Geographical distribution of salmonid alphavirus subtypes in marine farmed Atlantic salmon, Salmo salar L., in Scotland and Ireland.

Sequence data from salmonid alphavirus (SAV) strains obtained from farmed marine Atlantic salmon, Salmo salar L. , over a 20-year period between 1991 and 2011 was reviewed to examine the geographical distribution of the genetically defined SAV subtypes in twelve regions across Ireland and Scotland. Of 160 different Atlantic salmon SAV strains examined, 62 belonged to subtype 1, 28 to subtype 2, 34 to subtype 4, 35 to subtype 5 and 1 to subtype 6. SAV subtypes 1, 4 and 6 were found in Ireland, while subtypes 1, 2, 4 and 5 were found in Scotland. In the majority of regions, there was a clear clustering of subtypes, with SAV subtype 1 being the dominant subtype in Ireland overall, as well as in Argyll and Bute in Scotland. SAV subtype 2 predominated in the Shetland and Orkney Islands. The emergence in Atlantic salmon of subtype 2 strains typically associated with sleeping disease in rainbow trout in Argyll and Bute, strongly suggesting transmission of infection between these species, was noted for the first time. SAV subtype 4 was the most common subtype found in the southern Western Isles, while SAV subtype 5 predominated in the northern Western Isles and north-west mainland Scotland. No single strain was dominant on sites in the western Highlands, with a number of sites in this region in particular having more than one subtype detected in different submissions. The significance of these results in relation to aspects of the epidemiology of infection, including transmission, biosecurity and wildlife reservoirs are discussed and knowledge gaps identified.

Separation of the proximal femoral epiphysis after derotation varus osteotomy of the femur.

Proximal femoral varus and derotation osteotomy is a common procedure performed in the management of developmental dysplasia of the hip. This procedure imposes high shear stress on the femoral epiphysis, depending on the degree of varus obtained. We report two cases of proximal femoral epiphyseal slip after varus derotation osteotomy and discuss the management and outcome. Such epiphyseal slip may or may not be symptomatic, and a careful radiologic examination should be carried out in suspected cases. Management should be individualised. Surgical correction of varus may be required.

An unusual cause of chest pain in an adolescent presenting to the emergency department.

Chest pain as a chief complaint is very common in most emergency departments. While well defined and numerous causes of chest pain in adults are previously described, the adolescent presenting with chest pain raises the possibilities of other causes. Previously undiscovered congenital anomalies are rare as causes of pain in this age group. A case of coarctation of the aorta, previously undetected in a teenager, is presented. The signs of congenital heart disease are usually present on history and physical examination, which can lead the emergency physician to the appropriate diagnosis.

Comparison of the T helper cell response induced by respiratory syncytial virus and its fusion protein in BALB/c mice.

Specific proliferative T-cell responses were induced in the lymph node cells (LNC) of mice immunised with a sucrose density gradient purified preparation of respiratory syncytial (RS) virus or an immunoaffinity purified preparation of the F glycoprotein. Inhibition studies and flow cytometric analysis showed that the responding cell population were CD4+ T cells. The cytokines produced by virus-specific and F-specific cells were assessed using the CTLL cell line. Peak quantities of cytokine were consistently detected in the supernatants of stimulated cultures 24 h prior to maximum proliferation. The proportion of IL-2 released was determined by blocking IL-2 activity with an anti-IL-2 monoclonal antibody. In cultures of RS virus primed LNC challenged with whole virus there was a switch of cytokine production from 70% IL-2 at day 3 to 80% IL-4 by 6 days of culture. In contrast, LNC cultures from mice immunised with F protein secreted 75-100% IL-2 throughout the culture period. These data suggest that after 6 days of challenge with viral antigen, the RS virus-primed LNC response consists of T helper cells which are predominantly of the Th2 subset, secreting IL-4, whilst F protein-primed LNC secrete large quantities of IL-2 and can therefore be classified as predominantly of the Th1 subset.

Recognition of respiratory syncytial (RS) virus proteins by human and BALB/C CD4+ lymphocytes.

Lymphocyte proliferation assays were used to determine the ability of human and BALB/c T-lymphocytes to recognise and respond to in vitro challenge with purified preparations of four respiratory syncytial (RS) virus proteins. Human peripheral blood lymphocytes (PBLs) collected from adult donors as well as primed BALB/c mouse splenocytes each responded specifically to challenge with intact RS virus and preparations of the fusion (F), attachment (G), 23 kilodalton (23K), and 34K phospho- (P) proteins of the virus. F protein was recognised most frequently by human PBLs, and elicited higher levels of response than equivalent concentrations of the other protein preparations examined. The human PBL proliferative responses elicited by in vitro challenge with intact virus antigen as well as with each of the four protein preparations were found to be confined to the CD4+ T-helper (Th) sub-population of lymphocytes. However, proliferative responses to intact virus and F protein were found to be accompanied by only modest and inconsistent production of Interleukin-2 (IL-2). Finally, no evidence was obtained to indicate that any of the challenge antigens employed in this study were intrinsically mitogenic, as neither naive human cord blood lymphocytes, nor un-primed BALB/c mouse splenocytes proliferated when challenged with intact RS virus or with F, G, 23K, or P protein preparations.

A prospective study of hand-held Doppler ultrasonography by emergency physicians in the evaluation of suspected deep-vein thrombosis.

A prospective study was conducted in the emergency departments of two community hospitals to assess the accuracy of Doppler ultrasonography performed by emergency physicians in the evaluation of patients with symptoms suggestive of deep-vein thrombosis. Seventy-eight extremities in 76 patients were evaluated by both Doppler ultrasonography and contrast venography. Thirty-six Doppler examinations were normal, 26 were abnormal, and 15 were equivocal. Of the unequivocal examinations, three were false-negative and nine were false-positive. These data represent a sensitivity of 85%, specificity of 79%, negative predictive value of 92%, and positive predictive value of 65%. Negative predictive value improved to 100% among a subgroup of low-risk patients, and positive predictive value improved to 80% among a subgroup of high-risk patients. Our study suggests that Doppler ultrasonography is highly predictive of a negative venogram, particularly in the low-risk patient. Further study with a larger population is needed. The availability and noninvasiveness of Doppler ultrasonography make it a useful adjunct in the evaluation of suspected deep-vein thrombosis in the ED.

Utility of laboratory studies in the emergency department patient with a new-onset seizure.

Extensive laboratory testing is often performed in the emergency department evaluation of the new-onset seizure patient. To determine the utility of such testing, a prospective study of patients with a new-onset seizure presenting to the ED of an inner-city, university-affiliated teaching hospital was done. One hundred thirty-six patients were entered into the study between October 1984 and January 1988. All patients had uniform data collection performed. Pertinent historical information and physical examination findings were recorded on a standardized form before laboratory abnormality was a sole or contributory cause of the seizure disorder. These included four patients with hypoglycemia, four with hyperglycemia, two with hypocalcemia, and one with hypomagnesemia. Only two cases (hypoglycemia) were not suspected on the basis of findings on the history or physical examination. In ED patients, the incidence of a new-onset seizure due to a correctable metabolic disturbance is low. We conclude that, with the exception of the serum glucose, the extensive ED laboratory workup often done for the evaluation of a new-onset seizure is unnecessary. Further test ordering should be directed by the medical history and physical examination.

Prospective study of the effect of safety belts in motor vehicle crashes.

Trauma resulting from motor vehicle crashes (MVCs) is the leading cause of death in persons 1 to 38 years old. The following prospective study was undertaken to assess the effect of safety belts on the types of injuries sustained in MVCs. A total of 1,364 patients from four Chicago-area hospitals were evaluated prospectively during a six-month period. Safety belts reduced the incidence of head, facial, thoracic, abdominal, and extremity injuries sustained in MVCs. Spinal injuries comprised the only group in which safety belt wearers sustained injuries more frequently than safety belt nonwearers. Further research on the different safety belt designs and effects of air bags is needed to reduce the incidence of cervical and lumbar strain in restrained patients.

Cardiopulmonary abnormalities after smoking cocaine.

We recently treated a young man who had chest pain after smoking "freebase" cocaine. Pneumomediastinum was diagnosed, and the electrocardiographic changes that developed were characteristic of coronary artery spasm. Although pneumomediastinum has been linked to "freebasing," we believe electrocardiographic abnormalities in this situation have not been previously reported.

Effects of a novel cholecystokinin (CCK) receptor antagonist, MK-329, on gallbladder contraction and gastric emptying in humans. Implications for the physiology of CCK.

To explore the physiology of cholecystokinin (CCK) in humans, we investigated the effect on gallbladder contraction and gastric emptying of a recently developed CCK receptor antagonist, MK-329. In a double-blind, four-period crossover study eight subjects received single doses of 0.5, 2, or 10 mg MK-329, or placebo, followed by an intravenous infusion of CCK-8 (30 pmol/kg.h). In placebo-treated subjects gallbladder volumes decreased on average to 43% of initial volumes after 2 h of CCK infusion. MK-329 caused a dose-dependent inhibition of CCK-stimulated gallbladder contraction with 10 mg producing complete blockade (P less than 0.01, cf. placebo). Gallbladder contraction and gastric emptying rates after a mixed meal were then measured in a two-period crossover study. Subjects received placebo or 10 mg of MK-329 2 h before eating. Gastric emptying of both solids and liquids was measured simultaneously by gamma scintigraphy. In placebo-treated subjects plasma CCK levels increased postprandially to 2.3 pM, gallbladder volumes decreased 68.4 +/- 3.8% (SE), and the times for 50% emptying of liquids and solids from the stomach were 58 +/- 10 and 128 +/- 8 min, respectively. In MK-329-treated subjects there was a marked elevation in peak CCK levels to 13.8 pM (P less than 0.01, cf. placebo), and gallbladder contraction was completely inhibited. Solid and liquid emptying rates were unaffected. These findings demonstrate that (a) MK-329 is a potent, orally active antagonist of CCK in humans, and (b) CCK is the major regulator of postprandial gallbladder contraction. These data also support the concept of negative feedback regulation of CCK secretion and suggest that mechanisms other than CCK play a dominant role in the regulation of postprandial gastric emptying rates.

Complications and protocol considerations in carbon monoxide-poisoned patients who require hyperbaric oxygen therapy: report from a ten-year experience.

We conducted a study to determine the type, incidence, and timing of complications that occur in patients who have a carbon monoxide (CO) exposure serious enough to require hyperbaric oxygen therapy (HBOT). Complication data were retrospectively collected from a ten-year period for 297 consecutive CO-poisoned emergency department patients who received HBOT. HBOT was indicated for 41% of the patients because of an elevated carboxyhemoglobin (COHb) level alone. Central nervous system dysfunction, including loss of consciousness, and/or cardiovascular dysfunction, was the criteria for HBOT in 59% of patients, regardless of their COHb level. The mean peak COHb level was 38 mg%, with 88% of patients having a peak COHb level greater than 25 mg%. The mortality rate was 6% in this case series. Cardiac arrest occurred in 8% of patients; all experienced their first arrest prior to HBOT. The 3% of patients who sustained an isolated respiratory arrest and those who had a myocardial infarction did so prior to HBOT. Several complications, however, occurred for the first time or as a recurrent event during HBOT. These included emesis (6%), seizures (5%), agitation requiring restraints or sedation (2%), cardiac dysrhythmias or arrests (2%), and arterial hypotension (2%). No patient's level of consciousness deteriorated subsequent to the initial resuscitation except for those who later had a generalized seizure. The most significant complication attributable to HBOT was tension pneumothorax, noted in three patients (1%).(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency department use of hand-held Doppler ultrasonography.

Doppler ultrasonography (DU) using a hand-held Doppler device represents a readily available emergency department (ED) technique that has been used for diagnostic testing with conditions associated with abnormal vascular flow, such as deep venous thrombosis, testicular torsion, and arterial insufficiency. DU may serve as a useful initial diagnostic test in the ED setting. The appropriate indications, techniques of examination, and accuracy of DU are summarized for the aforementioned conditions.

Prospective study of the effect of safety belts on morbidity and health care costs in motor-vehicle accidents.

To assess the impact of safety belt use on the extent of injuries sustained in motor-vehicle accidents and the incurred health care costs, 1364 patients were prospectively evaluated at four Chicago-area hospitals. Of these, 791 (58%) were wearing a safety belt whereas 573 (42%) were not. The mean injury severity score for safety belt wearers was 1.8 +/- 0.07 vs 4.51 +/- 0.31 in those not wearing a safety belt. Only 6.8% of safety belt wearers required admission vs 19.2% of those not wearing a safety belt. Restrained occupants incurred mean charges of $534 +/- $67 compared with $1583 +/- $201 in unrestrained occupants. Thus, safety belt wearers had a 60.1% reduction in severity of injury, a 64.6% decrease in hospital admissions, and a 66.3% decline in hospital charges. Our findings demonstrate the significant societal burden of nonuse of safety belts in terms of morbidity and the costs of medical care.

Emergency department screening for unsuspected carbon monoxide exposure.

Carbon monoxide (CO) is the leading toxic cause of death in the United States today. Unsuspected exposure to this gas will sometimes result in clinically significant, but undiagnosed, toxicity. A high incidence of such unsuspected exposures would make screening for these worthwhile among high-risk populations. We conducted a two-part study to determine the value of screening for unsuspected CO exposure in a population of patients presenting to an emergency department. The first part of our study involved the prospective screening of ED patients using CO breath analysis, regardless of their chief complaint. In the second part, COHGB levels of all patients who underwent arterial blood gas analysis during the study period were reviewed retrospectively. Of 1,038 patients screened by this combined approach, only 29 (2.8%) had abnormal CO breath readings and/or COHGB levels. Of a condensed subgroup of 152 patients defined retrospectively by chief complaint, eight (5.3%) had abnormal values. We conclude that routine screening of ED patients for unsuspected CO exposure is not practical. Although yield increases when patients are screened in a more selective manner on the basis of chief complaint, such an increase still does not appear to justify the screening process.