Confirmation of the human-pathogenic microsporidia Enterocytozoon bieneusi, Encephalitozoon intestinalis, and Vittaforma corneae in water

Microsporidia, as a group, cause a wide range of infections, though two species of microsporidia in particular, Enterocytozoon bieneusi and Encephalitozoon intestinalis, are associated with gastrointestinal disease in humans. To date, the mode of transmission and environmental occurrence of microsporidia have not been elucidated due to lack of sensitive and specific screening methods. The present study was undertaken with recently developed methods to screen several significant water sources. Water concentrates were subjected to community DNA extraction followed by microsporidium-specific PCR amplification, PCR sequencing, and database homology comparison. A total of 14 water concentrates were screened; 7 of these contained human-pathogenic microsporidia. The presence of Encephalitozoon intestinalis was confirmed in tertiary sewage effluent, surface water, and groundwater; the presence of Enterocytozoon bieneusi was confirmed in surface water; and the presence of Vittaforma corneae was confirmed in tertiary effluent. Thus, this study represents the first confirmation, to the species level, of human-pathogenic microsporidia in water, indicating that these human-pathogenic microsporidia may be waterborne pathogens.     

The logic of Ménage à Trois

Recent studies of socially monogamous species have shown that in many cases females do not copulate exclusively with their pair mates, but are also receptive to other males. The explanation usually given for unfaithful female behavior is that most females are unable to bond with a male they would prefer as genetic father to their offspring. To secure male assistance the female therefore pairs with an available male but also copulates with males of supposedly higher genetic quality. Here we offer an alternative evolutionary explanation for female infidelity, which does not rely upon this 'Good Genes hypothesis of female choice. We show with a simple model that in an evolutionary game between three players, a male, a female and a male lover, solutions exist in which the female can secure more assistance from her mate by being receptive to other males. We conclude that female sexuality can have a decisive role in regulating social behaviour, in which the fertile female is the driving force.     

Conjunctival nevi in Denmark 1960-1980. A 21-year follow-up

The clinicopathological characteristics of 343 naevi of the conjunctiva were studied. A significant increase in the number of naevi excised per year was observed. This may have been caused by an increased exposure to actinic rays. An approximately even distribution was found between the three main locations: caruncle, limbal area and eye ball. Intrastromal naevi were excised at a higher median age than compound naevi, and the lowest median age at excision was for junction naevi, which is in accordance with the known histopathological nature of naevi. Recurrence occurred in nine patients (2.7%), and one had transformed into a malignant melanoma. Eight of the recurring naevi were located in the limbal area. Eight of the nine patients were women, suggesting hormonal factors as a possible cause. Recommendations for the handling of conjunctival naevi are given, based on the present findings and on previous reports.     

Combination of systemic acetazolamide and topical dorzolamide in reducing intraocular pressure and aqueous humor formation

BACKGROUND: Neuroendocrine tumors commonly metastasize to the liver. Although surgical resection is considered a treatment option for patients with localized metastases confined to the liver, the longterm survival benefit of liver resection has not been clearly demonstrated. We examined the survival of patients undergoing liver resection for this disease. STUDY DESIGN: Between 1984 and 1995, we evaluated 38 patients with liver-only metastases from neuroendocrine tumors, including 21 carcinoid, 13 islet cell, and 4 atypical neuroendocrine neoplasms. Data from a combined prospective and retrospective database and a tumor registry were analyzed. Of these patients, 15 underwent complete resection of all known disease. The remaining 23 patients, who also had disease confined to the liver, had comparable tumor burden but were believed to be unresectable. The longterm survival rates of these two groups were compared. RESULTS: Patients who underwent liver resection did not differ from those who were unresectable with regard to age, pathology, primary tumor site, serum alkaline phosphatase levels, or percentage of the liver involved. All resections were complete, leaving no residual disease, and consisted of lobectomy (n = 3), segmentectomy (n = 1), and wedge resections (n = 11). There were no operative deaths. Patients who underwent hepatic resection had a significantly longer survival than unresected patients. Although median survival had not been reached in resected patients, the median survival in the unresectable group was 27 months. Patients who underwent liver resection had a higher 5-year actuarial survival (73% versus 29%). CONCLUSIONS: Hepatic resection in selected patients with isolated liver metastases from neuroendocrine tumors may prolong survival. This conclusion was reached by comparing our resected group with an unresectable group with similar tumor burden.     

Functional dissociation between local and systemic immune response during anti-melanoma peptide vaccination

Peptide vaccination against tumor Ags can induce powerful systemic CTL responses. However, in the majority of patients, no tumor regression is noted. To study this discrepancy, we analyzed CTL reactivity in a melanoma patient (F001) vaccinated with g209-2M peptide, a single residue variant of gp100(209-217). G209/g209-2M-reactive CTL were identified in post- but not prevaccination PBL. Limiting dilution analysis identified one predominant CTL clone (C1-35), with TCR Vbeta6s2, recognizing g209/HLA-A*0201-expressing targets. Additionally, two autologous melanoma lines (F001TU-3 and -4) and 20 separate tumor-infiltrating lymphocyte cultures were generated from a fine needle aspirate of a metastatic lesion progressing after initial response to vaccination. Both F001TU did not express gp100 and were not recognized by C1-35. Loss of gp100 by F001TU correlated with a marked reduction of gp100 expression in the same metastatic lesion compared with prevaccination. Thus, ineffectiveness of C1-35 and tumor progression could be best explained by loss of target Ag expression. Interestingly, 12 of 20 tumor-infiltrating lymphocyte cultures recognized F001TU, but none demonstrated g209/g209-2M reactivity, suggesting a functional dissociation between systemic and local immune response. This study suggests that vaccination effects must be analyzed in the target tissue, rather than in the systemic circulation alone.     

Mass transport in layered polycrystalline thin films

Thin film specimens having the layered structure Pb/Ag/Au and Pb/Ag/Pd were prepared for a study of the reactions between Pb and Au, and Pb and Pd, respectively. These reactions require mass transport through the intermediate layer of Ag. In the case of the reaction between Pb and Au, it is found that after annealing at 200°C for more than 24 h the compound Pb₂Au can be detected in those specimens where the 3000 Å thick Ag layer is polycrystalline but not in specimens where the Ag layer is a single crystal. This result indicates that grain boundaries in the polycrystalline Ag layer act as paths for rapid transport of Au and Pb atoms. In the case of the reaction between Pb and Pd, we prepared only polycrystalline Ag as the intermediate layer and detected the compound Pb₂Pd after a few hours of annealing in the temperature range 160°–200°C. The lattice parameter of the polycrystalline Ag layer before and after annealing has been measured by X-ray diffraction and found to be unchanged, indicating that leakage into the Ag grains by lattice diffusion is negligible and that boundary transport is dominant. Separate study of grain boundary diffusion kinetics is now possible using this technique.     

Heptadecapeptide gastrin: measurement in blood by specific radioimmunoassay

The characteristics are described of an antibody (designated L6) which has virtually absolute specificity for heptadecapeptide gastrin. This antibody binds G17, but does not bind peptide fragments or molecular forms of gastrin comprising G17 with either amino acid deletions, or additions, at the carboxyl- and amino-terminals. In serum from patients with Zollinger-Ellison syndrome the only form of gastrin revealed by L6 was compatible with G17, and there was good agreement between estimated G17 concentrations in serum analyzed by gel filtration and by direct radioimmunoassay using L6. Using L6 in conjunction with antibodies specific for carboxyl- and amino-terminals of G17 it has been possible to measure concentrations of different forms of gastrin in serum of normal subjects after a meal in greater detail than previously possible. After a light meal consisting of eggs, toast, and Oxo, serum concentrations of G17 measured by L6 increased to a peak 20 min after feeding (delta gastrin, 19 pmoles per liter; n = 17). In contrast, concentration of G34 peaked at 50 min (delta gastrin, 27 pmoles per liter). Small amounts of amino-terminal fragments of G17 were present throughout the digestive period. Applying the known ratio of biological potencies of G34 and G17 for stimulation of acid secretion in man, it is estimated that G17 accounts for about 75% of the biological activity in blood after a meal, even though G34 is present in higher molar concentrations.     

The elusiveness of eminence.

Identifies sources of error in the analysis of the Social Sciences Citation Index (SSCI) for 1975 conducted by N. S. Endler et al (see record 1979-26949-001). Problems include combining citations of authors with the same names or initials, incorrectly attributing citations, and attributing citations from such sources as research anthologies to the author who edited the compilation rather than the author who wrote the original article. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of sediment addition on macrobenthic invertebrates in a Northern Canadian River

Two channels built into the Harris River, Northwest Territories were used to study responses of invertebrates to sediment addition. Sediment was added to one channel continuously for approximately 5 h. The other channel was used as a control. In August, 28.27 kg of sediment or 1.38 kg m⁻² of channel bottom were added. Values for September were 35.88 kg or 1.53 kg m⁻².As a result of sediment addition, numbers of macrobenthos drifting from the sediment addition channel (S) increased significantly over those drifting in the control (C) in August (= summer) and September (= fall). Total drift from S was > 3 times higher in August and > 2 times higher in September than from C. Significantly higher numbers of macrobenthos drifted in fall than summer. Numbers of macrobenthos drifting during sediment addition were significantly related to time in September but not in August, indicating a seasonal difference in temporal response to sediment addition. Two explanations are proposed for the response of the September community, as indicated by shape of a polynomial regression curve, to sediment addition. No significant difference existed in standing crops of macrobenthos in the substrate in C and S after sediment addition.Sediment addition caused (1) higher numbers of Oligochaeta and Simuliidae to drift in August and September; (2) higher numbers of Plecoptera and Ephemeroptera to drift in September but not in August; and (3) higher numbers of Hydracarina and Chironomidae to drift in August but not September.We suggest that future work try to relate amounts of settled rather than suspended sediments to quantitative responses of stream macrobenthos. We recommend that highway and pipeline construction undertaken in watersheds of Mackenzie Valley streams during the open-water period, resulting in sediment addition to these streams, should be done during summer rather than spring or fall, providing river discharge is adequate to transport the added sediment.