[Spatio-temporal distribution characteristics of soil-transmitted nematodiasis in Sichuan Province from 2016 to 2021]

OBJECTIVE

To investigate the trends in the prevalence of soil-transmitted nematode infections and the spatio-temporal distribution characteristics of soil-transmitted nematodiasis in Sichuan Province from 2016 to 2021, so as to provide the evidence for formulating the soil-transmitted nematodiasis elimination strategy in Sichuan Province.

METHODS

The soil-transmitted nematodiasis surveillance data in Sichuan Province from 2016 to 2021 were collected, and the epidemic trend of soil-transmitted nematode infections was identified. The distribution maps of soil-transmitted nematode infections in Sichuan Province were plotted to identify their spatial distribution characteristics. In addition, the spatial clusters of soil-transmitted nematode infections were detected using globa and local spatial autocorrelation analyses.

RESULTS

The prevalence of soil-transmitted nematode infections appeared a decline with time in Sichuan Province from 2016 to 2021 (χ²= 400.24, P < 0.01). Global spatial autocorrelation analysis identified positive spatial autocorrelations in the prevalence of soil-transmitted nematode infections (Moran's I = 0.322, Z = 16.293, P < 0.01), hookworm infections (Moran's I = 0.425, Z = 21.290, P < 0.01), Ascaris lumbricoides infections (Moran's I = 0.102, Z = 5.782, P < 0.01) and Trichuris trichiura infections (Moran's I = 0.084, Z = 6.873, P < 0.01). Local spatial autocorrelation analysis showed that the high-high clusters of soil-transmitted nematode infections were mainly located in 37 counties (cities, districts) of Sichuan Province, and the high-high clusters of hookworm, A. lumbricoides and T. trichiura infections were mainly identified in 39 counties (cities, districts) in mountainous areas around Sichuan Basin and hilly areas, 9 counties (cities, districts) in mountainous areas in southwestern Sichuan Province, and 8 counties (cities, districts) in mountainous areas in southwestern Sichuan Province, respectively.

CONCLUSIONS

The prevalence of soil-transmitted nematode infections appeared a tendency towards a decline in Sichuan Province from 2016 to 2021, which showed spatial clusters. The management of soil-transmitted nematodiasis requires to be reinforced in high-risk areas of Sichuan Province with adaptations to local epidemiological features.

[Relationship between valve ablation and bladder function in children with posterior urethral valves disorder]

This study is to investigate the effect of valve ablation on bladder function in patients with posterior urethral valves. The clinical data of patients with posterior urethral valves who received urodynamic examination before and after valve ablation were retrospectively analyzed.The bladder compliance improved during urine storage after operation, and the maximum detrusor pressure decreased during micturition. The postoperative urinary system ultrasound showed that the residual urine volume of the group with significantly improved upper urinary tract hydrocephalus was significantly less than that of the group with no improvement. The bladder compliance was significantly higher than that of the group with no improvement, and the maximum urine flow rate was significantly higher than that of the group with no improvement (all P<0.05). Valve ablation has limited effect on improving bladder function in patients with PUV. Valve incision can help improve the maximum bladder volume, residual urine volume and maximum urinary flow rate. It has a certain effect on bladder compliance and maximum detrusor pressure.

Effectiveness of a community-based integrated strategy to control soil-transmitted helminthiasis and clonorchiasis in the People's Republic of China

Soil-transmitted helminthiases (STHs) are caused by a group of intestinal nematode infections due to poor hygiene and environments, and clonorchiasis is a food-borne trematode (FBT) infection caused by ingestion of raw freshwater fish. Both are endemic in the People's Republic of China. To explore a suitable control strategy, integrated interventions were applied between 2007 and 2009 in ten pilot counties (eight for the STHs and two for clonorchiasis). Drug administration was used for treatment and complementary efforts to improve the situation based on health education, provision of clean water and sanitation were carried out. Significant achievements were gained as reflected by a drastic decrease in prevalence these infections were demonstrated. The overall prevalence of STHs and clonorchiasis decreased from 35.9% to 7.8% and from 41.4% to 7.0%, respectively. The reduction of prevalence and high cost-effectiveness were documented supporting large-scale application of this integrated intervention in China and elsewhere.

[Effect of comprehensive control pattern on soil-transmitted nematodiasis in Danling County]

The comprehensive control pattern centering on health education, deworming and improving drinking water and lavatories was adopted to control soil-transmitted nematodiasis in Danling County, Sichuan Province from 2007-2009. In 2009, the infection rate of soil-transmitted nematodes decreased from 57.12% of the baseline survey in 2006 to 10.06%.

[Investigation on prevalence of soil-transmitted nematode infections and influencing factors for children in southwest areas of China]

OBJECTIVE

To understand the infection status and main risk factors of soil-transmitted nematodes in southwest China so as to provide the evidence for making the control programs for soil-transmitted nematodiasis.

METHODS

The prevalence of soil-transmitted nematode infections was determined by Kato-Katz technique and influencing factors were surveyed by using a standardized questionnaire, and in part of the children, the examination of Enterobius vermicularis eggs was performed by using the cellophane swab method. The relationship between soil-transmitted nematode infections and influencing factors was analyzed by the multiple probit estimated method.

RESULTS

A total of 1 707 children were examined, with a soil-transmitted nematode infection rate of 22.2%, the crowd infection rates ofAscaris lumbricoides, hookworm, and Trichuris trichiura were 16.0%, 3.8% and 6.6% respectively and 495 children were examined on Enterobius vermicularis eggs, with the infection rate of 5.1%. The results of probit estimated analysis suggested that the effects of 4 factors on soil-transmitted nematode infections were significant (all P values were less than 0.05), namely the number of sib, educational level of mother, drinking unboiled water and raising livestock and poultry. Among the factors above, the educational level of mother could reduce the probability of infection (ME = -0.074), while the number of sib, drinking unboiled water and raising livestock and poultry could increase the probability of the infections (with ME of 0.028, -0.112 and 0.080, respectively).

CONCLUSIONS

Soil-transmitted nematode infection rates are still in a high level for children in southwest poor areas of China, with Ascaris lumbricoides as a priority. The changes of children's bad health habits, raising livestock and poultry habits, and implementing the health education about parasitic diseases in mothers would be of great significance for the prevention and control of soil-transmitted nematodiasis.

Cell-layer interactions influence the number and position of lateral shoot meristems in Nicotiana

In higher plants the formation of lateral shoot meristems (i.e., axillary meristems) in the axils of leaves establishes potential growth centers along the principal axis of the stem. The position and number of lateral buds in Nicotiana glauca, two genotypes of Nicotiana tabacum, and a series of interspecific periclinal chimeras composed of these species was studied to establish the role of position (location of the node along the main axis), flowering, and cell-layer interactions on the pattern of lateral meristem initiation. In N. glauca, both the number of nodes generated and the transition to flowering influenced the number and position of lateral meristems. A short-day mutant of N. tabacum grown under long days remained vegetative and never produced multiple lateral buds per node, indicating that attaining a certain node number was not sufficient to cause the formation of multiple buds. Yet, flowering plants of both short-day and day-neutral N. tabacum possessed multiple buds in their upper nodes. An analysis of the number of buds per node and bud position along the main axis in periclinal chimeras indicated that the genotype of the third apical layer (LIII) of the meristem had the greatest influence on the pattern of lateral shoot meristems in both vegetative and flowering plants. The lineage of the three apical layers (LI, LII, and LIII) of the terminal shoot meristem was preserved in primary (1 degree) lateral meristems but minor deviations in lineage were observed in secondary (2 degrees) buds (i.e., those formed later but in the same node as the 1 degree bud). An analysis of the phenotype of 2 degrees shoots that displayed deviations from expected lineage indicated that in most cases the periclinal cell divisions that destabilized the lineage occurred at the flanks of the meristem and began before the most basal node, indicating that periclinal cell divisions most likely occurred prior to the inception of the 2 degrees lateral meristem. Based on our studies, we conclude that both 1 degree and 2 degrees lateral meristems in Nicotiana ultimately descend from derivatives of all three apical layers of the terminal shoot meristem.

Protective effects of silybin and tetrandrine on the outcome of spontaneously hypertensive rats subjected to acute coronary artery occlusion

The effects of silybin and tetrandrine on the survival of spontaneously hypertensive rats subjected to acute coronary artery occlusion were investigated. The mortality after acute coronary occlusion in spontaneously hypertensive rats (66.7%) was higher than that of control Wistar-Kyoto rats (20%, P < 0.05). Oral administration of silybin (300 mg/kg daily) for 8-12 days reduced mortality in spontaneously hypertensive rats (0, P < 0.01 in comparison with untreated spontaneously hypertensive rats). Administration of tetrandrine 40 mg/kg daily for 8-12 days reduced the mortality to some extent (22.2%, P = 0.051, as compared with control rats). Silybin reduced blood pressure and the incidence of post-occlusion arrhythmias in spontaneously hypertensive rats to the same extent as tetrandrine. Both silybin and tetrandrine decreased the severity of ventricular hypertrophy. Although there were significant decreases in risk zone and infarct zone in silybin- and tetrandrine-treated rats, the ratio of infarct to risk zone was not changed. The results implies that silybin may be beneficial when used in hypertensive patients who develop acute myocardial infarction.

Origin and development of adventitious shoot meristems initiated on plant chimeras

Most studies concerning the initiation and development of the shoot apical meristem have been performed on meristems that developed during embryogenesis. We characterized the in situ formation of adventitious shoots originating from cells located near leaf axils in a series of six interspecific periclinal tobacco chimeras. Shoots were generated by decapitating the plants and removing all of the axillary buds. Eighty-four of the 413 shoots regenerated were chimeral. Many of the shoots were complex mericlinal chimeras, with several of their axillary buds possessing meristems arranged as periclinal chimeras. The adventitious shoots originated from derivatives of only the second and third cell layers in the meristem of the source plant since derivatives of the outermost meristem layer were removed with the removal of the axillary buds. With time, nearly all adventitious shoot apices that were initially chimeral became nonchimeral or stabilized as periclinal chimeras. A statistical analysis indicated that the arrangement of genetically distinct tissues in the cell layers of adventitious meristems was influenced by competition between cell types. Our method for generating these shoots can be used to create small genetically distinct sectors analogous to radiation-induced sectors as well as a complete series of periclinical chimeras, both of which have potential for use in determining tissue-to-tissue interactions. An analysis of sector length and position on chimeral shoots indicates that the first one to three leaves of adventitious shoots do not arise as derivatives of the shoot apical initials of a meristem proper.

A new model of global postischemic reperfusion in rabbit

An ideal model of global ischemia in rabbits has not yet been developed. The present study describes a new model of global postischemic reperfusion (GPIR) in the rabbit, characterized by lack of systemic hypotension. The experimental procedure involves reversible occlusion of the bilateral internal carotid arteries (ICA) and bilateral external carotid arteries (ECA) for 60 min combined with permanent ligation of bilateral vertebral arteries (VA). This grouping is called 6-artery occlusion (6AO). Sixty minutes after the occlusion, bilateral ICA and bilateral ECA were released for 120 min at which time the experiment was terminated. The results revealed severely depressed EEG activity; Water content of brain tissue increased to 80.33 +/- 1.20% (control 78.28 +/- 0.59%, p less than 0.01); K, Mg, and Zn decreased (p less than 0.05 or p less than 0.01), and were negatively correlated with tissue water content. Na increased (p less than 0.05) and correlated with water content of brain. No significant changes were observed in lipid peroxide (LPO) levels, but the activity of superoxide dismutase (SOD) of brain tissue decreased (p less than 0.01), and was negatively correlated with water content (r = -0.5808, p less than 0.05). These results were compared with those obtained with the model of 4-artery (bilateral common carotid arteries (CCA) and VA) occlusion (4AO) and suggested that the brain damage be more severe with 6AO than with 4AO.