The puzzle of chloroplast vesicle transport - involvement of GTPases

In the cytosol of plant cells vesicle transport occurs via secretory pathways among the endoplasmic reticulum network, Golgi bodies, secretory granules, endosome, and plasma membrane. Three systems transfer lipids, proteins and other important molecules through aqueous spaces to membrane-enclosed compartments, via vesicles that bud from donor membranes, being coated and uncoated before tethered and fused with acceptor membranes. In addition, molecular, biochemical and ultrastructural evidence indicates presence of a vesicle transport system in chloroplasts. Little is known about the protein components of this system. However, as chloroplasts harbor the photosynthetic apparatus that ultimately supports most organisms on the planet, close attention to their pathways is warranted. This may also reveal novel diversification and/or distinct solutions to the problems posed by the targeted intra-cellular trafficking of important molecules. To date two homologs to well-known yeast cytosolic vesicle transport proteins, CPSAR1 and CPRabA5e (CP, chloroplast localized), have been shown to have roles in chloroplast vesicle transport, both being GTPases. Bioinformatic data indicate that several homologs of cytosolic vesicle transport system components are putatively chloroplast-localized and in addition other proteins have been implicated to participate in chloroplast vesicle transport, including vesicle-inducing protein in plastids 1, thylakoid formation 1, snowy cotyledon 2/cotyledon chloroplast biogenesis factor, curvature thylakoid 1 proteins, and a dynamin like GTPase FZO-like protein. Several putative potential cargo proteins have also been identified, including building blocks of the photosynthetic apparatus. Here we discuss details of the largely unknown putative chloroplast vesicle transport system, focusing on GTPase-related components.

Multidrug-resistant endemic clonal strain of Candida auris in India

Candida auris is a recently described rare agent of fungemia. It is notable for its antifungal resistance. A total of 15 C. auris isolates, originating from seven cases of fungemia, three cases of diabetic gangrenous foot, and one case of bronchopneumonia from a tertiary care hospital in south India, were investigated. All of the 15 isolates were identified by sequencing and 14 of these along with 12 C. auris isolates previously reported from two hospitals in Delhi, north India, two each from Japan and Korea were genotyped by amplified fragment length polymorphism (AFLP). In vitro antifungal susceptibility testing (AFST) was done by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Candida auris isolates were misidentified as Candida haemulonii by VITEK. All were resistant to fluconazole [geometric mean minimum inhibitory concentration (MIC) 64 μg/ml] and 11 isolates were resistant to voriconazole (MIC ≥1 μg/ml). Forty-seven percent of the C. auris isolates were resistant to flucytosine (MIC ≥64 μg/ml) and 40% had high MIC (≥1 μg/ml) of caspofungin. Breakthrough fungemia developed in 28.6% of patients and therapeutic failure in 4 (66.7%) patients. Interestingly, the 26 Indian C. auris isolates from north and south India were clonal and phenotypically and genotypically distinct from Korean and Japanese isolates. The present study demonstrates that C. auris is a potential emerging pathogen that can cause a wide spectrum of human mycotic infections. The prevalence of a C. auris endemic clonal strain resistant to azoles and other antifungals in Indian hospitals with high rates of therapeutic failure in cases of fungemia is worrisome.

Evolutionary, molecular and genetic analyses of Tic22 homologues in Arabidopsis thaliana chloroplasts

The Tic22 protein was previously identified in pea as a putative component of the chloroplast protein import apparatus. It is a peripheral protein of the inner envelope membrane, residing in the intermembrane space. In Arabidopsis, there are two Tic22 homologues, termed atTic22-III and atTic22-IV, both of which are predicted to localize in chloroplasts. These two proteins defined clades that are conserved in all land plants, which appear to have evolved at a similar rates since their separation >400 million years ago, suggesting functional conservation. The atTIC22-IV gene was expressed several-fold more highly than atTIC22-III, but the genes exhibited similar expression profiles and were expressed throughout development. Knockout mutants lacking atTic22-IV were visibly normal, whereas those lacking atTic22-III exhibited moderate chlorosis. Double mutants lacking both isoforms were more strongly chlorotic, particularly during early development, but were viable and fertile. Double-mutant chloroplasts were small and under-developed relative to those in wild type, and displayed inefficient import of precursor proteins. The data indicate that the two Tic22 isoforms act redundantly in chloroplast protein import, and that their function is non-essential but nonetheless required for normal chloroplast biogenesis, particularly during early plant development.

Varieties of foetal congenital abnormality

The purpose of the study is to determine the type of fetal congenital abnormalities found among high risk pregnancies admitted in Fetomaternal Unit of Obs & Gynae Department in BSMMU. This is a cross sectional study done during the period July 2007 to June 2010. All the patients admitted with congenital abnormality in fetomaternal unit during this study period were included in this study. One hundred five cases had congenital abnormality of fetus among 1134 deliveries. Out of which 46.66% had CNS abnormalities and 19.04% had renal abnormalities. Out of CNS abnormalities Hydrocephalous (40.81%) was the most common, 31.42% patients were of age between 20-24 years, 69.52% patients had parity between 1-3, 35.37% had deliveries ≥ 37 weeks, 69.52% patients had vaginal deliveries, 82.89% patients were terminated by prostaglandins, 96.19% patients had no drug history other than intake of iron and calcium, 26.67% babies had birth weight between 1.1-1.5 kg and 70.4% were of male babies. Advances in ultrasound technology have made possible the prenatal identification of an increasingly large number of fetal congenital malformations. Now fetal anatomical survey is performed routinely between 18 to 22 weeks.

A painful perineal lump: an unusual case of ectopic breast tissue

We report the case of a 40-year-old lady who presented with an episodically painful perineal lump. Clinical and radiological investigations were inconclusive. Excision biopsy confirmed an ectopic breast mass. Ectopic breast tissue is difficult to diagnose but close attention to clinical findings can help to guide further investigation and diagnosis.

Effect of crystallographic texture on magnetic characteristics of cobalt nanowires

Cobalt nanowires with controlled diameters have been synthesized using electrochemical deposition in etched ion-track polycarbonate membranes. Structural characterization of these nanowires with diameter 70, 90, 120 nm and length 30 μm was performed by scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction techniques. The as-prepared wires show uniform diameter along the whole length and X-ray diffraction analysis reveals that [002] texture of these wires become more pronounced as diameter is reduced. Magnetic characterization of the nanowires shows a clear difference of squareness and coercivity between parallel and perpendicular orientations of the wires with respect to the applied field direction. In case of parallel applied field, the coercivity has been found to be decreasing with increasing diameter of the wires while in perpendicular case; the coercivity observes lower values for larger diameter. The results are explained by taking into account the magnetocrystalline and shape anisotropies with respect to the applied field and domain transformation mechanism when single domain limit is surpassed.

Study to see the efficacy and toxicity profile of docetaxel-based chemotherapy in advanced stomach cancer in Bangladeshi patient population

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Background: Gastric cancer is the second most common cause of cancer death worldwide. In Bangladesh it is one of the major causes of cancer death. Advanced gastric cancer patients have a poor prognosis of 3 to 5 months. Docetaxel has shown activity against gastric cancer as monotherapy and in combination with other agents. The purpose of this study was to investigate the efficacy and toxicity profile of docetaxel based chemotherapy in advanced stomach cancer in Bangladeshi patient population. Methods: From January 2004 to December 2006, thirty patients with advanced inoperable gastric cancer (Gastric or esophagogastric adenocarcinoma) were included in the study. Patients received no prior chemotherapy. Patients were given docetaxel 75mg/m2 I/V in 1 hour infusion and Cisplatin 75mg/m2 (d1) plus 5-fluorouracil 750mg/m2/d (days 1 to 5) I/V with adequate hydration every 3 weeks. The primary end point was time to tumour progression. Secondary end point was overall survival and toxicity profile. Results: Among the 30 evaluable patients time to tumour progression was 11.5 months. Overall response rate was 87% (26 patients). Complete response rate was 20% (6 patients), 27% (8 patients) had stable disease, 7% (2 patients) had developed progressive disease. Two-year survival rate was 21%. Grade 3 to 4 treatment related adverse events occurred in 63%. Among the toxicities there were: neutropenia (80%), stomatitis (19%), and diarrhea (15%). There was no treatment related death. Conclusions: Adding docetaxel to CF regimen significantly improved time to tumour progression and survival rate in advanced gastric cancer patients. In context with the survival benefit the toxicities of this regimen are acceptable. Docetaxel in combination with Cisplatin and 5-fluorouracil is a very safe and active in patients of Bangladesh with advanced gastric cancer. Larger studies involving higher number of patients are needed to evaluate these results in case of Bangladeshi patient population.

No significant financial relationships to disclose.

Tuning the characteristics of electrochemically fabricated gold nanowires

We have developed different electrochemical procedures for the production of gold nanowires with variable and controllable crystallographic and morphological properties using etched ion track templates. The texture of the nanowires is tuned by the variation of the electrodeposition parameters. Potentiostatic plating at low overvoltage provides strongly (110) textured wires for diameters below 100 nm. With the increase in diameter above 100 nm, this texture decreases and the signal from ({111} planes becomes more pronounced. Under reverse pulse deposition conditions, (100) textured wires are generated. The growth mechanism is discussed in detail in terms of the surface energy minimum principle. In addition, wires are shaped in a reliable way from cylindrical to conical geometry by engineering the pore structure in the template.

Monogalactosyldiacylglycerol deficiency in Arabidopsis affects pigment composition in the prolamellar body and impairs thylakoid membrane energization and photoprotection in leaves

Monogalactosyldiacylglycerol (MGDG) is the major lipid constituent of chloroplast membranes and has been proposed to act directly in several important plastidic processes, particularly during photosynthesis. In this study, the effect of MGDG deficiency, as observed in the monogalactosyldiacylglycerol synthase1-1 (mgd1-1) mutant, on chloroplast protein targeting, phototransformation of pigments, and photosynthetic light reactions was analyzed. The targeting of plastid proteins into or across the envelope, or into the thylakoid membrane, was not different from wild-type in the mgd1 mutant, suggesting that the residual amount of MGDG in mgd1 was sufficient to maintain functional targeting mechanisms. In dark-grown plants, the ratio of bound protochlorophyllide (Pchlide, F656) to free Pchlide (F631) was increased in mgd1 compared to the wild type. Increased levels of the photoconvertible pigment-protein complex (F656), which is photoprotective and suppresses photooxidative damage caused by an excess of free Pchlide, may be an adaptive response to the mgd1 mutation. Leaves of mgd1 suffered from a massively impaired capacity for thermal dissipation of excess light due to an inefficient operation of the xanthophyll cycle; the mutant contained less zeaxanthin and more violaxanthin than wild type after 60 min of high-light exposure and suffered from increased photosystem II photoinhibition. This is attributable to an increased conductivity of the thylakoid membrane at high light intensities, so that the proton motive force is reduced and the thylakoid lumen is less acidic than in wild type. Thus, the pH-dependent activation of the violaxanthin de-epoxidase and of the PsbS protein is impaired.

Cholinesterase inhibitors for delirium

BACKGROUND

Delirium is now the preferred term to describe acute confusional states. It is experienced by 10 to 30% of all hospital inpatients. Delirium is potentially reversible and is related to several adverse outcomes, including increased hospital length of stay, poor functional status, persistent cognitive impairment, need for institutional care and probably mortality. Disruption of the cholinergic system has been proposed as a key mechanism of delirium. Cholinesterase inhibitors enhance the cholinergic system and there have been reports that they might be beneficial in treating delirium.

OBJECTIVES

To assess the efficacy and safety of cholinesterase inhibitors in the treatment of delirium.

SEARCH STRATEGY

The Cochrane Dementia and Cognitive Improvement Group's Register of Clinical Trials (which includes records from MEDLINE, EMBASE, PsycINFO, CINAHL, CENTRAL, LILACS and other databases) was searched for relevant randomised controlled trials using the terms: donepezil or aricept, galantamine or reminyl, rivastigmine OR exelon and tacrine OR cognex on 19 April 2005. As this Specialised Register only contains trials relating to dementia and cognitive impairment, in addition all years of MEDLINE, EMBASE, PsycINFO and CINAHL were searched for trials of cholinesterase inhibitors for delirium in non-demented people.

SELECTION CRITERIA

Unconfounded, blinded randomised controlled trials, published or unpublished in which treatment with cholinesterase inhibitors was administered and compared with alternative interventions in patients with delirium are included.

DATA COLLECTION AND ANALYSIS

Two reviewers (RO, SK) independently assessed the quality of the studies according to parameters such as randomisation, blinding and how dropouts were managed. Each cholinesterase inhibitor was to be examined separately and together as a group. The primary outcome measures of interest are length of delirium, severity of delirium and presence and severity of behavioural symptoms (e.g. agitation and hallucinations). Other outcomes of interest include: cognition, need for institutionalisation, length of hospital admission and adverse effects.

MAIN RESULTS

There was one included trial of donepezil compared with placebo in 15 patients. No significant difference between the treatment and placebo groups was found in the duration of delirium. The mean duration of postoperative delirium for the donepezil group was 1.0 day (Standard Error 0.0) while for the placebo group it was 1.3 days (Standard Error 0.19). No other outcomes were measured for the patients who developed delirium.

AUTHORS' CONCLUSIONS

There is currently no evidence from controlled trials that donepezil is effective in the treatment of delirium. Further trials using cholinesterase inhibitors for the treatment of delirium are needed.

Development of the Dementia Quality of Life questionnaire (D-QOL): UK version

The importance of using quality of life measures for clinical practice and research in dementia is well established. Quality of life being people's perception of their position in life in context of their culture, hence the need for developing culturally sensitive quality of life measures. This study aimed at producing the UK version of the US Dementia-Quality of Life (D-QOL), a validated instrument for measuring quality of life in people with mild to moderate dementia. The study was conducted in three stages--adaptation, piloting and validation. In the adaptation stage, the US D-QOL was translated by a panel comprising lay people and researchers. In the piloting stage the draft was tested by administering it to fifteen patients with dementia and their feedback on acceptability, relevance and clarity. In the validation stage, 36 patients with mild to moderate dementia were administered UK D-QOL on two occasions with an interval of two weeks. The results showed that the UK version of D-QOL has comparable psychometric properties to the US version. We conclude that the UK version of D-QOL is a reliable and valid measure of quality of life in UK population with mild to moderate dementia.

Improved drought tolerance without undesired side effects in transgenic plants producing trehalose

Most organisms naturally accumulating trehalose upon stress produce the sugar in a two-step process by the action of the enzymes trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP). Transgenic plants overexpressing TPS have shown enhanced drought tolerance in spite of minute accumulation of trehalose, amounts believed to be too small to provide a protective function. However, overproduction of TPS in plants has also been found combined with pleiotropic growth aberrations. This paper describes three successful strategies to circumvent such growth defects without loosing the improved stress tolerance. First, we introduced into tobacco a double construct carrying the genes TPS1 and TPS2 (encoding TPP) from Saccharomyces cerevisiae. Both genes are regulated by an Arabidopsis RuBisCO promoter from gene AtRbcS1A giving constitutive production of both enzymes. The second strategy involved stress-induced expression by fusing the coding region of ScTPS1 downstream of the drought-inducible Arabidopsis AtRAB18 promoter. In transgenic tobacco plants harbouring genetic constructs with either ScTPS1 alone, or with ScTPS1 and ScTPS2 combined, trehalose biosynthesis was turned on only when the plants experienced stress. The third strategy involved the use of AtRbcS1A promoter together with a transit peptide in front of the coding sequence of ScTPS1, which directed the enzyme to the chloroplasts. This paper confirms that the enhanced drought tolerance depends on unknown ameliorated water retention as the initial water status is the same in control and transgenic plants and demonstrates the influence of expression of heterologous trehalose biosynthesis genes on Arabidopsis root development.

Poverty is not the main obstacle for quality cancer care in diagnosed cases: Experience of 520 cases from Bangladesh

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Background: Cancer management is expensive everywhere. In the developing countries poverty is always blamed for as to be the main obstacle for quality cancer care. According to WHO report (globocan) 1.295 to 1.36 million people in Bangladesh suffer from cancer. Our health care service is not extensive to diagnose all these cases. A number of diagnosed cases do not get standard specific treatment of cancer. The objective of the study is to find out the main possible reason behind it. Methods: We made a prospective analysis of pre-diagnosis and post-diagnosis expenses using hospital documents & taken interview with specific questionnaire form of 520 cases regardless of age, indication and management who are treated from January 2002 to December 2005 in NICRH, City General Hospital & Bangladesh Medical College Hospital. We calculated the total expenses incurred to each case before specific diagnosis (EBD). These include all investigations, and non-specific treatment costs from the onset of symptoms up to the specific diagnosis. We have estimated the total expenses after diagnosis (EAD). This includes planned specific cancer management according to diagnosis. We made a ratio in percent between them (EBD/EAD×100). Results: 219 cases (42%) spent = 100% of EAD before diagnosis. 94 cases (18%) spent = 200% of EAD before diagnosis. The more this ratio, less the quality of management they could afford. Among them 349 cases (67%) failed to complete planned management, 57 cases (11%) failed to receive any planned management. Only 114 cases (22%) completed their planned management. Queries revealed that 78% patients who failed to complete planned management is due to their financial exhaustion for high pre-diagnostic expenses. Conclusions: We conclude that poverty is not the main obstacle for quality cancer care in diagnosed cases of Bangladesh. High unnecessary pre-diagnostic expenses, which result in financial exhaustion, is one of the major obstacles for quality cancer care. Further study is required to determine how to reduce the redundant pre-diagnostic expenses & find out other removable factors for quality cancer care in developing countries like Bangladesh.

No significant financial relationships to disclose.

Peripheral blood lymphocyte subpopulations in patients with cervical cancer

OBJECTIVE

Impairment of cell-mediated immunity in carcinoma of the cervix (CA CX) and cervical intraepithelial neoplasia (CIN) are reported. Contradictory reports exist on lymphocyte subpopulations associated with this disease. The present study aims to quantitatively analyze peripheral blood lymphocytes subsets in patients with CA CX and CIN.

METHOD

Systemic T lymphocyte subsets, CD19+, CD16+ and CD56+ cells in 58 CA CX and 10 CIN patients were studied. The lymphocyte phenotypes were quantified by monoclonal antibodies (anti-CD4, CD8, CD16, CD19 and CD56).

RESULT

Significant decrease in CD4+ cell population was observed in CA CX and CIN patients as compared to controls (P< or =0.05). CD4+/CD8+ ratio was observed to be less in CIN patients (P< or =0.001). Other lymphocyte subpopulations appeared to be comparable between the groups.

CONCLUSION

Results indicate immunological abnormalities in invasive CA CX and CIN patients. Study on a larger patient population may provide a biomarker for early detection of this disease.

AtPTR3, a wound-induced peptide transporter needed for defence against virulent bacterial pathogens in Arabidopsis

Mutation in the wound-induced peptide transporter gene AtPTR3 (At5g46050) of Arabidopsis thaliana has been shown to affect germination on media containing a high salt concentration. The heterologous expression in yeast was utilized to verify that the AtPTR3 protein transports di-and tripeptides. The T-DNA insert in the Atptr3-1 mutant in the Arabidopsis ecotype C24 revealed two T-DNA copies, the whole vector sequence, and the gus marker gene inserted in the second intron of the AtPTR3 gene. An almost identical insertion site was found in the Atptr3-2 mutant of the Col-0 ecotype. The AtPTR3 expression was shown to be regulated by several signalling compounds, most clearly by salicylic acid (SA), but also methyl jasmonate (MeJA) and abscisic acid. Real-time PCR experiments suggested that the wound-induction of the AtPTR3 gene was abolished in the SA and JA signalling mutants. The Atptr3 mutant plants had increased susceptibility to virulent pathogenic bacteria Erwinia carotovora subsp. carotovora and Pseudomonas syringae pv. tomato, and produced more reactive oxygen species when grown on media containing paraquat or rose bengal. Public microarray data suggest that the AtPTR3 expression was induced by Pseudomonas elicitors and by avirulent P. syringae pathovars and type III secretion mutants. This was verified experimentally for the hrpA mutant with real-time PCR. These results suggest that AtPTR3 is one of the defence-related genes whose expression is reduced by virulent bacterium by type III dependent fashion. Our results suggest that AtPTR3 protects the plant against biotic and abiotic stresses.

Older people with chronic schizophrenia

Older people with chronic schizophrenia are a numerically small but important group with complex clinical and service needs. Along with a reduction in positive schizophrenic symptoms with increasing age, a majority suffer from negative symptoms, cognitive deficits, depression, side effects due to long-term use of antipsychotics and co-morbid medical problems. They may have social disabilities making them vulnerable to poverty, isolation and poor quality of life. Evidence suggests that judicious use of antipsychotics combined with psychotherapy and psychosocial interventions are effective. There are shortcomings in the standard of both hospital and community care, and the cost implications of providing adequate services are high.

Structural and functional characterization of AtPTR3, a stress-induced peptide transporter of Arabidopsis

A T-DNA tagged mutant line of Arabidopsis thaliana, produced with a promoter trap vector carrying a promoterless gus (uidA) as a reporter gene, showed GUS induction in response to mechanical wounding. Cloning of the chromosomal DNA flanking the T-DNA revealed that the insert had caused a knockout mutation in a PTR-type peptide transporter gene named At5g46050 in GenBank, here renamed AtPTR3. The gene and the deduced protein were characterized by molecular modelling and bioinformatics. Molecular modelling of the protein with fold recognition identified 12 transmembrane spanning regions and a large loop between the sixth and seventh helices. The structure of AtPTR3 resembled the other PTR-type transporters of plants and transporters in the major facilitator superfamily. Computer analysis of the AtPTR3 promoter suggested its expression in roots, leaves and seeds, complex hormonal regulation and induction by abiotic and biotic stresses. The computer-based hypotheses were tested experimentally by exposing the mutant plants to amino acids and several stress treatments. The AtPTR3 gene was induced by the amino acids histidine, leucine and phenylalanine in cotyledons and lower leaves, whereas a strong induction was obtained in the whole plant upon exposure to salt. Furthermore, the germination frequency of the mutant line was reduced on salt-containing media, suggesting that the AtPTR3 protein is involved in stress tolerance in seeds during germination.

Comparative effect of different types of food on the bioavailability of cefaclor extended release tablet

This randomized, six-treatment, six-period, six sequence, single dose, crossover pharmacokinetic study assessed the effect of different types of food on the bioavailability of 500-mg cefaclor extended release tablet in 23 healthy male volunteers. A single dose of cefaclor extended release 500-mg tablet was administered at six occasions: after overnight fasting, after two vegetarian (high-fat and low-fat), two non-vegetarian (high-fat and low-fat) and rice diets. Serial blood samples were collected up to 12 h after dose. Serum cefaclor concentrations were determined by a validated HPLC method. An almost equivalent increase in both Cmax and AUC was observed with both high-fat non-vegetarian and low-fat vegetarian breakfasts. However, when MIC90 values, a pharmacodynamic end-point were compared, the low-fat vegetarian diet fared better than the high-fat non-vegetarian diet. The results obtained favor low-fat vegetarian diet (breakfast) to be taken with cefaclor extended release tablet to achieve maximum benefit in terms of clinical efficacy.

The effect of four different types of food on the bioavailability of cefaclor

This randomized, open-label, balanced, five-treatment, five-period, five-sequence, single-dose and crossover pharmacokinetic study assessed the effect of different types of food on the bioavailability of cefaclor in 18 healthy male volunteers. A single dose of cefaclor, 250-mg capsule was administered at five occasions: after overnight fasting, after two vegetarian (high-fat and low-fat) diets and two non-vegetarian (high-fat and low-fat) diets. Serial blood samples were collected upto 8 h post dose. Serum cefaclor concentrations were determined by a validated HPLC method. AUC values were not significantly affected by food intake, but the T(max) was prolonged and C(max) was decreased, depending on the type of meal. The non-vegetarian diets affected the rate of absorption of cefaclor more than the vegetarian diets. The least decrease in C(max) was produced by low-fat vegetarian diet, while the maximum decrease was produced by high-fat non-vegetarian diet. The results of this study indicate that while the rate of absorption of cefaclor is significantly decreased, the extent of absorption and the rate of elimination are not significantly decreased in the presence of food. As compared to high-fat non-vegetarian diet, the time above MIC50 concentration was significantly increased by low-fat vegetarian diet. The implications of these findings for the large vegetarian Indian population are considerable.

Comparison of CT and MRI in the pre-operative staging of rectal adenocarcinoma and prediction of circumferential resection margin involvement by MRI

OBJECTIVE

It has been suggested that MRI may be used as the sole modality of choice in pre-operative staging in rectal cancers. Knowledge of tumour stage and a threatened Circumferential Resection Margin (CRM) pre-operatively are essential for planning neo-adjuvant therapy and as predictors of local recurrence. At present most units utilize CT scanning to assess these parameters. The aim of our study was two fold: firstly to examine the accuracy of preop CT and MRI staging of rectal cancers compared with final histology and secondly to assess the accuracy of MRI in predicting penetration of the mesorectal envelope (ME).

PATIENTS AND METHODS

All patients with biopsy proven rectal adenocarcinoma underwent thin slice MRI and CT scan pre-operatively. Forty-seven patients have been prospectively entered into the study: 24 male (median age 68 years; range 38-91 years). Eleven patients were unsuitable for surgery leaving 36 patients available for study.

RESULTS

CT correctly staged patients with T1/T2 rectal cancers more often than MRI (77% vs. 43%, P = 0.226). Patients with T1/T2 tumours were overstaged more often by MRI compared with CT (54% vs. 23%, P = 0.226). A greater proportion of patients with T3 tumours were correctly staged by MRI than CT (76% vs. 41%, P = 0.08); and more T3 disease was understaged by CT than MRI (54 vs. 18%, P = 0.032). CT and MRI staged T4 disease equally. In the assessment of mesorectal envelope integrity, MRI had a sensitivity of 80% and a specificity of 84%. The positive predictive value was 44% and the negative predictive value 96%.

CONCLUSIONS

These results suggest significant differences between accurate pre-operative "T" staging by CT and MRI for rectal cancer. MRI has the potential however, to accurately assess mesorectal envelope invasion. Further analysis is required to assess whether MRI can be used as the sole modality in pre-operative staging of rectal cancers.

Identification of SNARE and cell trafficking regulatory proteins in the salivary glands of the lone star tick, Amblyomma americanum (L.)

Prostaglandin E(2) (PGE(2)) stimulates secretion of tick salivary gland proteins via a phosphoinositide signaling pathway and mobilization of intracellular Ca(2+) (). Highly conserved intracellular SNARE (soluble NSF attachment protein receptors) complex proteins are associated with the mechanism of protein secretion in vertebrate and invertebrate neuronal and non-neuronal cells. Proteins in the salivary glands of partially fed female lone star ticks cross-react individually with antibodies to synaptobrevin-2 (vesicle (v)-SNARE), syntaxin-1A, syntaxin-2 and SNAP-25 (target (t)-SNAREs), cytosolic alpha/beta SNAP and NSF (N-ethylmaleimide-sensitive fusion protein), Ca(2+) sensitive synaptotagmin, vesicle associated synaptophysin, and regulatory cell trafficking GTPases Rab3A and nSec1. V-SNARE and t-SNARE proteins form an SDS-resistant, boiling sensitive core complex in the salivary glands. Antibodies to SNARE complex proteins inhibit PGE(2)-stimulated secretion of anticoagulant protein in permeabilized tick salivary glands. We conclude that SNARE and cell trafficking regulatory proteins are present and functioning in the process of PGE(2)-stimulated Ca(2+) regulated protein secretion in tick salivary glands.

Hybrid capture as a means of detecting human papillomavirus DNA from liquid-based cytology specimens: a preliminary evaluation

The connection between human papillomavirus (HPV) and cervical cancer is well documented, as is the benefit of an adjunctive, standardised objective test to complement cervical screening. Here, 197 liquid-based cytology (LBC) specimens previously processed for cytological examination (75 negative, 108 borderline/mild dyskaryosis, and 14 moderate/severe dyskaryosis) are examined for the presence of HPV using a hybrid capture assay. Of the 197 specimens tested for HPV DNA, 97 (49.2%) were positive using the combined high/low-risk probe, and 59 (29.9%) were negative cytologically and with the hybrid capture HPV test; however, 16/175 (21.3%) specimens classified as negative cytologically with LBC proved positive for HPV by hybrid capture. Of the 122 samples that showed abnormal cytology, 81 (66.4%) were positive for HPV. Although the number of samples tested is small, the results show that the use of LBC technology for both cervical cytological screening and the hybrid capture test has the potential to reduce both false-negative and -positive rates associated with cytological screening alone.

Socioeconomic and cultural influence in the causation of burns in the urban children of Bangladesh

This prospective case-control study was conducted on 105 consecutive cases admitted to the burn units of Dhaka Shishu Hospital and Dhaka Medical College Hospital. The same number of controls were selected randomly from the community and matched with respect to age group, sex, and location of residence within the defined metropolitan area during the period January to September 1997. Both the controls and cases were divided into three age groups. Group A (19 controls and 19 cases) included neonates and infants, group B included children from 1 to 4 years, and group C included children from 4 to 12 years. The mean age of the controls in group A was 8.42+/-3.86 months and in group B and C was 5.72+/-4.05 years. The mean age of cases in group A was 4.79+/-4.05 months and in group B and C was 5.08+/-2.87 years. A scoring system was used to analyze 14 socioeconomic and cultural factors, which indicated highly significant differences between controls and cases (P < 0.001), and also between male (P < 0.001) and female (P < 0.001) controls and cases. There were significant differences between controls and cases in group A (P < 0.001), group B (P < 0.01), and group C (P < 0.001). Differences were not significant between males and females within groups A, B, and C for cases or controls (P > 0.05). Regression analysis of the total scores for cases and controls indicated a negative correlation between burns and the socioeconomic variables included in the study. There were highly significant associations between burns and lack of alertness to burns among parents (P < 0.001), clothing of manmade fabrics (P < 0.001), and cooking equipment in the kitchen within reach of children (P < 0.001). There was a significant association between burns and illiteracy of the mother (P < 0.01), housing located in slums and congested areas (P < 0.01), illiteracy of the father (P < 0.02), presence of preexisting impairment in children (P < 0.05), presence of a history of burns among siblings (P < 0.05), and low economic status of the parents (P < 0.05). No significant associations were indicated between controls and cases with respect to number of children in the family (P > 0.1), family pattern (P > 0.1), conjugal bonding between parents (P > 0.5), and sibling's death and disability from burns (P > 0.5). It is evident that an increase in alertness to burns, easy availability of clothing of natural fabrics, keeping cooking equipment beyond the reach of the children, increased literacy among parents and children, and improvement in family income might decrease the incidence of burns in children.

Metabolic effects of alcoholism and its relationship with alcoholic liver disease

BACKGROUND

Chronic and excessive ethanol consumption is associated with cellular proliferation, fibrosis, cirrhosis and cancer of liver. It was planned to study the effect of alcohol on different biochemical parameters as distribution of these parameters may lead to several complications in gastrointestinal tract, liver, kidney, brain etc.

METHODS

50 alcoholic males and 20 normal subject (with no history of alcohol) with an age ranges 30-45 years were included in the study. Biochemical parameters related to liver were estimated by standard kit. Besides, ions and electrolytes were also determined by standard kit and flame photometry.

RESULTS

It was observed that level of alkaline phosphatase, alanine transferase, protein and globulin were significantly increased as compared to normal subjects. Besides, ions like calcium and phosphate were significantly decreased. On the other hand the level of potassium and magnesium was significantly decreased as compared to normal subjects. Electrophoresis shows a protein of 100 Kda is present in the patients sample as compared to control subjects.

CONCLUSION

It is therefore concluded that abnormal biochemical function of liver in alcoholism can lead to several complications, hence further research is needed to reach a definite conclusion.