Reversible induction of rat hepatoma cell polarity with bile acids

A dynamic model for inducing and isolating polarized cell colonies from differentiated rat hepatoma was established with chenodeoxycholic acid (CDCA). Cells were treated with 75 microM CDCA in a 1% solvent mix (DMSO/ethanol: 0.5%/0.5%) for 11 days and positive Fao-BA1 and C2rev7-BA1 clones were isolated, respectively, from Fao and C2rev7. Cell polarization in these two clones was demonstrated by (i) the detection of (gamma)-glutamyl transpeptidase activity (gamma)-GT) and the presence of specific proteins, namely aminopeptidase N (APN), bile acid export pump (Bsep), multidrug resistance-associated protein 2 (Mrp2) at the canalicular pole, (ii) the expression of tight junction (ZO-1) and basolateral (1–18) marker proteins, (iii) the presence of regular microvilli in the cavities sealed by tight junctions, and (iv) functional bile canaliculi-like structures with the capacity to metabolise and secrete carboxyfluorescein diacetate dye. The polarized phenotype was maintained for more than 200 cell generations in the presence of CDCA and could be modulated by cell density or omitting the inducing agent. Hence this cellular model is well suited for studies on hepatic differentiation, polarization and bile salt trafficking with therapeutic implications.

Mammographic image quality and exposure in South East Asia

Generally there is a significant delay before optimized performance of mammography is fully realized in the developing countries. To evaluate the status of mammographic performance, a survey of mammographic image quality and exposure was performed in nine hospitals from four selected South East Asian countries. The entrance exposure on the surface of the American College of Radiology (ACR) mammographic phantom (ACR-RMI model 156) was made using both thermoluminescent dosimeters (TLDs) and an ionization chamber. The TLDs were mailed from the University of Wisconsin Radiation Calibration Laboratory (UWRCL) to the cooperating hospitals. The surveyed hospitals processed the images and returned them to the UWRCL for subsequent evaluation of the image quality of the mammographic phantom. Machine-specific data, technique factors and sensitometric data were also obtained. At 28 kVp, the mean entrance exposure is 0.91 R (0.46 to 2.6 R), mean glandular dose is 1.61 mGy (0.90 to 4.15 mGy), mean optical density is 1.37 (0.66 to 2.30), mean total phantom image score is 9.1(4-12). Only three of the nine hospitals tested achieved an acceptable score above the minimum 10. Results for 25 and 30 kVp showed similar trend. The variation between the ion chamber measurements and TLD measurements ranged from 4 to 24%. There is a wide variation in the image quality and entrance exposure among hospitals in South East Asia. There is a need for a quality assurance program. The factors that cause low score in the phantom images must be corrected. Calibration and the use of appropriate ionization chambers for mammography is important.

Evaluating the quality of images produced by soft X-ray units

For broad-beam soft X-ray sources, assessment of the quality of image produced by such units is made complex by the low penetration capabilities of the radiation. In the present study we have tested the utility of several types of test tool, some of which have been fabricated by us, as part of an effort to evaluate several key image defining parameters. These include the film characteristic, focal-spot size, image resolution and detail detectability. The two sources of X-rays used in present studies were the University of Malaya flash X-ray device (UMFX1) and a more conventional soft X-ray tube (Softex, Tokyo), the latter operating at peak accelerating potentials of 20 kVp. We have established, for thin objects, that both systems produce images of comparable quality and, in particular, objects can be resolved down to better than 45 microm.

Clinicopathological study of peripheral odontogenic fibromas (WHO-type) in Malaysians (1967-95)

Analysis of case records of 46 patients with peripheral odontogenic fibroma (1967-95) diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, disclosed a relatively young age of onset (mean, 32.2 years; range 5 months-64 years; peak incidence second decade of life), a slight female preponderance (M:F ratio 1:1.3), no racial predilection, a slight bias towards location in the mandible (52%) and a wide histomorphological range. All cases were treated by simple excision. Follow-up records were generally not available, so we do not know what the recurrence rate is.

Dependence of scatter on atomic number for x rays from tungsten and molybdenum anodes in the mammographic energy range

A study was done to determine the relative amounts of scatter for the following materials with atomic numbers ranging from Z=6 to Z=82: C, Al, Ti, Fe, Cu, Zn, Zr, Y, Mo, Ta, and Pb. Measurements were performed for each material on two constant potential x-ray units--one fitted with a molybdenum (Mo) anode-Mo filter and the other with a tungsten (W) anode-aluminum (Al) filter (medium filtration) at 30 kVp. Theoretical calculations were also performed for each anode to explain the scatter behavior and to aid in predicting the behavior for materials where measurements were not made. There was good agreement between the theoretical calculations and the experimental data.

Medical radiation exposures for diagnostic radiology in Malaysia

The medical radiation usage for diagnostic radiology in Malaysia (a Level II country) for 1990-1994 is reported, enabling a comparison to be made for the first time with the United Nations Scientific Committee on the Effects of Atomic Radiation Report. In 1994, the number of physicians, radiologists, x-ray units, and x-ray examinations per 1,000 population was 0.45, 0.005, 0.065, and 183, respectively. (Level I countries had averages of 2.6, 0.072, 0.35, and 860, respectively). In 1994, a total of 3.6 million x-ray examinations were performed; the annual effective dose per capita to the population was 0.05 mSv, and the collective effective dose was 1,000 person-Sv. Chest examinations contributed 63% of the total. Almost all examinations experienced increasing frequency from 1990 to 1994 except for barium studies, cholecystography, and intravenous urography (-23%, -36%, -51%). These decreases are related to the increasing use of ultrasound and greater availability of fiberoptic endoscopy. Notable increases during the same period were observed in computed tomography (161%), cardiac procedures (190%), and mammography (240%). In order to progress from Level II to Level I status Malaysia needs to expand and upgrade radiological service in tandem with the health care development of the country.

The impact of teleradiology in clinical practice--a Malaysian perspective

Teleradiology is the most mature and rapidly evolving specialty in telemedicine. The use of teleradiology has grown tremendously during the past few years. This article describes the role of teleradiology in health care along with a brief history of its development in tandem with advances in telecommunications and computer technologies. Teleradiology standards, image acquisition, data compression, transmission and image interpretation are summarised. The impact of teleradiology in the practice of radiology, traces the evolution of the modality especially in the Malaysian perspective and its current and future role are discussed.

X-ray based radiological procedures in Malaysia--1990-1994

X-ray based radiological procedure statistics and trend in Malaysia for 1990-1994 is reported; this information allows comparisons to be made with the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) Report. Additionally it is essential information for health care planners and providers. Malaysia is categorised as a health care level II country based on the UNSCEAR definition. In 1994, the number of physicians, radiologists, x-ray units and x-ray examinations per 1000 population was 0.45, 0.005, 0.065 and 183 respectively. 3.6 million x-ray examinations were performed in 1994, with chest radiography being the commonest study (63%). Information on x-ray examinations, number of hospitals and x-ray units is reported for the Ministry of Health, private practice and teaching hospitals. Examination frequency increased in computed tomography (161%), cardiac procedures (190%), and mammography (240%); while a decrease in barium studies (-23%), cholecystography (-36%), and intravenous urography (-51%) was noted. There is a potential and need to expand and upgrade radiological services.

An in vitro study comparing two different film-screen combinations in the detection of impacted fish bones

Dried fish bones from eight species of Malaysian fish were placed in an animal cadaver at four sites (tonsil, valleculae, larynx and oesophagus) and radiographed using a double and a single film-screen combination. The use of the single film-screen combination resulted in visibility of all fish bones placed in the larynx, two of which were not visible on the double film-screen combination. There was a 50% increase of the visibility of the fish bones in the oesophagus using the single film-screen combination. The difference in dose and cost between the two different film-screen combinations was not significant.

Doses to patients in routine X-ray examinations in Malaysia

A collaborative national survey initiated by the University of Malaya and the Ministry of Health was conducted from 1993 to 1995 to establish baseline patient dose data for seven common types (12 projections) of X-ray examinations in Malaysia. A total of 12 randomly selected public hospitals and 867 patients were included in this survey. The entrance surface doses (ESD) received by the patients were measured using thermoluminescent dosemeters (TLDs) attached to the patient's skin. Histograms are presented showing wide, positively skewed distributions of measured entrance surface doses for each examination. Mean, median, first and third quartile values of ESD and median effective dose are reported. Survey results are generally comparable with those reported in the UK, USA and by the International Atomic Energy Agency (IAEA). The results also provide information on dose level for a lower weight population (mean weight 60 kg) compared with the international reference dose values based on a 70 kg standard. The findings support the importance of the on-going national quality assurance programme to ensure doses are kept to a level consistent with optimum image quality. The data will also be useful for the formulation of national guidance levels as recommended by the IAEA. Furthermore, this study provides patient dosimetry information on healthcare level II countries.

A prospective randomized control study to compare the effect of serum and a commercial serum substitute (Plasmanate) on the outcome of assisted reproduction program

OBJECTIVES

To compare the effect of supplementation of serum and Plasmanate, a commercial serum substitute, to culture medium on the IVF outcome.

METHODS

One hundred eighty-nine subfertile couples were prospective randomized into the serum and the Plasmanate group during their IVF treatment. In vitro experiment was also performed to determine the fraction of Plasmanate that might affect embryo development.

RESULTS

The pregnancy rate were similar in both groups. The fertilization rate, the number of gestational sacs and good quality spare embryos suitable for cryopreservation were higher in the serum group than the Plasmanate group. However, these differences did not reach statistical significance. Significantly more embryos in the former cleaved to more than 4 cells at the time of transfer than the latter (p < 0.05). Ultrafiltration study showed that this inhibitory effect resided in the low molecular weight fraction (< 30-KD) of Plasmanate.

CONCLUSION

Serum is slightly better than Plasmanate as a protein supplement. However, Plasmanate may still be used for short term embryo culture in assisted reproduction.

A clinicopathologic study of odontomas: Malaysian findings

This report reviews the clinicopathologic characteristics of 104 cases of odontomas diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period (1967-1995). The results showed no real predilection in terms of sex (M:F ratio, 1:1), race (45.2% Malays, 40.4% Chinese, 10.6% Indians and 3.8% other races) or site (maxilla:mandible ratio, 1: 1.04) distribution. The mean age at presentation was 24.8 years and the age range was 3-74 years. There were 102 intraosseous and 2 extraosseous odontomas. Swelling was the most common presenting complaint. The majority of cases (81.9%) were clinically diagnosed as odontomas. The treatment of choice was surgical enucleation. Compound (43.3%) and complex (35.5%) odontomas were the two most common histological types encountered. The present findings correlate favorably with reported studies from other geographic areas.

Entrance skin exposure and mean glandular dose: effect of scatter and field gradient at mammography

PURPOSE

To investigate the effect of scatter and x-ray field gradient on entrance skin exposure and mean glandular dose by using the measurement protocol of the American College of Radiology.

MATERIALS AND METHODS

The exposure difference between the off-axis geometry of the American College of Radiology protocol and the central-axis geometry was measured by using eight common ionization chambers and two mammographic units (Senographe DMR; GE Medical Systems, Milwaukee, Wis; and Mam-CP II; Transcontinental X-ray, Charlotte, NC) at 25, 28, and 30 kVp. The field gradient was also measured on film with a scanning densitometer.

RESULTS

The central-axis exposure was 2.0%-3.6% higher than the off-axis exposure for the Senographe DMR unit and 3.1%-8.0% higher for the Mam-CP II unit. The maximum phantom scatter was 0.7% (Senographe DMR) and 1.3% (Mam-CP II).

CONCLUSION

Entrance skin exposure varies, depending on the type of ionization chamber and the characteristics of the mammographic unit. Determination of mean glandular dose with the American College of Radiology protocol may lead to underestimates of the actual measured dose by 4%-8% for the x-ray machines used in this study.

Sarcoid-like foreign body reaction in body piercing: a report of two cases

We report two cases of body piercing as a religious practice that subsequently led to the development of granulomatous nodules at previously punctured sites of the skin and oral mucosa. These lesions were diagnosed as sarcoid-like foreign body reaction after other possible causes including sarcoidosis, tuberculosis, tuberculoid leprosy, fungal infections, viral infections, and Crohn's disease were excluded.

Antigen-induced interferon-gamma and interleukin-2 responses of cattle inoculated with Mycobacterium bovis

Bovine purified protein derivative (PPD)-induced interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) mRNA expression was measured in peripheral blood lymphocyte cultures of cattle inoculated with Mycobacterium bovis and compared to cytokine protein levels as measured by IFN-gamma enzyme-linked immunosorbent assay and IL-2 bioassay. For individual animals, positive correlations were observed between mRNA and protein levels of bovine PPD-induced IFN-gamma and IL-2, although the correlations were stronger for IFN-gamma. Expression of these two cytokines also correlated with responses from a comparative intradermal test and a M. bovis antibody test. At 7 and 20 weeks after inoculation, bovine PPD-induced IFN-gamma and IL-2 mRNA expression was detected in all animals with tuberculous lesions and in a proportion of the M. bovis-inoculated animals with no lesions. Correlation of antigen-induced IFN-gamma and IL-2 with other immune parameters suggests that these two cytokines play an important role in the immune response to bovine tuberculosis.

Elevated trace element concentrations in malignant breast tissues

In vitro neutron activation analysis (NAA) was performed on malignant and adjacent normal tissue from 46 human female breast tumours. The objective was to investigate the chemical environment of the tissues within which microcalcifications develop and to develop a method for discrimination between malignant and normal breast tissue. The elements Al, Br, Ca, Cl, Co, Cs, Fe, K, Mn, Na, Rb and Zn were significantly higher in the cancer tissues (all p < 0.001; except for Co, p < 0.003, Wilcoxon signed-ranks test). In addition, a significant correlation (0.80, Spearman rank correlation) was found for Rb and Zn in tumour tissues. Present results are supported by the findings of others. The relevance of elevated concentrations of these elements in cancer breast tissue remains a matter of conjecture. Evidence suggests that there is a connection both with increased cellular activity and blood supply and the formation of microcalcifications in malignant breast tissues. This study suggests an association between the elemental composition of breast tissues and the formation of breast particles. That is, elevations of elemental concentration and clustered calcifications in breast are possibly related.

Discriminant analysis of normal and malignant breast tissue based upon INAA investigation of elemental concentration

Discriminant analysis of six trace element concentrations measured by instrumental neutron activation analysis (INAA) in 26 paired-samples of malignant and histologically normal human breast tissues shows the technique to be a potentially valuable clinical tool for making malignant-normal classification. Nonparametric discriminant analysis is performed for the data obtained. Linear and quadratic discriminant analyses are also carried out for comparison. For this data set a formal analysis shows that the elements which may be useful in distinguishing between malignant and normal tissues are Ca, Rb and Br, providing correct classification for 24 out of 26 normal samples and 22 out of 26 malignant samples.

A clinicopathological and immunohistochemical study of the calcifying epithelial odontogenic tumour (Pindborg tumour) in Malaysians

We reviewed the clinicopathological characteristics of 13 cases of calcifying epithelial odontogenic tumour (CEOT) (Pindborg tumour) diagnosed in the Division on Stomatology, Institute for Medical Research, Kuala Lumpur, over a 29-year period. There were eight female and five male patients. These consisted of eight (61.5 per cent) Malays, three (23.1 per cent) Chinese, one (7.7 per cent) Indian and one (7.7 per cent) Melanau. Their ages at presentation ranged from 19-61 years (mean age, 31.8 years). There were 12 central and one peripheral CEOT. Of these, 76.9 per cent of cases were located in the maxilla, the remaining in the mandible. The commonest clinical diagnosis was a dentigerous cyst (66.7 per cent). Enucleation was the main mode of treatment. Histologically, sheets and strands of polyhedral epithelial cells containing eosinophilic, homogeneous globules with Liesegang rings were observed. One case also showed extensive calcification and clear cell differentiation. Immunohistochemistry revealed a variable keratin staining of the CEOT epithelium, confirming its heterogeneity.

Adenomatoid odontogenic tumour: a case study with radiographic differential diagnostic considerations

Adenomatoid odontogenic tumours (AOT) are benign, hamartomatous odontogenic lesions that not uncommonly mimic a dentigerous cyst radiographically. Such a case as found involving an unerupted left maxillary canine in a 19-year-old Chinese female is described. The differential diagnosis of some common odontogenic cysts and neoplasms occurring in Malaysians, that may present in a dentigerous relationship to an unerupted tooth is discussed. A brief review of the radiographic literature on AOT is also included.

A prospective study of 924 digital fractures of the hand

A prospective study of 1129 patients with 1358 digital fractures of the hand was carried out between March 1984 and March 1994; of these, 924 fulfilled the criteria for inclusion. Functionally stable fractures with acceptable alignment were managed with immediate active mobilization. Unstable fractures, or fractures with unacceptable alignment, were openly reduced and fixed internally so that active mobilization could begin immediately after operation. The function results using various systems of evaluation were excellent or good in over 90 per cent of the fractured thumbs, and excellent or good in 58.7 per cent to 76.5 per cent of the fingers. Patients who did not require surgery did much better than those in the operated group. Comminuted, open and multiple fractures proved to be of poor prognostic value. However, rigid fixation was statistically significant in influencing the outcome.

Microcalcification clustering parameters in breast disease: a morphometric analysis of radiographs of excision specimens

X-ray microradiography of surgically excised breast specimens offers the possibility of morphological characterization of calcifications. When combined with digital imaging techniques there exists added potential for obtaining valuable basic quantitative morphometric information regarding differences between microcalcifications in tissues exhibiting evidence of fibrocystic change, benign and malignant tumours. A total of 157 excised breast specimens from 84 patients were microradiographed using a Softex Super Soft X-ray unit and Kodak AA high resolution industrial film. A Quantimet 570C image analysis system was used to digitize and analyse the microradiographs. Of the 157 microradiographs, 51 (from 30 patients) revealed microcalcification clusters. The existence of significant differences between the three identified categories of tissue were indicated by clustering parameters. These included the number of particles per cluster, area of clusters, maximum distance to nearest neighbour, and geometric mean distance to nearest neighbour. The distribution pattern index (DPI), another of the clustering parameters used in this study, has been observed to be a particularly powerful discriminator. The value for fibrocystic change was found to be significantly smaller (0.514) than that for benign tumour (0.796) whilst that for benign tumour was observed to be significantly larger than that for malignant tumour (0.604) at a p-value of less than 0.05 (Kruskal-Wallis one-way analysis of variance).

Review of oral histoplasmosis in Malaysians

We reviewed biopsy records for 37 cases of oral histoplasmosis for patient characteristics, clinical features, and histopathologic findings. These represented cases diagnosed in the Division of Stomatology, Institute for Medical Research, Kuala Lumpur between July 1967 and October 1994. All were male patients who ranged in age from 11 to 79 years (mean age, 56.7 years). There were 40.6% Malays, 37.8% Chinese, 18.9% Indians, and 2.7% other races. Five patients with mouth lesions as the initial presenting lesions were proven to be cases of disseminated histoplasmosis. In the remaining cases apart from the biopsy-proven oral histoplasmosis lesions, the extent of the disease elsewhere was unknown. The majority of these lesions involved the gingiva, tongue, and palate in decreasing order of frequency. The most frequent presenting symptom was oral mucosal ulceration. Squamous cell carcinoma and tuberculosis were the two most common clinical differential diagnoses. Our present findings compare favorably with published reports from other regions.

Accurate three-dimensional reconstruction of intravascular ultrasound data. Spatially correct three-dimensional reconstructions

BACKGROUND

The geometrical accuracy of conventional three-dimensional (3D) reconstruction methods for intravascular ultrasound (IVUS) data (coronary and peripheral) is hampered by the inability to register spatial image orientation and by respiratory and cardiac motion. The objective of this work was the development of improved IVUS reconstruction techniques.

METHODS AND RESULTS

We developed a 3D position registration method that identifies the spatial coordinates of an in situ IVUS catheter by use of simultaneous ECG-gated biplane digital cinefluoroscopy. To minimize distortion, coordinates underwent pincushion correction and were referenced to a standardized calibration cube. Gated IVUS data were acquired digitally, and the spatial locations of the imaging planes were then transformed relative to their respective 3D coordinates, rendered in binary voxel format, resliced, and displayed on an image-processing workstation for off-line analysis. The method was tested by use of phantoms (straight tube, 360 degrees circle, 240 degrees spiral) and an in vitro coronary artery model. In vivo feasibility was assessed in patients who underwent routine interventional coronary procedures accompanied by IVUS evaluation. Actual versus calculated point locations were within 1.0 +/- 0.3 mm of each other (n = 39). Calculated phantom volumes were within 4% of actual volumes. Phantom 3D reconstruction appropriately demonstrated complex morphology. Initial patient evaluation demonstrated method feasibility as well as errors if respiratory and ECG gating were not used.

CONCLUSIONS

These preliminary data support the use of this new method of 3D reconstruction of vascular structures with use of combined vascular ultrasound data and simultaneous ECG-gated biplane cinefluoroscopy.

Schisandrin B protects against carbon tetrachloride toxicity by enhancing the mitochondrial glutathione redox status in mouse liver

Previous studies in our laboratory have demonstrated the effect of Schisandrin B (Sch B),an active ingredient of the fruit of Schisandra chinensis, on enhancing the hepatic glutathione antioxidant system in mice, as evidenced by the hepatoprotection against carbon tetrachloride (CCl4) toxicity. In the present study, the mechanism involved in the hepatoprotection afforded by Sch B treatment was investigated. Treating female Balb/c mice with 1, 3-bis(2-chloroethyl)-1-nitrosourea, an inhibitor of glutathione reductase (GRD), at a dose of 2 mmol/kg (i.p.) did not abrogate the hepatoprotective action of Sch B in CCl4-treated mice. The result indicates that the increased activity of hepatic GRD is not ascribable to the hepatoprotective action of Sch B. In control mice, the same Sch B treatment regimen caused an enhancement in hepatic mitochondrial glutathione redox status, as indicated by the significant increase and decrease in reduced and oxidized glutathione levels, respectively. While the CCl4 intoxication greatly impaired mitochondrial glutathione redox status, the beneficial effect of Sch B treatment became more evident after CCl4 challenge. Our results strongly suggest that the mechanism of hepatoprotection afforded by Sch B treatment may involve the enhancement of mitochondrial glutathione redox status.

Effect of schisandrin B on hepatic glutathione antioxidant system in mice: protection against carbon tetrachloride toxicity

Pretreating female Balb/c mice with schisandrin B (Sch B) at increasing daily doses (1-4 mmol/kg) for 3 days caused dose-dependent increases in hepatic glutathione S-transferase (GST) and glutathione reductase (GRD) activities. However, the activities of glucose-6-phosphate dehydrogenase (G6PDH), Se-glutathione peroxidase (GPX), and gamma-glutamylcysteine synthetase (GCS) were down-regulated to varying degrees in a dose-dependent manner. While there were biphasic changes in hepatic reduced glutathione (GSH) level as well as susceptibility of hepatic tissue homogenates to in vitro peroxide-induced GSH depletion, a gradual decrease in hepatic malondialdehyde content was observed. The beneficial effect of Sch B on the hepatic GSH anti-oxidant system became more evident after CCl4 challenge. The same Sch B pretreatment regimen caused a dose-dependent protection against carbon tetrachloride (CCl4)-induced hepatotoxicity. The hepatoprotection was associated with significant enhancement in hepatic GSH status, as indicated by the substantial increase in tissue GSH levels and the corresponding decrease in susceptibility of tissue homogenates to GSH depletion. Where the activities of GST and GRD were increased linearly over non-CCl4 control values, there was also a gradual elevation in G6PDH activity upon administration of increasing doses of Sch B. In contrast, GPX activity was moderately down-regulated. The ensemble of results suggests that the hepatoprotection afforded by Sch B pretreatment may mainly be attributed to the enhancement in the functioning of the hepatic GSH anti-oxidant system, possibly through stimulating the activities of GSH related enzymes.