PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-13 (13)
 

Clipboard (0)
None

Select a Filter Below

Journals
Authors
more »
Year of Publication
Document Types
1.  Dosimetric and radiobiological comparison of helical tomotherapy, forward-planned intensity-modulated radiotherapy and two-phase conformal plans for radical radiotherapy treatment of head and neck squamous cell carcinomas 
The British Journal of Radiology  2011;84(1008):1083-1090.
Objectives
The usual radical radiotherapy treatment prescribed for head and neck squamous cell carcinoma (HNSCC) is 70 Gy (in 2 Gy per fraction equivalent) administered to the high-risk target volume (TV). This can be planned using either a forward-planned photon-electron junction technique (2P) or a single-phase (1P) forward-planned technique developed in-house. Alternatively, intensity-modulated radiotherapy (IMRT) techniques, including helical tomotherapy (HT), allow image-guided inversely planned treatments. This study was designed to compare these three planning techniques with regards to TV coverage and the dose received by organs at risk.
Methods
We compared the dose–volume histograms and conformity indices (CI) of the three planning processes in five patients with HNSCC. The tumour control probability (TCP), normal tissue complication probability (NTCP) and uncomplicated tumour control probability (UCP) were calculated for each of the 15 plans. In addition, we explored the radiobiological rationality of a dose-escalation strategy.
Results
The CI for the high-risk clinical TV (CTV1) in the 5 patients were 0.78, 0.76, 0.82, 0.72 and 0.81 when HT was used; 0.58, 0.56, 0.47, 0.35 and 0.60 for the single-phase forward-planned technique and 0.46, 0.36, 0.29, 0.22 and 0.49 for the two-phase technique. The TCP for CTV1 with HT were 79.2%, 85.2%, 81.1%, 83.0% and 53.0%; for single-phase forward-planned technique, 76.5%, 86.9%, 73.4%, 81.8% and 31.8% and for the two-phase technique, 38.2%, 86.2%, 42.7%, 0.0% and 3.4%. Dose escalation using HT confirmed the radiobiological advantage in terms of TCP.
Conclusion
TCP for the single-phase plans was comparable to that of HT plans, whereas that for the two-phase technique was lower. Centres that cannot provide IMRT for the radical treatment of all patients could implement the single-phase technique as standard to attain comparable TCP. However, IMRT produced better UCP, thereby enabling the exploration of dose escalation.
doi:10.1259/bjr/53812025
PMCID: PMC3473826  PMID: 22101580
2.  Corticosteroid therapy in nephrotic syndrome: a meta-analysis of randomised controlled trials 
AIMS—To determine the benefits and toxicity of different corticosteroid regimes in preventing relapse in steroid responsive nephrotic syndrome.
DESIGN—Meta-analysis of randomised controlled trials.
SUBJECTS—Twelve trials involving 868 children aged 3 months to 18years.
MAIN OUTCOME MEASURE—Frequency of relapse.
RESULTS—A meta-analysis of five trials, which compared two months of prednisone with three months or more in the first episode, showed that the longer duration significantly reduced the risk of relapse at 12-24 months (relative risk 0.73; 95% confidence interval 0.60to 0.89) without an increase in adverse events. There was an inverse linear relation (relative risk 1.382 (SE 0.215) − 0.133 (SE 0.048) duration; r2 = 0.66; p = 0.05) between the duration of treatment and risk of relapse.
CONCLUSIONS—Children in their first episode of steroid responsive nephrotic syndrome should be treated with prednisone for at least three months, with an increase in benefit being shown for up to seven months of treatment.


doi:10.1136/adc.83.1.45
PMCID: PMC1718389  PMID: 10868999
3.  Syndrome X and hyperventilation. 
British Heart Journal  1991;65(2):94-96.
The cardiorespiratory responses to exercise and forced hyperventilation were measured in 17 unselected patients with syndrome X (angina, positive exercise test, normal coronary arteriogram, no other cardiovascular disease) and compared with those in 15 healthy subjects. Forced hyperventilation produced hypocapnia and metabolic alkalosis but no chest pain or electrocardiographic change. Patients with syndrome X showed reduced maximum oxygen consumption with an increased respiratory exchange ratio at peak exercise, confirming that exercise was limited by skeletal muscle perfusion--and thus that the increase in cardiac output with exercise is limited in syndrome X as in heart failure. Arterial carbon dioxide tension (PCO2) homoeostasis during exercise was normal but the ventilatory cost of carbon dioxide excretion was increased in syndrome X (as in heart failure). End tidal PCO2 measurements correlated only poorly with arterial PCO2 in individual patients with syndrome X, providing a possible explanation for previous reports, based on end tidal PCO2 of inappropriate hyperventilation. Patients with syndrome X did not show inappropriate hyperventilation but they did show hyperventilation that was appropriate to maintain normal arterial PCO2 in the face of reduced cardiac reserve.
PMCID: PMC1024499  PMID: 1907837
4.  Gamma ray inactivation of some animal viruses. 
Twenty samples of animal viruses comprising 14 different viruses in 12 families were subjected to varying doses of gamma irradiation from a 60Co source in a Gamma Cell 220 (Atomic Energy of Canada Limited) to determine lethal dose levels. The dose responses appeared linear throughout inactivation. The D10 values, that is the dose necessary to reduce infectivity by one log10, ranged from less than 0.20 Megarads to approximately 0.55 Megarads. There was not a complete inverse correlation between the target size (virion core) and the D10 value.
PMCID: PMC1320171  PMID: 6802472
5.  The isolation of salmonellae, Newcastle disease virus and other infectious agents from quarantined imported birds in Canada. 
Necropsy and culture results are presented for 269 consignments of imported birds (mainly psittacine and passerine species) examined between January 1977 and August 1980. Consignments were submitted for diagnosis of clinical illness or deaths occurring among these birds while they were in quarantine before entry into Canada. Enteritis and injury were the most frequent diagnoses. Pathogens or potential pathogens were isolated from 77% of consignments. Newcastle disease virus was isolated nine times, and Chlamydia psittaci was isolated once. Escherichia coli (from 113 consignments) and salmonellae (from 49) were the most common bacteria isolated, and reoviruses (from 22) and paramyxoviruses other than Newcastle disease virus (from 22) were the most common viruses. Salmonella typhimurium was the most common Salmonella serovar. Salmonella hadar was isolated from turkey poults imported from Great Britain. The possible public health significance of the role of imported birds in the introduction of exotic Salmonella serovars, or of serovars resistant to several antimicrobials is discussed.
PMCID: PMC1320165  PMID: 7039785
6.  Viral susceptibility of a cell line derived from the pig oviduct. 
Seventeen of 24 RNA viruses and eight of nine DNA viruses replicated in a cell line derived from a pig fallopian tube. The following RNA viruses grew poorly in it: the virus of transmissible gastroenteritis of pig and the swine-influenza, Sendai and bovine para-influenza type 3 viruses. Among other RNA viruses an untyped swine para-myxovirus and some picornaviruses, rhabdoviruses and togaviruses attained high titers and produced an extensive cytopathic effect. Among the DNA viruses a porcine adeno, equine rhinopneumonitis, infectious bovine rhinotraceheitis, pseudorabies and porcine cytomegalo viruses replicated in pig fallopian tube cells as well as in other cells generally used to grow them.
PMCID: PMC1277495  PMID: 169971
7.  Eye Signs of Neurological Disorders 
Canadian Family Physician  1974;20(12):42-46.
The author discusses common neurologic abnormalities as they involve the visual pathway and the ocular motor system. Mention is also made of the corneal reflex, eyelid closure and the pupillary response. Emphasis is placed on routine examination techniques that would assist the family physician in his office. The importance of early diagnosis is stressed and criteria for referral reviewed.
PMCID: PMC2274345  PMID: 20469140
9.  VI. Animal Transmission Studies 
The Cyprus strain of bluetongue virus was successfully transmitted through six passages and the Station strain through one passage in calves. Although the animals developed no visible evidence of infection, viremia as shown by both passage and fluorescent antibody examination of infected foetal bovine kidney culture, and by serological conversion was nevertheless demonstrated. No enhancement of virulence for calves or sheep was shown following bovine passage. A ewe inoculated in late pregnancy with blood drawn from a calf 59 days after its infection, gave birth to a lamb from whose blood the virus was isolated. Significant complement-fixation titres persisted for at least 200 days.
PMCID: PMC1494706  PMID: 4227048
10.  I. Antiserum Production 
These studies report on the production of African swine fever antiserum for use in serological tests. The first attempt to obtain antiserum was made by inoculating ASF virus - infected pig blood into the lactiferous sinus of lactating bovines. This failed to result in the development of detectable antibody, but resulted in propagation of the virus over a 14 to 21 day period.
In the second attempt use was made of a tissue culture - attenuated virus to produce resistance in normal pigs. Clinical response to inoculation with the attenuated virus was limited to a one day increase of temperature. These pigs were subsequently orally exposed to virulent ASF virus and later challenged by intramuscular injection. The sera were subjected to testing by the modified direct complement-fixation test and the agar gel double-diffusion technique in order to follow the development of antibodies. Some sera were also conjugated with fluorescein isothiocyanate and used for the detection of viral antigen by the fluorescent antibody technique.
It was found that inoculation with the attenuated virus brought about the development of low antibody levels in the pigs. This antibody level did not increase following oral exposure. One pig following intramuscular challenge underwent a series of ascending temperature peaks, coinciding with increased complement-fixing titres.
PMCID: PMC1494628  PMID: 4292646
11.  IV. Demonstration of the Viral Antigen by Means of Immunofluorescence 
African swine fever immunofluorescent conjugates were prepared in swine and used successfully in the demonstration of viral antigen in frozen tissue sections and in inoculated tissue culture cells. Cross reactivity was observed with the six strains used in the inoculation of swine. The high antibody content of the serum of immune swine did not interfere with demonstration of the antigen in frozen tissue sections of certain of their organs. The localisation and extent of antigen varied with the stage of infection. The virus was demonstrated in spleen and other organs as early as after one day of pyrexia and until after death of the animal. A pool of hog cholera and African swine fever conjugates stained with dyes of different colours was used in the localisation of respective antigens in experimental mixed infection.
Images
PMCID: PMC1494627  PMID: 4291678
12.  II. Detection of the Virus in Swine Tissues by Means of the Modified Direct Complement-Fixation Test 
The modified direct complement-fixation test, supplemented with unheated normal calf serum, was used to demonstrate antibodies in sera of swine immunized to African swine fever virus. These antibodies did not react in the ordinary direct non-supplemented complement-fixation test.
African swine fever complement-fixing antigen in infected swine tissue is not denatured by extraction with fat solvents. Consequently, good antigens devoid of non-specific reactivity were obtained by extraction with a mixture of acetone and ether.
The virus was detected in infected swine tissue harvested one day after beginning of pyrexia. The modified direct complement-fixation test demonstrated cross-reactions between the six strains of virus studied.
PMCID: PMC1494626  PMID: 4291680
13.  III. The Use of the Agar Double-Diffusion Precipitation Test For the Detection of the Virus in Swine Tissue 
The agar double-diffusion precipitation test was applied successfully in the demonstration of ASF viral antigen in spleen and liver from swine experimentally infected by the oral route.
Positive reactions were obtained with tissues collected as early as 24 hours after the onset of pyrexia and before other clinical manifestation of the disease. Cross-reactions were observed between the various ASF strains used in the study, making the test practical for routine diagnosis in which different strains may be encountered.
Images
PMCID: PMC1494621  PMID: 4291677

Results 1-13 (13)