Molecular epidemiologic surveillance of salmonellosis in Arkansas

OBJECTIVES: Salmonella serotype Newport and Salmonella serotype Typhimurium are the most commonly identified serotypes of Salmonella causing human disease in the state of Arkansas. The purpose of our study was to compare the results of standard and molecular epidemiologic methods of investigating human salmonellosis cases due to Salmonella serotype Newport and Salmonella serotype Typhimurium. METHODS: All isolates of Salmonella serotype Newport and Salmonella serotype Typhimurium collected and submitted to the Arkansas Department of Health between July 1, 1997 and June 30, 1998 were gathered and underwent pulsed-field gel electrophoresis (PFGE). Patients from whom the isolates were collected were contacted and completed a questionnaire. RESULTS: There were 84 patients from whom Salmonella serotype Newport was isolated and 83 from whom Salmonella serotype Typhimurium was isolated during the study period. In the 124 patients (74%) who completed the questionnaire, Salmonella serotype Newport was more likely to be the infecting agent in younger, white, and pet-owning patients (P < 0.05). The use of PFGE confirmed that approximately 20% of the organisms had genetic fingerprint patterns identical to those of at least one other individual in the state. One third of the patients from whom these isolates were obtained were linked by standard epidemiologic methods. CONCLUSIONS: The use of PFGE on our state's most common isolates provides additional confirmation that despite being linked by time of onset and location of residence, the majority of the human salmonellosis cases in our region are still sporadic. Low-level, intermittent transmission of these organisms through environmental contamination and contact with asymptomatically infected individuals would be likely vehicles of transmission in our state. Molecular techniques are important in surveillance systems that investigate human salmonellosis. Eighty-one percent of the Salmonella serotype Newport and 92% of the Salmonella serotype Typhimurium cases that appeared to be outbreak-related based upon time of onset and location were actually found not to be outbreak-related by PFGE. Using techniques such as PFGE will allow for more focused evaluations of potential outbreaks and will save the already limited financial and human resources that would otherwise be spent on investigations that are not warranted.     

Thymoma-associated neuromyotonia with antibodies against voltage-gated potassium channels presenting as chronic intestinal pseudo-obstruction

Chronic intestinal pseudo-obstruction can occur as a paraneoplastic disorder, and several cases have been reported in association with thymoma or small-cell lung cancer. Autoantibodies against voltage-gated potassium channels (VGKCs) are found in acquired neuromyotonia (Isaac's syndrome), and have been reported in one case of slow transit constipation without apparent neurological disease. We describe a patient with VGKC antibodies, acquired neuromyotonia and thymoma, who first presented with a severe slow-transit constipation and in whom the gastrointestinal symptoms responded well to plasmapheresis. We suggest that VGKC antibodies might be helpful in patients with possible paraneoplastic chronic intestinal pseudo-obstruction, and a positive result should stimulate the search for a thymoma or other tumour and raise the possibility of immunotherapy.     

Effect of interhospital transfer on resource utilization and outcomes at a tertiary care referral center

OBJECTIVE: Mortality and length of stay are two outcome variables commonly used as benchmarks in rating the performance of medical centers. Acceptance of transfer patients has been shown to affect both outcomes and the costs of health care. Our objective was to compare observed and predicted lengths of stay, observed and predicted mortality, and resource consumption between patients directly admitted and those transferred to the intensive care unit (ICU) of a large academic medical center. DESIGN: Observational cohort study. SETTING: Mixed medical/surgical ICU of a university hospital. PATIENTS: A total of 4,569 consecutive patients admitted to a tertiary care ICU from April 1, 1997, to March 30, 2000. INTERVENTIONS: None. MEASUREMENTS: Acute Physiology and Chronic Health Evaluation (APACHE) III score, actual and predicted ICU and hospital lengths of stay, actual and predicted ICU and hospital mortality, and costs per admission. MAIN RESULTS: Crude comparison of directly admitted and transfer patients revealed that transfer patients had significantly higher APACHE III scores (mean, 60.5 vs. 49.7, p < .001), ICU mortality (14% vs. 8%, p < .001), and hospital mortality (22% vs. 14%, p < .001). Transfer patients also had longer ICU lengths of stay (mean, 6.0 vs. 3.8 days, p < .001) and hospital lengths of stay (mean, 20 vs. 15.9 days, p < .001). Stratified by disease severity using the APACHE III model, there was no difference in either ICU or hospital mortality between the two populations. However, in the transfer group with the lowest predicted mortality of 0-20%, ICU and hospital lengths of stay were significantly higher. In crude cost analysis, transfer patients' costs were $9,600 higher per ICU admission compared with nontransfer patients (95% confidence interval, $6,000-$13,400). Risk stratification revealed that the higher per-patient cost was entirely confined to the transfer patients with the lowest predicted mortality. CONCLUSIONS: Patients transferred to a tertiary care ICU are generally more severely ill and consume more resources. However, they have similar adjusted mortality outcomes when compared with directly admitted patients. The difference in resource consumption is mainly attributable to the group of patients in the lowest predicted risk bracket.     

Severe axonal polyneuropathy with onset in the postpartum period

We report two patients who presented severe polyneuropathy in the postpartum period. Electrophysiological studies evidenced an axonal process which was associated with proximal demyelination in the second patient. In both cases, a peripheral nerve biopsy showed severe axonal Wallerian-like degeneration and no feature of demyelination. The first patient had a dramatic loss of myelinated fibres, and severe disability persisted for several months. These two patients are different from cases of acute or chronic inflammatory demyelinating polyradiculoneuropathy previously reported in relation with pregnancy.     

The effect of acute aerobic exercise on pulse wave velocity and oxidative stress following postprandial hypertriglyceridemia in healthy men

Oxidative stress is postulated to be responsible for the postprandial impairments in vascular function. The purpose of this study was to measure pulse wave velocity (PWV) and markers of postprandial oxidative stress before and after an acute bout of moderate exercise. Ten trained male subjects (age 21.5 ± 2.5 years, VO₂ max 58.5 ± 7.1 ml kg⁻¹ min⁻¹) participated in a randomised crossover design: (1) high-fat meal alone (2) high-fat meal followed 2 h later by a bout of 1 h moderate (60% max HR) exercise. PWV was examined at baseline, 1, 2, 3, and 4 h postprandially. Blood Lipid hydroperoxides (LOOHs), Superoxide dismutase (SOD) and other biochemical markers were measured. PWV increased at 1 h (6.49 ± 2.1 m s⁻¹), 2 h (6.94 ± 2.4 m s⁻¹), 3 h (7.25 ± 2.1 m s⁻¹) and 4 h (7.41 ± 2.5 m s⁻¹) respectively, in the control trial (P < 0.05). There was no change in PWV at 3 h (5.36 ± 1.1 m s⁻¹) or 4 h (5.95 ± 2.3 m s⁻¹) post ingestion in the exercise trial (P > 0.05). LOOH levels decreased at 3 h post ingestion in the exercise trial compared to levels at 3 h (P < 0.05) in the control trial. SOD levels were lower at 3 h post ingestion in the control trial compared to 3 h in the exercise trial (0.52 ± 0.05 vs. 0.41 ± 0.1 units μl⁻¹; P < 0.05). These findings suggest that a single session of aerobic exercise can ameliorate the postprandial impairments in arterial function by possibly reducing oxidative stress levels.     

Diagnostic yield and characteristic features in a series of decomposed bodies subject to coronial autopsy

A study was undertaken of 629 cases autopsied at Forensic Science SA, Adelaide, Australia over a 10-year period from 1994 to 2004 where significant decomposition had been documented. The age range of victims was 10 months to 92 years (mean 51.5 ± 18.1 years). There were 498 males (79%) and 131 females (21%) (M:F = 3.8:1). Deaths in 289 of the 629 cases (46%) were due to natural causes, with 179 suicides (28%), 83 accidents (13%), and 36 homicides (6%). The cause of death was ascertained in 89% of cases and the manner of death in 93% of cases. In 35 cases (6%) both the cause and manner could not be determined. Numbers of suicides were higher in younger age groups while deaths from organic illnesses predominated in later life. The number of cases in summer was significantly greater than in winter. Despite technical difficulties in handling decomposed bodies, and artifactual alteration of tissue structure and microscopic features, the autopsy was still a useful diagnostic exercise. While it is likely that more information may be gleaned from fresh bodies in perfectly preserved states, decomposed bodies may reveal significant anatomical and pathological features that enable both the cause and manner of death to be established.     

Stability of buffered lidocaine and epinephrine used for local anesthesia

Buffered lidocaine has been recently recommended for local anesthesia, as there is less pain on injection of the buffered solution. Reduced pain on injection of lidocaine and epinephrine buffered to a neutral pH was confirmed in 20 subjects (P less than .01). Concentrations of buffered lidocaine and epinephrine were performed in order to evaluate their stability. Buffered lidocaine dropped to 66.1% of initial concentrations after 4 weeks when stored at 25 degrees C. Buffered epinephrine fell to 1.34% of its initial concentration under similar conditions. Buffered lidocaine and epinephrine maintained 94.54% and 82.04%, respectively, of their initial concentrations after 4 weeks when refrigerated at 0-4 degrees C. Both lidocaine and epinephrine maintained greater than 90% concentration 2 weeks after buffering when stored at 0-4 degrees C. This permits batch buffering of lidocaine with epinephrine and storage for periods up to 2 weeks when properly refrigerated.