Sacrococcygeal teratoma and anorectal malformation.
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Abnormalities, Multiple↗
Biomedical subjects
T K Ng
Publications and source records attributed to T K Ng.
Rapid high performance liquid chromatographic assay for antifungal agents in human sera.
Serum concentration of seven antifungal agents, amphotericin B, 5-flucytosine, ketoconazole, fluconazole, itraconazole, miconazole and econazole were assayed using a single step sample preparation and an isocratic High Performance Liquid Chromatography (HPLC) procedure based on three mobile phases of similar components. Our method was simple, flexible and rapid, the assays being completed within half an hour. The method showed high reproducibility, good sensitivity with detection limits of 0.078 to 0.625 mg/L except for miconazole and econazole, and high recovery rates of 86-l05%. Out of 24 therapeutic agents tested only aztreonam and trimethoprim were found to interfere with the assay of 5-flucytosine and fluconazole respectively, using this protocol. HPLC assay should be useful in the clinical laboratory for monitoring patients on antifungal therapy.
Amphotericin B↗
Susceptibilities to 23 antimicrobial agents and beta-lactamase production of blood culture isolates of Acinetobacter sp in Hong Kong.
The susceptibility of 140 Acinetobacter spp. isolated from blood cultures of patients from the Prince of Wales Hospital, Hong Kong, from 1990 to 1994 to 23 antimicrobial agents was studied by an agar dilution method. Resistance to most of the beta-lactams, aminoglycosides and fluoroquinolones tested was high, being 11%-92%. Only amikacin, imipenem and meropenem were reliably active against this organism. Most of the isolates produced cephalosporinases with very high pIs while 33% produced beta-lactamases with pI ranges of 5.2-8.7.
Acinetobacter↗
A retrospective study of clinical characteristics of acinetobacter bacteremia.
High rates of acinetobacter bacteremia were observed in a large teaching hospital in Hong Kong. A retrospective study of 94 acinetobacter bacteremic episodes in patients in 1993-94 revealed 70 episodes of significant bacteremia. 53% of the patients were over 60 years with a male to female ratio of 1.5:1. Cases were most rare during the fourth quarter. The intensive care unit was the commonest location of acquisition of bacteremia. Most infections were hospital acquired. Intravascular catheters, urinary catheters, antibiotic therapy and respiratory tract manipulations were common risk factors. Lower respiratory tract infections and catheter-related sepsis were predominant foci of bacteremia. One-third of the patients received appropriate antibiotics within 48 hours after bacteremia onset. Mortality attributable to acinetobacter infection was 27%. Prognosis of underlying diseases, location in intensive care unit, lower respiratory tract infection as foci of infection as well as diabetes mellitus were associated with mortality.
Acinetobacter Infections↗
The prevalence and clinical significance of pulmonary infection due to non-tuberculous mycobacteria in Hong Kong.
An unexpected increase in positive sputum cultures of non-tuberculous mycobacteria (NTM) was noted in Hong Kong in 1990 compared to previous years, in contrast to a steady decline in the number of positive cultures of Mycobacterium tuberculosis. A retrospective case note study was therefore undertaken to ascertain the clinical importance of the rise in NTM isolates. A representative sample of 183 of the 675 patients with NTM isolates from sputum during 1990 was identified. Cases were assigned to groups according to whether there was evidence of progressive pulmonary disease due to NTM (group 1), persisting colonization without evidence of progressive disease (group 2) or transient isolation of NTM without evidence of progressive disease (group 3). Of 168 cases with adequate clinical and radiological records, 28 (16.7%) represented progressive disease due to NTM and 6 (3.6%) represented persisting colonization. The remainder were both transient and clinically insignificant. Most patients (71%) with progressive pulmonary disease due to NTM had pre-existing lung damage, and 50% had received anti-tuberculous therapy for documented M. tuberculosis previously. The commonest organism involved was the M avium complex. Eighty-six percent of patients with progressive disease and 83% of those with persisting colonization had at least one smear positive sputum specimen, whereas only 2% of patients with sputum contamination had a smear positive sputum sample (P < 0.0001). M. malmoense, M. xenopi and M. fortuitum all appear to be rare causes of significant NTM disease in Hong Kong. However, M. chelonei caused four cases of progressive disease within the study population, two of which were fatal.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Blood cholesterol screening: influence of fasting state, biological variation and the single cholesterol assay on total cholesterol level.
Postprandial changes in plasma total cholesterol (TC) are minimal and there is essentially no difference between fasting vs random TC concentrations, as reflected in the small diurnal coefficient of variation (CV) for TC of 2.5%. Similarly, a cholesterol-rich meal within the last 24 hours lacked an impact on plasma TC. Thus, random specimens are acceptable in blood cholesterol screening. The intraindividual biological CV (CVb) for plasma TC as measured over a long period was estimated from the data of several published studies to be 6.0%, which, when combined with a probable analytical CV (CVa) of 5% during screening, gave a total intraindividual CV (CVt) of about 8% for the single cholesterol assay. There is consensus that 'high TC values' acquired during screening should be confirmed under the conventional laboratory setting capable of CVa of 3% or less.
Cholesterol↗
Activity of two long-acting rifamycins, rifapentine and FCE 22807, in experimental murine tuberculosis.
The efficacy of the long-acting rifamycins, rifapentine (RPE) and FCE 22807 (FCE) in experimental murine tuberculosis was studied by counting viable bacilli in spleens. At 2 weeks after infection with Mycobacterium tuberculosis, strain H37Rv, treatment with isoniazid 25 mg/kg, rifampicin 10 mg/kg and pyrazinamide 150 mg/kg was given daily for 6 weeks. The mice were then divided into groups given RPE or FCE at intervals of 1, 2 or 3 weeks with spleen counts after 18 and 24 weeks of chemotherapy. The first experiment showed the great effect of the size of the dose of RPE, which, in once-weekly regimens, caused rapid sterilization at 16 mg/kg, less rapid sterilization at 10 mg/kg and incomplete activity at 6.25 mg/kg. Regimens of RPE given every 2 or 3 weeks were less effective, though 16 mg/kg fortnightly was as good as 6 mg/kg once-weekly. The second experiment compared RPE and FCE each given at 12 or 8 mg/kg. The results were similar though, at 8 mg/kg every 2 or 3 weeks, FCE was slightly more effective than RPE. Serum assays showed that the levels with 8 and 12 mg/kg FCE were lower than those produced even by 6.25 mg/kg RPE, suggesting that FCE would be a better drug than RPE if its bioavailability could be improved, and that the levels following 16 mg/kg RPE were similar to those found in man after 8 mg/kg RPE taken with a fat-rich meal, suggesting good prospects for effective once-fortnightly human treatment. The potential for long-acting rifamycins in the management of pulmonary tuberculosis is discussed.
Animals↗
Dietary palmitic and oleic acids exert similar effects on serum cholesterol and lipoprotein profiles in normocholesterolemic men and women.
To compare the effects of dietary palmitic acid (16:0) vs oleic acid (18:1) on serum lipids, lipoproteins, and plasma eicosanoids, 33 normocholesterolemic subjects (20 males, 13 females; ages 22-41 years) were challenged with a coconut oil-rich diet for 4 weeks. Subsequently they were assigned to either a palm olein-rich or olive oil-rich diet followed by a dietary crossover during two consecutive 6-week periods. Each test oil served as the sole cooking oil and contributed 23% of dietary energy or two-thirds of the total daily fat intake. Dietary myristic acid (14:0) and lauric acid (12:0) from coconut oil significantly raised all the serum lipid and lipoprotein parameters measured. Subsequent one-to-one exchange of 7% energy between 16:0 (palm olein diet) and 18:1 (olive oil diet) resulted in identical serum total cholesterol (192, 193 mg/dl), low-density lipoprotein cholesterol (LDL-C) (130, 131 mg/dl), high-density lipoprotein cholesterol (HDL-C) (41, 42 mg/dl), and triglyceride (TG) (108, 106 mg/dl) concentrations. Effects attributed to gender included higher HDL in females and higher TG in males associated with the tendency for higher LDL and LDL/HDL ratios in men. However, both sexes were equally responsive to changes in dietary fat saturation. The results indicate that in healthy, normocholesterolemic humans, dietary 16:0 can be exchanged for 18:1 within the range of these fatty acids normally present in typical diets without affecting the serum lipoprotein cholesterol concentration or distribution. In addition, replacement of 12:0 + 14:0 by 16:0 + 18:1, but especially 16:0 or some component of palm olein, appeared to have a beneficial impact on an important index of thrombogenesis, i.e., the thromboxane/prostacyclin ratio in plasma.
Adult↗
Cubic regression analysis for radioimmunoassay data processing.
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Electronic Data Processing↗
Nonhypercholesterolemic effects of a palm-oil diet in Malaysian volunteers.
The effects on serum lipids of diets prepared with palm olein, corn oil, and coconut oil supplying approximately 75% of the fat calories were compared in three matched groups of healthy volunteers (61 males, 22 females, aged 20-34 y). Group I received a coconut-palm-coconut dietary sequence; group II, coconut-corn-coconut; and group III, coconut oil during all three 5-wk dietary periods. Compared with entry-level values, coconut oil raised the serum total cholesterol concentration greater than 10% in all three groups. Subsequent feeding of palm olein or corn oil significantly reduced the total cholesterol (-19%, -36%), the LDL cholesterol (-20%, -42%%) and the HDL cholesterol (-20%, -26%) concentrations, respectively. Whereas the entry level of the ratio of LDL to HDL was not appreciably altered by coconut oil, this ratio was decreased 8% by palm olein and 25% by corn oil. Serum triglycerides were unaffected during the palm-olein period but were significantly reduced during the corn-oil period.
Adult↗
Effects of palm oil on cardiovascular risk.
A major public health concern of affluent nations is the excessive consumption of dietary fats which are now closely linked to coronary heart disease. Against this scenario, the tropical oils and palm oil in particular, have been cast as major villains in the U.S.A., despite the fact that palm oil consumption there is negligible. The unsuspecting public may not realise that the call to avoid palm oil is nothing more than a trade ploy since in recent years palm oil has been very competitive and has gained a major share of the world's edible oils and fats market. Many also lose sight of the fact that, palm oil, like other edible oils and fats, is an important component of the diet. The allegation that palm oil consumption leads to raised blood cholesterol levels and is therefore atherogenic is without scientific foundation. Examination of the chemical and fatty acid composition of palm oil or its liquid fraction should convince most nutritionists that the oil has little cholesterol-raising potential. The rationale for these are: it is considered cholesterol free. its major saturated fatty acid, palmitic acid (16:0) has recently been shown to be neutral in its cholesterolaemic effect, particularly in situations where the LDL receptors have not been down-regulated by dietary means or through a genetic effect. palm oil contains negligible amounts (less than 1.5%) of the hypercholesterolemic saturated fatty acids, namely lauric acid (12:0) and myristic acid (14:0). it has moderately rich amounts of the hypocholesterolaemic, monounsaturated oleic acid (18:1, omega-9) and adequate amounts of linoleic acid. (18:2, omega-6). It contains minor components such as the vitamin E tocotrienols which are not only powerful antioxidants but are also natural inhibitors of cholesterol synthesis. Feeding experiments in various animal species and humans also do not support the allegation that palm oil is atherogenic. On the contrary, palm oil consumption reduces blood cholesterol in comparison with the traditional sources of saturated fats such as coconut oil, dairy and animal fats. In addition, palm oil consumption may raise HDL levels and reduce platelet aggregability. As with all nutrients, there is a need to obtain a balance of different fatty acids found in fats in edible oils and other food sources. There is no single ideal source of fat that answers to the recent American Heart Association's call to reflect a 1:1:1 ratio of saturated, monounsaturated and polyunsaturated fats in relation to the recommended dietary fat intake of 30% of calories or less.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Message from WHO: importance of research on organic dusts to the Workers' Health Program of the World Health Organization.
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Dust↗
Effect of Phosphate on the Corrosion of Carbon Steel and on the Composition of Corrosion Products in Two-Stage Continuous Cultures of Desulfovibrio desulfuricans.
A field isolate of Desulfovibrio desulfuricans was grown in defined medium in a two-stage continuous culture apparatus with different concentrations of phosphate in the feed medium. The first state (V1) was operated as a conventional chemostat (D = 0.045 h) that was limited in energy source (lactate) or phosphate. The second stage (V2) received effluent from V1 but no additional nutrients, and contained a healthy population of transiently starved or resting cells. An increase in the concentration of phosphate in the medium fed to V1 resulted in increased corrosion rates of carbon steel in both V1 and V2. Despite the more rapid corrosion observed in growing cultures relative to that in resting cultures, corrosion products that were isolated under strictly anaerobic conditions from the two culture modes had similar bulk compositions which varied with the phosphate content of the medium. Crystalline mackinawite (Fe(9)S(8)), vivianite [Fe(3)(PO(4))(2) . 8H(2)O], and goethite [FeO(OH)] were detected in amounts which varied with the culture conditions. Chemical analyses indicated that the S in the corrosion product was almost exclusively in the form of sulfides, while the P was present both as phosphate and as unidentified components, possibly reduced P species. Some differential localization of S and P was observed in intact corrosion products. Cells from lactate-limited, but not from phosphate-limited, cultures contained intracellular granules that were enriched in P and Fe. The results are discussed in terms of several proposed mechanisms of microbiologically influenced corrosion.
Journal Article↗
Descriptive occupational morbidity statistics.
In spite of their value to indicate the magnitude of occupational health problems, descriptive occupational morbidity statistics tend to be neglected. The accuracy of occupational morbidity statistics depends on counting the morbid condition as well as the occupational element. At present, there is no clearcut model for counting the occupational element. The International Conferences of Labour Statisticians have contributed greatly to the development of statistics on employment injuries. Such statistics are a by-product of the provision of compensation to workers with occupational injuries and diseases. Statistics which are a by-product of investigation into occupational injuries and diseases followed by intervention seem to have received much less attention. Comments are made on the present situation regarding national statistics on occupational injuries and pneumoconiosis. The statistical issues with respect to work-related diseases and sickness absence are also examined and discussed.
Absenteeism↗
Single dose ofloxacin in treatment of uncomplicated gonorrhoea.
78 patients (66 male and 12 female) suffering from uncomplicated gonorrhoea were randomly selected to receive a single oral dose of either 400 mg or 600 mg ofloxacin. Of the 59 patients completely followed up penicillinase-producing Neisseria gonorrhoeae strains were cultured in 15 (25.4%) and the overall cure rate was 100%. Both groups showed excellent clinical effectiveness in over 80% and adverse reactions were uncommon and transient. We conclude that a single oral dose of ofloxacin in the studied dosage regimens was highly effective and safe in the treatment of uncomplicated gonorrhoea.
Adult↗
Synthesis of [C]Cellobiose with Clostridium thermocellum Cellobiose Phosphorylase.
Cellobiose labeled either at the reducing end (4-O-beta-d-glucopyranosyl-d-[U-C]glucopyranose) or at the nonreducing end (4-O-beta-d-[U-C]glucopyranosyl-d -glucopyranose) was synthesized with Clostridium thermocellum cellobiose phosphorylase at greater than 98% purity. The radioactive cellobioses were identical to authentic cellobiose in melting point, optical rotation, isotopic dilution, and chromatographic properties.
Journal Article↗
Thermophilic anaerobic bacteria which ferment hemicellulose: characterization of organisms and identification of plasmids.
Seven thermophilic anaerobic bacteria which ferment xylan were isolated from natural geothermal features in the western United States. Typically, these strains were Gram-negative non-sporeforming rods with an unusual double-layered cell wall which resembled that observed in Thermobacteroides acetoethylicus. The strains differed from known thermophilic anaerobes in their ability to utilize a very wide variety of carbohydrates and in their ability to grow in a chemically-defined medium and/or at pH 3.5. Four of the strains contained cryptic plasmids of 1.2 or 1.5 X 10(6) daltons. The taxonomic characteristics of the strains are discussed in terms of their relatedness to those of Thermoanaerobium, Thermoanaerobacter, and Thermobacteroides species.
Bacteria, Anaerobic↗