Direct inactivation of herpes simplex virus type-2 by rat epidermal protein.

Proteins were extracted from corneocytes of skin of 2-day-old rats and fractionated by gel filtration and cation exchange column chromatography. The different protein fractions were tested for direct inactivation of herpes simplex virus infectivity as determined by reduction of plaque formation. The most effective protein fractions against herpes simplex virus were a neutral pH buffer soluble and mol. wts. ranging from 20 K to 30 K. Amino acid composition of the proteins were virtually identical to epidermal histidine-rich proteins. The activity was significantly (P less than 0.001) stronger against type-2 than type-1. The activity was most stable at pH 7.2 and the rate of inhibition increased in a time-dependent manner up to 4 h. The 50% effective dose was estimated as 1.1 micrograms protein/ml.     

Development of a new wound dressing with antimicrobial delivery capability

A bilaminar wound dressing composed of an outer membrane and an inner three-dimensional matrix of a fabric or a sponge may be considered to constitute an ideal structure that promotes wound healing: the outer membrane prevents body fluid loss, controls water evaporation, and protects the wound surface from bacterial invasion, and the inner matrix encourages adherence by tissue growth into the matrix. Using this concept, we developed a biosynthetic wound dressing with a drug delivery capability. This medicated wound dressing is composed of a spongy sheet of a chitosane derivative and collagen mixture that is laminated to an antimicrobial-impregnated polyurethane membrane. In this study, a gentamycin sulfate-impregnated wound dressing was prepared and evaluated. The antimicrobial efficacy of this wound dressing was examined on an agar plate seeded with Pseudomonas aeruginosa. Also, the cytotoxicity of an antimicrobial released from this wound dressing was examined in an in vitro system with cultured skin substitutes. Both in vitro tests have shown that this wound dressing is capable of suppressing bacterial growth and minimizing cellular damage. In addition, in the treatment of wounds inflicted on rats and rabbits, this wound dressing was shown to be efficacious in covering full-thickness and split-thickness skin defects. Finally, the efficacy of this wound dressing was evaluated in a nonrandomized open-label study of 31 clinical cases. In 31 cases treated with this wound dressing, good or excellent wound healing was achieved.     

Use of a Strecker oesophageal stent in the treatment of benign oesophageal stricture

The use of self-expanding prostheses in the management of malignant oesophageal strictures has become well established. The majority of benign peptic oesophageal strictures can be successfully managed using endoscopic or fluoroscopically guided balloon oesophageal dilatation combined with long-term drug therapy, particularly using proton pumper inhibitors. Although endoscopic oesophageal dilatation can be performed on an outpatient basis, it requires repeated hospital visits. There is a small risk of oesophageal perforation whilst cardio-respiratory complications may be encountered during the use of intravenous sedation in an elderly population. The use of a self-expanding Strecker stent in a 98 year old woman with a benign oesophageal stricture is described.     

The vascular supply of splenic autotransplants.

The close opposition of blood to phagocytic cells lining the pulp cords and marginal sinus has been proposed as a contributing factor in the clearance mechanism of the spleen. The vasculature of splenic autotransplants was investigated in rats using microcorrosion casts. Six-month-old splenic autotransplants and unoperated control spleens were selectively perfused and a methyl methacrylate cast was made. Scanning electron microscopy of these corroded casts was performed. In autotransplants, the marginal zone capillary network was abnormal with the fine network of capillaries replaced by dilated blood vessels. The red pulp cords were also found to be abnormal with increased diameter and loss of the fine saccular dilations found in normal spleens. The abnormally dilated capillaries and cords in the autotransplants may decrease antigen contact with these cells and hence explain previous reports of reduced phagocytic function.     

The hevein domain of the major latex-glove allergen Hev b 6.01 contains dominant T cell reactive sites

BACKGROUND: Sensitization to natural rubber latex (Hevea brasiliensis) is a major cause of occupational asthma and rhinitis affecting frequent latex-glove users. Hev b 6.01, a known major latex allergen, is cleaved naturally into hevein (4.7 kDa) and a C-terminal fragment (14 kDa). Hevein is an abundant protein in latex-glove extracts. As the immune response to allergens is initiated by activation of allergen-specific CD4(+) T cells, identification of dominant T cell epitopes is crucial for the development of specific immunotherapy. OBJECTIVE: To identify dominant T cell epitopes of Hev b 6.01 in latex-allergic glove users. METHODS: Ten latex-allergic frequent glove users and six non-latex-allergic atopic control subjects were selected, based on clinical symptoms and positive latex-specific serum IgE. Serum IgE reactivity to glove extract and recombinant Hev b 6.01 (rHev b 6.01) were analysed by ELISA. Latex-specific short-term oligoclonal T cell lines were generated from peripheral blood of latex-allergic subjects. These lines were tested for proliferative responses to overlapping 20-mer peptides of the Hev b 6.01 molecule. CD4(+) T cell intracellular cytokines, IL-4 and IFN-gamma were assessed following stimulation with immobilized anti-CD3 in the presence of IL-2. RESULTS: All ten of the latex-allergic patients showed serum IgE binding to glove extract while eight of these also showed IgE binding to rHev b 6.01 by ELISA. Western blotting confirmed reactivity with rHev b 6.01 at around 20 kDa. T cell proliferation assays showed that latex-specific T cell lines from all subjects responded to one or more peptides, with greatest frequency of reactivity to peptides Hev b 6.01 p(10-29) and Hev b 6.01 p(19-38) in the hevein domain. An allergic-type cytokine profile with considerable IL-4 in addition to IFN-gamma was evident from intracellular cytokine staining. CONCLUSION: Hevein is an important T cell as well as B cell immunogen and contains dominant T cell reactive sites.     

Application of circular statistics to the study of neuronal discharge during locomotion.

An application of circular statistics is described which permits one to readily and efficiently describe neuronal discharge patterns recorded during locomotion. The method can be adapted to any data which are normally plotted as post-event histograms (PEHs) and can also be used to describe the pattern of electromyographic (EMG) activity during the step cycle. Data can be objectively classified with respect to both the mean direction and amplitude of their discharge, as well as to the variability (angular deviation) of that discharge. In addition, the Rayleigh test for directionality can be used to determine whether cells are modulated or unmodulated. Finally, the ability to describe each cell's discharge as a single vector allows the data from several different neurones to be displayed on a single figure and provides an efficient method for comparing the discharge of a population of cells under two or more different conditions.     

Controversies in viral diagnosis

A number of fallacies concerning viral diagnosis persist. It is said that viral studies are useless since there is no treatment for viral diseases, but suitable therapies are available for a number of severe viral infections. Viral culture results are thought to be too slow to affect patient management, but the average time for detection of a virus is three to four days, and greater than 70% can be reported within five days; detection of viral antigen can be provided in hours. It is thought that viral infections are best diagnosed by serologic tests. However, serologic tests requiring demonstration of a rise in titer or seroconversion are inherently slower than cultures and therefore less useful. Genetic probes are insensitive compared with cultures, and enzyme-linked immunosorbent assay methods for detecting viral antigen are no more sensitive than fluorescent antibody techniques and do not provide a means of assaying the quality of the sample. Finally, it is often stated that viral studies should be performed only in reference or regional laboratories. Regional virus laboratories should be located in teaching hospitals, and networks should be established to permit hospital laboratories to be involved at different levels.