Investigation of an outbreak of Escherichia coli O157 infection caused by environmental exposure at a scout camp

In May 2000 a scout camp was held on an agricultural showground in New Deer, Aberdeenshire. There were 337 campers at the event, comprising 233 cubs, scouts, and venture scouts, and 104 adults. The event was abandoned early because of heavy rainfall. Twenty campers who became ill between 28 May and 3 June were confirmed as having E. coli O157 infection. Preliminary investigation did not suggest a food vehicle but did indicate environmental exposure at the camp as a risk factor. Subsequent investigations supported the hypothesis that transmission of E. coli O157 was from the environment to cases by contaminated hands, either directly from hand to mouth, or via food. As a result of the investigation the Aberdeenshire Council and the Scout Association jointly prepared interim guidelines to reduce the risk of E. coli O157 infection at scout camps.

Chlamydia species as a cause of community-acquired pneumonia in Canada

Chlamydia pneumoniae has been implicated as a cause of community-acquired pneumonia (CAP) in several studies. However, there has been no comprehensive study of the role of Chlamydia species (C. pneumoniae, C. psittaci (avian and feline strains) and C. pecorum) as a cause of CAP. The aim of the present study was to determine the role of C. pneumoniae, C. psittaci and C. pecorum as causes of CAP. A prospective cohort observational study of CAP was conducted at 15 teaching centres in eight Canadian provinces between January 1996-October 1997. Acute (n=539) and convalescent (n=272) serum samples were obtained for determination of antibody titres to C. pneumoniae, C. psittaci, C. pecorum, C. trachomatis, Mycoplasma pneumoniae, Legionella pneumophila serogroups I-VI, Streptococcus pneumoniae and various respiratory viruses. Twelve of 539 (2.2%) patients had acute C. pneumoniae pneumonia and an additional 32 (5.9%) had possible acute infection. C. pneumoniae was the sole pathogen in 16 of 42 (38.1%) of these patients. The most common copathogens were S. pneumoniae, respiratory syncytial virus and influenza virus type A. C. pneumoniae pneumonia patients were older and more likely to show congestive heart failure compared to bacteraemic S. pneumoniae patients. The latter had a lower mean diastolic blood pressure, a higher white blood cell count and a lower arterial carbon dioxide tension. Two patients had antibody titres suggestive of recent infection with the feline strain of C. psittaci. Although numerically Chlamydia pneumoniae is an important cause of community-acquired pneumonia, no distinctive clinical features associated with this pathogen were detected in the present study. Feline Chlamydia psittaci may cause a few cases of community-acquired pneumonia. Avian Chlamydia psittaci should be considered only if there is a compatible epidemiological history.

Effects of alpha-tocopherol on platelets and the coagulation system

Vitamin E is one of the most widely used antioxidants in cryopreservation and preservation technology. The objective of this study is to examine the effect of vitamin E on platelets and the coagulation system. Vitamin E was added at different concentrations in the range between 0.25 and 5 mM to donor plasma. Using a STA/STA Compact coagulation analyzer the following clotting tests were performed: prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT). The control clotting times PT (13.80 +/- 0.4 s), APTT (27.4 +/- 2.4 s) and TT (17.6 +/- 0.4 s) remained unchanged in the presence of vitamin E. The effect of vitamin E on platelets was assessed by platelet-induced clot retraction (PICR) and aggregation by thrombin. PICR was unaffected by vitamin E. Platelet aggregation, however, was profoundly inhibited by vitamin E. We found that inhibition of platelet aggregation by vitamin E was concentration dependent: increasing with increasing vitamin E concentration. This inhibitory effect, however, was widely reversible upon dilution of vitamin E with autologous platelet-poor plasma.

Impact of waiting time on the quality of life of patients awaiting coronary artery bypass grafting

BACKGROUND

A lack of resources has created waiting lists for many elective surgical procedures within Canada's universal health care system. Coronary artery bypass grafting (CABG) for the treatment of atherosclerotic ischemic heart disease is one of these affected surgical procedures. We studied the impact of waiting times on the quality of life of patients awaiting CABG.

METHODS

A prospective cohort of 266 patients from 3 hospitals in Montreal was used. Patients who gave informed consent were followed from the time they were registered for CABG until 6 months after surgery; recruitment began in November 1993, and the last follow-up was completed in July 1995. Patient groups were classified according to the duration of the wait for CABG (< or = 97 days or > 97 days). We measured the following outcomes: quality of life (using the Medical Outcomes Study 36-item Short Form [SF-36]), incidence of chest pain (using the New York Heart Association angina classification), frequency of symptoms (using the Cardiac Symptom Inventory) and rates of complications and death before and after surgery.

RESULTS

There were no differences in quality of life at baseline between the 2 groups. Immediately before surgery, compared with patients who waited 97 days or less, those who waited longer had significantly reduced physical functioning (change from baseline SF-36 score 0 v. -4 respectively, p = 0.001), vitality (change from baseline score -0.1 v. -1.3, p = 0.01), social functioning (change from baseline score 0.4 v. -0.4, p = 0.03) and general health (change from baseline score 1.1 v. -1.7, p = 0.001). At 6 months after surgery, compared with patients who waited 97 days or less for CABG, those who waited longer had reduced physical functioning (change from baseline SF-36 score 4.0 v. -0.1 respectively, p = 0.001), physical role (change from baseline score 0.8 v. 0.0, p = 0.001), vitality (change from baseline score 2.2 v. 0.9, p = 0.001), mental health (change from baseline score 1.2 v. 0.0, p = 0.001) and general health (change from baseline score 1.8 v. -0.3, p = 0.001). The incidence of postoperative adverse events was significantly greater among the patients with longer waits for CABG than among those with shorter waits (32 v. 14 events respectively, p = 0.005). Longer waits before CABG were associated with an increased likelihood of not returning to work after surgery (p = 0.08): 10 (53%) of the 19 patients with longer waiting times remained employed after CABG, as compared with 17 (85%) of the 20 with shorter waiting times.

INTERPRETATION

The significant decrease in physical and social functioning, both before and after surgery, for patients waiting more than 3 months for CABG is an important observation. Longer waiting times were also associated with increased postoperative adverse events. By decreasing waiting times for CABG, we may improve patients' quality of life and decrease the psychological morbidity associated with CABG.

A physical map of the human genome

The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.

Intra-arterial administration of a replication-selective adenovirus (dl1520) in patients with colorectal carcinoma metastatic to the liver: a phase I trial

Both replication-incompetent and replication-selective adenoviruses are being developed for the treatment of cancer and other diseases. Concerns have been raised about the safety of intra-vascular adenovirus administration following a patient death on a clinical trial with a replication-defective adenovirus. In addition, the feasibility of vascular delivery to distant tumors has been questioned. dl1520 (ONYX-015) is a replication-selective adenovirus that has previously shown safety and antitumoral activity following intratumoral injection. This is the first report of intra-vascular administration with a genetically engineered, replication-selective virus. A phase I dose-escalation trial was performed in patients with liver-predominant gastrointestinal carcinoma (n = 11 total; primarily colorectal). dl1520 was infused into the hepatic artery at doses of 2 x 10(8)-2 x 10(1)2 particles for two cycles (days 1 and 8). Subsequent cycles of dl1520 were administered in combination with intravenous 5-fluorouracil (5-FU) and leucovorin. No dose-limiting toxicity, maximally tolerated dose or treatment-emergent clinical hepatotoxicity were identified following dl1520 infusion. Mild to moderate fever, rigors and fatigue were the most common adverse events. Antibody titers increased significantly in all patients. Viral replication was detectable in patients receiving the highest two doses. An objective response was demonstrated in combination with chemotherapy in a patient who was refractory to both 5-FU and dl1520 as single agents. Therefore, hepatic artery infusion of the attenuated adenovirus dl1520 was well-tolerated at doses resulting in infection, replication and chemotherapy-associated antitumoral activity.

GenMapDB: a database of mapped human BAC clones

GenMapDB (http://genomics.med.upenn.edu/genmapdb) is a repository of human bacterial artificial chromosome (BAC) clones mapped by our laboratory to sequence-tagged site markers. Currently, GenMapDB contains over 3000 mapped clones that span 19 chromosomes, chromosomes 2, 4, 5, 9-22, X and Y. This database provides positional information about human BAC clones from the RPCI-11 human male BAC library. It also contains restriction fragment analysis data and end sequences of the clones. GenMapDB is freely available to the public. The main purpose of GenMapDB is to organize the mapping data and to allow the research community to search for mapped BAC clones that can be used in gene mapping studies and chromosomal mutation analysis projects.

Selective replication and oncolysis in p53 mutant tumors with ONYX-015, an E1B-55kD gene-deleted adenovirus, in patients with advanced head and neck cancer: a phase II trial

ONYX-015 is an E1B-55kDa gene-deleted adenovirus engineered to selectively replicate in and lyse p53-deficient cancer cells. To evaluate the selectivity of ONYX-015 replication and cytopathic effects for the first time in humans, we carried out a Phase II clinical testing of intratumoral and peritumoral ONYX-015 injection in 37 patients with recurrent head and neck carcinoma. Patients received ONYX-015 at a daily dose of 1 x 10(10) plaque-forming units (pfu) via intratumoral injection for 5 days during week 1 of each 3-week cycle (n = 30; cohort A), or 1 x 10(10) pfu twice a day for 10 days during weeks 1 and 2 of each 3-week cycle. Posttreatment biopsies documented selective ONYX-015 presence and/or replication in the tumor tissue of 7 of 11 patients biopsied on days 5-14, but not in immediately adjacent normal tissue (0 of 11 patients; P = 0.01). Tissue destruction was also highly selective; significant tumor regression (>50%) occurred in 21% of evaluable patients, whereas no toxicity to injected normal peritumoral tissues was demonstrated. p53 mutant tumors were significantly more likely to undergo ONYX-015-induced necrosis (7 of 12) than were p53 wild-type tumors (0 of 7; P = 0.017). High neutralizing antibody titers did not prevent infection and/or replication within tumors. ONYX-015 is the first genetically engineered replication-competent virus to demonstrate selective intratumoral replication and necrosis in patients. This agent demonstrates the promise of replication-selective viruses as a novel therapeutic platform against cancer.

Effects of high-molecular-weight cryoprotectants on platelets and the coagulation system

The objective of this study is to examine the effects of the most widely used high-molecular-weight cryoprotectants on the coagulation system. Dextran, hydryoxyethyl starch (HES), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), and albumin were added at different concentrations in the range between 0.01-1% (w/v) to solvent/detergent-treated plasma. Using a STA/STA Compact coagulation analyzer the following clotting tests were performed: prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), Factor V, and Factor VIII percentage of activity. PVP and PEG caused a significant increase in APTT, a decrease in Factor VIII percentage of activity, and a slight decrease in TT, while PT and Factor V percentage of activity remained unchanged. Dextran, HES, and albumin did not effect the clotting tests. The effect of high-molecular-weight cryoprotectants on platelets was assessed by platelet-induced clot retraction (PICR) and aggregation with thrombin and agglutination with ristocetin. Platelet aggregation and agglutination were unaffected by all cryoprotectants tested; however, PICR was significantly reduced in the presence of PVP or PEG. Possible mechanisms by which PVP and PEG interfere with the coagulation system are discussed. We also raise issues concerning the development of one-step blood cryopreservation techniques which do not require cryoprotectant removal prior to transfusion.

Response of a Pseudomonas aeruginosa biofilm community to DNA-damaging chemical agents

Pseudomonas aeruginosa strain RM4440 carries a plasmid-borne fusion of the P. aeruginosa recA gene promoter to a promoterless lux operon from Vibrio fisheri. We tested the response of RM4440 in a biofilm to exposure to a 1-h pulse of each of 17 chemicals known to be toxic to bacteria and other organisms. The induction of light produced from the recA-lux fusion present in RM4440 proved to be sensitive and specific for DNA-damaging chemicals when included in a biofilm environment. This study demonstrates the potential usefulness of this construct for in situ investigation of bacterial communities.

Effects of high-molecular-weight cryoprotectants on platelets and the coagulation system

The objective of this study is to examine the effects of the most widely used high-molecular-weight cryoprotectants on the coagulation system. Dextran, hydryoxyethyl starch (HES), polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG), and albumin were added at different concentrations in the range between 0.01-1% (w/v) to solvent/detergent-treated plasma. Using a STA/STA Compact coagulation analyzer the following clotting tests were performed: prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), Factor V, and Factor VIII percentage of activity. PVP and PEG caused a significant increase in APTT, a decrease in Factor VIII percentage of activity, and a slight decrease in TT, while PT and Factor V percentage of activity remained unchanged. Dextran, HES, and albumin did not effect the clotting tests. The effect of high-molecular-weight cryoprotectants on platelets was assessed by platelet-induced clot retraction (PICR) and aggregation with thrombin and agglutination with ristocetin. Platelet aggregation and agglutination were unaffected by all cryoprotectants tested; however, PICR was significantly reduced in the presence of PVP or PEG. Possible mechanisms by which PVP and PEG interfere with the coagulation system are discussed. We also raise issues concerning the development of one-step blood cryopreservation techniques which do not require cryoprotectant removal prior to transfusion.

Generation of annexin V-positive platelets and shedding of microparticles with stimulus-dependent procoagulant activity during storage of platelets at 4 degrees C

BACKGROUND

The ability of propyl gallate to activate platelet factor 3 has been determined through the activated partial thromboplastin time, but its effect on phosphatidylserine has not been established.

STUDY DESIGN AND METHODS

A novel platelet activator, propyl gallate, was introduced to a study of platelets stored at 4 degrees C. The effects of storage on platelet coagulation activity, on phosphatidylserine, and on the shedding of activated and activable membrane particles (microparticles) were examined by activated plasma clotting time, and the effect on annexin V binding was examined by gated flow cytometry. The ratios of annexin V binding and microparticle shedding in stored platelet samples were compared with those in fresh platelets stimulated with propyl gallate.

RESULTS

Microparticle shedding by stored platelets compensated for the diminished procoagulant potential of intact platelets (shown as the total propyl gallate-dependent platelet factor 3 activity), which did not change during prolonged (20-day) storage, but levels of phosphatidylserine confined to microparticles increased dramatically as platelet counts fell. Both annexin V binding and microparticle shedding increased spontaneously with storage and artificially with propyl gallate stimulation. However, at the same level of annexin V binding, stored platelets shed more microparticles than did fresh platelets stimulated with propyl gallate.

CONCLUSION

Propyl gallate induces platelet procoagulant activity and annexin V binding. Stored platelets differ from fresh platelets in a lower reactivity to propyl gallate activation and a higher rate of microparticle shedding.

Strategic processing and episodic memory impairment in obsessive compulsive disorder

There is evidence that nonverbal memory problems in obsessive compulsive disorder (OCD) are mediated by impaired strategic processing. Although many studies have found verbal memory to be normal in OCD, these studies did not use tests designed to stress organizational strategies. This study examined verbal and nonverbal memory performance in 33 OCD patients and 30 normal control participants with the Rey-Osterrieth Complex Figure Test and the California Verbal Learning Test. OCD patients were impaired on verbal and nonverbal measures of organizational strategy and free recall. Multiple regression modeling indicated that free recall problems in OCD were mediated by impaired organizational strategies used during learning trials. Therefore, verbal and nonverbal episodic memory deficits in OCD are affected by impaired strategic processing. Results are consistent with neurobiological models proposing frontal-striatal system dysfunction in OCD.

Using medical services claims to assess injuries in the elderly: sensitivity of diagnostic and procedure codes for injury ascertainment

The sensitivity of using physician claims data for injury ascertainment was examined in a cohort of 1,181 elderly who were treated in the emergency department of one of 10 hospitals for injuries in 1993-1994. The clinical record of the type and date of injury was compared with diagnostic and procedure codes in the Quebec health insurance agency records of physician billing claims for the same patients. The proportion of patients correctly classified by claims data was determined for the exact date of injury and for a time window around the date of injury. The most common injuries were fractures (55.4%) and lacerations (19.3%), and 78.9% of injuries were fall related. Overall, the combination of treatment procedure codes and diagnostic codes provided the most sensitive measure of injury occurrence; a sensitivity of 67.3% for the exact date and 81.3% for an expanded data window (95.6% of injuries were within -1 day to +3 days of the injury date). Sensitivity varied by injury type form a low of 14% for abrasions to a high of 97.2% for hip fractures. The combination of diagnostic and procedure codes in physician claims is a sensitive indicator of some common injuries that would not be documented in hospitalization databases.

Nucleoli in a pronuclei-stage mouse embryo are represented by major satellite DNA of interconnecting chromosomes

OBJECTIVE

To investigate the arrangement of chromosomes within pronuclei-stage mouse zygotes.

DESIGN

In vitro study.

SETTING

Academic medical center.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Location of major alpha-satellite DNA, centromeres, and telomeres, and relative location of chromosomes.

RESULT(S)

Chromosomes appeared to be oriented inward by centromeres and to be interconnected by major alpha-satellite DNA, which appeared to be the sole DNA component of the nucleoli. This chromosomal arrangement persisted throughout interphase. Chromosomal painting failed to identify chromosomal ordering within pronuclei.

CONCLUSION(S)

Pronuclear nucleoli are represented by alpha-satellite sequences of interconnecting chromosomes that hold all chromosomes together during interphase. Chromosomes within the pronucleus are randomly positioned relative to each other.

Strategic processing and episodic memory impairment in obsessive compulsive disorder

There is evidence that nonverbal memory problems in obsessive compulsive disorder (OCD) are mediated by impaired strategic processing. Although many studies have found verbal memory to be normal in OCD, these studies did not use tests designed to stress organizational strategies. This study examined verbal and nonverbal memory performance in 33 OCD patients and 30 normal control participants with the Rey-Osterrieth Complex Figure Test and the California Verbal Learning Test. OCD patients were impaired on verbal and nonverbal measures of organizational strategy and free recall. Multiple regression modeling indicated that free recall problems in OCD were mediated by impaired organizational strategies used during learning trials. Therefore, verbal and nonverbal episodic memory deficits in OCD are affected by impaired strategic processing. Results are consistent with neurobiological models proposing frontal-striatal system dysfunction in OCD.

Maternal identity in preterm birth

The development of maternal identity appears to be considerably delayed in the event of preterm birth. Women with high risk pregnancies may be afforded some protection by means of adaptation prior to birth. Tactile contact appears to make the experience more real for women who are attempting to make the transition to motherhood. Even in a group of moderate risk preterm infants, the psychological challenges facing mothers experiencing neonatal intensive care are considerable. Conflicting responsibilities and time pressures contribute significantly to the stressful experience of mothers in NICU.