A review of typical biological activities of glycyrrhetinic acid and its derivatives

Glycyrrhetinic acid, a triterpenoid compound primarily sourced from licorice root, exhibits noteworthy biological attributes, including anti-inflammatory, anti-tumor, antibacterial, antiviral, and antioxidant effects. Despite these commendable effects, its further advancement and application, especially in clinical use, have been hindered by its limited druggability, including challenges such as low solubility and bioavailability. To enhance its biological activity and pharmaceutical efficacy, numerous research studies focus on the structural modification, associated biological activity data, and underlying mechanisms of glycyrrhetinic acid and its derivatives. This review endeavors to systematically compile and organize glycyrrhetinic acid derivatives that have demonstrated outstanding biological activities over the preceding decade, delineating their molecular structures, biological effects, underlying mechanisms, and future prospects for assisting researchers in finding and designing novel glycyrrhetinic acid derivatives, foster the exploration of structure-activity relationships, and aid in the screening of potential candidate compounds.

Highly Anthropomorphic Finger Design With a Novel Friction Clutch for Achieving Human-Like Reach-and-Grasp Movements

In the design of prosthetic hand fingers, achieving human-like movement while meeting anthropomorphic demands such as appearance, size, and lightweight is quite challenging. Human finger movement involves two distinct motion characters during natural reach-and-grasp tasks: consistency in the reaching stage and adaptability in the grasping stage. The former one enhances grasp stability and reduces control complexity; the latter one promotes the adaptability of finger to various objects. However, conventional tendon-driven prosthetic finger designs typically incorporate bulky actuation modules or complex tendon routes to reconcile the consistency and adaptability. In contrast, we propose a novel friction clutch consisting of a single tendon and slider, which is simple and compact enough to be configurated within the metacarpal bone. Through tactfully exploiting the friction force to balance the gravity effect on each phalanx during finger motion, this design effectively combines both consistency and adaptability. As a result, the prosthetic finger can maintain consistent motion unaffected by any spatial posture during reaching, execute adaptive motion during grasping, and automatically switch between them, resulting in human-like reach-and-grasp movements. Additionally, the proposed finger achieves a highly anthropomorphic design, weighing only 18.9 g and possessing the same size as an adult's middle finger. Finally, a series of experiments validate the theoretical effectiveness and motion performance of the proposed design. Remarkably, the mechanical principle of the proposed friction clutch is beneficial to achieve highly anthropomorphic design, providing not only a new strategy to prosthetic hand design but also great potential in hand rehabilitation.

Hybrid Swarming Algorithm With Van Der Waals Force

This paper proposes a hybrid swarming algorithm based on Ant Colony Optimization and Physarum Polycephalum Algorithm. And the Van Der Waals force is first applied to the pheromone update mechanism of the hybrid algorithm. The improved method can prevent premature convergence into the local optimal solution. Simulation results show the proposed approach has excellent in solving accuracy and convergence time. We also compare the improved algorithm with other advanced algorithms and the results show that our algorithm is more accurate than the literature algorithms. In addition, we use the capitals of 35 Asian countries as an example to verify the robustness and versatility of the hybrid algorithm.

Design of a seed implantation robot with counterbalance and soft tissue stabilization mechanism for prostate cancer brachytherapy

This article focuses on the topic of the structural design of surgical radioactive surgery robot for prostate cancer. To improve the weight-to-payload ratio of surgery robot end-effector, the energy consumption and stability of robot joint drive and reducing the displacement and deformation of needle insertion in soft tissue. This article discusses the new static torque balancing method and multi-needle insertion soft tissue stabilization mechanisms that may be used in previously articulated seed implantation robots. Compared with the existing balancing system schemes, we adopt the idea of mutual conversion of gravitational potential energy and elastic potential energy and establish a static balancing model. With preloaded displacement parameter of the spring α, the variable gravity torque balance of robot arm can be achieved. Torque and equivalent gravity balancing distribution with the spring balance system and the quantitative evaluation experiment were performed, and experiment results provide evidence that these spring balance devices can basically compensate the gravity torque of the robot arm. In addition, we used nonlinear spring–damper model to establish multi-needles insertion soft tissue force model. Then, a variable multi-needle insertion soft tissue stabilization device is designed with six working modes. The innovative design of this device is the use of the first four needles that are introduced simultaneously on either side of the midline. Initially completed displacement simulation of different numbers of needle insertion prostate tissue, experiment results indicate that multi-needle puncture mechanism could reduce prostate displacement in the y- or z-direction. By this method, the prostate may be fixed, thus this mechanism maybe reduces rotation of the prostate and enabling subsequent needles to be inserted accurately.

Design and Implementation of Arch Function for Adaptive Multi-Finger Prosthetic Hand

Although arch motions of the palm substantially contribute to frequent hand grasping, they are usually neglected in the development of prosthetic hands which focuses on digit movements. We designed the arch function for its implementation on an adaptive multi-finger prosthetic hand. The digits from the developed hand can perform adaptive grasping, and two carpometacarpal joints enable the palm of the prosthetic hand to form an arch with the thumb. Moreover, the arch posture can be passively released, mimicking the human hand switching between sphere and medium wrap grasps according to the situation. Other requirements such as weight, cost, and size limitations for hand prostheses were also considered. As a result, we only used three actuators fully embedded in the palm through a novel tendon-driven transmission. Although the prosthetic hand is almost the same size of an adult hand, it weighs only 146 g and can perform 70% of the 10 most frequent grasps.

Ergonomic Mechanical Design and Assessment of a Waist Assist Exoskeleton for Reducing Lumbar Loads During Lifting Task

The purpose of this study was to develop a wearable waist exoskeleton to provide back support for industrial workers during repetitive lifting tasks and to assess reductions in back muscular activity. The ergonomic mechanical structure is convenient to employ in different applications. The exoskeleton attaches to the wearer’s body with 4 straps, takes only 30 s to put the exoskeleton on without additional help, weighs just 5 kg and is easy to carry. The mechanical clutch can assist the wearer as needed. Inertia Measurement Unit (IMU) was used to detect wearers’ motion intention. Ten subjects participated in the trial. Lower back muscle integrated electromyography (IEMG) of the left and right lumbar erector spinae (LES), thoracic erector spinae (TES), latissimus dorsi (LD) were compared in symmetrical lifting for six different objects (0, 5, 10, 15, 20, 25 kg) under two conditions of with and without the exoskeleton. The exoskeleton significantly reduced the back muscular activity during repetitive lifting tasks. The average integrated electromyography reductions were 34.0%, 33.9% and 24.1% for LES, TES and LD respectively. The exoskeleton can reduce burden and the incidence of strain on lumbar muscles during long-term lifting work.

Clinical analysis of minimally invasive McKeown esophagectomy in a single center by a single medical group

OBJECTIVE

McKeown esophagectomy followed by cervical and abdominal procedures has been commonly used for invasive esophageal carcinoma. This minimally-invasive operative procedure in the lateral prone position has been considered to be the most appropriate method. We describe our experiences in minimally invasive McKeown esophagectomy (MIME) for esophageal cancer.

METHODS

Between March 2016 and February 2018, a total of 82 patients underwent MIME by a single group in our department (a single center). All procedure, operation, oncology, and complication data were reviewed.

RESULTS

All MIME procedures were completed successfully, with no conversions to open surgery. The median operative time was 260 min, and median blood loss was 100 ml. The average number of total harvested lymph nodes was 20.1 in the chest and 13.5 in the abdomen. There were no deaths within 30 postoperative days. Twenty cases (24.4%) developed postoperative complications, including anastomotic leak in 4 (4.9%), single lateral recurrent nerve palsy in 4 (4.9%), bilateral recurrent nerve palsy in 1 (1.2%), pulmonary problems in 3 (3.7%), chyle leak in 1 (1.2%), and other complications in 7 (including pleural effusions in 4, incomplete ileus in 2, and neck incision infection in 1; 8.54%). Average postoperative hospitalization time was 12 d. Blood loss, operation time, morbidity rate, and the number of harvested lymph nodes were analyzed by evaluating learning curves in different periods. Significant differences were found in operative time (P=0.006), postoperative hospitalization days (P=0.015), total harvested lymph nodes (P=0.003), harvested thoracic lymph nodes (P=0.006), and harvested abdominal lymph nodes (P=0.022) among different periods.

CONCLUSIONS

Surgical outcomes following MIME for esophageal cancer are safe and acceptable. The MIME procedure for stages I and II could be performed proficiently and reached an experience plateau after approximately 25 cases.

Salivary human beta-defensins affected by oral Candida status in Chinese HIV/AIDS patients undergoing ART

OBJECTIVES

To observe relationships between oral Candida status and salivary human beta-defensin 2 and 3 (hBD-2 and hBD-3) levels in HIV/AIDS patients of Guangxi, China during the first year of antiretroviral therapy (ART) dynamically, and to understand the influence of ART on oral Candida status and salivary hBDs expressions.

METHODS

A prospective self-controlled study was carried to observe the dynamic changes of CD4⁺ T cell counts, oral Candida carriages and salivary hBD-2,3 expressions in HIV/AIDS patients during the first year of ART. A total of 90 HIV/AIDS patients were enrolled and were examined at the baseline, 3rd, 6th, 12th month of ART. Thirty healthy individuals were enrolled as control. Peripheral blood, oral rinse sample, and unstimulated whole saliva were collected to test CD4⁺ T cell counts, oral Candida carriages, and hBD-2,3 expressions.

RESULTS

In the first year of ART, CD4⁺ T cell counts increased significantly. However, oral Candida carriages and oral candidiasis decreased significantly, and salivary hBD-2 expressions in HIV/AIDS patients decreased gradually, salivary hBD-3 levels were highly variable. Salivary hBD-2 concentrations were positively related to oral Candida carriages.

CONCLUSIONS

The incidence of oral candidiasis among HIV/AIDS patients gradually decreased due to the immune reconstruction of ART. Salivary defensins might play an important role in Candida-host interaction in HIV/AIDS patients.

Short- and mid-term outcomes of robotic versus laparoscopic distal pancreatosplenectomy for pancreatic ductal adenocarcinoma: A retrospective propensity score-matched study

BACKGROUND

Robotic distal pancreatectomy exhibits short-term benefits over laparoscopic distal pancreatectomy. The use of minimal invasive techniques to carry out distal pancreatosplenectomy (DPS) for pancreatic ductal adenocarcinoma (PDAC) remains controversial and has not gained popular acceptance. A comparative study was designed to analyze the short- and mid-term outcomes of robotic DPS (RDPS) versus laparoscopic DPS (LDPS) on patients with PDAC.

METHODS

The baseline characteristics, perioperative outcomes and survival data among patients who underwent RDPS (n = 35) versus LDPS (n = 35) for PDAC between December 2011 and December 2015 were compared after a 1:1 propensity score matching.

RESULTS

There were no significant differences in the operative time, blood loss, blood transfusion rate, and morbidity and pancreatic fistula rates between the RDPS and LDPS groups. RDPS significantly reduced the rate of conversion to laparotomy (5.7% vs. 22.9% when compared with LDPS, p = 0.04). There were no significant differences in R0 resection rates, number of harvested lymph nodes, positive to harvested lymph node ratios, and disease-free survival and overall survival rates between the two groups. A Cox proportional hazards analysis showed N1 stage to be significantly associated with worse survival and suggested that chemotherapy might prolong overall survival in these PDAC patients.

CONCLUSIONS

This single-center study demonstrated that RDPS was safe and efficacious in treatment of PDAC. When compared with LDPS, RDPS was associated with a reduced rate of conversion to open surgery. There were no significantly differences in oncological outcomes and mid-term survival rates between the groups of patients who underwent RDPS or LDPS.

Examining different NEMD methods in simulating nanoscale fluid at high shear rates

In this paper, the non-Newtonian behaviour of a simple fluid is simulated via three different non-equilibrium molecular dynamics (NEMD) algorithms: boundary-driven shear; homogeneous shear; and reverse-NEMD (RNEMD). The pros and cons of each approach are discussed and results are compared. It is found that the accessible shear rate is very limited when using boundary-driven shear and RNEMD, whereas homogeneous shear is capable of imposing a substantially higher shear rate. However, the boundary-driven shear reproduces rheological experiment setups and the RNEMD yields much better statistically calculated properties. The material functions, velocity profiles, and microstructures of the fluid are examined and the formations of fluid structures are elucidated. The homogeneous shear is shown to be the most appropriate NEMD method to simulate fluids under strong shear, with the smallest number of limitations.

[Cadherin switching induced by P120-catenin can promote the migration and invasion of oral squamous cell cancer cells]

OBJECTIVE

The main goal is to investigate the role of P120-catenin (P120ctn) in cadherin switching, as well as migration and invasion, of oral squamous cell cancer (OSCC) cells.

METHODS

The plasmid pGFP-V-RS-P120ctn shRNA was used to transfect TSCCA cells and significantly reduce the expression of P120ctn in these cells. Real-time fluorescent quantitative polymerase chain reaction and Western blot were conducted to determine the mRNA and protein expression levels of P120ctn, E-cadherin (E-cad), and N-cadherin (N-cad). By contrast, the Transwell cell invasion and cell migration assay was used to determine the invasion and migration capacities before and after the transfection.

RESULTS

After the plasmid pGFP-V-RS-P120ctn shRNA was transfected into the TSCCA cells, we found that as the P120ctn expression significantly decreased, E-cad mRNA and protein expression decreased significantly. Moreover, N-cad mRNA and protein expression increased significantly (P<0.05). Lastly, the cell migration and invasion capacities were augmented significantly (P<0.05).

CONCLUSIONS

In OSCC cells, P120ctn may be involved in cadherin switching and promote metastasis and invasion.

A Case of Successful Treatment of Infective Endocarditis Complicated with Intracranial Hemorrhage, and Literature Review

The risks of neurological deteriorations during open heart surgery under heparinization in patients with infective endocarditis complicated by intracranial hemorrhage remain unknown. The optimal timing for heart surgery is still a point of conflict. We report a case in which a young man who had suffered from infective endocarditis complicated with intracranial hemorrhage successfully received mitral valve replacement on day 9 after the onset of intracranial hemorrhage.

Evaluation of microvascularization in focal salivary gland lesions by contrast-enhanced ultrasonography (CEUS) and Color Doppler sonography

OBJECTIVE

To evaluate the dynamic microvascularization of focal salivary gland lesions by contrast-enhanced ultrasound (CEUS) and Color Doppler sonography.

MATERIALS AND METHODS

One hundred and sixty-eight patients with 183 major salivary gland lesions (mean age, 56 years; age range, 12-83 years) underwent gray-scale ultrasonography (US), Color Doppler (CD) and CEUS. The CD and CEUS patterns were classified into three types (scores 0-3). Combined score grades were calculated based on the CD and CEUS pattern scores. The time-intensity curve (TIC) parameters of CEUS were then analyzed. Sensitivity, specificity, negative predictive value and positive predictive value of combined score grades were also calculated.

RESULTS

Among all the lesions, there were 161 in parotid gland, 22 in submandibular gland and 157 lesions were benign and 26 were malignant. For score grades (combined CEUS patterns with CD types), scores 1-2 were graded as benign; scores 3-4 were graded as indetermination-suspicious benign or malignant and scores 5-6 were graded as malignant.score 5-6 and score 1-2 indicated 24 (92.3%) and 135 (85.9%) malignant and benign lesions confirmed pathologically, respectively. The sensitivity and negative predicted value of combined score grades for malignant lesions were 92.3% and 98.5%, respectively. In addition, TIC analysis indicates that PI and AUC in malignant lesions were higher than those in benign lesions (p = 0.04 and 0.02, respectively).

CONCLUSION

The combined score grade could be a useful method to assess the macro-and micro-vascularization and to differentiated diagnose benign and malignant lesions in major salivary glands.

Enhanced cadmium resistance and accumulation in Pseudomonas putida KT2440 expressing the phytochelatin synthase gene of Schizosaccharomyces pombe

Phytochelatins (PCs) are cysteine-rich peptides with high binding affinity for toxic metals. Expressing the PC synthase gene (PCS) in plant growth-promoting bacteria may enhance its metal resistance and accumulation, consequently increasing phytoremediation efficiency in heavy metal pollution. In this study, PCS from Schizosaccharomyces pombe was cloned and expressed in Pseudomonas putida KT2440, which was confirmed by real-time RT-PCR through an increase in SpPCS mRNA expression level when induced by 20 μmol of CdCl2 in the transformed Ps. putida cells. The recombined strain KT2440-SpPCS exhibited enhanced Cd, Ag and Hg resistance. Compared with the original strain, KT2440-SpPCS also displayed a threefold to fivefold increase in Cd accumulation (14·32 μmol g(-1) to 17·38 μmol g(-1) ; dry weight) when grown in 30 and 50 μmol CdCl2 , along with an increase in nonprotein thiols. Further experiments showed significantly enhanced germination rates and growth of wheat seeds in 0·1 mmol to 1·0 mmol Cd when inoculated with KT2440-SpPCS. This study shows potential use of Ps. putida KT2440-SpPCS in plants to construct a symbiotic system for an enhanced phytoremediation of heavy metal-contaminated environments.

SIGNIFICANCE AND IMPACT OF THE STUDY

The symbiotic system of using plant growth-promoting bacteria Pseudomonas putida to express phytochelatin synthase gene of Schizosaccharomyces pombe together in plants resulted in high heavy metal resistance and high accumulation capacity, suggesting potential enhancement in phytoremediation of heavy metal-contaminated environments.

IB-LBM simulation of the haemocyte dynamics in a stenotic capillary

To study the behaviour of a haemocyte when crossing a stenotic capillary, the immersed boundary-lattice Boltzmann method was used to establish a quantitative analysis model. The haemocyte was assumed to be spherical and to have an elastic cell membrane, which can be driven by blood flow to adopt a highly deformable character. In the stenotic capillary, the spherical blood cell was stressed both by the flow and the wall dimension, and the cell shape was forced to be stretched to cross the stenosis. Our simulation investigated the haemocyte crossing process in detail. The velocity and pressure were anatomised to obtain information on how blood flows through a capillary and to estimate the degree of cell damage caused by excessive pressure. Quantitative velocity analysis results demonstrated that a large haemocyte crossing a small stenosis would have a noticeable effect on blood flow, while quantitative pressure distribution analysis results indicated that the crossing process would produce a special pressure distribution in the cell interior and to some extent a sudden change between the cell interior and the surrounding plasma.

A three-year prospective longitudinal cohort study of medical students' attitudes toward anatomy teaching and their career aspirations

Today's medical students are faced with numerous learning needs. Continuously developing curricula have reduced time for basic science subjects such as anatomy. This study aimed to determine the students' views on the relevance of anatomy teaching, anatomical knowledge, and the effect these have on their career choices. A Likert scale questionnaire was distributed to second year medical students [response rate 91% (n = 292/320)]. The same questionnaire was subsequently distributed to the cohort three years later when they were final year students [response rate 37% (n = 146/392)]. Students in both the cohorts of study agreed strongly that clinically correlated anatomical teaching was relevant to clinical practice (92% and 86% of second and final year respondents, respectively) and helped them during their clinical placements (73% and 92%, respectively). Only 28% of the second year and 31% of the final year students agreed that their anatomy teaching prepared them to interpret clinical images (P = 0.269). Only 14% of the final year students felt confident in their knowledge of anatomy. Of the final year students, 30% felt that they had enough opportunity to scrub in the operating room. Nearly half of those students who would consider surgery as a career (19%) think that they will eventually become surgeons (11%). This data suggests that modern anatomy curriculum should focus on clinical correlations and clinical image interpretation. Students would value more opportunities to participate in surgeries. Vertical integration of anatomy teaching throughout the full medical course may be useful.

[Evaluation of five D-dimer assays for the exclusion of venous thromboembolism]

OBJECTIVE

To evaluate the diagnostic performance of five D-dimer assays for the exclusion of suspected venous thromboembolis (VTE).

METHODS

The plasma D-dimer levels of 75 suspected VTE patients were tested with ELISA, VIDAS DD, DD Plus, Liatest STAGO DD, and NycoCard DD. The results of the five assays were compared with the gold standard of diagnosis of VTE.

RESULTS

Liatest STAGO DD, DD Plus, VIDAS DD and ELISA had good diagnostic performance for the exclusion of suspected VTE. Liatest STAGO DD had the greatest accuracy for differentiating diagnosis, with 0.814 of area under the curve (AUC), 96.7% of sensitivity, and 95.5% of negative predictive value. ELISA had the greatest specificity (48.9%). The five assays showed good correlations, with VIDAS DD and Liatest STAGO DD having the greatest correlation coefficient (r = 0.9106). VIDAS DD and Liatest STAGO DD correlated well with ELISA (r = 0.8764 and r = 0.8360 respectively).

CONCLUSION

Liatest STAGO DD, DD Plus, and VIDAS DD have good diagnostic performance for the exclusion of VTE. They are easier and quicker to perform and can serve as an alternative test for ELISA. Further validation is needed for clinical applications.

Nicotinic Acetylcholine Receptor α4 Subunit Gene Variation Associated with Chinese Han Patients with Attention Deficit Hyperactivity Disorder

Previous pharmacological, human genetical, and animal models have implicated the nicotinic acetylcholine receptor α4 subunit (CHRNA4) gene in the pathogenesis of ADHD. The objective of this study is to examine genetic association between single nucleotide polymorphisms (SNPs) in the CHRNA4 gene (rs2273502, rs1044396, rs1044397 and rs3827020 loci) and ADHD. Both case-control and family-based design were used in this study. Children aged 6 to 16 years were interviewed and assessed with the CBCL and CPRS-R to identify probands. No significant differences in frequency distribution of genotypes or alleles between the case and control groups were found. However, further haplotype analyses showed CCGG haplotype on risk for ADHD in 164 case-control sample and TDT analysis suggested that the allele C of rs2273502 over-transferred in 98 ADHD parent-offspring trios. Our findings suggest that CHRNA4 gene may play a role in the pathogenesis of ADHD, and further work is necessary to replicate and confirm what role the CHRNA4 gene may play in the etiology and pathogenesis of ADHD in large independent samples.

Peptide nucleic acid antisense prolongs skin allograft survival by means of blockade of CXCR3 expression directing T cells into graft

CXCR3, predominantly expressed on memory/activated T cells, is a receptor for both IFN-gamma-inducible protein 10/CXC chemokine ligand (CXCL)10 and monokine induced by IFN-gamma/CXCL9. It was reported that CXC chemokines IFN-gamma-inducible protein 10/CXCL10 and monokine induced by IFN-gamma/CXCL9 play a critical role in the allograft rejection. We report that CXCR3 is a dominant factor directing T cells into mouse skin allograft, and that peptide nucleic acid (PNA) CXCR3 antisense significantly prolongs skin allograft survival by means of blockade of CXCR3 expression directing T cells into allografts in mice. We found that CXCR3 is highly up-regulated in spleen T cells and allografts from BALB/c recipients by day 7 of receiving transplantation, whereas CCR5 expression is moderately increased. We designed PNA CCR5 and PNA CXCR3 antisenses, and i.v. treated mice that received skin allograft transplantations. The PNA CXCR3 at a dosage of 10 mg/kg/day significantly prolonged mouse skin allograft survival (17.1 +/- 2.4 days) compared with physiological saline treatment (7.5 +/- 0.7 days), whereas PNA CCR5 (10 mg/kg/day) marginally prolonged skin allograft survival (10.7 +/- 1.1 days). The mechanism of prolongation of skin allograft survival is that PNA CXCR3 directly blocks the CXCR3 expression in T cells, which is responsible for directing T cells into skin allograft to induce acute rejection, without interfering with other functions of the T cells. These results were obtained at mRNA and protein levels by flow cytometry and real-time quantitative RT-PCR technique, and confirmed by chemotaxis, Northern and Western blot assays, and histological evaluation of skin grafts. The present study indicates the therapeutic potential of PNA CXCR3 to prevent acute transplantation rejection.

Diversity and modulation of plasminogen activator activity in human transitional carcinoma cell lines

Baseline cellular plasminogen activator (PA) activity, the cellular proteins responsible for variations in PA activity and the effect of cellular PA activity on cellular adherence to and lysis of fibrin substrate were evaluated in three human transitional carcinoma cell lines. Net PA activity in the cell lines 253J, 639V and 647V was measured using a chromogenic substrate assay. These lines were then analyzed to determine the specific protein(s) responsible for differences in PA activity. mRNA and protein levels of cellular uPA, tPA, PAI1 and PAI2 were measured using Northern blot analysis and ELISA assays. Intact cells were used in an in vitro fibrinolysis assay so as to correlate cell biology with protein and mRNA level observations. Net cellular PA activity in the three cell lines varied over a 20-fold range (253J > 639V > 647V). Net PA activity demonstrated a direct correlation with mRNA transcript and protein levels of uPA/low levels of tPA mRNA were detected in the 253J line. However, tPA protein was not detectable in any of the lines. Both PAI1 and PAI2 were detected in varying amounts in each of the three cell lines. In vitro assays demonstrated a direct correlation between net PA activity and plasminogen dependent fibrin substrate lysis. Cellular adherence to fibrin varied as an inverse function of net PA activity. These findings suggest that variations in cellular uPA levels are principally responsible for variations in PA activity between cell lines. Variations in net PA activity are in turn reflected at the cellular level by differences in ECMP substrate lysis and cellular adherence to fibrin.

Epidemiological features of an outbreak of diphtheria and its control with diphtheria toxoid immunization

An outbreak of diphtheria primarily involving adults occurred in seven townships and one farm in Jiangling county, Hubei, China from September 1988 to January 1989. Of the 103 reported cases, 80 were aged over 16 years, and there were two deaths. One hundred cases were reported in Jingzhou and its surrounding townships, only three occurred in townships distant from Jingzhou. The incidence and case fatality rates were 11.54/100,000 and 1.94% respectively. Twenty-one strains of diphtheria bacillus were isolated from 68 patients. A special immunization programme using adsorbed diphtheria toxoid was conducted 1 month into the outbreak, following which the incidence declined rapidly. Five vaccinees subsequently developed diphtheria.