Volume 112  ·   Issue 08  ·  1999

OBJECTIVE To study prospectively the use of maternal serum alpha-fetoprotein (AFP) and total β-human chorionic gonadotropin (hCG) concentrations for screening of Down syndrome in Hong Kong. METHODS AFP and total β-hCG were measured in serum samples from 1638 singleton Chinese pregnancies at 14-22 weeks of gestation, recruited over a twelve-month period. Gestational ages were determined by ultrasonographic parameters measured at the same visit as the test for all cases. The gestational-age-specific and weight-adjusted medians for serum AFP and total β-hCG were calculated. Risk for fetal Down syndrome (FDS) was derived by mathematical modeling of the medians together with maternal age. Amniocenteses were offered to women with a calculated FDS risk of 1:270 or greater. RESULTS The gestational-age-specific and weight-adjusted medians for maternal serum AFP were similar to previous studies while that of total β-hCG were higher. A total of 101 patients (6.1%) were classified as being high risk for FDS, including 3.4% (48/1394) of those younger than 35 years of age and 21.7% (53/244) of those who were 35 or above. There were 4 cases of Down syndrome, 1 case of Tumer syndrome and 1 of Edward syndrome. Three out of the four cases of Down syndrome were screened positive, corresponding to a detection rate of FDS of 75%. A case of Tumer syndrome was also screened positive. A case of trisomy 18 was found to have very low levels of AFP [0.262 multiple of median (MoM)] and total β-hCG (0.115 MoM). CONCLUSIONS Maternal serum screening using double biochemical markers (AFP and total β-hCG) in combination with gestational dating by ultrasonography is effective in the detection of fetal Down syndrome and possibly other chromosomal disorders in Chinese pregnant women.

OBJECTIVE To select and identify the specific and protective antigens of Mycobacterium tuberculosis (M. tuberculosis) for searching a new approach to diagnose and treat tuberculosis. METHODS Extract and culture filtrates of M. tuberculosis were obtained by ultrasonic treatment and millipore membrane filtration, respectively. The protein samples were tested with monoclonal antibody (MAb) and patient sera. The proteins showing positive reaction were sequenced on Beckman/LF 3200/peptide amino acid sequencer. RESULTS Proteins of M. tuberculosis with molecular weight of 31 ku and 30 ku showed positive results when reacted with anti-M. tuberculosis MAb and sera of tuberculosis patients, but not with normal mouse serum and healthy human sera. N-terminal sequences of the 31 ku and 30 ku antigen were Ala Glu Val Asp Trp Leu Val Phe Ala Val and Phe Ser Arg Pro Gly Leu Pro Val Glu Try respectively. CONCLUSIONS 31 ku and 30 ku proteins ofM. tuberculosis are immune protective proteins. They play important or dominant roles in determination of immunorecognization.

OBJECTIVE To obtain full-length sequence of a Chinese hepatitis G virus (HGV) strain (HGVch) and investigate the genetic characteristic of HGVch and its identity to other isolates. METHODS Reverse transcription (RT) and nested-PCR were used to screen HGV RNA positive serum and amplify cDNA fragments. A positive serum without known hepatitis virus markers was selected for isolating HGV RNA template. The HGV genome was divided into 12 overlapping fragments and directly cloned into pGEM-T vector. Sequences were determined by dideoxy terminus-end method of DNA sequencing and then analyzed by computer. RESULTS The twelve fragments of HGVch cover 9213 nucleotides in length, containing a large open reading frame (ORF) encoding 2873 animo acids polyprotein that began with a methonine residue and ended at termination codon. HGVch is about 86.5%-89.5% identical to other known HGV isolates at the nucleotide level and about 93.9%-96.2% at the deduced animo acid level. CONCLUSIONS HGV is a non-A-E hepatitis causal agent, proved to be related with posttransfusion hepatitis in all over the world. Chinese HGV isolate has very close relationship to other isolates from Africa, Europe, Japan, without significant difference across the entire genome. It is suggested that the sequences of HGV isolates are very conservative and the evolution is very slow.

OBJECTIVE To investigate the effect of alpha-fetoprotein (AFP) antisense phosphorothioate oligodeoxynucleotides in combination with 5-fluorouracil (5-FU) on the growth of BEL-7404 human hepatoma cells in vitro. METHODS Phosphorothioate oligodeoxynucleotides were synthesized by beta-cyanoethyl-phosphoramidite chemistry. AFP gene expression in human hepatoma cells was determined by avidin-biotin-peroxidase complex (ABC) immunocytochemical method. Cell growth in the presence or absence of experimental agents was measured using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheny ltetrazolium (MTT) microculture tetrazolium assay. RESULTS AFP antisense oligomers markedly suppressed the growth of BEL-7404 human hepatoma cells in vitro by sequence-specific blocking of the AFP gene expression in the cells (P<0.05). 5-FU also inhibited the hepatoma cell growth in a dose-dependent manner when used alone (P<0.05). The combined treatment with AFP antisense oligomers and 5-FU showed significantly enhanced hepatoma cell growth inhibition than either AFP antisense or 5-FU treated cells alone (P<0.05). CONCLUSIONS Combined use of AFP antisense oligomers and 5-FU could more effectively inhibit the growth of BEL-7404 human hepatoma cells in vitro.

OBJECTIVE To assess the accuracy of three-dimensional electron beam CT angiography (3D-EBCTA) in the detection of intracranial aneurysms. METHODS 31 patients with suspected cerebral aneurysms (including 3 post-operative patients) were examined by 3D-EBCTA. Those receiving angiography or surgery acted as controls. Maximum intensity projection (MIP) and shaded surface display (SSD) reconstruction ways were selected. RESULTS 24 aneurysms were found in 23 patients. Of the 31 patients, false positive was noted in 1 patient, and false negative in 2 on 3D-EBCTA. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 92.0%, 88.9%, 91.2%, 95.8% and 80.0% respectively. CONCLUSIONS 3D-EBCTA is an noninvasive, rapid, valuable method in diagnosis and screening of patients with suspected aneurysms. The reconstruction modes such as MIP and SSD should be used together to optimise the visualization.

OBJECTIVE To investigate the role of digital subtraction angiography (DSA) in evaluation of carotid cavernous fistulas, and to initiate a new classification for carotid cavernous fistula. METHODS Cerebral angiography and selective external and internal carotid angiography were carried out in 56 patients who were classified into 5 types according to their hemodynamic features. RESULTS The types were A (38 patients), B (4), C (10), D (2), and E (2). One of the 38 direct fistulas was located at C1 of the cavernous segment. Fistulas at C2 were observed in 10 patients, at C3 in 4, at C4 in 10 and at C5 in 5. The anterior communicating arteries were patent and well compensated in 33 of the 56 patients. The posterior communicating arteries were patent and well compensated in 39 patients. Both communicating arteries were well compensated in 31 patients. Fifty of the 56 patients were drained by ophthalmic veins, 47 by inferior petrous sinuses, 18 by cortical veins, and 8 to the posterior fossa region. CONCLUSIONS Digital subtraction angiography was helpful in localization of the rents in carotid cavernous fistulas, in evaluation of function of Willis circles and provided valuable information for treatment of carotid cavernous fistulas. Carotid cavernous fistulas were divided into 5 categories: type A, B, C, D and E, among which type E was not previously described elsewhere.

OBJECTIVE To determine the expression of fibroblast growth factor (FGF) on olfactory bulb in rats and its relation with senile hyposmia, and to discuss the effects of rhidosin on expression of FGF on olfactory bulb in senile rats and its significance. METHODS Four groups of rats, i.e., young group, senile group, rhidosin group, and physiological saline control group were used in this study. After the removal of the heads of these rats, olfactory mucosa and olfactory bulbs were immediately fixed with neutral formalin, followed with paraffin-embedding, serial sectioning, immunohistochemical staining and light microscopic observation. RESULTS The positive expression rate of FGF on olfactory bulb in young group was significantly higher than that in senile group (P < 0.01). The positive expression rate of FGF on olfactory bulb in rhidosin group was significantly higher than that in physiological saline control group (P < 0.01). No positive expression of FGF on olfactory mucosa was observed in these four groups. CONCLUSIONS These results suggest that the expression of FGF on olfactory bulb gradually decline with aging. The decrease of expression of FGF on olfactory bulb may play a key role in the occurrence of senile hyposmia. Rhidosin can increase the expression of FGF on olfactory bulbs in senile rats and this may be one of the mechanisms by which rhidosin promotes the growth of olfactory cells and inhibits aging effects on the olfactory system.

OBJECTIVE To investigate the role of peripheral immunocompetent lymphocytes during the immune response in the inner ear. METHODS Sensitized lymphocytes from peripheral blood, neck lymph nodes and spleen of three groups of donor animals, i.e., group A immunized intradermally with keyhole limpet hemocyanine (KLH) and both inner ears challenged with KLH, group B received only KLH intradermally without inner ear challenge, and group C used as control, were isolated and labelled with 51Cr. The labelled lymphocytes were injected intravenously into the recipients. They were immunized intradermally with right inner ears challenged with KLH. Twenty to 24 h later, the radioactivities in the temporal bones of the recipients were assayed to detect the infiltration of labelled cells. RESULTS In groups A and B, the radioactivity in the right temporal bones was higher than that in the left temporal bones (P<0.05). The highest labelling radioactivity was detected in the right temporal bones of group A. The lowest migration of51Cr-labelled cells to the inner ear was found in group C. The ratio of radioactivity between right (challenged) and left (unchallenged) inner ears was higher in group A than in groups B and C, with the difference being significant (P<0.05). CONCLUSIONS The immune reaction in response to antigenic stimulation in the inner ear is immunologically modulated by the peripheral systemic circulation.

OBJECTIVE To introduce the use of the StealthStation neuronavigator combined with preoperative computerized tomography (CT) in resection of intracranial cavernous angiomas (CAs). METHODS The StealthStation neuronavigator was used to provide a realtime correlation of the operating field and the computerized images in 6 patients with CAs. All patients suffered from epileptic seizures. Four patients underwent keyhole surgery and 2 underwent small skin-flap craniotomy. The mean follow-up was 4.5 months. RESULTS With the guidance of neuronavigator, lesionectomy associated with removal of hemosiderin deposition, gliosis and calcification was performed precisely. The mean fiducial error was from 1.65 mm to 4.53 mm, the predicted accuracy at 10 cm was between 1.82 mm and 3.28 mm, and the sustained accuracy ranged from 0.50 mm to 3.45 mm. CONCLUSIONS The StealthStation neuronavigator is reliable and accurate in the resection of CAs.

OBJECTIVE To investigate the effect of Burn Healing Liquid (BHL) on the proliferation of keratinocytes and fibroblasts and to explore the potential effect of BHL on fibroblast contraction. METHODS Human keratinocytes and dermal fibroblasts were cultured in media containing serial dilutions of BHL followed by cell proliferation determination assessed with MTT (3-[4, 5-dimehtylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay at different time intervals. The in vitro collagen lattice contraction model was utilized for determining the contractility of fibroblasts cultured in BHL containing medium. RESULTS The 1:107 dilution of BHL enhanced the growth of both keratinocytes and fibroblasts whereas the 1:10 dilution increased the growth of keratinocytes only. Collagen lattice contraction was inhibited dose-dependently by BHL and such an inhibition could be reversed by switching BHL containing medium to normal medium containing 10% fetal calf serum. CONCLUSIONS BHL enhances the growth of both keratinocytes and fibroblasts and reversibly inhibits the fibroblast contraction in collagen lattice.

OBJECTIVE To analyze the clinical feature, efficacy of treatment and prognosis in familial benign chronic pemphigus (FBCP). METHODS Sixty-nine cases of FBCP were retrospectively analyzed. RESULTS The ratio of male to female is 3.93:1 in 69 patients (55 males, 14 females). The mean age at the onset was 29.09 years (3-60 years). There was familial history in 27 families in all of the cases. The lesion usually involved in genital area, neck, axillae and popliteal fossa. Erythemas and vesicles on the soles were seen only in 1 case. Histopathologically 44 cases had special features of FBCP, and immunopathologically 8 cases were direct immunofluorescence (DIF) negative, in which one case had C3 linear deposition along dermoepidermal junction. The combined regimen was more effective. The low-dose X-ray could improve the effect. CONCLUSIONS The disease is transmitted as an irregular autosomal dominant trait. The condition in males is more frequent than that in females, probably owing to the different level of female hormone in both sexes. Our patients have the same clinical features as those reported in the literature, but the erythema, vesicle lesions on sole have not been documented in the literature. The combined therapy should be adopted in this condition.

OBJECTIVE To study the expression of vascular endothelial growth factor (VEGF) in different parts of heart during early acute myocardial ischemia. METHODS The expression of VEGF in control and study group in rats was performed with the Strept Avidin-Biotin-Peroxidase Complex (SABC) method. RESULTS A rapid expression of VEGF in ischemic areas was observed 1 hour after the ligation of rat left anterior descending (LAD) coronary artery, and in peri-ischemic and non-ischemic areas 3 hours after ischemia. The grade of expression of VEGF increased with the continuation of myocardial ischemia, the positive myocytes of SABC-VEGF staining mainly localized in peri-ischemic areas 5 hours after ischemia. No expression of VEGF in control group was found. CONCLUSIONS The expression of VEGF may be up-regulated in rapid and continuous manner with characteristic spatial and temporal kinetic during early acute myocardial ischemia.