Streptomyces sanglieri which colonised and enhanced the growth of Elaeis guineensis Jacq. seedlings was antagonistic to Ganoderma boninense in in vitro studies.

Actinomycete strain AUM 00500 was 99.5 % similar to Streptomyces sanglieri NBRC 100784(T) and was evaluated for antagonistic activity towards Ganoderma boninense, the causative fungus of basal stem rot of oil palm. The strain showed strong antifungal activity towards G. boninense in in vitro and SEM analysis showed various modes of inhibition of the fungus. Ethyl acetate extracts of single culture and inhibition zone of cross-plug culture by HPLC indicated that strain AUM 00500 produced two different antibiotics of the glutarimide group namely cycloheximide and actiphenol. In greenhouse trials, oil palm seed treated with spores of S. sanglieri strain AUM 00500 at 10(9) cfu/ml showed significant (P < 0.05) increase in oil palm seedlings growth when compared to the control. Streptomyces sanglieri strain AUM 00500 successfully colonised the epidermal surface of the roots of treated oil palm seedlings and it was recovered from root fragments plated on starch casein agar.

Rapid identification of cyclic tetrapyrrolic photosensitisers for photodynamic therapy using on-line hyphenated LC-PDA-MS coupled with photo-cytotoxicity assay.

INTRODUCTION: Photodynamic therapy is a treatment modality that involves site-directed generation of cytotoxic reactive oxygen species by light-activated photosensitisers. OBJECTIVE: In order to rapidly identify new photosensitisers from natural extracts, we developed a liquid chromatography-photodiode array-mass spectrometry (LC-PDA-MS) method to rapidly identify plant extracts that contain photosensitisers, particularly those possessing a cyclic tetrapyrrole structure. METHOD: Six previously isolated compounds (1-6) were identified in bioactive fractions derived from 15 plant extracts on the basis of their chromatographic retention times, UV-visible profiles, accurate mass and fragmentation patterns. RESULTS: Samples containing uncommon photosensitisers were rapidly identified using this method, and subsequent scale-up isolation efforts led to two new compounds (7 and 8) which were confirmed to be active photosensitisers in a photo-cytotoxicity assay. CONCLUSION: This method serves as a useful tool in prioritising samples that may contain new photosensitisers out of a larger group of photo-cytotoxic natural products extracts.

Iron deficiency anemia and cardiac mortality in patients with left ventricular systolic dysfunction undergoing coronary stenting.

AIM: The aim of this study was to assess cardiac mortality in patients with reduced ejection fraction (EF< or =45%) and anemia (Hb< or =12 g/dL) undergoing coronary stenting and to investigate whether iron-deficiency anemia influenced outcome when compared to non-anemic patients or patients with other types of anemia. METHODS: One hundred twenty consecutive patients undergoing percutaneous coronary intervention (PCI) between April 2003 and December 2005 were identified and followed for a median of 30 months. Patients were divided into 2 groups, anemic (Hb< or =12 g/dL) and non-anemic. Anemic patients were then divided into 3 sub-groups based on laboratory analysis and anemia work-up: iron-deficiency, malignancy-associated, and anemia of chronic disease (including chronic kidney disease). Mortality rates and cause of death were retrieved using both the Social Security database and the hospital records. RESULTS: Thirty-one percent of patients had iron deficiency, 24% had a malignancy-associated anemia and 45% had anemia of chronic disease. Overall mortality was 12% of which 29% was cardiac death. All-cause and cardiac mortality were significantly higher in anemic vs. non-anemic patients, (31% vs. 6%, P<0.001, and 10% vs. 1%, P=0.016, respectively). Iron-deficiency anemia strongly predicted cardiac mortality (33% vs. 1% in non-anemic patients, P<0.001), while malignancy-associated anemia was the strongest predictor of non-cardiac death (57% vs. 4% in non-anemic patients, P<0.001). Anemia of chronic disease neither predicted cardiac nor non-cardiac death. CONCLUSIONS: To the authors' knowledge, this is the first study to show that iron-deficiency anemia is a strong predictor of cardiac death when compared to patients with other types of anemia or to non-anemic patients.

Imaging appearances and endovascular management of uncommon pseudoaneurysms.

Pseudoaneurysms are uncommon and their aetiology is varied. They occur in numerous anatomical locations and present with a multitude of clinical presentations sometimes life-threatening. This review describes the causes, sites, and presentations of uncommon pseudoaneurysms, as well as illustrating their diagnostic appearances and endovascular management.

Congenital disorder of glycosylation type 1a: three siblings with a mild neurological phenotype.

We report 3 siblings (1 male and 2 female) recently diagnosed with congenital disorder of glycosylation type Ia (CDG-Ia) in their mid-20s. They experience mild mental retardation but manage to function independently in society. Their professions are library assistant, professional artistic painter and secretarial work. All three siblings have cerebellar hypoplasia and ataxia, but are able to ambulate easily. Two of the siblings have required strabismus surgical repairs. All have antithrombin III deficiency, osteoporosis, and mild dysmorphic features. Hypergonadotrophic hypogonadism was a feature of the two female siblings. A type 1 sialotransferrin pattern and phosphomannomutase (PMM) deficiency have been demonstrated. They are compound heterozygotes for R141H and L32R mutations in the PMM2 gene. While there is clinical heterogeneity in CDG-Ia, we believe that our patients are among the mildest of intellectually affected CDG-Ia patients reported to date.

Dosing obese cats based on body weight spuriously affects some measures of glucose tolerance.

The primary objective was to investigate whether dosing glucose by body weight results in spurious effects on measures of glucose tolerance in obese cats because volume of distribution does not increase linearly with body weight. Healthy research cats (n = 16; 6 castrated males, 10 spayed females) were used. A retrospective study was performed using glucose concentration data from glucose tolerance and insulin sensitivity tests before and after cats were fed ad libitum for 9 to 12 mo to promote weight gain. The higher dose of glucose (0.5 vs 0.3 g/kg body weight) in the glucose tolerance tests increased 2-min glucose concentrations (P < 0.001), and there was a positive correlation between 2-min and 2-h glucose (r = 0.65, P = 0.006). Two-min (P = 0.016 and 0.019, respectively), and 2-h (P = 0.057 and 0.003, respectively) glucose concentrations, and glucose half-life (T1/2; P = 0.034 and <0.001 respectively) were positively associated with body weight and body condition score. Glucose dose should be decreased by 0.05 g for every kg above ideal body weight. Alternatively, for every unit of body condition score above 5 on a 9-point scale, observed 2-h glucose concentration should be adjusted down by 0.1 mmol/L. Dosing glucose based on body weight spuriously increases glucose concentrations at 2 h in obese cats and could lead to cats being incorrectly classified as having impaired glucose tolerance. This has important implications for clinical studies assessing the effect of interventions on glucose tolerance when lean and obese cats are compared.

Basal plasma insulin and homeostasis model assessment (HOMA) are indicators of insulin sensitivity in cats.

The objective of this study was to compare simpler indices of insulin sensitivity with the minimal model-derived insulin sensitivity index to identify a simple and reliable alternative method for assessing insulin sensitivity in cats. In addition, we aimed to determine whether this simpler measure or measures showed consistency of association across differing body weights and glucose tolerance levels. Data from glucose tolerance and insulin sensitivity tests performed in 32 cats with varying body weights (underweight to obese), including seven cats with impaired glucose tolerance, were used to assess the relationship between Bergman's minimal model-derived insulin sensitivity index (S(I)), and various simpler measures of insulin sensitivity. The most useful overall predictors of insulin sensitivity were basal plasma insulin concentrations and the homeostasis model assessment (HOMA), which is the product of basal glucose and insulin concentrations divided by 22.5. It is concluded that measurement of plasma insulin concentrations in cats with food withheld for 24 h, in conjunction with HOMA, could be used in clinical research projects and by practicing veterinarians to screen for reduced insulin sensitivity in cats. Such cats may be at increased risk of developing impaired glucose tolerance and type 2 diabetes mellitus. Early detection of these cats would enable preventative intervention programs such as weight reduction, increased physical activity and dietary modifications to be instigated.

Sulindac enhances cell proliferation in DMH-treated mouse colonic mucosa.

In a previous study we reported that the NSAID sulindac had a marked inhibitory effect on the development of colonic tumours in mice treated with the carcinogen 1,2-dimethylhydrazine (DMH). In this study we examined the effects of sulindac in respect of cell-kinetic changes in mouse colonic mucosa as determined by flash labelling with the thymidine analogue bromodeoxyuridine (BrdUrd) at varying intervals during the process of colonic carcinogenesis. We also investigated the possibility that these changes may be modulated by misoprostol a prostaglandin E1 analogue. Four groups of 36 mice each were treated for 18 weeks with the following drug/s respectively: (1) DMH; (2) DMH and sulindac; (3) DMH, sulindac and misoprostol; and (4) DMH and misoprostol. Three animals from each group were killed each week between the sixth week and the eighteenth week after the start of the experiment. A 1-h flash label technique was employed and paraffin sections of colonic mucosa were examined. For each animal a total of 50 perfect axially cut crypts were chosen and the following parameters determined: crypt length, labelling index and labelling index distribution: the data were analysed using the computer program GLIM. For each of the four groups, crypt lengths increased significantly with the duration of treatment with no significant difference between the groups. In sulindac-treated animals the labelling index for all positions increased with duration of treatment whereas for animals not treated with sulindac there was no significant difference in labelling index with respect to duration of treatment. The administration of misoprostol did not appear to significantly alter the effects of sulindac. It is postulated that the observed increase in cell proliferation could be a compensatory phenomenon occurring secondary to loss of crypt epithelial cells by apoptosis induced by sulindac. Also the finding of an increase in labelling index mediated by a chemopreventive agent indirectly questions the rationale behind the therapeutic manipulation of crypt cell proliferation in order to reduce the risk of colon cancer.

Simulation of cell proliferation in mouse oral epithelium, and the action of epidermal growth factor: evidence for a high degree of synchronization of the stem cells.

Computer simulation has been carried out to help to determine the cell-proliferative mechanisms underlying data gathered from a double-labelling experiment on the dorsal tongue of the mouse. Good fits to the data have been obtained by assuming that there is a high degree of synchrony in the stem cells, which have a 24-h cell cycle time, and that daughters of these cells undergo two further divisions, with mean cell cycle times of 48 h, before differentiating. This results in one-seventh of proliferative cells being stem cells, which ties in well with the concept of epidermal proliferative units. There is no need to assume that S-phase duration changes diurnally. The administration of epidermal growth factor seems to increase the degree of synchrony. In such systems, the influx to S-phase and the efflux from it have very sudden short peaks, which it is impossible to observe unless observations are taken very frequently. There are therefore implications for the designs of experiments that attempt to study diurnal rhythms or the effect of factors that disturb the normal proliferative pattern of cells.

Cell kinetic studies in the murine ventral tongue epithelium: thymidine metabolism studies and circadian rhythm determination.

The oral mucosa is a rapidly replacing body tissue that has received relatively little attention in terms of defining its cell kinetics and cellular organization. The tissue is sensitive to the effects of cytotoxic agents, the consequence of which can be stem cell death with the subsequent development of ulcers and the symptoms of oral mucositis. There is considerable interest in designing strategies to protect oral stem cells and, hence, reduce the mucositis side-effects in cancer therapy patients. Here we present details of a new histometric approach designed to investigate the changing patterns in cellularity in the ventral tongue mucosa. This initial paper in a series of four papers presents observations on the changing patterns in the labelling index following tritiated thymidine administration, which suggest a delayed uptake of tritiated thymidine from a long-term intracellular thymidine pool, a phenomenon that will complicate cell kinetic interpretations in a variety of experimental situations. We also provide data on the changing pattern of mitotic activity through a 24-h period (circadian rhythms). Using vincristine-induced stathmokinesis, the data indicate that 54% of the basal cells divide each day and that there is a high degree of synchrony in mitotic activity with a mitotic peak occurring around 13.00 h. The mitotic circadian peak occurs 9-12 h after the circadian peak in DNA synthesis. The data presented here and in the subsequent papers could be interpreted to indicate that basal cells of BDF1 mice have an average turnover time of about 26-44 h with some cells cycling once a day and others with a 2- or 3-day cell cycle time.

The proliferative response of the coagulating gland of the castrated mouse under continuous androgen stimulation: an experimental and computer simulation model.

The proliferative response of the coagulating gland of the castrated male mouse has been examined during continuous treatment with testosterone propionate. Fourteen days after castration, s.c. daily injections of testosterone propionate were begun. Mitotic (Im) and labelling (IL) index values were obtained at 3 h intervals for up to 100 h after the initial injection. These showed a biphasic response, in which IL reached a maximum at 30 and 70 h, and Im at approximately 45 and 75 h. Fraction-labelled mitoses (FLM) curves were begun 24, 48, and 72 h after the first androgen injection. In each curve the first wave of labelled mitoses rose to 100% and showed a square form indicating little spread in the durations of the G2 and S phases. Values of 7.5, 1.3 and 0.7 h were obtained for the durations of DNA synthesis (ts), the post-synthetic period (tG2) and of mitosis (tm) respectively. In none of the FLM curves was it possible to demonstrate a second wave of labelled mitoses and direct measurement of the cell cycle time (Tc) was not obtained. Continuous tritiated thymidine labelling indices revealed that after a latent period of 25 h, DNA synthesis began and labelling rose rapidly to 80% by 45 h and then more slowly to 95% by 97 h. Cell population changes during androgen stimulation estimated from measurements of total glandular DNA indicated that the number of cells present in the glands remained constant during the first 30 h after stimulation and thereafter increased to approximately 2-3 times the original value. The data are compared with a mathematical model which assumes that the cell population of castrated mice when stimulated passes from a GO compartment through successive waves of DNA synthesis and mitosis. After each cell division the cells may leave or remain in the proliferative cycle. This model has been subjected to computer simulation using the cell cycle parameters obtained in the kinetic experiments. There was good agreement between the stimulation and experimental results in the Im and IL curves, continuous labelling, and total cell number experiments. The simulation of FLM curves was less successful. Although the first wave of labelled mitoses was clearly seen the model predicts a distinct second wave of labelled mitoses. It is concluded that this does not appear because of variation in the duration of G1.

Modulation by verapamil of vincristine pharmacokinetics and sensitivity to metaphase arrest of the normal rat colon in organ culture.

The in-vitro pharmacokinetics of vincristine (VCR) in normal rat colonic mucosa were studied. Two complementary approaches were adopted using an explant organ-culture system. Firstly [G-3H]vincristine (3HVCR) accumulation, retention and efflux were characterized under basal conditions and compared with measurements made either under energy-depleted conditions, or in the presence of VRP. Secondly, a histological method--the postmetaphase index (PMI)--was used to compare the sensitivity of explants to VCR in the presence or absence of verapamil (VRP). This latter technique involves the measurement, by counting, of the proportion of mitotic figures escaping from metaphase arrest. The studies yielded the following results: 3HVCR accumulation in colonic mucosa showed no evidence of saturability up to the maximum dose studied (130 nM), at a dose of 52 nM accumulation was enhanced in energy-depleted conditions by a factor of 1.8, and in the presence of VRP (6.6 microM) by a factor of 1.4. In the presence of VRP (6.6 microM) retention of 3HVCR was increased by a factor of 1.3 and efflux was reduced by a factor of 0.8 after 2 hr. VRP (6.6 microM) reduced the PMI of colonic mucosal epithelial cells exposed to 11 nM VCR from 18.8% to 11.4% (i.e. 40% reduction) indicating sensitization of the cells to this property of VCR. These results provide evidence that the sensitivity of normal colonic mucosa to vincristine is, at least in part, regulated by drug transport. Qualitatively our observations resemble those described in multidrug resistance. Given that P-glycoprotein has been demonstrated by several groups in colonic mucosal cells, the results support a normal role for this membrane transport molecule in the protection of intestinal cells from plant alkaloids and other xenobiotic agents ingested in the diet.

Cytokinetic studies of crypts in convoluted human small-intestinal mucosa.

Forty-seven peroral biopsy specimens of duodenojejunal mucosa showing convolutions were obtained from patients with a variety of clinical disorders. These mucosal samples were divided into three groups according to the extent of the convolutions and the severity of the accompanying histopathological changes; the cytokinetic status of the crypts in the three groups was then analysed and compared. Those in which the mucosae were predominantly or totally convoluted (group 3) showed the most notable cytokinetic changes: crypts were hyperplastic and crypt cell production rate was markedly increased compared with the other two groups and with morphologically normal control mucosae. In the case of one patient with mucosal changes of group 3 severity, additional studies were carried out using vincristine to produce metaphase arrest. The cell cycle time of 27 hours was greatly shortened compared with a control value of 45 hours.We find that the presence of convolutions in small-intestinal mucosal biopsy specimens is accompanied by an increase in the rate of cell production from the crypts, which is presumably related directly or indirectly to the rate of loss of mature enterocytes from the surface of the mucosa. Furthermore, an increase in the proportion of convolutions may reflect an increase in the rates of cell production and cell loss. In the group 3 convoluted mucosae the cytokinetic profile of the crypts resembled that of some of the flat avillous coeliac mucosae previously studied although the rates of cell production did not reach the levels attained by the most productive of the flat coeliac mucosae.

Assessment of thyroid hormone assays.

Four techniques for estimating serum T4 and three for estimating serum T3 have been investigated and found to be satisfactory in routine use. Normal ranges for each techniques have been established. Estimation of serum T3 by the commerical kits tested appears to have a high discriminant value in the diagnosis of hyperthyroidism, although the diagnostic definition used inevitably enhances the apparent sensitivity of these techniques. Estimation of serum T4 will identify the majority of patients with symptomatic hypothyroidism. The low sensitivity of T3 in the diagnosis of thyroid failure is confirmed.

Presence of epidermal growth factor receptor as an indicator of poor prognosis in patients with breast cancer.

Epidermal growth factor receptors are present in some breast cancers in man, and there is an inverse relation to oestrogen receptor state. We assessed the presence of epidermal growth factor receptors as a single prognostic indicator in a series of breast tumours by comparing this with the Bloom and Richardson scores for these tumours. One hundred and eight ductal tumours were examined for epidermal growth factor receptors by radioligand binding. There was a significant (p less than 0.01) correlation between the presence of the growth factor receptor and poor prognosis as assessed by the Bloom and Richardson score, suggesting that epidermal growth factor receptor state could be a useful prognostic marker. Epidermal growth factor receptor state was not significantly correlated with the lymph node state but showed a tendency to be associated with large tumours.

Disturbances of lactate metabolism in patients with liver damage due to paracetamol overdose.

Six patients with liver damage following paracetamol overdose, one patient with viral hepatitis and six control subjects were infused with sodium L(+) lactate. In controls the results were analysed using a single compartment model while in paracetamol patients a two compartment system was used to derive the fractional rate removal constant and lactate distribution volume. Forearm arterio-venous differences of lactate were also determined in order to assess the role of voluntary muscle in removal of a lactate load. In paracetamol patients with fractional rate removal constant was decreased to less than half the control value (P less than 0.001) while total distribution volume was similar to the two groups. Fasting lactate concentrations were significantly increased in paracetamol patients due to diminished lactate removal since the endogenous production rate of lactate was not significantly different from controls. A greater proportion of the lactate load was removed in voluntary muscle in paracetamol patients (39%) than controls (17%). Since the balance of lactate removal occurs principally in the liver, the decrease in the fractional rate removal constant in patients following paracetamol overdose indicates a severe derangement of hepatic lactate metabolism with a compensatory increase in lactate metabolism in voluntary muscle.

High resolution magnetic resonance imaging of atherosclerosis and the response to balloon angioplasty.

OBJECTIVE: To explore the use of high resolution magnetic resonance imaging (MRI) of the popliteal artery in defining atheroscelerotic lesions and to monitor the remodelling response to balloon angioplasty. METHODS: Four patients (aged 49-67) with symptomatic discrete popliteal artery stenoses, as demonstrated by conventional angiography, underwent balloon angioplasty. MRI of the diseased vessel was performed before and one week, one month, three months, and six months after therapeutic balloon angioplasty. Cine phase contrast MRI was used to estimate blood flow just proximal to the lesion before and after angioplasty. RESULTS: In all patients the extent of the atherosclerotic plaque could be defined, such that even in segments of vessel which were angiographically "normal", atherosclerotic lesions with cross sectional areas ranging from 49% to 76% of potential lumen area were identified. Following angioplasty, plaque fissuring and local dissection were easily identified and serial changes in lumen diameter, blood flow. and lesion size could be documented. CONCLUSIONS: High resolution MRI can define the extent of atherosclerotic plaque in the peripheral vasculature and demonstrate the changes that occur with remodelling and restenosis following angioplasty. As a safe, reproducible technique MRI is ideal for assessing plaque and monitoring intervention, but further technological developments will be needed if similar or better images are to be achieved in other vascular beds.

Interpreting the correlation coefficient when one of the variables is discrete.

The effect on the correlation coefficient of discretizing data was investigated in two ways. First, the theoretical effect of dichotomizing data was calculated, and it was shown that the resulting correlation coefficient is considerably less than that between the underlying bivariate normally distributed variables. Second, computer simulations were performed of a model in which a continuous variable (measured with some error) gives rise to a counting variable through a mechanism in which the count is zero below a certain threshold value for the continuous variable and then increases linearly as the continuous variable increases. It was shown that the correlation coefficient between the observed values of the continuous and counting variables decreased as (a) the measurement error increased, (b) the slope of the relationship decreased, and (c) the number of counts decreased. It is concluded that caution is required when interpreting correlation coefficients when one or both of the variables consist of a few (say only four or five) discrete scores.

Thyroid hormone concentrations in a large scale community survey. Effect of age, sex, illness and medication.

Total thyroid hormone concentrations have been measured in the course of a large scale community survey to determine the distribution of these variables in the normal population and to assess the effect of age, sex, previously undectected thyroid disease and medication upon these parameters. 2779 subjects were studied. Serum T4 concentrations were normally distributed. A progressive increase in T4 levels with age was noted in the males, and a smaller increase in females which was concealed by the raised T4 values secondary to oral contraceptive therapy in females under the age of 45. Serum T3 levels were also normally distributed. There was a small reduction in T3 with age in the males but this fall was not seen in the females. T3 values were relatively higher in females under the age of 45 but this increase was not noted after exclusion of subjects taking an oral contraceptive. The changes in thyroid hormone concentrations with age are relatively minor (particularly with respect to T3) in a randomly selected sample from an English town. It is suggested that the changes reported by other authors reflect the process of selection used, and the high frequency of undetected thyroid disease, other illness and medication in hospital-based communities.

Pleomorphic xanthoastrocytoma: report of two cases.

Two cases of pleomorphic xanthoastrocytoma are presented to draw attention to this relatively benign variant of glioma. The circumscribed tumors, each with a cystic component, were located superficially, one in the mesial right temporal lobe and one in the right temporoparietal region. The patients were aged 12 and 14 years, and it is now almost 7 years since the onset of symptoms in the 12-year-old boy. The optimal plan of management is discussed.