Previously, we demonstrated the ability of radiolabeled antibodies recognizing the cryptococcal polysaccharide capsule to kill Cryptococcus neoformans both in vitro and in infected mice. This approach, known as radioimmunotherapy (RIT), uses the exquisite ability of antibodies to bind antigens to deliver microbicidal radiation. To create RIT reagents which would be efficacious against all major medically important fungi, we have selected monoclonal antibodies (mAbs) to common surface fungal antigens such as heat shock protein 60 (HSP60), which is found on the surface of diverse fungi; beta (1,3)-glucan, which is a major constituent of fungal cell walls; ceramide which is found at the cell surface, and melanin, a polymer present in the fungal cell wall.
Methods
MAbs 4E12, an IgG2a to fungal HSP60; 2G8, an IgG2b to beta-(1,3)-glucan; and 6D2, an IgM to melanin, were labeled with the alpha particle emitting radionuclide 213-Bismuth (213Bi) using the chelator CHXA”. B11, an IgM antibody to glucosylceramide, was labeled with the beta emitter 188-Rhenium (188Re). Model organisms Cryptococcus neoformans and Candida albicans were used to assess the cytotoxicity of these compounds after exposure to either radiolabeled mAbs or controls.
Results
213Bi-mAbs to HSP60 and to the beta-(1,3)-glucan each reduced the viability of both fungi by 80–100%. The 213Bi-6D2 mAb to melanin killed 22% of C. neoformans, but did not kill C. albicans. B11 mAb against fungal ceramide was effective against wild-type C. neoformans, but was unable to kill a mutant lacking the ceramide target. Unlabeled mAbs and radiolabeled irrelevant control mAbs caused no killing.
Conclusion
Our results suggest that it is feasible to develop RIT against fungal pathogens by targeting common antigens and such an approach could be developed against fungal diseases for which existing therapy is unsatisfactory.
ABSTRACT: BACKGROUND: The city of Sao Paulo has the highest AIDS case rate, with nearly 60% in Brazil. Despite,several studies involving molecular epidemiology, lack of data regarding a large cohort studyhas not been published from this city.ObjectivesThis study aimed to describe the HIV-1 subtypes, recombinant forms and drug resistancemutations, according to subtype, with emphasis on subtype C and BC recombinants in thecity of S?o Paulo, Brazil.Study designRNA was extracted from the plasma samples of 302 HIV-1-seropositive subjects, of which211 were drug-naive and 82 were exposed to ART. HIV-1 partial pol region sequences wereused in phylogenetic analyses for subtyping and identification of drug resistance mutations.The envelope gene of subtype C and BC samples was also sequenced. RESULTS: From partial pol gene analyses, 239 samples (79.1%) were assigned as subtype B, 23 (7.6%)were F1, 16 (5.3%) were subtype C and 24 (8%) were mosaics (3 CRF28/CRF29-like). Thesubtype C and BC recombinants were mainly identified in drug-na?ve patients (72.7%) andthe heterosexual risk exposure category (86.3%), whereas for subtype B, these values were69.9% and 57.3%, respectively (p = 0.97 and p = 0.015, respectively). An increasing trend ofsubtype C and BC recombinants was observed (p < 0.01). CONCLUSION: The HIV-1 subtype C and CRFs seem to have emerged over the last few years in the city ofS?o Paulo, principally among the heterosexual population. These findings may have animpact on preventive measures and vaccine development in Brazil. 相似文献
Excessive training (i.e. overtraining, OT) may result in underperformance, which can be characterized by the time needed to re-establish performance (i.e. functional overreaching (FOR), nonfunctional overreaching, OT syndrome). The present study is an initial screening for proteins presenting altered abundance in the red (RG) and white (WG) portions of the gastrocnemius muscle from rats submitted to an OT protocol that induced FOR. In the RG, compared to the nontrained control, FOR demonstrated an increased abundance of proteins normally related to adaptation to endurance training (e.g. proteins of oxidative phosphorylation complexes, proteins related to lipid metabolism, antioxidants, and chaperones). In the WG, spots identified as mitochondrial aconitase and a component of the succinate dehydrogenase complex were downregulated in FOR, as were proteins related to myofibril stabilization; these latter were upregulated in the RG. This initial study shows that skeletal muscles with different fiber-type compositions respond differently to an OT period. Also, it is likely that actin-interacting proteins have an important role in muscle adaptation to endurance exercise. 相似文献
Mean or maximal intima-media thickness (IMT) is commonly used as surrogate endpoint in intervention studies. However, the effect of normalization by surrounding or median IMT or by diameter is unknown. In addition, it is unclear whether IMT inhomogeneity is a useful predictor beyond common wall parameters like maximal wall thickness, either absolute or normalized to IMT or lumen size. We investigated the interrelationship of common carotid artery (CCA) thickness parameters and their association with the ipsilateral internal carotid artery (ICA) stenosis degree.
Methods
CCA thickness parameters were extracted by edge detection applied to ultrasound B-mode recordings of 240 patients. Degree of ICA stenosis was determined from CT angiography.
Results
Normalization of maximal CCA wall thickness to median IMT leads to large variations. Higher CCA thickness parameter values are associated with a higher degree of ipsilateral ICA stenosis (p?<?0.001), though IMT inhomogeneity does not provide extra information. When the ratio of wall thickness and diameter instead of absolute maximal wall thickness is used as risk marker for having moderate ipsilateral ICA stenosis (>50%), 55 arteries (15%) are reclassified to another risk category.
Conclusions
It is more reasonable to normalize maximal wall thickness to end-diastolic diameter rather than to IMT, affecting risk classification and suggesting modification of the Mannheim criteria.
Chili pepper is one of the main crops of economic importance in Mexico, and Fusarium wilting is a disease that limits its production. In addition, the inappropriate use of agrochemicals in farming activities generate environmental and health problems. Therefore, in this study the effectiveness of Streptomyces sp PRIO41 was evaluated as a (1) biocontrol agent of Fusarium spp and (2) plant growth promoter bacteria. Assays of pathogenicity and virulence of Fusarium spp. in jalapeño pepper seeds, and interactions of these pathogens with Streptomyces PRIO41 were evaluated under two nutritional conditions. In the greenhouse, the effectiveness of Streptomyces sp. PRIO41 was determined as a (1) biocontrol of Fusarium, and (2) plant growth promoter of wilt of pepper plants. The results showed that all fungal isolates caused symptoms in pepper seeds and seedlings with different degrees of virulence. Interactions in vitro showed that Streptomyces showed the most effective range of virulence against Fusarium isolates in the poor medium (37.6%-100%), with fungicidal effects in some cases. In the greenhouse, Streptomyces PRIO41 reduced Fusarium wilting up to a 40%, and positively affected all vegetative growth parameters, particularly plant height, leaf area, root length, and leaf and root dry biomasses. This study showed the potential of Streptomyces PRIO41 as a biocontrol agent of Fusarium spp., and as a biofertilizer of pepper plants. 相似文献
An advanced backcross breeding strategy was used to identify quantitative trait loci (QTLs) associated with eight agronomic
traits in a BC2F2 population derived from an interspecific cross between Caiapo, an upland Oryza sativa subsp. japonica rice variety from Brazil, and an accession of Oryza rufipogon from Malaysia. Caiapo is one of the most-widely grown dryland cultivars in Latin America and may be planted as a monoculture
or in a multicropping system with pastures. The objectives of this study were: (1) to determine whether trait-enhancing QTLs
from O. rufipogon would be detected in 274 BC2F2 families grown under the drought-prone, acid soil conditions to which Caiapo was adapted, (2) to compare the performance
with and without pasture competition, and (3) to compare putative QTL-containing regions identified in this study with those
previously reported for populations adapted to irrigated, low-land conditions. Based on analyses of 125 SSLP and RFLP markers
distributed throughout the genome and using single-point, interval, and composite interval mapping, two putative O. rufipogon derived QTLs were detected for yield, 13 for yield components, four for maturity and six for plant height.We conclude that
advanced backcross QTL analysis offers a useful germplasm enhancement strategy for the genetic improvement of cultivars adapted
to stress-prone environments. Although the phenotypic performance of the wild germplasm would not suggest its value as a breeding
parent, it is noteworthy that 56% of the trait-enhancing QTLs identified in this study were derived from O. rufipogon. This figure is similar to the 51% of favorable QTLs derived from the same parent in crosses with a high-yielding hybrid
rice cultivar evaluated under irrigated conditions in a previous study. In conclusion, parallel studies in rice using AB-QTL
analysis provide increasing evidence that certain regions of the rice genome are likely to harbor genes of interest for plant
improvement in multiple environments.
Received: 3 September 1999 / Accepted: 16 May 2000 相似文献
The identification of biologically interesting genes in a temporal expression profiling dataset is challenging and complicated
by high levels of experimental noise. Most statistical methods used in the literature do not fully exploit the temporal ordering
in the dataset and are not suited to the case where temporal profiles are measured for a number of different biological conditions.
We present a statistical test that makes explicit use of the temporal order in the data by fitting polynomial functions to
the temporal profile of each gene and for each biological condition. A Hotelling T2-statistic is derived to detect the genes for which the parameters of these polynomials are significantly different from each
other. 相似文献
The aims of the work were (1) to develop statistical tests to identify
whether substitution takes place under a covariotide model in sequences
used for phylogenetic inference and (2) to determine the influence of
covariotide substitution on phylogenetic trees inferred for photosynthetic
and other organisms. (Covariotide and covarion models are ones in which
sites that are variable in some parts of the underlying tree are invariable
in others and vice versa.) Two tests were developed. The first was a
contingency test, and the second was an inequality test comparing the
expected number of variable sites in two groups with the observed number.
Application of these tests to 16S rDNA and tufA sequences from a range of
nonphotosynthetic prokaryotes and oxygenic photosynthetic prokaryotes and
eukaryotes suggests the occurrence of a covariotide mechanism. The degree
of support for partitioning of taxa in reconstructed trees involving these
organisms was determined in the presence or absence of sites showing
particular substitution patterns. This analysis showed that the support for
splits between (1) photosynthetic eukaryotes and prokaryotes and (2)
photosynthetic and nonphotosynthetic organisms could be accounted for by
patterns arising from covariotide substitution. We show that the additional
problem of compositional bias in sequence data needs to be considered in
the context of patterns of covariotide/covarion substitution. We argue that
while covariotide or covarion substitution may give rise to
phylogenetically informative patterns in sequence data, this may not always
be so.
相似文献
Data from population- and clinic-based epidemiologic studies of rheumatoid arthritis patients suggest that individuals with
rheumatoid arthritis are at risk for developing clinically evident congestive heart failure. Many established risk factors
for congestive heart failure are over-represented in rheumatoid arthritis and likely account for some of the increased risk
observed. In particular, data from animal models of cytokine-induced congestive heart failure have implicated the same inflammatory
cytokines produced in abundance by rheumatoid synovium as the driving force behind maladaptive processes in the myocardium
leading to congestive heart failure. At present, however, the direct effects of inflammatory cytokines (and rheumatoid arthritis
therapies) on the myocardia of rheumatoid arthritis patients are incompletely understood. 相似文献