The assessment of limb apraxia: Relationship between performances on single- and multiple-object tasks by left hemisphere damaged aphasic subjects

Two types of object manipulation tests, commonly advocated for the assessment of limb apraxia, were administered to 30 left hemisphere damaged aphasic (LHD) adults and 10 non-neurologically impaired control subjects. The tests were a multiple-object (MOT), requiring the manipulation of several related objects (e.g., lighting a candle when given a candle, a handle holder, and a match), and a single-object test (SOT) (e.g., lighting a match). Each of the subject's responses was assigned to one of six response categories: Standard (in which the response met all criteria for a faultless response) and five Nonstandard categories (Clumsy, Mislocation, Object Misuse, Perplexity, Omission). The results on comparing performances on the two tests showed that the SOT was “harder” than the MOT. Also, analyses of the relationship between MOT and SOT performances for the LHD subjects resulted in strong correlations between tests, loadings on the same two factors, and no evidence of double dissociations between the two tests for individual subjects. The two factors were interpreted to be a “conceptual/semantic” and a “motor execution” factor. The strong relationship and absence of double dissociations between response categories across the SOT and MOT suggest that both tasks are mediated by the same two neuropsychological processes. Clinical and theoretical implications of the findings are discussed.     

An unusual presentation of placental malaria: a single persisting nidus of sequestered parasites

Placental malaria caused by Plasmodium falciparum is a public health concern in tropical countries. Peripheral blood smears to detect placental malaria are often negative, and recrudescences are common during pregnancy. We performed placental histology on a series of first-time mothers delivering in an area endemic for P falciparum. A single nidus of malaria-infected erythrocytes was identified by placental histology in a single intervillous space from a woman who had no other evidence of peripheral or placental blood parasitemia. This finding suggests ring stage-infected erythrocytes sequester in vivo, or P falciparum can persist as a dormant blood stage form.     

Genomewide scans of red cell indices suggest linkage on chromosome 6q23

Background

The red cell indices quantify the size, number and oxygen‐carrying ability of erythrocytes. Although the genetic basis of many monogenic forms of anaemia is well understood, comparatively little is known about the genes responsible for variation in the red cell indices among healthy participants.

Objective

To identify quantitative trait loci (QTLs) responsible for normal variation in the red cell indices of 391 pairs of dizygotic twins who were measured longitudinally at 12, 14 and 16 years of age.

Results

Evidence suggesting linkage of red cell indices to haemoglobin concentration (LOD  = 3.03) and haematocrit (LOD  = 2.95) on chromosome 6q23, a region previously identified as possibly harbouring a QTL for haematocrit, was found. Evidence for linkage to several other regions of the genome, including chromosome 4q32 for red cell count and 7q for mean cell volume, was also found. In contrast, there was little evidence of linkage to the chromosomal regions containing the genes for erythropoietin (7q21) and its receptor (19p13.2), nor to the regions containing the genes for the haemoglobin α (16p13.3) and β chains (11p15.5).

Conclusion

Findings provide additional evidence for a QTL affecting haemoglobin and haematocrit on chromosome 6q23. In contrast, polymorphisms in the genes coding for erythropoietin, its receptor and the haemoglobin α and β chains do not appear to contribute substantially to variation in the red cell indices between healthy persons.The red cell indices describe the size, number and oxygen‐carrying capacity of erythrocytes. Haemoglobin concentration indicates the amount of oxygen‐carrying protein haemoglobin in a given volume of blood; red blood cell count (RBC), the concentration of erythrocytes; mean corpuscular volume (MCV), the average volume of each red cell; and haematocrit (HCT), the proportion of blood that consists of erythrocytes. Together, these indices assist in the differential diagnosis of anaemia and are risk factors for a number of clinical conditions. For example, a high haematocrit is associated with increased risk of cerebrovascular^1,2 and coronary artery diseases.¹Approximately 7% of the world''s population are carriers for different inherited disorders of haemoglobin, making them one of the most prevalent Mendelian diseases.³ Although the genetic basis of many of these haemoglobinopathies is well understood, comparatively little is known regarding the genetic causes of variation in the normal range of red cell values. Studies on twins have shown that a substantial proportion of the variation between persons is due to genetic factors with heritability estimates ranging from 20% to 96%.^4,5,6,7,8,9 A recent genomewide linkage study by Lin et al⁷ identified a locus on chromosome 6q23–24 linked to HCT, and a pleiotropic locus affecting haemoglobin and HCT on chromosome 9q.⁷ Interestingly, the authors found no evidence of linkage to regions containing the genes for the α and β haemoglobin chains (on chromosomes 16p13.3 and 11p15.5), nor erythropoietin and its receptor (on chromosomes 7q21 and 19p13.2), which have all been implicated in Mendelian forms of anaemia. The implication is that the quantitative trait loci (QTLs) responsible for normal variation in the red cell indices might differ from the loci which cause monogenic forms of anaemia.In a previous study, we reported that variation in the red cell indices was highly heritable, with genetic factors explaining between 61% and 96% of the phenotypic variance in our sample of adolescent twins.⁵ In this paper, we extend these results by performing a genomewide linkage scan of the 391 dizygotic twin pairs from that study. We measured the red cell indices of twins at 12, 14 and 16 years of age and performed univariate multipoint sib‐pair linkage analyses across the genome. Our study is the first to report linkage results for RBC and MCV, and will hopefully constitute the first stage in the identification and subsequent positional cloning of QTLs responsible for normal variation in the red cell indices.     

Nurses' satisfaction with medication administration point-of-care technology

Efforts to promote safe care prompted the development point-of-care technology, but successful adoption requires acceptance by nursing staff. To assess the satisfaction of nurses who use point-of-care technology that integrates nurse scanning of bar-coded medications with the patient's electronic medication administration record, the authors examined nurses' satisfaction with barcode/electronic medication administration record before and after introduction in an academic medical center.     

Using the Quality-Caring Model to organize patient care delivery

The organization of patient care in many acute care institutions lacks a foundation in nursing theory, yet preliminary evidence of the value of professional nursing care is increasing. The process and preliminary benefits of organizing patient care according to a professional practice model are presented using a collaborative partnership between an acute care organization and a school of nursing. A pilot implementation plan with formative and summative evaluation provided preliminary evidence used in project expansion.     

Maxillary transverse discrepancies and potentially impacted maxillary canines in mixed-dentition patients

OBJECTIVE: To investigate the correlation between maxillary transverse discrepancy and the occurrence of impacted canines in patients during the mixed-dentition stage. MATERIALS AND METHODS: Panoramic radiographs and dental casts were evaluated of randomly selected patients in the mixed dentition. The experimental group consisted of 84 orthodontic patients with a maxillary transverse discrepancy. The control group included 100 orthodontic patients without a maxillary transverse discrepancy. Intermolar widths of the experimental group were measured and recorded. The permanent canines of both groups were placed into a sector classification by using a panoramic radiograph. The experimental group was then analyzed to identify whether these patients had an impacted maxillary canine associated with the transverse discrepancy. The results were further evaluated based on type of impaction (unilateral or bilateral). RESULTS: Results of this study showed that patients with a transverse discrepancy are more likely to have an impacted canine than those patients without a transverse discrepancy, with the impaction more likely being unilateral. However, patients with a transverse discrepancy do not have a greater likelihood of having a bilateral impaction compared with patients without a transverse discrepancy. CONCLUSIONS: There appears to be an association between potentially impacted canines and transverse discrepancies. Identification can be made early based on proper panoramic evaluation and clinical detection. If a possibly impacted canine is detected early, appropriate treatment should be taken to minimize complications and avoid definitive impaction.     

Antiphospholipid syndrome and perioperative hemostatic management of cardiac valvular surgery

Hemostatic aspects of antiphospholipid syndrome (APS) present unique challenges to clinicians and laboratory personnel alike, particularly in the perioperative period. These challenges are especially evident in patients requiring cardiac valve replacement surgery. However, the literature outlining the optimal approach in such patients is limited. We present the case of a 25-year-old woman with severe aortic regurgitation as a result of APS with particular reference to the precautions necessary during perioperative care. Particularly important are the prevention of thrombotic or hemorrhagic complications, management of associated thrombocytopenia, and laboratory methods of perioperative anticoagulation monitoring in the setting of prolonged clotting times.