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Biomedical subjects

D Ramsay

Publications and source records attributed to D Ramsay.

49 records · Page 3Linked to original sources

Ecological distribution of Legionellaceae in the Quebec city area.

One hundred environmental water samples, which were collected in the Quebec city area and cultured on buffered charcoal yeast extract medium and three selective media, were inoculated to guinea pigs and were screened by direct immunofluorescent staining (DFA) for the presence of Legionellaceae. Six isolates were made (four Legionella pneumophila and two Tatlockia (Legionella) micdadei: three by animal inoculation and three by culture). No samples were simultaneously positive by both methods. After screening by DFA, 43 of the 100 samples were positive for Legionellaceae and 27 of those contained more than one serogroup and (or) species of Legionellaceae. Legionella pneumophila (serogroups 1 to 6) was the most frequent species seen by DFA. These results clearly show that Legionellaceae are frequent members of the freshwater microbial flora of the Quebec city area.

Culture Media↗

Serogrouping and subtyping of Legionella pneumophila with monoclonal antibodies.

Monoclonal antibodies directed against Legionella pneumophila serogroups 1 to 6 were produced by fusing splenocytes of BALB/c mice with the Sp 2/0-Ag14 or the NSO mouse myeloma cell lines. Specificity of these antibodies was determined by indirect fluorescent-antibody staining: 8 reacted with L. pneumophila serogroup 1 and, respectively, 13, 6, 6, 5, and 10 reacted with serogroups 2, 3, 4, 5, and 6; all except 5 were serogroup specific, and none presented cross-reactions with six other species of Legionellaceae. Serogroup determination of 35 isolates of L. pneumophila with seven selected monoclonal antibodies resulted in correct serogrouping in all instances; a pool of the same seven monoclonal antibodies stained intensely all strains of L. pneumophila without any staining of the other species of Legionellaceae. When 24 serogroup 1 isolates of L. pneumophila were stained with eight serogroup 1-specific monoclonal antibodies, the staining patterns could be clustered in five distinct groups. These hybridomas thus represent an unlimited source of standard reagent that could be used in the detection and serogrouping of L. pneumophila; differences in staining patterns could be used as epidemiological markers for these bacteria.

Animals↗

Preoperative assessment of pancreatic malignancy using endoscopic ultrasound.

BACKGROUND: Endoscopic ultrasound (EUS) has been regarded as the most accurate modality for locoregional staging of pancreatic malignancy. However, several recent studies have questioned this. The current study assessed the accuracy of EUS in determining preoperative resectability of pancreatic neoplasia. METHODS: A retrospective review was performed of patients with pancreatic malignancy who had preoperative EUS and underwent surgery. EUS-predicted resectability was compared with surgical resectability. Where available, accuracies of vascular and nodal staging were also assessed. RESULTS: Forty-five patients were identified (mean age 60 years, age range = 36-79 years). All patients underwent surgical exploration; vascular staging was available in 32 cases and 17 cases underwent surgical resection. The sensitivity, specificity, and accuracy of EUS in determining unresectability were 66%, 100%, and 78% respectively. Overall EUS stage concurred with surgical stage in 56%, greater than surgical stage in 4%, and less than surgical stage in 40%. Vascular staging on EUS had a sensitivity of 69% and a specificity of 100%. Accuracy of nodal staging was 71%. CONCLUSION: EUS had a high specificity for assessing unresectable pancreatic malignancy. This technique should be used to avoid unnecessary surgical exploration of incurable lesions. However, EUS had only a moderate sensitivity, and a proportion of patients staged preoperatively as having resectable disease will not be surgically resectable.

Carcinoma, Pancreatic Ductal↗

[Epidemic of gastroenteritis of viral origin associated with eating imported raspberries].

Several episodes of food poisoning affected the region of Quebec City in July and August 1997. In the first two episodes, the analysis of two cohorts (A and B) demonstrated that the consumption of a raspberry mousse with raspberry sauce increased the risk of contracting gastroenteritis (A, RR = 2.6 p = 0.001; B, RR = 4.7 p = 0.02). More than 200 people were sick after eating a raspberry dessert. The common ingredient of all those desserts was raspberries imported from Bosnia. Viral studies on the raspberry sauce (2) and stool samples (5) using the genome amplification method by PCR indicated the presence of genomic material compatible with a virus of the Caliciviruses family. Southern hybridization and sequence analysis showed that the nucleotide sequences found in the raspberry sauce and in the stool samples were identical. It is important to maintain active surveillance to detect and limit the spread of this kind of outbreak.

Bosnia and Herzegovina↗

Effects of lidocaine with epinephrine on fear related arousal among dental phobics.

The effects of 2% lidocaine containing 72 μg epinephrine on fear related arousal were tested using a cross-over design on dental patients fearful of injections and other dental procedures. Heart rate and body movement in the dental operatory were monitored, and subjects' self-reported upset in the Epinephrine condition than in the No-Epinephrine condition (F = 4.8, p = .04), but the clinical significance was negligible. No interaction between initial fear levels and the drug condition could be established. Results suggest that pre-existing dental fear levels may produce greater self-report, behavioral or physiological arousal in the dental operatory than exogenous epinephrine.

Adult↗