香港回归话电信

１９９７年７月１日，中国政府半恢复对香港行使主权，香港的电信发展前景引人注目。本文回顾香港通信的发展简史，剖析了香港今天的电信管制和业务市场，并勾绘出香港通信的未来前景。     

芯片业2004年增长强劲存储器市场风光再现

iSuppli公司公布的全球半导体厂商市场份额排名结果显示，尽管半导体产业在2004年第4季度营收增长明显趋缓，但对于大多数芯片厂商来说，2004年仍是一个业绩卓著之年。     

给我一双“慧眼”不可小视的显卡做工细讲解（下）

前言自从上期我们刊登了显卡做工细讲解的上篇后,相信不少读者已经可以初步判断一款显卡做工的好坏,然而奸商毕竟是奸商,如果他们准备充分,仅仅凭借一点皮毛知识我们很难做出正确的判断。本期,我们将继续讲解显卡做工的方方面面,只要将两篇文章的精髓慢慢体会,相信我们所有人都可以让奸商显形。     

Drugs causing dyslipoproteinemia

Diuretics and beta-blockers have a strong tendency to affect serum lipids adversely, whereas the peripherally acting alpha-blocking agents consistently result in beneficial effects. Most of the other antihypertensive agents (calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists, and drugs that act centrally) are lipid neutral. The effect of steroid hormones varies with the drug, dose, and route of administration. In general, androgens lower HDL-C and have a variable effect on LDL-C. The effects of progestins vary greatly depending on their androgenicity, and estrogens are beneficial except when hypertriglyceridemia occurs with oral estrogens. Glucocorticoids raise HDL-C and may also increase triglycerides and LDL-C. Retinoids increase triglycerides and LDL-C and also reduce HDL-C. Interferons can cause hypertriglyceridemia. Following organ transplantation, a dyslipidemia often ensues. This is caused in part by the medications used to prevent rejection (glucocorticoids, cyclosporine, and FK-506) and requires close attention and, in some patients, drug therapy to prevent coronary artery disease.     

The controversy regarding diagnostic criteria for early myoclonic encephalopathy

To re-evaluate the diagnostic criteria for early myoclonic encephalopathy (EME), the following study was done. During the past 2 years, five patients with erratic, fragmentary myoclonus of neonatal onset, in association with other types of seizures, were analyzed with regard to etiologies, electroclinical features and their evolution, using a series of examinations including electroencephalographies (EEGs) and metabolic investigations. Of these five patients, three were diagnosed to have non-ketotic hyperglycinemia (NKH); one was pyridoxine-dependent; the other was cryptogenic. Only two cases (one NKH and one cryptogenic) had initial typical suppression-burst (S-B) EEG pattern, which subsequently evolved into multiple paroxysmal abnormalities with random asynchronous attenuation (MP-AA) pattern. The other two cases with NKH had MP-AA EEG pattern throughout both awake and sleep recordings in two consecutive EEG studies. All three cases with NKH survived with increasing microcephaly, muscle tonicity; all developed infantile spasm with hypsarrhythmia on EEGs. The patient with pyridoxine-dependency had an initial MP-AA EEG pattern, which converted into S-B pattern after the first use of pyridoxine, eventually becoming normal after a supplement with the second-dose of pyridoxine. In conclusion, either S-B or MP-AA pattern may reflect the severity of the underlying pathologies or the disease stages. These results suggest that, from both etiological and electroclinical viewpoints, EME may represent a broader spectrum than previously recognized. The still ongoing controversy regarding whether the S-B pattern should be recognized as the sole EEG criteria for the diagnosis of EME needs further experience to clarify.     

Infection control issues and intraoperative care

The incidence of congenital dislocation of the hip (CDH) in Singapore and Malaysia has been reported as being lower than in the West. In our hospital, we have seen an increasing number of congenital hip dislocation as well as dysplastic hips. We undertook a prospective study from December 1989 to December 1994 of 20,000 live births. The neonates were all screened by a consultant neonatologist and the findings were confirmed by a consultant paediatric orthopaedic surgeon. All babies had plain X-rays at 3 months and an acetabular index (AI) of 30 degrees or more was considered dysplastic. All babies with positive signs were followed up for 1 year and again had radiographs taken at 1 year. Comparison of plain X-rays and ultrasound assessment in a subgroup of 130 neonates showed that 64% of patients with AI > 20 degrees had hip dysplasia by ultrasonographic (alpha angle < 60 degrees) The incidence of dysplastic hips was 16.8 per 1000 live births. The overall incidence of neonates with dislocated hips was 4.7 per 1000 live births. The Malays were most affected with an incidence of 5.4 per 1000 live births. The incidence of developmental dysplasia of the hip in Singapore is higher than previously reported, with the Malays having the highest incidence. A significant number of babies with clicking hips have radiological evidence of acetabular dysplasia (AI > 30 degrees). One-third of the babies' hips were still dysplastic at 1 year of age. A well-organised screening programme with experienced examiners has proved to be useful in making early and accurate clinical diagnosis.     

Efficacy of lasalocid against murine Pneumocystis carinii pneumonitis

The efficacy of the ionophore lasalocid against Pneumocystis carinii pneumonitis in corticosteroid-immunosuppressed Sprague-Dawley rats was investigated. Lasalocid was effective in the prevention of the pneumonitis in a dose-dependent manner. At dosages of 0, 5, 10, and 20 mg/kg/day, P. carinii infection rates were 92, 60, 20, and 0%, respectively, during dexamethasone immunosuppression. Also, lasalocid compared favorably with other drugs known to have anti-P. carinii activity, including trimethoprim-sulfamethoxazole, atovaquone, and dapsone-trimethoprim.