Ultrasonic features of pyogenic liver abscesses

Ultrasonic features of 21 surgically confirmed pyogenic liver abscesses in 18 patients were analyzed. Typical lesions were round or ovoid with a discrete, irregular, echo-poor margin. The number and intensity of internal echoes and sound transmission were variable. Such lesions can be aspirated percutaneously for definitive preoperative diagnosis. Pyogenic liver abscesses appear to have more ragged walls and are less frequently elliptical or multilocular than abscesses elsewhere in the abdomen.     

Bayesian estimation of dynamical systems: an application to fMRI

This paper presents a method for estimating the conditional or posterior distribution of the parameters of deterministic dynamical systems. The procedure conforms to an EM implementation of a Gauss-Newton search for the maximum of the conditional or posterior density. The inclusion of priors in the estimation procedure ensures robust and rapid convergence and the resulting conditional densities enable Bayesian inference about the model parameters. The method is demonstrated using an input-state-output model of the hemodynamic coupling between experimentally designed causes or factors in fMRI studies and the ensuing BOLD response. This example represents a generalization of current fMRI analysis models that accommodates nonlinearities and in which the parameters have an explicit physical interpretation. Second, the approach extends classical inference, based on the likelihood of the data given a null hypothesis about the parameters, to more plausible inferences about the parameters of the model given the data. This inference provides for confidence intervals based on the conditional density.     

D2 lymphadenectomy in the management of gastric cancer

Background Gastric carcinoma is a significant cause of death in Ireland. Surgery offers the best option of cure, but the five-year survival following resection remains dismal at 10–15%. Experience from Japan and from some Western units suggest that an extended (D2) lymphadenectomy in association with gastrectomy increases the prospect of cure, but concern about the morbidity and mortality of this operation and lack of evidence from randomised studies has limited its acceptance. Aims This study reports the experience of a specialist upper gastrointestinal unit with D2 gastrectomy in a four-year audit. Methods Sixty-two resections were performed for gastric cancer. Results Nineteen patients were deemed unsuitable for the D2 procedure and underwent a more limited lymphadenectomy (DO or D1). Forty-three patients underwent D2 resection, 12 with an oesophagogastrectomy, 22 with total gastrectomy and nine with a sub-total distal resection. Eight patients undergoing D2 resection had extended resections, five with splenectomy and three with a distal pancreatectomy. Post-operative complications occurred in 31% of patients. Thirty-day and 90-day mortality were zero. Median survival was 822 days in the D2 group (range 120–1,320). Conclusions These results show that a D2 gastrectomy can be performed with a low morbidity and mortality and a median survival of greater than two years.     

ENDOTHELIAL CELL CULTURE AND SEEDING OF PROSTHETIC VASCULAR GRAFTS: AN EXPERIMENTAL STUDY

Current synthetic vascular prostheses do not acquire lining of vascular endothelium in humans or dogs. Endothelial seeding of vascular grafts has been proposed as a means of reducing the thrombogenicity of these grafts. We examined feasibility of cultivating endothelial cells (EC) by tissue culture technique and their subsequent seeding onto small diameter polytetra fluoroethylene (PTFE) grafts. Twenty adult dogs underwent common carotid artery interposition with 4 mm PTFE grafts. Ten dogs received seeded and the remaining ten received unseeded grafts. Grafts were removed at 4 and 12 weeks and their gross/morphological features compared. Cumulative patency rates for seeded grafts were 70% as compared to unseeded ones 30%. Seeded grafts were completely surfaced with a mono-layer of endothelium by 4 weeks. Small graft patency appears to be related to the establishment of an endothelial surface, the development of which is clearly facilitated by seeding with autogenous endothelium.KEY WORDS: Endothelial cell seeding, Vascular grafts     

Cloning of cDNA coding for connective tissue activating peptide III from a human platelet-derived lambda gt11 expression library

We report here the cloning of the cDNA coding for platelet connective tissue-activating peptide-III (CTAP-III) from a lambda gt11 expression library prepared using messenger RNA (mRNA) isolated from human platelets. The open reading frame of the clone coded for a protein with 128 amino acid residues. Since the precursor of CTAP-III, platelet basic protein (PBP is 94 amino acids long, the 5'-translated region of the cDNA codes for a leader sequence 34 amino acids long. This leader sequence, like the sequence of mature CTAP-III, shows significant homology to the sequence of platelet factor 4 (PF4), the only other platelet specific alpha-granule protein cloned until now, from a human erythroleukemic (HEL) cell line-derived cDNA library. These leader sequences are probably critical for targeting such proteins to the alpha-granule. Northern blot hybridization with platelet and megakaryocyte mRNA shows a single species mRNA of approximately 0.8 kb, suggesting that the corresponding cDNA is full length. The cloning of platelet specific CTAP-III provides additional evidence for the platelet specificity of the cDNA library used.     

Scanning patients with tasks they can perform.

We present an overview of the types of imaging experiments that can be performed on psychologically impaired patients. The critical observation from such studies is a differential pattern of activation in the patients and normals. Underactivity is interpretable only when the patients make normal responses. In this context, a failure to activate a component region of the normal system implies that this region was not necessary for task performance. Overactivity indicates either cognitive or neuronal reorganisation. Neuronal reorganisation is indicated only if the patient performs the task using the same set of cognitive operations as normal subjects. Cognitive reorganisation can be demonstrated if the same activation pattern is elicited by normals when they are co-erced into using the same cognitive implementation as the patient. We conclude that the interpretation of neuroimaging studies of psychologically impaired patients depends on intact task performance and a detailed task analysis. When these criteria are met, patient studies can be used to identify: (1) necessary and sufficient brain systems, (2) dysfunction at sites distant to damage, (3) peri-damage activation, and (4) compensation either at a neuronal level when pre-existing cognitive strategies are re-instantiated using duplicated neuronal systems (degeneracy), or at a cognitive level when alternative cognitive strategies (and their corresponding brain systems) are adopted.