Limitations of current diagnostic procedures for the diagnosis of Taenia solium cysticercosis in rural pigs

New evidence has been presented from our laboratory that the gliding bacterium, Myxococcus xanthus, does not home by chemotaxis toward a nutrient source. Our experiments, those of others, and the theory presented here combine to suggest a model, called the 'Pied Piper' model. It hypothesizes a gene that has a high mutation rate forward and back (say something in excess 10(-4) mutations per cell generation) which leads to switching between two motility states. Occasionally rare organisms become genetically, but reversibly, changed so that they move unidirectionally instead of mostly forward and back as do the bulk of the cells. When such a 'leader' cell arises, it continues to move in its original orientation, and causes a cohort of cells to move together away from the bulk of the cells. That is, in the less common mutational state it counteracts the usual tendency to just move forward and backward achieving little net movement. The assumption of a genetic element that mutates in a reversible way is suggested by numerous cases of reversible switches now known in a wide range of bacteria serving a variety of functions. A second aspect of the model is that mechanisms exist that cause cells to move in the same direction as their nearby neighbors. This process results in a regular spacing of bands of cells to form mounds in the absence of a leader. The action of C-factor, a factor-secreted by the cells which has been largely studied in the laboratory of Dale Kaiser, and extracellular fibrils, (rod-shaped protein and carbohydrate bodies) largely studied in the laboratory of Martin Dworkin, may be key elements in coordinating (or linking) the movements of neighboring cells. Based on the assumption of the absence of chemotaxis, computer simulations of pattern formation for gliding bacterial swarms and flares are consistent with observed behaviors and thus are additional evidence that chemotactic motility of the type exhibited by Escherichia coli, is not necessary for the group movements of M. xanthus. Some tests for this model are suggested.     

Glomerular endothelial cells synthesize collagens but little gelatinase A and B

Mesangial sclerosis is a major feature of progressive renal disease. The mesangium contains mesangial cells and is bounded by the peripheral glomerular basement membrane and endothelial cells. Mesangial cells synthesize and degrade extracellular matrix. Whereas both mesangial and endothelial cells synthesize extracellular matrix components, the degradative pathway, well studied in the former, has not been investigated in endothelial cells. This study examines lines of all three glomerular cell types derived from female B6SJLF1/J mice, as well as mRNA levels for collagens alpha1(I), alpha1(IV), alpha3 (IV), alpha5 (IV), and alpha1 (VI), laminin, tenascin, matrix metalloproteinase-2 (MMP-2), and MMP-9. Type I and IV collagen synthesis was confirmed by enzyme-linked immunosorbent assay. MMP-2 and MMP-9 enzyme activity was measured by zymography. It was found that glomerular endothelial cells are a significant source of collagens, laminin, and tenascin. However, they express only low levels of MMP-2 and no detectable MMP-9. Stimulation with exogenous transforming growth factor-beta1 leads to a significant increase in collagen I, tissue inhibitors of metalloproteinase-1, and MMP-9 in conditioned media. These data suggest that glomerular endothelial cells may play an active role in extracellular matrix remodeling in glomerular disease.     

Performance of children with ADHD on the Rey-Osterrieth complex figure: a pilot neuropsychological study

This study evaluates the performance of boys with Attention Deficit Hyperactivity Disorder (ADHD) on the Rey-Osterrieth Complex Figure (ROCF) taking into consideration familiality and comorbid psychiatric and learning disorders (LD). Sixty-five children with ADHD performed at developmentally lower levels of Copy Organization and Recall Style than did 45 controls. ADHD children with LD scored significantly lower on Copy Organization than did ADHD children without LD, whereas psychiatric comorbidity and familiality had no effect. These results suggest that a developmental analysis of the ROCF identifies organizational difficulties associated with ADHD and that these impairments cannot simply be attributed to comorbidities associated with ADHD.     

Endovascular stent treatment of cervical internal carotid artery aneurysms with parent vessel preservation

BACKGROUND: Aneurysms involving the cervical portion of the internal carotid artery (ICA) frequently result from prior trauma or dissection. CASE DESCRIPTIONS: Two patients are reported with cervical internal carotid artery aneurysms. In both cases, disease involving the contralateral ICA precluded safe treatment of the aneurysms by ICA occlusion. Endovascular stents placed across the diseased portion of the artery resulted in thrombosis of the aneurysm with preservation of the parent artery. CONCLUSION: Endovascular stent placement should be considered for treatment of aneurysms involving the cervical ICA when preservation of the parent vessel is necessary.     

Helicobacter pylori eradication as a surrogate marker for the reduction of duodenal ulcer recurrence

OBJECTIVES: An abundance of data exists documenting the association of H. pylori eradication with the reduction in duodenal ulcer recurrence. AIM: To evaluate the validity of using H. pylori eradication as a surrogate marker for the reduction in duodenal ulcer recurrence using rigorously controlled studies. METHODS: Three controlled clinical trials were conducted in patients with uncomplicated, active duodenal ulcers. Patients were treated with various combinations of omeprazole and amoxycillin. Ulcer healing and H. pylori eradication were assessed. For patients whose duodenal ulcer healed, duodenal ulcer recurrence was determined over a 6-month period in patients with H. pylori eradication and those remaining positive for H. pylori at least 4 weeks after treatment. To support the data obtained from these clinical trials, a search of the medical literature was conducted to identify additional human clinical trials in which duodenal ulcer recurrence rates were measured and categorized by H. pylori status at least 1 month post-treatment. RESULTS: In 11 controlled trials, the overall 6-18-month duodenal ulcer recurrence rate was 54% among patients remaining positive for H. pylori at least 4 weeks after treatment compared to 6% among patients with H. pylori eradication following treatment. This finding was corroborated by the uncontrolled trials, in which the duodenal ulcer recurrence rate was 64% among patients found to be H. pylori-positive and 6% for patients found to be H. pylori-negative at least 4 weeks after treatment. A time course of duodenal ulcer recurrence rates using pooled data from both controlled and uncontrolled studies demonstrated that duodenal ulcer recurrence rates for H. pylori-negative patients persisted for up to 4 years following treatment. Duodenal ulcer recurrence rates for H. pylori-positive patients increased for the first year, then levelled off. A comparison of the duodenal ulcer recurrence rates for different treatment regimens revealed that eradication regimens based on omeprazole plus antibiotics and bismuth plus antibiotics exhibited similar duodenal ulcer recurrence rates for H. pylori-positive and -negative patients. CONCLUSION: Regardless of treatment regimens, H. pylori eradication produced a consistent and significant reduction in duodenal ulcer recurrence. Therefore H. pylori eradication, 4 weeks post-therapy, can be used as a surrogate marker for reduced duodenal ulcer recurrence in investigational clinical trials.     

Parathyroid hormone-related protein in patients with primary breast cancer and eucalcemia

Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia in breast cancer and other malignancies. We studied circulating PTHrP levels with three different immunoassays directed against different parts of the PTHrP molecule in 48 patients with breast cancer and eucalcemia. The methods used were: (a) a RIA with antibodies directed toward the midregion (63-78); (b) an immunofluorometric assay with two antibodies against 1-34 and 38-67; and (c) an immunoradiometric assay with antibodies against 1-40 and 1-72. Although most patients had PTHrP levels indistinguishable from normal when measured by all three methods, four patients had increased serum levels in the IFMA. PTHrP was detected by immunohistochemistry in tumors from nearly all patients. One patient with elevated PTHrP in plasma measured by IFMA showed intense staining of tumor by immunohistochemistry; the tumor was histologically graded as III (severe) and was the largest of all tumors in this patient group. The IFMA can identify increased serum PTHrP in some patients with breast cancer who are not hypercalcemic. This assay may be especially useful in screening patients for this tumor during a relative early phase of the disease.     

Effect of bonding agents on adhesion of composite resin following CO2 laser etching of dental enamel

This paper looks at the process of setting up a Head Injury Register whose aims are: (1) to identify reliably and rapidly patients who have sustained a head injury so that service can be offered to them; and (2) to obtain epidemiological data to identify needs and inform future service planning and development. The register records all cases of head injury in patients aged 16-65, regardless of severity, which present to hospital services in Oxfordshire whether or not admitted as inpatients. It was set up as part of a research project into the value of providing an early follow-up service for head injury patients. The paper highlights the difficulty of identifying these patients reliably. It details the administrative and technological problems encountered, together with some of their solutions.