Rapid digital filtering

Image filtering with the larger, and potentially most valuable, digital filters is very time-consuming, thus precluding use of these filters in routine clinical applications. A recently developed algorithm for spatial-domain filtering is described, and its speed is compared with those of conventional methods with and without an array processor. Using the new Chebyshev method, a 64 by 64 pixel image can be filtered on a standard 16-bit minicomputer with filters of size 3 by 3 to 23 by 23 in 1.4-9.2 sec. The conventional spatial-domain algorithm requires 3.8-71 sec. With an array processor, filtering is accomplished in 0.19-0.54 sec. Filtering in the frequency domain requires 34 sec without an array processor and 0.12 sec with one. Thus with this new Chebyshev algorithm, clinically practical digital filtering can be performed with large filters even without an array processor.     

The effects of West Nile virus on major histocompatibility complex class I and II molecule expression by Lewis rat Schwann cells in vitro

The expression of major histocompatibility complex (MHC) class I and II molecules by Lewis rat Schwann cells after infection with West Nile virus (WNV) in vitro was examined by fluorescence microscopy and flow cytometry. WNV enhanced the expression of MHC class I molecules and induced the expression of MHC class II molecules by Schwann cells. Irradiated medium from WNV-infected Schwann cell cultures upregulated class I molecule expression on dissociated Schwann cell cultures but did not induce the expression of class II molecules. This finding has implications for virally triggered autoimmune diseases of nervous tissue.     

Unemployment and child abuse

The employment state of men living in the homes of children at the time that child abuse was diagnosed was determined. The series included a wide range of abuse, including non-accidental injury, failure to thrive, neglect, and emotional deprivation. Two cohorts of children seen during 1974-9 and 1980-5 were compared; these periods were chosen because a large increase in unemployment began in Sheffield in 1980. Although the proportion of the men without work was significantly increased during the second period, this increase could not be ascribed to the rise in either long term or short term unemployment among those who had previously been in regular employment. It was accounted for by a rise in the proportions of single parent families and families in which the resident man had never had regular employment. This may reflect an increase in pregnancies among young mothers. There was no evidence to support the belief that the loss of a job in otherwise stable families leads to an increase in child abuse.     

Rapid VAC high dose melphalan regimen, a novel chemotherapy approach in childhood soft tissue sarcomas

Forty-three children with malignant soft tissue sarcomas (IRS Groups II-IV) were treated with rapid dose delivery chemotherapy protocol comprising six courses of vincristine, adriamycin and cyclophosphamide, given in most cases within 8 weeks (Rapid VAC). This was followed in 36 patients by high dose melphalan with autologous bone marrow rescue. Twenty-six patients also received irradiation to the site of primary tumour. The Rapid VAC regimen was well tolerated and largely administered as an out-patient. There was one toxic death which occurred 2 months after high dose melphalan due to a combination of infection and possible anthracycline cardiomyopathy. Stages were, (Intergroup Rhabdomyosarcoma Study (IRS) system) Group, Group II--four patients. Group III--27 patients and Group IV--12 patients; International Society of Paediatric Oncology (SIOP) staging, Stage I--11, Stage II--13, Stage III--7, Stage IV--12. Actuarial survival at 5 years for all stages is 57% and event free survival 44%. For patients with non-metastatic diseases, 62% and 53% respectively. This treatment strategy utilises the philosophy of rapid drug delivery with high dose consolidation and enables all chemotherapy to be finished within a 4 month period. In general, a conservative approach was applied to both radiation and surgery to minimise late sequelae related to these treatment modalities. Although the small number of high risk patients in this study limits conclusions regarding efficacy in these subgroups the overall results with this regimen appear to be comparable to that with other approaches.     

Delineating the sites and progression of in vivo atrophy in multiple system atrophy using fluid-registered MRI.

We describe the pattern and progression of atrophy delineated using fluid registration of serial magnetic resonance imaging scans in a case of multiple system atrophy (MSA). The in vivo findings were consistent with those found at postmortem, including significant supratentorial atrophy concurrent with an unusual degree of cognitive impairment for MSA.     

Intravenous Phenylephrine Preconditioning of Cardiac Grafts From Non–Heart-Beating Donors

Background. Hypoxia and warm ischemia produce severe injury to cardiac grafts harvested from non–heart-beating donors. To potentially improve recovery of such grafts, we studied the effects of intravenous phenylephrine preconditioning.Methods. Thirty-seven blood-perfused rabbit hearts were studied. Three groups of non–heart-beating donors underwent intravenous treatment with phenylephrine at 12.5 (n = 8), 25 (n = 7), or 50 μg/kg (n = 7) before initiation of apnea. Non–heart-beating controls (n = 8) received saline vehicle. Hypoxic cardiac arrest occurred after 6 to 12 minutes of apnea, followed by 20 minutes of warm in vivo ischemia. A 45-minute period of ex vivo reperfusion ensued. Nonischemic controls (n = 7) were perfused without antecedent hypoxia or ischemia.Results. Phenylephrine 25 μg/kg significantly delayed the onset of hypoxic cardiac arrest compared with saline controls (9.6 ± 0.5 versus 7.7 ± 0.4 minutes; p = 0.00001), yet improved recovery of left ventricular developed pressure compared with saline controls (57.1 ± 5.3 versus 41.0 ± 3.4 mm Hg; p = 0.04). Phenylephrine 25 μg/kg also yielded a trend toward less myocardial edema than saline vehicle (p = 0.09).Conclusions. Functional recovery of nonbeating cardiac grafts is improved by preconditioning. We provide evidence that the myocardium can be preconditioned with phenylephrine against hypoxic cardiac arrest.(Ann Thorac Surg 1997;63:1664–8)     

Parental Perceptions, Early Maladaptive Schemas, and Depressive Symptoms in Young Adults

Cognitive models of depression propose that negative schemas contribute to depressive symptoms. Early experiences, particularly parenting, have been proposed to influence cognitive schemas and have also been shown to correlate with depression. This study explores the concurrent relationship between retrospective reports of parenting, Early Maladaptive Schemas (EMSs) described by J. E. Young (1994), and symptoms of depression in a sample of undergraduate students (N = 194). The EMSs of defectiveness/shame, insufficient self-control, vulnerability, and incompetence/inferiority were associated with perceptions of parenting and depressive symptomatology. There was evidence that these four EMSs partially mediate the relationship between parental perceptions and depressive symptomatology. Results are discussed in relation to previous findings, theory, and the measurement of EMSs.