[Meta analysis of the prevalence and influencing factors of WMSDs among dentists in China].

Objective: To explore the relevant factors of work-related musculoskeletal disorders (WMSDs) among dentists through Meta analysis, providing a basis for the prevention and control of WMSDs among dentists. Methods: In April 2022, cross-sectional research literatures on the prevalence correlation of WMSDs among Chinese dentists were searched in databases such as China National Knowledge Infrastructure, Wanfang, VIP, PubMed, Web of Science, and Em Base database. The search was conducted from the establishment of the database until April 2022, literatures were selected using keywords such as musculoskeletal disorders and dentists. To extract gender, age, length of service, disease classification and other related influencing factors as indicator, and prevalence was selected as the outcome indicator. After evaluating the quality of the literatures, RevMan 5.3 software was used to calculate the combined RD (95%CI) values of the included literatures. Results: A total of 15 articles were included, with a total sample size of 3646 people. Meta analysis results showed that the prevalence of WMSDs among dentists in China was 80%, and the top three parts of the incidence rates were 65% of the waist, 58% of the neck, and 50% of the back. Gender, age, length of service, region and disease classification all increased the risk of WMSDs, and the combined effect size were 75%, 78%, 71%, 77% and 82% respectively (P<0.05) . Conclusion: The occurrence of WMSDs among dentists in China is related to multiple factors such as gender, age, length of service and disease classification. The above risk factors should be taken into account in the workplace and preventive measures should be actively implemented to prolong the working life of dentists.

MiR-378 promotes the cell proliferation of non-small cell lung cancer by inhibiting FOXG1.

OBJECTIVE: To identify the functioning mode of miR-378 on non-small cell lung cancer (NSCLC) and provide therapeutic targets for NSCLC. PATIENTS AND METHODS: Expression levels of miR-378 in human NSCLC tissue samples and NSCLC-derived cell lines were measured by using quantitative Real-time polymerase chain reaction (PCR). Cell proliferation capacity was assessed by methyl thiazolyl tetrazolium (MTT) assay and colony formation assay. Cell apoptosis and cell cycle distribution were identified by flow cytometry. Downstream target gene was confirmed by using luciferase and Western blotting assays. RESULTS: MiR-378 was significantly elevated in NSCLC tissues when compared with para-carcinoma tissues (n=42). Decreased-miR-378 could attenuate cell proliferation capacity, as well as promoted cell apoptosis and induced cell cycle arrest at G0/G1 phase. FOXG1 was chosen as the target gene of miR-378 by bioinformatics analysis and luciferase reporter assay. Moreover, restoration of miR-378 could impair the tumor suppression role of downregulated-miR-378 on NSCLC growth. CONCLUSIONS: Decreased-miR-378 exerted tumor-suppressive effects on NSCLC growth via targeting FOXG1 in vitro, which provided an innovative and candidate target for diagnosis and treatment of NSCLC.

Effects of lung volume and alveolar surface tension on pulmonary vascular resistance.

Utilizing the arterial and venous occlusion technique, the effects of lung inflation and deflation on the resistance of alveolar and extraalveolar vessels were measured in the dog in an isolated left lower lobe preparation. The lobe was inflated and deflated slowly (45 s) at constant speed. Two volumes at equal alveolar pressure (Palv = 9.9 +/- 0.6 mmHg) and two pressures (13.8 +/- 0.8 mmHg, inflation; 4.8 +/- 0.5 mmHg, deflation) at equal volumes during inflation and deflation were studied. The total vascular pressure drop was divided into three segments: arterial (delta Pa), middle (delta Pm), and venous (delta Pv). During inflation and deflation the changes in pulmonary arterial pressure were primarily due to changes in the resistance of the alveolar vessels. At equal Palv (9.9 mmHg), delta Pm was 10.3 +/- 1.2 mmHg during deflation compared with 6.8 +/- 1.1 mmHg during inflation. At equal lung volume, delta Pm was 10.2 +/- 1.5 mmHg during inflation (Palv = 13.8 mmHg) and 5.0 +/- 0.7 mmHg during deflation (Palv = 4.8 mmHg). These measurements suggest that the alveolar pressure was transmitted more effectively to the alveolar vessels during deflation due to a lower alveolar surface tension. It was estimated that at midlung volume, the perimicrovascular pressure was 3.5-3.8 mmHg greater during deflation than during inflation.

Role of beta-receptor in the radix Angelicae sinensis attenuated hypoxic pulmonary hypertension in rats.

Acute pulmonary hypertension was caused by inhalation of 5% O2 in rats. Pulmonary vascular resistance (PVR) increased, but heart rate (HR), cardiac output (CO) and carotid arterial pressure (CAP) were not obviously changed. After an intravenous administration of Radix Angelicae sinensis, the acute pulmonary hypertension induced by inhalation of 5% O2 could be attenuated, but this effect disappeared if propranolol was given before Radix Angelicae sinensis. In chronic experiments, the same results were obtained, but the protective effect of Radix Angelicae sinensis on heart function was not influenced by propranolol. It is suggested that Radix Angelicae sinensis might play a role by stimulating the beta 2-receptor in the prevention of acute and chronic hypoxic pulmonary hypertension. However, prevention of hypertrophy of the right ventricle and enhancement of heart function in chronic hypoxic rats might not be attributed to the beta 1-receptor in the heart.

[Pharmacokinetic analysis of enterogastric circulation of diazepam in rabbits].

The concentration-time curves of diazepam exhibited double peaks after i.v. 5 mg.kg-1 to 6 rabbits. A pharmacokinetic model taking account of enterogastric circulation was proposed to explain this double-peak phenomenon and showed good agreement with data. This model provides not only the ordinary pharmacokinetic parameters: T1/2 (alpha) = 0.21 +/- 0.15 h, T1/2 (beta) = 2.2 +/- 0.6 h, Ke = 1.5 +/- 0.6 h-1, K12 = 2.0 +/- 1.0 h-1, K21 = 1.0 +/- 0.4 h-1, V1 = 3.1 +/- 1.6 L.kg-1, AUC = 1.7 +/- 0.5 microgram.h-1.ml-1, but also the parameters of enterogastric circulation of diazepam: lag time of reabsorption T' = 0.25 +/- 0.24 h, reabsorption rate constant Ka = 3.5 +/- 1.4 h-1, reabsorption rate Ra = 24 +/- 7%.

[Effect of enterogastric circulation of diazepam on its CNS inhibitory action in mice].

The present study was designed to examine whether disturbance of the enterogastric circulation of diazepam would obviously affect its inhibitory action on CNS. Intragastric administration of acidic liquid (pH 1) elicited a marked increase in the amount of diazepam in the gastric juice of mice 1 h after i.v. diazepam, as measured by HPLC method. The effects of ig acidic charcoal (2 g.kg-1, pH 1), neutral charcoal and normal saline on diazepam-induced CNS depression were compared by studying the duration of hypnotic action, inhibition of spontaneous activity, dropping rate in rotating rod test and mortality after i.v. diazepam (10-40 mg.kg-1) in mice. The results showed that the animals receiving ig acidic charcoal recovered more rapidly from CNS depression and exhibited lower mortality than the animals in neutral charcoal group and normal saline group.

[Site of endotoxic pulmonary vasoconstriction and the effect of anisodamine].

Using arterial and venous occlusion techniques in an in situ, isolated left goat lung preparation, the total arteriovenous pressure drop across the lung was partitioned vertically into pressure drops across the relatively indistensable arteries (delta Pa) and veins (delta Pv) and the middle distensible vessels (delta Pm). Endotoxin primarily increased delta Pv and Pc. Anisodamine only showed a slight effect on pressure drops in different segment under normal conditions. It could attenuate the endotoxin effect however. Serotonin mainly increased delta Pa and showed no effect on delta Pv and delta Pm. Norepinephrine and histamine increased delta Pv and Pc while it showed almost no effect on delta Pa. It is possible that the norepinephrine and histamine mediate the pulmonary hypertension caused by endotoxin.

[Effect of activated leukocytes on pulmonary arterial pressure].

Shock model was established by intravenous injection of E Coli endotoxin with a dosage of 5 mg/kg wt in dog. An immediate fall in systemic arterial pressure (SAP) was found after injection, while an increase in pulmonary arterial pressure (PAP) and a markedly leukopenia in circulatory blood were also found. Rats lung was perfused with warm (37 degrees C) krebs solution in constant flow rate. There was an obviously increase in PAP when activated leukocytes had been added to the perfusion solution. The results suggested that activated leukocytes in the lung blood vessels may play an important role in the pathogenesis of pulmonary hypertension.

[Observation on the development of Plasmodium falciparum in Anopheles dirus].

This paper is a record of our observation on the stages of development of Plasmodium falciparum in Anopheles dirus. The malarial parasites were derived from 5 infected patients living in Guizhou Province and used to infect 8 batches of An.dirus. The morphology of various developmental stages studied under light microscope and their average size were as follows: Microgametes were filament-shaped, 13.31 +/- 2.22 microns; macrogametes and zygotes oval or round, 4.36 +/- 0.59 microns and 3.39 +/- 0.39 microns respectively; ookinetes banana shaped, 13.56 +/- 0.80 microns x 2.90 +/- 0.48 microns; oocysts ovoid or spherical in shape, the smallest one being 7.086 microns in equivalate diameter (2 days old) and the largest one 72.60 microns (11 day old); slender sporozoites measured 10.625 +/- 0.82 microns x 1.179 +/- 1.3 microns. The late sporogonic stage of P. falciparum was observed with scanning electron microscope. The sporozoite buds developed on the surface of the sporoblast bodies, being round or elliptic or irregular-shaped. The anterior end of sporozoites was truncate and sometimes a micropyle could be seen at a distance 1/3 from the anterior end. A description was given of the different characteristics of the macrogametes and zygotes, together with the arrangement of the pigment granules of oocysts.