Comparing the performance of storage phosphor plate and Insight film images for the detection of proximal caries depth.

OBJECTIVES: To compare proximal caries depth between conventional film images, unenhanced and enhanced storage phosphor plate images. METHOD: Bitewing radiographs were taken on 100 patients presenting for Conservative and Periodontal treatment. Only one bitewing was taken on a patient either the right or left hand side of the patient A DenOptics storage phosphor plate and size 3 Kodak Insight film were simultaneously placed into a Rinn bitewing holder. The Insight film was placed behind the phosphor plate. Both were simultaneously exposed to radiation. The unenhanced phosphor plate images were copied four times. Contrast and brightness were either increased or decreased on the copied images. A five point scale was chosen for proximal caries depth: 0--sound, 1--caries in enamel, 2--caries reaching dentino-enamel junction, 3--caries into dentine, 4--caries in a restored area. The bitewing images were evaluated by 4 clinicians. Images with technical errors were excluded from the study. RESULTS: Altogether 1848 tooth surfaces were evaluated of which 136 surfaces were excluded due to technical errors. The results show that for the detection of proximal caries there is no significant difference in accuracy between unenhanced storage phosphor plate and Kodak Insight film images (p > 0.001). When decreasing both contrast and brightness there was no significant difference in diagnostic accuracy (p > 0.001) between unenhanced and enhanced storage phosphor plate images. More surfaces were analyzed for caries into the dentine on the enhanced images when both contrast and brightness were increased. CONCLUSION: Although contrast-enhanced and brightness-enhanced images retween conventional film, unenhanced and enhanced images.

A phylogenetic study of South African Newcastle disease virus strains isolated between 1990 and 2002 suggests epidemiological origins in the Far East.

Genetic comparisons were made of the fusion protein sequences of 155 Newcastle disease virus isolates collected in South Africa between 1990 and 2002. Their evolutionary relationships and origins are described. All of the lentogenic field isolates were shown to be derived from commercial vaccines. No true South African lentogenic wild type strain was identified. Furthermore, it was shown that almost all mesogenic isolates had avirulent F(0) cleavage site sequences. Three major epizootics occurred in South Africa during the period of this study. The first outbreak (1990/1991) was caused by viruses endemic to South Africa since the 1960's (genotype VIII) but were occasionally also isolated in 2000. Genotype VIIb viruses, implicated in the severe outbreaks during 1993/1994, persisted until 1999. Genotype VIId viruses, responsible for the most recent outbreak in 1999/2000, had their origins in the Far East like those of the two previous outbreaks.

Atrial septal defects in Florida panthers.

Ostium secundum atrial septal defects (ASDs) were observed in six (3 M, 3 F) of 33 (20 M, 13 F) (18%) Florida panthers (Puma concolor coryi) necropsied by veterinary pathologists between 1985 and 1998. A seventh ASD was found in a female panther necropsied in the field and is included in the pathological description but not the prevalence of ASDs in Florida panthers. One panther (FP205) with severe ASD also had tricuspid valve dysplasia (TVD). Atrial septal defects and/or TVD are believed to have caused or contributed to the deaths of three (9%) Florida panthers in this study. Mean diameter +/- SD of ASDs was 9.0 +/- 4.7 mm (range 3 to 15 mm). Gross pathological changes attributed to ASDs/TVD in severely affected panthers (ASD > or = 10 mm) (n = 4) included mild right ventricular dilatation (n = 3) and hypertrophy (n = 2), mild to severe right atrial dilatation (n = 2), and acute pulmonary edema (n = 3). Panthers with mild ASDs (ASD < or = 5 mm) (n = 3) had no other detectable gross pathological changes associated with the ASDs. Histological examination of lungs of three panthers with severe ASDs revealed mild to moderate dilatation with fibrosis and smooth muscle atrophy of the tunica media of medium to large caliber arteries (n = 2), interstitial and/or pleural fibrosis (n = 2), perivascular fibrosis (n = 1), and acute to chronic edema (n = 3). Twenty-six necropsied panthers were examined one or more times while living; medical records were retrospectively evaluated. Antemortem radiographic, electrocardiographic, and echocardiographic examinations were performed on two panthers with severe ASDs (FP20 and FP205). Thoracic radiographic abnormalities in both included right heart enlargement, and in FP205 (severe ASD and TVD), mild pulmonary overperfusion. Electrocardiographic examination of FP205 revealed a right ventricular hypertrophy pattern, while FP205 had a normal electrocardiogram. Echocardiographic examination of FP20 revealed marked right atrial dilatation; a bubble contrast study indicated regurgitation across the tricuspid valve. Echocardiographic abnormalities in FP20 included right atrial and ventricular lilatation, atrial septal drop-out, and severe tricuspid regurgitation; non-selective angiography revealed significant left to right shunting across the ASD. All panthers with severe ASDs ausculted (n = 3) had systolic right or left-sided grade I-V/VI murmurs loudest at the heart base. All male panthers with ASDs (n = 3) (100%) and 9 of 17 (53%) male panthers without ASDs in this study were cryptorchid.

Impaired pulmonary diffusion during exercise in patients with chronic heart failure.

BACKGROUND: Pulmonary diffusion is impaired at rest in patients with chronic heart failure (CHF) and has been implicated in the generation of symptoms and exercise intolerance. The aim of this study was to determine whether pulmonary diffusion is impaired during exercise in CHF, to examine its relationship to pulmonary blood flow, and to consider its functional significance in relation to metabolic gas exchange. METHODS AND RESULTS: Carbon monoxide transfer factor (TLCO) and pulmonary blood flow (Q(C)) were measured by a rebreathe technique at rest and during steady-state cycling at 30 W in 24 CHF patients and 10 control subjects. Both patients and control subjects were able to raise TLCO and Q(C) during exercise. However, the patient group had a lower diffusion for a given blood flow (TLCO/Q(C)) both at rest (3.6+/-0.16 and 4.8+/-0.23 mL x L(-1) x mm Hg(-1); P<0.001) and during exercise (2.8+/-0.16 and 3.4+/-0.13 mL x L(-1) x mm Hg(-1) for CHF patients and control subjects, respectively; P<0.05). TLCO/Q(C) was related to the ventilatory equivalent for carbon dioxide (VEVCO(2)) production at 30 W (TLCO/Q(c) versus VEVCO(2), r = -0.58, P<0.01) and to peak exercise oxygen consumption measured during a progressive test (TLCO/Qc versus VO(2peak), r = 0.57, P<0.01) in these patients. CONCLUSIONS: Patients with CHF are able to recruit reserves of TLCO and Q(C) during exercise. However, the TLCO/Q(C) ratio is consistently impaired in these patients and relates to both exercise hyperpnea and peak exercise oxygen consumption. Whether this impairment in alveolar gas exchange is reversible in CHF and therefore is a potential target for therapy has yet to be determined.

Genetic characterization of canine distemper virus in Serengeti carnivores.

The lion (Panthera leo) population in the Serengeti ecosystem was recently afflicted by a fatal epidemic involving neurological disease, encephalitis and pneumonia. The cause was identified as canine distemper virus (CDV). Several other species in the Serengeti were also affected. This report presents CDV H and P gene sequences isolated from Serengeti lions (Panthera leo), spotted hyenas (Crocuta crocuta), bat-eared fox (Otocyon megalotis) and domestic dog (Canis familiaris). Sequence analyses demonstrated that the four Serengeti species carry closely related CDV isolates which are genetically distinct from other CDV isolates from various species and locations. The results are consistent with the conclusions that: (1) a particularly virulent strain of CDV emerged among Serengeti carnivores within the last few years; (2) that strain has recognizable shared-derived (synapomorphic) genetic differences in both H and P genes when compared to CDV from other parts of the world; and (3) that the CDV strain has frequently crossed host species among Serengeti carnivores.

African buffalo maintain high genetic diversity in the major histocompatibility complex in spite of historically known population bottlenecks.

Historical population collapses caused by rinderpest epidemics are hypothesized to have resulted in notable genetic losses in populations of the African buffalo. Polymorphism in the major histocompatibity complex (MHC) DRB3 gene was probed by means of restriction analysis of the sequence encoding the peptide-binding region. Nucleotide substitution patterns agreed with a positive selection acting on this fitness-relevant locus. Buffalo populations from four National Parks, situated in eastern and southern Africa, each revealed a surprisingly high allelic diversity. Current high levels of heterozygosity may be reconciled with historical bottlenecks by assuming that local extinctions were followed by fast recolonization, in accordance with the high dispersive capabilities of buffalo. The specific amplification of DRB3 alleles also enabled the assignment of individual genotypes. For each population sample a deficiency in the expected number of heterozygous animals was found. As overdominant selection on the MHC is predicted to yield an excess of heterozygous individuals, this may not be a locus-specific effect. Several other explanations are discussed, of which increased homozygosity caused by nonrandom mating of buffalo in populations seems the most probable.

Trichinella nelsoni in carnivores from the Serengeti ecosystem, Tanzania.

A survey of trichinellosis among sylvatic carnivore mammals from the Serengeti ecosystem (Tanzania) demonstrated the presence of Trichinella nelsoni in 5 of 9 species examined. Muscle samples were collected from carcasses of 56 carnivores from 1993 to 1995 and frozen before transport and examination. Following artificial digestion of the samples, collected larvae were analyzed by the random amplified polymorphic DNA technique. Trichinella nelsoni was identified in 1 bat-eared fox (Otocyon megalotis), 1 cheetah (Acinonyx jubatus), 1 leopard (Panthera pardus), 3 lions (Panthera leo), and 3 spotted hyenas (Crocuta crocuta). The numbers of bat-eared foxes (6), cheetahs (5), and leopards (3) examined were too small to reveal the roles of these carnivore species in the ecology of T. nelsoni. The numbers of lions and spotted hyenas examined, with a prevalence of 12% and 23%, respectively, suggest that these species may be reservoirs of T. nelsoni in the area under study.

A canine distemper virus epidemic in Serengeti lions (Panthera leo).

Canine distemper virus (CDV) is thought to have caused several fatal epidemics in canids within the Serengeti-Mara ecosystem of East Africa, affecting silver-backed jackals (Canis mesomelas) and bat-eared foxes (Otocyon megalotis) in 1978 (ref. 1), and African wild dogs (Lycaon pictus) in 1991 (refs 2, 3). The large, closely monitored Serengeti lion population was not affected in these epidemics. However, an epidemic caused by a morbillivirus closely related to CDV emerged abruptly in the lion population of the Serengeti National Park, Tanzania, in early 1994, resulting in fatal neurological disease characterized by grand mal seizures and myoclonus; the lions that died had encephalitis and pneumonia. Here we report the identification of CDV from these lions, and the close phylogenetic relationship between CDV isolates from lions and domestic dogs. By August 1994, 85% of the Serengeti lion population had anti-CDV antibodies, and the epidemic spread north to lions in the Maasai Mara National reserve, Kenya, and uncounted hyaenas, bat-eared foxes, and leopards were also affected.

Phylogenetic evidence of canine distemper virus in Serengeti's lions.

Recently an epizootic, reported to be due to a morbillivirus infection, affected the lion population of the Tanzanian Serengeti National Park. A morbillivirus phosphoprotein (P) gene fragment was amplified by PCR from tissue samples of several affected lions. Sequencing of the amplificates and subsequent phylogenetic analyses revealed that a wild-type strain of canine distemper morbillivirus (CDV) was involved. Vaccination of the local domestic dog population with proven safe CDV vaccines is proposed.

Aesthetic knowing grounded in an explicit conception of nursing.

This article presents an expanded perspective of aesthetic knowing in nursing grounded in the theory of nursing as caring. The authors highlight Carper's contributions to nursing, applauding the value of her work. However, a major limitation of Carper's work on aesthetic knowing is the failure to provide an explicit conception of nursing to guide the search for patterns and structure of nursing knowledge, thus the limited development of the aesthetic pattern of knowing in nursing. The authors propose that aesthetic knowing in nursing is the creating experience in the nursing situation, expression of the experience, and appreciation of it through encounter.