DNA barcoding of common soft scales (Hemiptera: Coccoidea: Coccidae) in China.

The soft scales (Hemiptera: Coccoidea: Coccidae) are a group of sap-sucking plant parasites, many of which are notorious agricultural pests. The quarantine and economic importance of soft scales necessitates rapid and reliable identification of these taxa. Nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene (barcoding region) and 28S rDNA were generated from 340 individuals of 36 common soft scales in China. Distance-based [(best match, Automated Barcode Gap Discovery (ABGD)], tree-based (neighbor-joining, Bayesian inference), Klee diagrams, and general mixed Yule coalescent (GMYC) models were used to evaluate barcoding success rates in the data set. Best match showed that COI and 28S sequences could provide 100 and 95.52% correct identification, respectively. The average interspecific divergences were 19.81% for COI data and 20.38% for 28S data, and mean intraspecific divergences were 0.56 and 0.07%, respectively. For COI data, multiple methods (ABGD, Klee, and tree-based methods) resulted in general congruence with morphological identifications. However, GMYC analysis tended to provide more molecular operational taxonomic units (MOTUs). Twelve MOTUs derived from five morphospecies (Rhodococcus sariuoni, Pulvinaria vitis, Pulvinaria aurantii, Parasaissetia nigra, and Ceroplastes rubens) were observed using the GMYC approach. In addition, tree-based methods showed that 28S sequences could be used for species-level identification (except for Ceroplastes ceriferus - Ceroplastes pseudoceriferus), even with low genetic variation (<1%). This report demonstrates the robustness of DNA barcoding for species discrimination of soft scales with two molecular markers (COI and 28S) and provides a reliable barcode library and rapid diagnostic tool for common soft scales in China.

Impaired phagocytosis and susceptibility to infection in pediatric-onset systemic lupus erythematosus.

OBJECTIVES: Impaired function of polymorphonuclear cells (PMNs) in systemic lupus erythematosus (SLE) leads to severe gram-positive and gram-negative bacterial infection, and to major morbidity and mortality. Few studies have focused on the association of impaired function of PMNs and SLE patients' susceptibility to infection. This study aimed to analyze function of PMNs in peroxidase production, chemotaxis, and phagocytosis in pediatric-onset SLE with severe infection. METHODS: This study compared function of PMNs among pediatric-onset SLE patients with and without histories of severe infection and in normal control subjects. Human peripheral blood PMNs were isolated from patients and controls. Function of PMNs was measured by analyzing peroxidase, chemotaxis, and phagocytic activities. Different disease activity and severity, and drug use in newly diagnosed SLE patients were also compared. RESULTS: In total, 34 SLE patients (12 patients with severe infection, 22 patients without infection) and 25 healthy controls were analyzed. There were no differences in function of PMNs between SLE patients with or without severe infection. Regardless of infection status, medication, and disease activity, SLE patients had impaired phagocytic ability against Salmonella-specific lipopolysaccharides (LPS) compared with normal controls (p < 0.01). The use of immunosuppressants did not influence phagocytic ability against Salmonella-derived LPS. CONCLUSIONS: Immunosuppressant agents do not influence phagocytic ability against Salmonella in SLE subjects. Impaired phagocytosis against Salmonella is prominent in pediatric-onset SLE subjects, which may result in the high prevalence of Salmonella infection. There is no deficiency of peroxidase production and chemotaxis activity among SLE subjects.

[Mercury concentration in fish taken from the second Songhua River and mercury intake by fish-consumers].

Dynamic changes of standardized mercury concentration in fish taken from the Second Songhua River were evaluated from 1973 to 1991. It decreased 82.6% during this period. And, mercury intake of fish-consuming population and its source were studied. The results proved mercury concentration accumulated in some of the high risk population in 70's came up to and exceeded the threshold for chronic methylmercury poisoning. But, since 1983 mercury level in human body has been dropping greatly, and now falls down below the safety limit. The above facts showed mercury contamination in the Second Songhua River has been under control. But, fish intake should be still limited to appropriate amount to prevent from risk of poisoning.

Spatial properties of ganglion cell activity in the turtle retina.

Ganglion cell activity in response to drifting or alternating stimulus patterns was recorded in an eyecup preparation of the turtle. The stimuli were sinusoidal gratings with various spatial frequencies and spatial phases. Spike histograms of the activity were Fourier-analyzed. The results indicated that the retinal circuitry always functioned in a nonlinear manner. The average, first, and second harmonics of the activity were all a function of stimulus conditions, including spatial phase. Similar outcomes were obtained with full-field (retina-wide) and a small-field (1 mm diameter) stimulation. In the middle of the spatial-frequency range, the ratio of second to first harmonic activity was higher in response to static, contrast-reversing gratings than for drifting, constant-contrast ones. The findings suggest that, as distinct from the usual X, Y, and W segregation of ganglion cell properties in other retinas, there is a single class of cells whose responses seem to have attributes of one or another of the usual categories depending on stimulus characteristics. This may be the result of a degree of stimulus-dependent functional modification in the retinal input circuitry to the turtle ganglion cells.

Isolation of scotopic human electroretinograms using color adaptation and pattern reversal stimuli.

The human electroretinogram was recorded in response to alternations of a 500 nm checkerboard stimulus pattern presented against adaptation backgrounds of different wavelengths. A modification of Stiles' color adaptation paradigm was adapted to electroretinography. The results provided electrophysiological t.v.i. curves (threshold versus intensity curves) and permitted a determination of spectral sensitivity. The t.v.i. curves matched those seen in psychophysics. The spectral curve showed a close agreement with the scotopic CIE function.

Sequence investigation of the major gastrointestinal tumor-associated antigen gene family, GA733.

The monoclonal antibody-defined, tumor-associated antigen GA733 was purified from the SW948 human colorectal carcinoma cell line and its partial amino acid sequence was determined. By using a synthetic oligonucleotide probe, two recombinants were isolated from a total human genomic library. We prove the existence of a family of GA733 genes. One of the genomic isolates is demonstrated to be an intronless gene, which is transcribed in pancreatic carcinoma cell lines and in placenta. The GA733 proteins were observed to contain sequences homologous to a repeat unit occurring 10 times in thyroglobulin and once in the HLA-DR-associated invariant chain. A more evolutionarily distant relationship was found with the alpha chain of the interleukin 2 growth factor receptor.

A new method of measuring brain atrophy: the effect of aging in its application for diagnosing dementia.

A new method of measuring cerebral atrophy using a ratio of brain parenchyma to ventricular and subarachnoid space is described. It uses digitized brain CT. This ratio was measured prospectively on 117 consecutive elderly patients referred for evaluation of cognitive dysfunction. Diagnosis was determined by preestablished criteria and confirmed by follow-up. Despite the improved accuracy and reproducibility of this method, its ability to differentiate persons with senile dementia of the Alzheimer's type (SDAT) from those suffering from pseudodementia was confounded by age, and was hence of limited utility. We conclude that even with sophisticated measures of cerebral atrophy, CT is unable to discriminate among common causes of cognitive dysfunction in the elderly.