In vivo magnetic resonance spectroscopy of gynaecological tumours at 3.0 Tesla.

BACKGROUND: Magnetic resonance spectroscopy (MRS) uses the same hardware as MR imaging and allows us to analyse the biochemistry of tissues in vivo. Published data for gynaecological lesions are limited and are largely based on MRS carried out at the lower magnetic field strength of 1.5 Tesla (T). OBJECTIVE: The purpose of this study was to determine whether in vivo proton MRS could be performed at the higher magnetic field strength of 3 T to characterise the spectra of a variety of benign and malignant gynaecological lesions. DESIGN: Prospective, non-randomised study. SETTING: MRI department within a tertiary referral centre for gynaecological cancers. SAMPLE: All women with a pelvic mass under going 3T MRI. METHODS: We carried out MRS on nonrandomised women undergoing routine 3 T MRI within our MRI department during investigation for gynaecological lesions from February 2006 to April 2008. Only those women for whom histopathological data were available were included. MAIN OUTCOME MEASURES: The presence of choline detected by in vivo 3T MRS. RESULTS: Eighty-seven women underwent MRS, 57 of whom had newly diagnosed neoplasms. MRS data for 39 of these new women (18 were excluded because of technical errors or missing data) were used to detect the presence of choline, an indicator of basement membrane turnover. Overall, choline was present in 13 of the 14 ovarian cancers, 8 of the 11 cervical tumours and all 4 of the uterine cancers. There was no statistical significant difference between choline levels in various lesion types (P=0.735) or between benign and malignant disease (P=0.550). CONCLUSIONS: In vivo MRS can be performed at 3 T to provide biochemical information on pelvic lesions. The way in which this information can be utilised is less clear but may be incorporated into monitoring tissue response in cancer treatments.

The accurate staging of ovarian cancer using 3T magnetic resonance imaging--a realistic option.

OBJECTIVES: The aim of the study was to determine whether staging primary ovarian cancer using 3.0 Tesla (3T) magnetic resonance imaging (MRI) is comparable to surgical staging of the disease. DESIGN: A retrospective study consisting of a search of the pathology database to identify women with ovarian pathology from May 2004 to January 2007. SETTING: All women treated for suspected ovarian cancer in our cancer centre region. SAMPLE: All women suspected of ovarian pathology who underwent 3T MRI prior to primary surgical intervention between May 2004 and January 2007. METHODS: All women found to have ovarian pathology, both benign and malignant, were then cross checked with the magnetic resonance (MR) database to identify those who had undergone 3T MRI prior to surgery. The resulting group of women underwent comparison of the MR, surgical and histopathological findings for each individual including diagnosis of benign or malignant disease and International Federation of Gynecology and Obstetrics (FIGO) staging where appropriate. MAIN OUTCOME MEASURES: Comparisons were made between the staging accuracy of 3T MRI and surgical staging compared with histopathological findings and FIGO stage using weighted kappa. Sensitivity, specificity and accuracy were calculated for diagnosing malignant ovarian disease with 3T MRI. RESULTS: A total of 191 women identified as having ovarian pathology underwent imaging with 3T MR and primary surgical intervention. In 19 of these women, the ovarian disease was an incidental finding. The group for which staging methods were compared consisted of 77 women of primary ovarian malignancy (20 of whom had borderline tumours). 3T MRI was able to detect ovarian malignancy with a sensitivity of 92% and a specificity of 76%. The overall accuracy in detecting malignancy with 3T MRI was 84%, with a positive predictive value of 80% and negative predictive value of 90%. Statistical analysis of the two methods of staging using weighted kappa, gave a K value of 0.926 (SE +/-0.121) for surgical staging and 0.866 (SE +/-0.119) for MR staging. A further analysis of the staging data for ovarian cancers alone, excluding borderline tumours resulted in a K value of 0.931 (SE +/-0.136) for histopathological staging versus MR staging and 0.958 (+/-0.140) for histopathological stage versus surgical staging. CONCLUSION: Our study has shown that MRI can achieve staging of ovarian cancer comparable with the accuracy seen with surgical staging. No previous studies comparing different modalities have used the higher field strength 3T MRI. In addition, all other studies comparing radiological assessment of ovarian cancer have grouped the stages into I, II, III and IV rather than the more clinically appropriate a, b and c subgroups.

Boerhaave's syndrome presenting as tension pneumothorax.

Boerhaave's syndrome can present initially as a case of tension pneumothorax. Mortality rate with delayed treatment is very high, therefore diagnosis should be made rapidly in the emergency department. Multidisciplinary cooperation, immediate radiological confirmation, prompt aggressive resuscitation, and surgical intervention offer the best chance of survival.

HLA-D types and serum IgG responses to Capnocytophaga in diabetes and periodontitis.

Serum IgG responses to the cell envelope proteins (CEPs) from Capnocytophaga sputigena, Capnocytophaga ochracea, and Capnocytophaga gingivalis were examined in periodontally healthy and periodontitis subjects, both with and without type 1 diabetes (n = 60). Serum IgG responses to CEPs were determined by immunoblotting with biotin-goat anti-human IgG and an alkaline phosphatase-streptavidin system. Reactivity was analyzed by transmission densitometry, digitization, and computer manipulation. The patients with diabetes showed significantly (p < 0.01) fewer responses to 14 CEPs (from 81 to 10 kDa) from C. sputigena, 5 CEPs (from 90 to 17 kDa) from C. gingivalis, and the 27-kDa CEP from C. ochracea than in the non-diabetic group. The periodontitis patients showed significantly (p < 0.01) fewer responses to the 25- and 11-kDa CEPs from C. sputigena, the 125- and 17-kDa CEPs from C. gingivalis, and the 42-kDa CEP from C. ochracea than in the periodontally healthy group. HLA-DR4, HLA-DR53, and HLA-DQw3 were associated with periodontitis, while only HLA-DR4 was associated with diabetes (p < 0.02). Significant (p < 0.01) correlations were found between HLA-DR2 and IgG reactivity patterns associated with non-diabetics, and between HLA-DR4 and IgG reactivity patterns associated with diabetic and periodontitis subjects. These results indicate that both type 1 diabetics and periodontitis subjects have a depressed IgG antibody profile to Capnocytophaga, which may account for an increased susceptibility to periodontitis infection. Periodontitis in type 1 diabetes may be related more to the HLA-D type and altered immune function than to the diabetes itself.

Computers, communication and confidentiality: tales of Baron Munchausen.

The aim was to examine the use of computer and paper based systems in accident and emergency (A&E) departments in the management of patients who are frequent attenders. More than half of the A&E consultants in the Thames regions who were sent a questionnaire responded (44 of the 80). 82% of the respondents use such systems predominantly to monitor violent patients, those with Munchausen syndrome, and children on the "at risk" register. Systems currently in use fail to fulfil many of the functions that would be required of an ideal system. When using computers to store and communicate clinical data, several ethical problems were identified but these appeared to be outweighed by the practical need and were also present with paper based systems. Safeguards could also be built into computer based systems to reduce some of the ethical problems. Computer systems should be deliberately chosen and implemented in response to a specific management problem. The potential benefits should be weighed against possible damaging side effects, such as a breach of confidentiality.

Deck-chairs: putting a finger on the problem, rather than in it.

Although often portrayed as something of a joke, injuries sustained in the setting-up and use of deck-chairs can have fairly serious consequences. Six patients who sustained finger injuries in some of London's Royal Parks during the Summer are presented together with data from the Department of Trade and Industry suggesting that, taken throughout the country as a whole, large numbers of injuries may be occurring. Notably, four of our patients were foreign tourists who may be less familiar with the traditional wooden folding deck-chair. Surprisingly no British Standards Institute (BSI) guidelines exist relating to deck-chair safety. These finger injuries can have marked morbidity if they involve victims who depend upon manual dexterity in their work or hobbies.

The Victoria bomb: a report from the Westminster Hospital.

On 18 February 1991 a bomb exploded on Victoria station, London. A total of 51 people were injured including one fatally. Of the most seriously wounded, 30 were treated at The Westminster Hospital. The majority of injuries were to the lower limbs, but serious wounds were also sustained to the chest, abdomen, forearm, orbit and cranium. Almost all injuries were caused by shrapnel. The low incidence of infection was attributed to thorough early surgical débridement. The administration of antibiotics was varied and uncoordinated, reflecting a lack of a common policy. The exhaustion of common external fixators necessitated the use of equipment unfamiliar to the surgeons and underlined the need for the rapid transfer of equipment between hospitals at the time of major incidents.

Establishment and characterization of a human CD4 positive cell bank for HIV related studies.

The human CD4 positive cell lines JM, CCRF, CEM, U937, HL60 and THP-1 have been cleared of mycoplasma contamination and defined by DNA fingerprinting and cell surface phenotype marker analysis. These cells have been banked and are now available as a source of standardized cell lines for HIV related research.

Comparison of media for screening of diarrheic stools for the recovery of Clostridium difficile.

Recoveries of Clostridium difficile from stool specimens by using three media, cycloserine-mannitol agar (M-CMA), cycloserine-mannitol-blood agar (M-CMBA), and cycloserine-cefoxitin agar (M-CCA), were compared. Of 321 clinical specimens, 37 yielded C. difficile. Thirty-four were positive on M-CCA, 21 were positive on M-CMA, and 20 were positive on M-CMBA. M-CCA recovered significantly more C. difficile than did M-CMBA or M-CMA.

Properties and characteristics of a bacteriocin-like substance produced by Propionibacterium acnes isolated from dental plaque.

A cell-associated bacteriocinlike substance with an approximate molecular weight of 78,000 was isolated from an oral isolate of Propionibacterium acnes. The substance was bacteriostatic and was active against both gram-positive and gram-negative anaerobes. Lysozyme inhibited the activity of the bacteriocinlike substance at low ionic strength.

Evidence for a membrane-bound form of a bacteriocin of Bacteroides uniformis Tl-1.

The bacteriocin of Bacteroides uniformis T1-1 had previously been reported to have a molecular weight of greater than or equal to 300 000. Reexamination of the B. uniformis bacteriocin revealed that the bacteriocin was found in association with membrane vesicles which had been released by bleb formation from the outer surface of the B. uniformis cells. The bacteriocin could be released from whole cells or purified membrane vesicles by treatment with 6 M guanidine hydrochloride or 7 M urea and had an apparent molecular weight of 5000-6200.

Transferable resistance to cefoxitin in Bacteroides thetaiotaomicron.

Cefoxitin resistance, but not resistance to clindamycin, erythromycin, lincomycin, or tetracycline, was transferred by a conjugation-like process from Bacteroides thetaiotaomicron UN101, a clinical isolate haboring four kinds of plasmids, to other Bacteroides species. Of a sample of 20 cefoxitin-resistant transconjugants, 8 contained all 4 plasmids, 10 contained 1 to 3 plasmids, and 2 contained no plasmids.

Tetracycline-inducible transfer of tetracycline resistance in Bacteroides fragilis in the absence of detectable plasmid DNA.

Tetracycline resistance of three Bacteroides fragilis strains was shown to be inducible by subinhibitory concentrations of tetracycline. Tetracycline resistance markers could be transferred to another B. fragilis strain by filter mating. The transferability was inducible by subinhibitory concentrations of tetracycline and did not take place in the absence of tetracycline. The optimum concentration of tetracycline for induction of transfer was about 2 microgram/ml. The transfer was shown to be a conjugation-like process requiring cell-to-cell contact between donor and recipient. Screening of parental donor strains for the presence of plasmid DNA did not demonstrate any detectable plasmids in two of the strains. A 3.0-megadalton plasmid, designated pBY5, was present in the third donor strain. Mobilization of pBY5 by another plasmid (pBF4) showed that pBY5 did not carry the genes responsible for tetracycline resistance. It appears that the genes responsible for resistance to tetracycline as well as those responsible for conjugal transfer may be carried on the chromosome in all three donor strains.

Stability in Escherichia coli of an antibiotic resistance plasmid from Bacteroides fragilis.

A Bacteroides fragilis strain resistant to penicillin G, tetracycline, and clindamycin was screened for the presence of plasmid deoxyribonucleic acid (DNA). Agarose gel electrophoresis of ethanol-precipitated DNA from cleared lysates of this strain revealed two plasmid DNA bands. The molecular weights of the plasmids were estimated by their relative mobility in agarose gel and compared with standard plasmids with known molecular weights. The molecular weights were 3.40 +/- 0.20 x 10(6) and 1.95 +/- 0.05 x 10(6) for plasmids pBY1 and pBY2, respectively. Plasmid DNA purified by cesium chloride-ethidium bromide gradient centrifugation was used to transform a restriction- and modification-negative strain of Escherichia coli. Penicillin G- and tetracycline-resistant transformants were screened for the presence of plasmid DNA. A plasmid band corresponding to a molecular weight of 1.95 x 10(6) was present in all transformants tested. Curing experiments demonstrated that the plasmid, referred to as pBY22 when present in transformants, was responsible for penicillin G and tetracycline resistance. Plasmid pBY22 was mobilized and transferred to other E. coli strains by plasmid R1drd-19. Stability of pBY22 was examined in different E. coli strains and was shown to be stably maintained in both restriction-negative and restriction-positive strains. Unexpectedly, pBY2 and pBY22 were resistant to digestion by 12 different restriction endonucleases.

Bacteriophages of Bacteroides.

Sixty-eight bacteriophages specific for nine species (DNA homology groups) of Bacteroides were isolated from sewage. Four distinct morphological types were isolated, three of which had not previously been described. Attempts to use these phages to transduce Bacteroides fragilis were unsuccessful. A total of 91 phage-susceptible strains of Bacteroides were used with these phages in a study of the feasibility of developing a scheme for identification of Bacteroides species. Blind trials were performed with 10 B. fragilis-specific phages and a collection of over 200 bacterial strains, including 144 strains of B. fragilis. Of the strains of B. fragilis, 78% were identified correctly within 24 hr. A phage-carrier state, or pseudolysogeny, was observed with most of the phage-host systems, and this state was studied in detail with B. fragilis phage Bf-1. The presence of a thick capsule around some cells in a pure culture of a host strain appears to render these cells resistant to phage infection, thus perpetuating the carrier state. It is suggested that such capsules may play a role in the virulence of strains of Bacteroides.

Bacteriocin production by strains of Bacteroides isolated from human feces and the role of these strains in the bacterial ecology of the colon.

Several human fecal isolates of Bacteroides have been found to produce bacteriocins. The bacteriocin-producing strain T1-1 was studied in the most detail. Strain T1-1 belongs to the 0061-1 deoxyribonucleic acid (DNA) homology group of Bacteroides. This homology group phenotypically resembles Bacteroides thetaiotaomicron but has little DNA homology with it. The bacteriocin-producing strains T1-12 and T1-48 belong to the 3452-A DNA homology group. This group has DNA homology with B. thetaiotaomicron and Bacteroides ovatus. The bacteriocin-producing strain T1-42 remains unidentified in that it does not belong to any recognized DNA homology group of the saccharolytic intestinal bacteroides. The extracellular bacteriocin produced by strain T1-1 was specifically bactericidal for other bacteria within the genus Bacteroides. The highest bacteriocin titers (32 to 64) were produced in complex media, with only trace amounts being produced in a defined medium. The bacteriocin appeared to have a high molecular weight (>/=300,000) and was unusual because it was stable from pH 1 to 12 and only a 50% reduction in activity resulted after 15 min at 121 degrees C in an autoclave. It was inactivated by trypsin and Pronase. Strain T1-1 was isolated from all three fecal samples obtained over a 25-week period from an individual who was part of a National Aeronautics and Space Administration mock Skylab flight. Strains T1-12, T1-48, and T1-42 were isolated only from the first fecal sample. Each of these strains was immune to the bacteriocins produced by the others. These strains were found to coexist in the colon with a larger population of non-bacteriocin-producing, bacteriocin-susceptible strains of Bacteroides.