Viruses Infecting Marine Brown Algae

Viruses infecting algal hosts possess large double-stranded DNA as genomes. We have recently identified a family of viruses specific for filamentous brown algae. In contrast to the better known Chlorella viruses with their lytic infection cycle, marine brown algal viruses latently occur in their host cells and are induced to multiply in response to a variety of external stimuli such as change in light and temperature. Here, I summarize the known properties of this family of viruses and discuss their taxonomic classification.     

Characterization of the epitope recognized by a mAb that reacts differentially with murine suppressor T cells

Although reliable antibodies are available that distinguishhuman suppressor T (T_s) cells from CTL and other T cells, feware available for murine T_s cells. We have developed a mAb (984D4.6.5)that, in the presence of complement, depletes alloantigen-specificT_s cells but not CTL. This antibody recognizes activated TT_scells but not their precursors. In these studies, flow cytometricanalysis demonstrates that 984D4.6.5 reacts with several T_scell hybridomas, cloned T_h cell lines and WEHI-3 (a myelomonocytictumor cell line). Reactivity was not detected with BW5147, T_hcell hybridomas, cloned T_h cells, CTL lines and hybridomas,B cell lines, thymocytes, splenocytes, bone marrow cells nora variety of tumor cells. Among 984D4.6.5 positive lines, expressionis heterogeneous and the number of cells expressing high levelsof the epitope is increased when the hybridomas are maintainedat a relatively high cell density. Neuriminidase and pronasedeplete the epitope recognized by mAb 984D4.6.5. Protein synthesisand glycosylation inhibitors also reduce expression of thisepitope. These observations suggest that the epitope recognizedby 984D4.6.5 is a carbohydrate linked to a polypeptide. Thisantibody was tested by ELISA for binding to a large panel ofcarbohydrates and glycollpids coupled to BSA. The only one thatbound 984D4.6.5 was LS tetrasaccharide c (NeuNAc2-6Galpß1-4GIcNAcß1-3GaIß1-4Glc),an O-linked carbohydrate. Comparative analysis shows that boththe sequence and the linkage of these sugars are essential tothe reactivity with the 984D4.6.5 antibody. This epitope isexpressed by a glycoprotein of-200 kDa, as shown by Westernblots. The identity of this glycoprotein remains to be determined,but indirect evidence suggests that it is not CD45.     

Suspension systems for prostheses

The appropriate suspension system results in a safe and well functioning lower extremity prosthesis. Residual limb length, joint ligament stability, and limb volume determine suspension methods as does activity level, dexterity, success of previous suspension, and cosmetic requirements. The supracondylar suspension cuff, prosthetic sleeves, and gel liners with locking mechanisms generally are indicated for the average to long transtibial amputation level. Short limbs are better fitted with supracondylar and suprapatellar suspension. Waist belts generally are indicated for patients with new amputations or those with vascular compromise. Suction suspension is the most desirable form of transfemoral suspension and is recommended for most standard to long residual limbs. Roll on silicone liners with or without locking pins and the hyperbaric sock offer the patient systems that are easier to don yet still provide unencumbered suspension. The total elastic suspension belt offers excellent auxiliary suspension and can be applied to the prosthesis by the patient. Multiple factors and patient preference should be considered when prescribing suspension systems for lower extremity prostheses.     

Alterations in Bacterial Metabolism Contribute to the Lifespan Extension Exerted by Guarana in Caenorhabditis elegans

Guarana (Paullinia cupana) is a widely consumed nutraceutical with various health benefits supported by scientific evidence. However, its indirect health impacts through the gut microbiota have not been studied. Caenorhabditis elegans is a useful model to study both the direct and indirect effects of nutraceuticals, as the intimate association of the worm with the metabolites produced by Escherichia coli is a prototypic simplified model of our gut microbiota. We prepared an ethanoic extract of guarana seeds and assessed its antioxidant capacity in vitro, with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and in vivo, utilizing C. elegans. Additionally, we studied the impact of this extract on C. elegans lifespan, utilizing both viable and non-viable E. coli, and assessed the impact of guarana on E. coli folate production. The extract showed high antioxidant capacity, and it extended worm lifespan. However, the antioxidant and life-extending effects did not correlate in terms of the extract concentration. The extract-induced life extension was also less significant when utilizing dead E. coli, which may indicate that the effects of guarana on the worms work partly through modifications on E. coli metabolism. Following this observation, guarana was found to decrease E. coli folate production, revealing one possible route for its beneficial effects.     

Sentinel Node Dissection Delays Recurrence and Prolongs Melanoma-Related Survival: An Analysis of 673 Patients from a Single Center with Long-Term Follow-Up

Background

The status of the sentinel lymph node is an important predictor for survival in melanoma patients, but it is still unclear if early removal of micrometastases by sentinel lymph node dissection (SLND) alters survival. A large series of melanoma patients from a single center with long-term follow-up was analyzed with regard to a possible effect of SLND on the prognosis.

Materials and Methods

A total of 673 consecutive melanoma patients were assessed treated in our center either without SLND (377 patients, pre-SLN group, between January 1995 and March 2000) or with SLND (296 patients, SLN group, between April 2000 and March 2003). The median follow-up was 64.0 months in the pre-SLN and 72.5 months in the SLN group.

Results

The pre-SLN group and SLN group did not differ significantly with regard to characteristics of the primary melanoma thickness and ulceration, sex, and age. Kaplan–Meier analyses showed a significantly better recurrence-free survival (P < .001), distant metastases free survival (P = .006), and overall survival (P = .049) for patients of the SLN group; the 5-year melanoma-specific survival rates were 80.3% in pre-SLN patients and 84.8% in SLN patients. Initial metastases in the in-transit region and distant locations were of similar frequency in the pre-SLN and SLN groups (P = .191 and P = .959, respectively), but initial regional lymph node metastases were significantly more frequent in the pre-SLN group (P < .001).

Conclusions

Our data point toward a subgroup of melanoma patients who might have a prognostic benefit from SLN.     

Electron Microscopic Characteristics of β2-Microglobulin Amyloid Deposits in Long-Term Haemodialysis

The electron microscopic features of β2-microglobulin amyloid, deposited in the synovial membrane, are presented and discussed. The patient, a 69-year-old woman underwent chronic hemodialysis for 3 years. Because of constant pain and destructive arthropathy, endoprosthesis of the hip joints were implanted. Extra- and intracellular filamentous–fibrillar amyloid deposits have been demonstrated in ultrathin sections. The extracellular amyloid deposits showed a loose, filamentous or fibrillar structure at the periphery and a dense central core. The loose, filamentous structure may represent an early stage of fresh, newly deposited β2-microglobulin amyloid, while the condensed and fragmented amyloid filaments may be an advanced “mature” stage of amyloid deposition.     

Ultrastructural Identification of Primary Tumor Site from Bone Metastases

The value of electron microscopy is demonstrated by ultrastructural identification of primary tumor site from bone metastases in 2 patients.