T helper 2-dominant antilymphoma immune response is associated with fatal outcome

The precise role of the endogenous immune system in modulating cancer development remains unclear. Tumor cells are generally thought to be nonimmunogenic because they are of 'self' origin. However, tumor-reactive lymphocytes can be isolated from patients with many types of cancer. It is unclear what role these lymphocytes play and why they fail to protect the host. Using a murine B-cell leukemia/lymphoma (BCL1) model, we showed the development of a vigorous antitumor T-cell response in the tumor-susceptible host. Specific T-cell responses against BCL1 developed as early as day 4. However, the nature of this nonprotective response is different from the protective response produced in a major histocompatibility complex-matched tumor-resistant host. Susceptible hosts developed a T helper 2 (Th2)-dominant response, whereas resistant hosts developed a Th1-dominant response to BCL1. Cytolytic activity against BCL1 developed in both resistant and susceptible hosts, but in the susceptible host, this response was weaker and delayed compared with that in the resistant host. Thus, tumor susceptibility does not necessarily mean the absence of an antitumor immune response. Rather, the nature of the antitumor immune response is critical in determining clinical outcome.     

Relationship between ABO blood group and levels of Gal alpha,3Galactose-reactive human immunoglobulin G

BACKGROUND: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine glycoproteins and glycolipids, but is not expressed by human cells. Consequently human sera contain anti-alphaGal natural antibodies. The human blood group B antigen [Gal alpha1,3(Fuc1,2)Galactose] is differentiated from the alphaGal epitope by the presence of a fucosyl group. METHODS: To determine whether the expression of the B antigen has any effect on the level of alphaGal-reactive natural antibodies, equal numbers (n=12) of A, B, AB, and O serum samples were evaluated by ELISA and flow cytometry. RESULTS: A significant reduction in IgG alphaGal reactivity was observed with serum samples from B antigen-expressing donors (B, AB) relative to non-B antigen-expressing donors (A, O). CONCLUSIONS: These results are consistent with the possibility that anti-alphaGal antibodies in non-B antigen-expressing individuals include a subset that is reactive with the structurally related B antigen and that this subset is absent in B and AB individuals.     

TEM investigations of biogenic magnetite extracted from the human hippocampus

Modification of chemical and magnetic extraction techniques has yielded biogenic magnetite/maghemite from human hippocampal tissue. Particles were identified using high resolution transmission electron microscopy, electron diffraction and elemental analysis. Though its presence has been inferred from magnetic analyses, this is the first direct observation of magnetic biominerals from the hippocampus.     

Percutaneous large-core biopsy of papillary breast lesions

Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae possess the ability to cleave human IgA1 antibodies, and all successfully colonize and occasionally invade the human upper respiratory tract. N. meningitidis invades the bloodstream after a period of nasopharyngeal colonization. We directly compared levels of IgA1 protease activity in strains (n=52) derived from the cerebrospinal fluid or blood of patients with meningococcal disease with strains of N. meningitidis obtained from asymptomatic carriers (n=25). IgA1 protease activity was determined by a sensitive semiquantitative ELISA assay. Levels of IgA1 protease activity were significantly higher (P<0.0001) in strains associated with invasive meningococcal disease (98% with detectable activity, mean = 580 mU) than with those obtained from asymptomatic carriers (76% with detectable activity, mean = 280 mU). Despite marked variation in enzyme activity, almost all strains (96%) possessed the gene for IgA1 protease. Given the panmictic population structure of the bacterial isolates investigated, these data, obtained from two groups infected with N. meningitidis, but with markedly different clinical outcomes, provide the first quantitative evidence that IgA1 protease activity is a virulence determinant that contributes to the pathogenic phenotype, and suggest IgA1 protease as a potential target for prophylaxis.     

Solitary fibrous tumor of the adrenal gland

Solitary fibrous tumors are rare neoplasms, most commonly involving the pleura, recently described in various other locations. We report a solitary fibrous tumor of the right adrenal gland in a 42-year-old woman, discovered incidentally during abdominopelvic ultrasonographic examination. Pathologic and immunohistologic features of the tumor were identical to those of other solitary fibrous tumors. Three-quarters of this unencapsulated infiltrating tumoral mass presented foci of hemorrhage and were made of small, round, epithelioid-like cells that expressed the CD34 antigen more weakly than do the typical spindle cells usually observed in solitary fibrous tumors. Despite hemorrhage and poor limitation, the tumor behaved in a innocuous manner; the mass remaining unchanged for more than 5 years before the patient agreed to surgical intervention, which was recommended because of a sudden enlargement of the mass.     

The effect of nerve injury on the incidence and distribution of branched pulpal axons in the ferret

In a previous electrophysiological study in ferrets, we demonstrated that some axons in the inferior alveolar nerve branch to supply the pulps of two teeth. We have now investigated the incidence and distribution of branched pulpal axons at various intervals after nerve injury and subsequent regeneration, to study the extent to which the innervation of the teeth returns to normal. In adult male ferrets under anesthesia, the left inferior alveolar nerve was either sectioned (31 animals) or crushed (10 animals). Following recovery periods of six weeks, three months, or one year after nerve section and three months after nerve crush, electrophysiological recordings were made by insertion of pairs of Ag/AgCl electrodes into cavities cut into left mandibular teeth. Electrical stimuli were applied to each tooth in turn, and averaged responses were recorded individually from the other teeth. Latency and amplitude of the action potentials were used to characterize responses from branched pulpal axons. For some branched units, the point of branching was established by determination of the site of the inferior alveolar nerve section which abolished the response. When compared with controls, the results indicated that, following short recovery periods after nerve section, there was an increase in the number of branched pulpal axons supplying non adjacent teeth, and this branching had occurred at the initial site of nerve injury. Following long recovery periods, there were fewer branched axons than at earlier stages of recovery, but this apparent remodeling had not selectively eliminated axons which branched at the injury site to supply widely separated targets. Nerve crush injury resulted in no increase in the incidence of branched pulpal axons, and branching at the injury site was rare.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-related changes in the autonomic ganglia

Debridement of nonviable tissue is crucial to optimal wound healing, which can be impaired unless all necrotic tissue, exudate, and metabolic wastes have been removed from the wound. Debridement methods are classified as sharp, mechanical, chemical, and autolytic. This article describes methods of debridement and their outcomes.