Inhibitory effects of Hibiscus sabdariffa L extract on low‐density lipoprotein oxidation and anti‐hyperlipidemia in fructose‐fed and cholesterol‐fed rats

Hibiscus sabdariffa L extract (HSE) is an aqueous extract of Hibiscus sabdariffa L flowers that is used as a local soft drink and medical herb in Taiwan. Oxidation of low‐density lipoprotein (LDL) has been shown to increase the incidence of atherosclerosis. In this study, we determined the antioxidative activity of HSE on LDL oxidation by examining relative electrophoretic mobilities (REM) and thiobarbituric acid‐reactive substances (TBARS). The data revealed an inhibitory effect of HSE on Cu²⁺‐mediated REM and TBARS. HSE exhibited a remarkable ability to reduce cholesterol degradation and ApoB fragmentation. Overall, HSE showed a high potency to inhibit the production of oxidized LDL induced by copper and, specifically, to reduce serum triglycerides in high‐fructose diet (HFD) fed rats and serum cholesterol in high‐cholesterol diet (HCD) fed animals. The levels of LDL and the ratio of LDL‐cholesterol (LDL‐C) to HDL‐cholesterol (HDL‐C) were reduced by HSE in both hyperlipidaemia models. Based on these findings, we suggest that HSE may be used to inhibit LDL oxidation and to prevent various types of hyperlipidaemia in HFD‐ or HCD‐fed rats. Copyright © 2004 Society of Chemical Industry     

Effects of two pomace insoluble fibres on the activities of faecal bacterial enzymes and intestinal health

The carrot and starfruit pomace produced in large quantity after juice extraction possessed high levels of insoluble fibres (50.8–56.3 g/100 g, dry weight) of desirable physicochemical and physiological properties. In this study, the effects of insoluble fibres isolated from these pomace on the faecal bacterial enzymes and some biochemical parameters along the intestine were investigated and compared with those of cellulose. It was found that the consumption of these pomace insoluble fibres at 5% level significantly (p<0.05) reduced the caecal pH (6.5–6.6), caecal ammonia level (up to −21.0%) and daily faecal ammonia output (up to −20.8%), and also decreased the activities of β-d-glucosidase (up to −20.1%), β-d-glucuronidase (up to −78.2%), mucinase (up to −20.2%) and urease (up to −63.5%) in faeces. Our results suggested that these insoluble fibres might exert favorable effects on improving intestinal functions and health and could be exploited as functional ingredients in fibre-rich food products.     

The impact of property price on construction output

The interaction between the construction market and the overall economy has attracted much attention, but few studies have investigated the influence of the property market on the construction market in terms of property price. The disaggregated data of Hong Kong’s housing and retail construction sectors are collected to investigate the impact of property price on construction output. The newly developed autoregressive distributed lag (ARDL) bounds testing approach and the error correction (EC)-based Granger causality test are employed. The bounds testing results suggest that there exist stable long-run relationships between construction output and property price for both housing and retail construction sectors. Specifically, a 1.00% increase in the housing price and retail price lead to a 0.55% and 0.42% increase in construction outputs for the two sectors respectively. In addition, the Granger causality tests confirm a distinct long-run causal flow from property price to construction output. Furthermore, the proposed ARDL approach provides an effective method for forecasting construction output.     

Subdiaphragmatic and intrathoracic paraspinal malignant peripheral nerve sheath tumors: a clinicopathologic study of 25 patients and 26 tumors

BACKGROUND: To determine the effects of anatomic site on the presentation and diagnosis of malignant peripheral nerve sheath tumors (MPNSTs) and on the treatment and outcomes of the patients, the authors initiated a study of these tumors at different sites. An earlier report described MPNSTs of the buttock and lower extremity, and the current series analyzes those presenting at intrathoracic (IT) and subdiaphragmatic (SD) paraspinal sites. METHODS: The authors reviewed data on patients with paraspinal MPNSTs who were seen at Memorial Hospital during the period 1960-1995 and for whom histologic slides were available. Various clinicopathologic parameters and their effects on patient outcomes were examined. RESULTS: Twenty-five patients with 26 tumors were evaluated. Seven tumors were IT and 19 were SD; 60% of the patients had neurofibromatosis type 1 (NF1). Most patients presented with pain, and a diagnostic delay (of 3 months to 2 years) was often noted. Mean tumor sizes for SD and IT tumors were 14.3 cm and 6.6 cm, respectively. Most MPNSTs were composed of spindle cells in fascicles. Twenty-seven percent exhibited divergent differentiation. Twenty-four tumors were high grade, and a low grade component was identified in 8 tumors. Surgical resection was attempted for 23 tumors (88%), but complete resection was achieved in only 6 cases (23%). Eighty percent of the patients died of their tumors, 2-year and 5-year survival rates were 35% and 16%, and median survival was 8.5 months. Significant prognostic factors were tumor size <5 cm, the presence of a low grade component, and complete tumor resection. CONCLUSIONS: Paraspinal MPNSTs have more aggressive behavior than peripherally located tumors, mainly because of the difficulty encountered in resecting them completely. Prognoses of patients with MPNST at this site appear to be affected by resection status, tumor size, and tumor grade.     

Hypermutability of mouse chromosome 2 during the development of x-ray-induced murine myeloid leukemia

In an effort to identify the precise role of a deletion at regions D-E of mouse chromosome 2 [del2(D-E)] during the development of radiation-induced myeloid leukemia, we conducted a serial sacrifice study in which metaphase chromosomes were examined by the G-banding technique. Such metaphase cells were collected from x-irradiated mice during the period of transformation of some of the normal hematopoietic cells to the fully developed leukemic phenotype. A group of 250 CBA/Ca male mice (10-12 weeks old) were exposed to a single dose of 2 Gy of 250-kilovolt-peak x-rays; 42 age-matched male mice served as controls. Groups of randomly selected mice were sacrificed at 20 hr, 1 week, and then at intervals of 3 months up to 24 months after x-irradiation. Slides for cytogenetic, hematological, and histological examination were prepared for each animal at each sacrifice time. An expansion of cells with lesions on one copy of chromosome 2 was evident in 20-25% of treated mice at each sacrifice time. The majority of such lesions were translocations at 2F or 2H, strongly suggesting hypermutability of these sites on mouse chromosome 2. No lesions were found in control mice. The finding leads to the possibility that genomic lesions close to 2D and 2E are aberrants associated with radiation leukemogenesis, whereas a single clone of cells with a del2(D-E) may lead directly to overt leukemia. The data also indicate that leukemic transformation arises from the cumulative effects of multiple genetic events on chromosome 2, reinforcing the thesis that multiple steps of mutation occur in the pathogenesis of cancer.     

Demonstration of protein-protein interaction specificity by NMR chemical shift mapping

Chemical shift mapping is becoming a popular method for studying protein-protein interactions in solution. The technique is used to identify putative sites of interaction on a protein surface by detecting chemical shift perturbations in simple (1H, 15N)-HSQC NMR spectra of a uniformly labeled protein as a function of added (unlabeled) target protein. The high concentrations required for these experiments raise questions concerning the possibility for non-specific interactions being detected, thereby compromising the information obtained. We demonstrate here that the simple chemical shift mapping approach faithfully reproduces the known functional specificities among pairs of closely related proteins from the phosphoenolpyruvate:sugar phosphotransferase systems of Escherichia coli and Bacillus subtilis.     

Laser-assisted preparation of single cells from stained histological slides for gene analysis

Individual cells are prepared from histological tissue sections of routinely formalin-fixed and paraffin-embedded tissues using an ultraviolet laser micromanipulator. This technology, in combination with polymerase chain reaction (PCR)-based gene analysis, will enable researchers to routinely detect a variety of nucleic acid abnormalities underlying cancer, infection, and genetic disease with previously unknown sensitivity: at the single cell level. The utility of this technique is demonstrated by PCR amplification and sequencing of the E-cadherin gene, which codes for a homophilic cell-to-cell adhesion molecule, in early gastric carcinomas of the diffuse type of Lauren's classification. The main characteristics of the laser-assisted microdissection technique are high precision without contamination and easy application. The assignment of individual gene sequences to single cells will now provide a direct link between molecular biology on the one hand and histology and pathology on the other.