the primary factors that modulate the selectivity in the present mode of PDT. We report herein a two-step method to make nonhydrolyzable saccharide-porphyrin conjugates in high yields using a tetra(pentafluorophenyl)porphyrin and the thio derivative of the sugar. As a demonstration of their properties, the selective uptake (and/or binding) of these compounds to several cancer cell types was examined, followed by an investigation of their photodynamic properties. As expected, different malignant cell types take up one type of saccharide-porphyrin conjugate preferentially over others; for example, human breast cancer cells (MDA-MB-231) absorb a tetraglucose-porphyrin conjugate over the corresponding galactose derivative. Doseametric studies reveal that these saccharide-porphyrin conjugates exhibit varying PDT responses depending on drug concentration and irradiation energy. (1) Using 20 microM conjugate and greater irradiation energy induces cell death by necrosis. (2) When 10-20 microM conjugate and less irradiation energy are used, both necrosis and apoptosis are observed. (3) Using 10 microM and the least irradiation energy, a significant reduction in cell migration is observed, which indicates a reduction in aggressiveness of the cancer cells.

Phospholipase D elevates the level of MDM2 and suppresses DNA damage-induced increases in p53

Phospholipase D (PLD) has been reported to generate survival signals that prevent apoptosis induced by serum withdrawal. We have now found that elevated expression of PLD also suppresses DNA damage-induced apoptosis. Since DNA damage-induced apoptosis is often mediated by p53, we examined the effect of elevated PLD expression on the regulation of p53 stabilization. We report here that PLD suppresses DNA damage-induced increases in p53 stabilization in cells where PLD has been shown to provide a survival signal. Elevated expression of PLD also led to increased expression of the p53 E3 ubiquitin ligase MDM2 and increased turnover of p53. PLD1-stimulated increases in MDM2 expression and suppression of p53 activation were blocked by inhibition of mTOR and the mitogen-activated protein kinase pathway. Although PLD did not activate the phosphatidylinositol 3-kinase (PI3K)/Akt survival pathway activate the basal levels of PI3K activity were partially required for PLD1-induced increases in MDM2. These data provide evidence that survival signals generated by PLD involve suppression of the p53 response pathway.

Melting behavior of one-dimensional zirconium nanowire

In this paper, we analyze the melting behavior of zirconium nanowire using the results of a series of molecular dynamics simulations. Our calculation employs a well-fitted, tight-binding many-body potential for zirconium atoms. The melting point of the nanowire is predicted by the root-mean-square displacements for inner and outer shells. Our simulations predict two melting behaviors: one is the inner melting and the other is the outer melting. Our results reveal that the melting of nanowire starts from the inner shell atoms. The melting point of zirconium nanowire is lower than the bulk value (2125 K). Moreover, the melting point of the inner shell is lower than that of the outer shell. A coexistence of crystal and liquid units is observed in the melting process of nanowire. An investigation of local clusters is carried out to further analyze the melting mechanism of the nanowire. The presence of the local clusters 1331, 1321, 1211, etc. is an indication of disordered structures. The pair and angular correlation functions are also presented for the analysis of the melting behavior. It is not only the diffusion of single atom but the diffusion of clusters result in the occurrence of the melting.

Overweight and obesity in children from Shenzhen, Peoples Republic of China

We describe overweight and obesity prevalence in Shenzhen school children (2146 girls and 2428 boys) aged 7 to 12 years, Guangdong Province, China. Nineteen percent of boys and 11% of girls were overweight or obese. Boys had odds of almost 2 to 1 (1.92, 95% CI 1.62,2.27) of being overweight or obese compared to girls and children aged 9 years and over were at greater odds of being overweight or obese than those aged 7 years (p<0.05). Overweight and obesity prevalence among children from Shenzhen rivals that of children from developed nations. Current obesity levels in Shenzhen may represent future levels for urban China.

Inhibition of human p53 basal transcription by down-regulation of protein kinase Cdelta

In response to DNA damage, signal transduction pathways are activated that result in the increase of p53 protein levels, leading to either growth arrest or apoptosis. Protein kinase C (PKC) delta has been implicated as a tumor suppressor that is down-regulated by tumor-promoting phorbol esters in both mouse skin and cell culture models. We report here that the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate prevents DNA damage-induced up-regulation of p53 by down-regulating PKC delta. Regulation of p53 in response to stress most commonly occurs by preventing ubiquitination and degradation of the p53 protein. Surprisingly, suppression of p53 expression by inhibition of PKC delta was caused by the inhibition of p53 synthesis, not increased degradation of p53 protein. Inhibiting PKC delta blocked both basal transcription of the human p53 gene and initiation of transcription from the human p53 promoter. Therefore, the tumor-suppressing effects of PKC delta are mediated at least in part through activating p53 transcription.

Clinical characteristics of 42 SARS patients and their treatment of integrative Chinese and western medicine

Objective: To understand the clinical manifestation of severe acute respiratory syndrome (SARS) and explore its effective treatment with integrative Chinese and western medicine (ICWM).Methods: The data of patients, whose diagnosis of SARS had been confirmed were summarized and analyzed, and clinical observation was conducted when the patients were treated with ICWM.Results: In the early stage of the 42 patients, the symptoms revealed were fever in 100% of SARS patients, headache in 92. 9%, aversion to cold in 76. 2%, chest stuffiness in 76. 2%, cough in 73. 8% and myalgia in 88. 1%; pulmonary lesion involves ≥3 lobes in 42. 9%, 2 lobes in 47. 6% and 1 lobe in 9. 5%; 61. 9% of them showed liver function abnormality (increase of ALT or AST), 47. 6% showed elevated myocardial enzyme (CK or CK-MB), 0. 48% showed an inclination of renal function (higher of BUN or Cr); in their T lymphocyte subsets, 91. 2% (31/34 patients) had lowered CD₃ and 76. 5% (26/34 patients) lowered CD₄/CD₈ ratio. In the mid-late stage, the symptoms were lassitude and weakness in 85. 7%, scare in 81. 0%, short of breath or chest stuffiness in 71. 4%, loss of appetite in 64. 3%; light dark tongue proper in 52.4%, yellow and white tongue coating in 45. 2%, and yellow thick coating on the middle-root part of the tongue in 21. 4%. Most of them were asymptomatic when discharged from hospital, with 92. 8% of their pulmonary lesion, according to chest film, completely absorbed and liver function, myocardial enzyme and renal function all normalized. However, of the 30 patients who had CD₃ reexamination, 70% of the CD₃ showed lower than normal range and 36. 7% showed their CD₄/CD₈ inclined to lower margin, follow-up should be done for these patients. Of the 42 patients, who received western medicine (WM) alone in the early stage and ICWM in the mid-late stage, 10 were severe cases and 3 critical cases, but none of them died. The mean defervescent time was 3. 52±0. 85 days, the time for complete absorption of pulmonary lesion judged by chest X-ray film was 26. 82±5. 98 days, and the mean hospitalization time was 33. 60±4. 37 days.Conclusion: The manifestation of SARS is multifarious, showing that there were damage in multiple organs. The T lymphocyte count percentage and its subsets, CD₃ and CD₄ /CD₈ ratio, are valuable for early diagnosis and follow-up in the rehabilitation stage. Majority of the patients could be clinically cured. Combined treatment of WM and TCM according to syndrome differentiation and psychiatric intervention are beneficial to remit partial symptoms and promote rehabilitation.

Domiciliary Treatment of Tuberculous Patients in China

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[The clinical characteristics of adhesive type cholesteatoma]

OBJECTIVE

To study the clinical characteristics of adhesive type cholesteatoma.

METHODS

Fifty-two cases (52 ears) of adhesive type cholesteatomas were reviewed. Of the 52 cases there were 30 males and 22 females; 24 left ears and 28 right ears. The age of the patients ranged from 8 to 70 years. All of the patients were treated by tympanoplasty, and the open and close methods were performed in 37 ears and 10 ears, respectively. Other methods were employed in the remaining 5 cases. Nine ears underwent tympanoplasty type "O" without ossicular re-construction for an increase in the threshold of the bone conduction. Types I, III and IV tympanoplasties were performed in 1, 16 and 26 ears, respectively.

RESULTS

The structures of the upper parts of the stapes had disappeared in 25 ears, which was significantly higher in this series than that in the attic type cholesteatoma. The over-all recovery rate of hearing was 69.8%, while 75.9% and 55.6% in the open and closed tympanoplasties, respectively. Postoperative complications of perforations and re-adhesions of the tense part of the tympanic membrane were observed in 3 and 4 ears, respectively.

CONCLUSIONS

Adhesive type cholesteatoma is not uncommon. The cause of this disease may be the functional defects in the pharynotympanic tube. A thorough and effective treatment for the secretory otitis media is crucial for the prevention of adhesive type cholesteatomas. The open method tympanoplasty was considered as the first choice for adhesive type cholesteatoma while the closed method must be great careful.

Evaluation of physiological work demands and low back neuromuscular fatigue on nurses working in geriatric wards

This study evaluated the physiological demands and low back neuromuscular fatigue patterns following a daytime work shift of 21 female nurses working in geriatric wards. Subjects' heart rate (HR) at work was monitored for 8 h and surface electromyogram (EMG) of their back muscle was recorded during a 1-minute horizontal trunk holding test before and after work. Results showed that the nurses had heart rates exceeding 90 beats/min in 57% and 110 beats/min in 19% of their working hours. The EMG revealed a significant drop in initial median frequency (MF) (p = 0.04) and increase in negative slope of the MF/time plot (p<0.001) of the back muscle after work. These suggest that the muscles were fatigued after work. The nurses rated patient lifting, transfer and turning as most physically demanding, and these corresponded to the highest heart rates recorded. The physiological and neuromuscular strain on the nurses indicated that extreme care should be exercised at work, particularly towards the end of a work shift when the muscles have become fatigued.

Relationship between hyperventilation and intracranial pressure in patients with severe head injury

With high fatality rate and disability rate, the pathophysiologic changes of severe head injury are complicated. But the method of lowering intracranial pressure (ICP) through artificial hyperventilation is called in question recently. To understand the related changes of the partial pressure of carbon dioxide in artery (PaCO(2)) and the ICP at the acute period of severe head injury, a total of 64 patients with severe head injury were monitored and analyzed on the 3rd day after injury.

[Phacoemulsification of the subluxated lens with cataract]

OBJECTIVE

To study the efficiency of phacoemulsification in the treatment of subluxated lens with cataract.

METHOD

Phacoemulsification combined with intraocular lens implantation was performed on 19 eyes of 18 patients.

RESULT

The visual acuity in 18 eyes was improved to different degrees. The visual acuity in one eye was not improved due to the preoperative macular contusion.

CONCLUSION

Phacoemulsification for treatment of subluxated lens with cataract may decrease many complications occurring in the past procedure.

Epidemiological survey of Trichinella infection in some areas of Henan province

During 1996-1998 epidemiological survey of domestic Trichinella spiralis infection and serological survey on human beings were carried out in Yanling, Xuchang counties and Luohe city. By the artificial digestion method, the positive rates of pork in market and mutton were 1.6% and 0.6% respectively. Meat samples of pigs from pig-farms, cats and dogs were all negative for Trichinella larvae. Trichinellosis infection levels in rats captured in peasant households and places around abattoirs were 0.5% and 4.1% respectively (P < 0.05). By ELISA (double-antibody) with excretion-secretion (ES) antigens of Trichinella larvae, the positive rates of antibodies against Trichinella in sera of peasants and professional drivers were 2.2% and 7.8% (P < 0.05). The positive rates of antibodies in pigs from pig-farms and from peasant households were 1% and 7% respectively (P < 0.05). The levels of anti-Trichinella antibodies in rats captured in peasant households and places close to abattoirs were 0% and 11.1% respectively. Trichinella spiralis larvae were found in the washing meat slop in abattoirs.