[Epidemic situation of imported malaria in Chengdu City from 2012 to 2016]

Objective To understand the malaria epidemic situation in Chengdu City, so as to provide the evidence for effectively carrying out the malaria elimination work. Methods The data of imported malaria in Chengdu City from 2012 to 2016 were collected from the Disease Surveillance Information Reporting System of Chinese Center for Disease Control and Prevention and analyzed respectively. Results A total of 240 imported malaria cases were reported in Chengdu City from 2012 to 2016. In detail, 68.75% of the cases were falciparum malaria cases, 20.41% were vivax malaria cases, 2.50% were quartan malaria cases, 6.25% were ovale malaria cases, and 2.08% were mixed Plasmodium infections. Among them three patients died, with a mortality of 1.25%. All of the cases were infected overseas, among which 224 patients returned from Africa and 16 patients from Southeast Asia. The annual average morbidity was 0.28/100 000, and there was a significantly difference among annual average morbidities (χ² = 23.87, P < 0.001). There were malaria cases reported in every month, and no significantly difference among seasons (χ² = 0.833, P > 0.05). Conclusion The number of overseas imported malaria in Chengdu City increases year by year. The effective measures to control the overseas imported malaria should be strengthened to consolidate the achievements of malaria elimination.

HPV 16 infection up-regulates Piwil2, which affects cell proliferation and invasion in cervical cancer by regulating MMP-9 via the MAPK pathway

PURPOSE OF INVESTIGATION

The present study aimed to investigate the effect of Piwil2 on proliferation and invasion of cervical cancer cells.

MATERIALS AND METHODS

Thirty-two HPV-positive or negative cervical cancer tissues and corresponding normal adjacent cervical tissues were obtained from General Hospital of Lanzhou Military Region. Piwil2 expression in these tissue samples, as well as two cervical cell lines were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical. A specific short hairpin RNA (shRNA) was used to knockdown the Piwil2 gene in SiHa cells. CCK-8 assay and flow cytometry (FCM) was used to evaluate cell proliferation. Cell invasion was detected by transwell chambers assays. Immunoblotting was used to assess the effect on relevant proteins.

RESULT

In the early stage (I A1-I B1) of curvival, 84.4% (27/32) tumor tissues have a more predominant expression of Piwil2 than the normal adjacent samples. Piwil2 overexpression was correlated with HPV16 infection (p < 0.05). Knockdown of Piwil2 gene in SiHa cells inhibited cell growth and invasion, and downregulated matrix metalloproteinase-9 (MMP-9) compared to scrambled shRNA transfected cells. Further analysis revealed that downregulation of Piwil2 gene induced inhibition of the MAPK signaling pathway activity.

CONCLUSION

Piwil2, which stimulated by HPV16 infection, plays an important role in regulating proliferation and invasion of cervical cells by regulating MMP-9 expression via alternation of the MAPK signaling pathway.

Electron and light microscopy of neutrophil responses in mice vaccinated and challenged with third-stage infective hookworm (Ancylostoma caninum) larvae

The role of neutrophils in mediating host inflammation was examined in mice vaccinated with living third-stage infective hookworm larvae (L3). Mice were vaccinated by oral immunization with 500 L3 (Ancylostoma caninum) once every 2 weeks for a total of three immunizations. The vaccinated mice were then challenged intraperitoneally with 2000 L3) 1 week after the final immunization. To stimulate peritoneal production of neutrophils, 2 ml of 2% glycogen were injected intraperitoneally at 16 h prior to the challenge infection. Neutrophils were found to comprise 85% of the peritoneal cell population. L3 from the challenge infection were collected and then examined at timed intervals by inverted light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Greater than a fivefold increase in the total numbers of peritoneal cells was noted in the vaccinated mice as compared to unvaccinated mice. In the peritoneal cavity of vaccinated mice, the neutrophils adhered to the L3 within 2 h, and over 55% of the L3 were surround by clusters of neutrophils to form a sausage-like sheath 4 h later. At 24-72 h after challenge, almost all of the L3 recovered from the vaccinated mice were covered with thick clusters of cells. Both SEM and TEM demonstrated extensive ultrastructural damage to the L3. In contrast, the L3 recovered from the unvaccinated mice appeared to be unaffected by neutrophils. These studies suggest that neutrophils, like macrophages, can have an important role as effector cells in L3-vaccinated mice.

Epidemiology of Necator americanus hookworm infections in Xiulongkan Village, Hainan Province, China: high prevalence and intensity among middle-aged and elderly residents

Hookworm is highly endemic to Hainan Province, an island located in the South China Sea. To investigate the prevalence and intensity of infection in the area, the village of Xiulongkan was surveyed between April and July 1998. A cross-sectional study was conducted in which fecal samples of 80% of the village residents (631 individuals) were tested for the presence of helminth eggs. Hookworm was the predominant intestinal helminth in Xiulongkan, where it was determined that 60% of those tested were infected. Necator americanus was the predominant species of hookworm in this population. The prevalence of hookworm increased with age, and then leveled to a plateau for ages 41 yr and up. This observation was in contrast to infections with Ascaris lumbricoides, where the highest prevalences occurred among school-aged children. Women had a significantly higher prevalence of hookworm than men and this difference emerged in early adulthood. The intensity of hookworm infection also significantly increased with age, with the highest intensity infections occurring among middle-aged and elderly residents. Females were more likely to have moderate or heavy infections, whereas males were more likely to have light infections. The rates of hookworm transmission are particularly high among the middle-aged and elderly residents of Xiulongkan.

Epidemiology of human ancylostomiasis among rural villagers in Nanlin County (Zhongzhou Village), Anhui Province, China: II. Seroepidemiological studies of the age relationships of serum antibody levels and infection status

Anti-hookworm antibody serologic responses were measured in residents of an Anhui provincial Chinese village where Ancylostoma duodenale is the predominant hookworm. Antibody responses were measured against either soluble infective third-stage larval (L3) or adult antigens. Immunoglobulins of the IgG class, especially IgG4 correlated with both the prevalence and intensity of A. duodenale hookworm infections. In contrast, there was an inverse correlation with IgM, but no correlation with IgA or IgE. Circulating IgG4 antibody responses might serve as a surrogate marker for active A. duodenale hookworm infection.

Variation between ASP-1 molecules from Ancylostoma caninum in China and the United States

Hookworm infection continues to be a serious problem in rural areas of China. Rapid reinfection and high cost limit the effectiveness of deworming programs. Vaccination offers an attractive alternative to mass chemotherapy. However, variation in vaccine antigens from field hookworm populations could conceivably limit efficacy of a vaccine developed from laboratory strains. Reported here are initial experiments to ascertain levels of molecular variation in a promising vaccine antigen, ASP-1, from the dog hookworm Ancylostoma caninum. ASP-1 from a Chinese strain of A. caninum was isolated from a third-stage larval cDNA library and compared to ASP-1 from a U.S. strain. There was 97% and 98% similarity in the DNA and amino acid sequences, respectively. There were 42 polymorphic sites between the sequences, 30 of which were synonymous. The 12 nonsynonymous substitutions resulted in 10 changes in the deduced amino acid sequence. Five of the amino acid changes were in the N-terminal domain, whereas the C-terminal domain was more highly conserved, containing only 2 amino acid changes. The results suggest that the effect of molecular variation in antigens from geographically separated parasite populations should be considered during vaccine development.

Hookworm burden reductions in BALB/c mice vaccinated with recombinant Ancylostoma secreted proteins (ASPs) from Ancylostoma duodenale, Ancylostoma caninum and Necator americanus

Vaccination of mice with alum-precipitated recombinant Ancylostoma secreted protein-1 from the canine hookworm Ancylostoma caninum (Ac-ASP-1) results in protection against A. caninum larval challenge. Vaccine protection is manifested by host reductions in hookworm burden compared to control mice. The goal of this study was to determine whether ASP antigens cloned and expressed from different hookworm species will cross protect against A. caninum larval challenge. Cross-species protection against A. caninum challenge infections was observed with immunizations using recombinant ASP-1 from the human hookworms Ancylostoma duodenale and Necator americanus. However, the degree of protection was proportional to the extent of amino acid sequence homology between the ASP immunogen used for vaccination and the Ac-ASP-1 produced by the challenge larval strain. Vaccine protection was noted to decrease significantly as amino acid sequence homologies diverged 10% or more. It was also determined that Ac-ASP-2, a molecule cloned from A. caninum having 55% amino acid sequence homology to the C-terminus of Ac-ASP-1, did not elicit vaccine protection. These observations were partly reflected in the titer of antibodies that recognize Ac-ASP-1. The studies reported here will help to design immunogenic peptide vaccines based on the sequence divergence of hookworm ASPs.

Epidemiology of human ancylostomiasis among rural villagers in Nanlin County (Zhongzhou village), Anhui Province, China: age-associated prevalence, intensity and hookworm species identification

Hookworm infection has traditionally been highly endemic to Anhui Province, China. Zhongzhou village in southwestern Anhui was identified as an endemic focus of infection caused by the hookworm Ancylostoma duodenale. This species was found to predominate over Necator americanus in ratios ranging from 35:1 based on the recovery of third-stage infective larvae (L,) to 21:1 based on the recovery of adult hookworms after anthelmintic chemotherapy. The overall prevalence of Ancylostoma infection in Zhongzhou was 33.2% with a greater prevalence among males. Unlike the age-associated prevalence patterns for N. americanus in Hainan and other southern Chinese provinces that show increasing prevalence with age and the highest prevalence among the elderly, the age-associated prevalence for A. duodenale in Zhongzhou exhibited a peak in middle-aged adults with subsequent decline. The age-associated intensity pattern exhibited a similar trend although the most of the hookworm infections were light or moderate infections as defined by quantitative egg counts.

Experimental approaches to the development of a recombinant hookworm vaccine

Hookworm infection is a major parasitic cause of morbidity in the developing nations of the tropics. Development of a genetically engineered vaccine would be a useful tool in the control of this infection in highly endemic areas. Recombinant polypeptides belonging to the Ancylostoma secreted protein (ASP)-1 family have shown promise for reducing hookworm burdens after larval challenge infections in mice. Typically, these polypeptides are expressed in Escherichia coli and administered as an alum precipitate. Vaccine protection is antibody dependent. It is anticipated that a cocktail of different recombinant hookworm antigens may be required in order to effectively prevent heavy hookworm infections and disease. The progress of this work has been hampered by the absence of both a convenient laboratory animal with which to study hookworm infections resembling human infection, as well as the lack of easy availability of native hookworm antigens. In addition, useful human serologic correlates of antihookworm immunity are still poorly defined.

Nitric oxide impacts endothelin-1 gene expression in intrapulmonary arteries of chronically hypoxic rats

This study aimed to investigate whether nitric oxide (NO) could inhibit the elevated endothelin-1 (ET-1) gene expression by pulmonary artery endothelial cells or smooth muscle cells in chronically hypoxic rats by use of in situ hybridization. Male Wistar rats (n = 40) were randomly divided into 1-week hypoxia group, 1-week hypoxia with L-arginine (L-arg) group, 1-week hypoxia with N(omega)-nitro-L-arginine methyl ester (L-NAME) group, 2-week hypoxia group, 2-week hypoxia with L-arg group, and 2-week hypoxia with L-NAME group. All rats were put into a normobaric hypoxic chamber with an oxygen concentration of 10 +/- 0.5% for hypoxic challenge. The results showed that most pulmonary arteries had 1-50% of the endothelial cells showing positive signals for ET-1 expression in hypoxic rats, which was significantly suppressed by L-arg. L-NAME, however, significantly augmented ET-1 gene expression in pulmonary artery endothelial cells and smooth muscle cells. The results suggest that endogenous NO markedly inhibits ET-1 mRNA expression in both pulmonary artery endothelial cells and smooth muscle cells in chronically hypoxic rats, which may be one of the mechanisms by which NO modulates hypoxic pulmonary circulation.

Three generations of hereditary chronic pancreatitis

The patient was a 22 year-old male. Hereditary chronic pancreatitis was suspected as a diagnosis since his mother's uncle had been operated on for chronic pancreatitis 14 years previously at the age of 64 years and his mother had been operated on for chronic pancreatitis with calculi 5 years previously at the age of 40 years. Surgery was needed, since: 1) he had experienced abdominal pain for 8 years; 2) endoscopic retrograde cholangiopancreatography (ERCP) revealed a marked irregular dilatation in the main pancreatic duct and a marked irregular dilatation and protein plugs in the ductule of the tail of the pancreas; and, 3) pancreatic functional diagnostic (PFD) test examination showed a 75% decrease in exocrine function. If a surgical procedure had not been performed, the patient would likely have experienced calculi formation in the pancreas and a further decrease in exocrine function. Since the patient was very young and had many protein plugs in the dilated ductule of the tail of the pancreas, we decided to perform a spleen-preserving Puestow's procedure with removal of the tail of the pancreas. Clinical and pathological findings of hereditary pancreatitis are reviewed.

Epidemiology of human intestinal nematode infections in Wujiang and Pizhou counties, Jiangsu Province, China

Intestinal nematode infections are considered highly endemic in the Chinese province of Jiangsu. In May 1997, the prevalence of intestinal nematodes infections was determined among all of the inhabitants aged 5 to 65 of the southern Jiangsu village of Yaojiakon (Wujiang County) and the northern Jiangsu village of Jianmiao (Pizhou County). It was determined that the prevalence of ascariasis, trichuriasis and hook worm infection was greatly reduced compared to when it was last measured in 1990. The reduction was noted to be particularly impressive in Yaojiakon village where the prevalence of ascariasis and trichiuriasis fell to 2% and 1.5% respectively. Much of this reduction was attributed to improvements in economic development which have occurred in southern Jiangsu Province at a rapid pace. In contrast, the reduction in nematode infections among villagers living in northern Jiangsu was more modest. The most striking reduction in both villages was in school-aged children who since 1988 have received yearly treatments with anthelminthic drugs. The intensity of nematode infections was investigated for hookworm where 70% of hookworm-infected Yaojiakon villagers were found to harbor light infections (< 400 eggs per gram) compared to 83% of hookworm-infected Jianmiao villagers. Necator americanus was the predominant hookworm in Yaojiakon village (South), whereas Ancylostoma duodenale predominated in Jianmiao village (North). The majority (76%) of hookworm-infected patients developed IgG antibodies against N. americanus antigen, although 20% of uninfected patients living in the village also had circulating antibodies. Intestinal nematode infections continue to be a significant public health problem in Jiangsu Province although their prevalence has decreased since 1990.

Diffraction property of an axicon in oblique illumination

The intensity distribution of a diffraction pattern in obliqueillumination is derived analytically. Experimental results arecompared with the results of theoretical analyses. Good agreementbetween them has been obtained.

Receptor-mediated endocytosis of decorin: involvement of leucine-rich repeat structures

Decorin, a small dermatan sulfate proteoglycan, is characterized by a core protein with central leucine-rich repeat structures and a single glycosaminoglycan chain. It is catabolized by receptor-mediated uptake and subsequent intralysosomal degradation. In the present study, the localization of the receptor binding site(s) along the core protein was investigated. Various recombinant decorin fragments were consistently able to inhibit the endocytosis of wild-type decorin. The most potent inhibitory peptides were those which encompassed the central Leu125-Val230 region, i.e., the fifth to eighth leucine-rich repeat, or at least a part of it. The peptide Leu125-Val230 bound directly to the 51-kDa endocytosis receptor, and Fab fragments of antibodies against this peptide inhibited the endocytosis of decorin in a dose-dependent manner. Decorin constructs expressed in human 293 cells and comprising the full-length coding region or lacking sequences N- and/or C-terminally of the Leu125-Val230 region were all endocytosed with similar clearance rates. These data suggest that the N- and C-terminal domains of the core protein are not required for endocytosis. The receptor binding site is rather represented by contiguous leucine-rich repeat structures of the central part of the core protein. This conclusion is supported by competition experiments with biglycan, a structurally related small proteoglycan.

[Histological observation on gingival fibers of upper molar region]

The purpose of this study was to investigate the structures and functions of the gingival fibers extending in the mesiodistal direction (mesiodistal fibers) in the human gingiva of the upper molar region. They were observed by light and scanning electron microscopes. The findings are as follows: 1. There is a large number of mesiodistal fibers in the buccal gingiva of the upper molar region. 2. In addition to the factor of the space, there exists a close relation between the development of the mesiodistal fibers of the buccal gingiva and the function in its region. 3. The mesiodistal fibers are made up of primary and secondary fiber bundles. 4. The bundles of the mesiodistal fibers compose the three dimensional network and are twisted.

Inhibition by glaucocalyxin A of aggregation of rabbit platelets induced by ADP, arachidonic acid and platelet-activating factor, and inhibition of [3H]-PAF binding

Glaucocalyxin A is a new diterpenoid isolated from the ethereal extract of the leaves of Rabdosia japonica (Burm f) Hara var glaucocalyx (Maxim) Hara (Labiatae) collected in the northeastern China. When it was incubated with washed rabbit platelets, glaucocalyxin A inhibited ADP- or arachidonic acid-induced platelet aggregation with IC50 values of 4.4 mumol/l, 14.1 mumol/l respectively. Glaucocalyxin A also inhibited PAF-induced aggregation of rabbit platelets which were refractory to ADP and arachidonic acid with an IC50 value of 13.7 mumol/l. Analysis of [3H]-PAF binding showed that glaucocalyxin A prevented [3H]-PAF binding to intact washed rabbit platelets with an IC50 value of 8.16 mumol/l, which was consistent with its inhibition of PAF-induced platelet aggregation.