[Physical activity and its influencing factors in patients with diabetes mellitus: a comparative study between China and the United Kingdom]

Objective: To compare the differences in low-level physical activity (PA) and related influencing factors in patients with diabetes mellitus in China and the United Kingdom (UK). Methods: Using baseline survey data from the China Kadoorie Biobank and the UK Biobank, we analyzed the association between diabetes mellitus and low-level PA using logistic regression, with the participants' self-reported whether they had diabetes mellitus as the independent variable, and low-level PA as the dependent variable. Results: We included 509 254 Chinese adults and 359 763 British adults in the analysis. After adjusting for multiple factors, we found that both Chinese and British patients with diabetes mellitus were at elevated risk for low-level PA, with corresponding ORs (95%CIs) of 1.15 (1.12-1.19) and 1.37 (1.32-1.41), respectively. Patients with diabetes mellitus with longer disease duration and poorer glycemic control were at greater risk of having low-level of PA. Female, rural-distributed, employed, never-smoking Chinese diabetics, and male, urban-distributed, retired/unemployed, quit-smoking British diabetics were more likely to have low-level PA. Conclusions: Chinese and British patients with diabetes mellitus were more likely to have low-level PA compared with the general population, but the risk of low-level PA for patients in both countries varied by population characteristics. Therefore, PA guidelines and intervention measures should be based on the characteristics of individuals in the target countries and regions, which could improve PA levels among patients with diabetes mellitus.

Anthropogenic, biogenic, and photochemical influences on surface formaldehyde and its significant decadal (2006-2017) decrease in the Lewiston-Clarkston valley of the northwestern United States

Formaldehyde (HCHO) is a key carcinogen and plays an important role in atmospheric chemistry. Both field measurements and Positive Matrix Factorization (PMF) modeling have been employed to investigate the concentrations and sources of HCHO in the Lewiston-Clarkston (LC) valley of the mountainous northwestern U.S. Different instruments were deployed to measure surface formaldehyde and other related compounds in July of 2016 and 2017. The measurements reveal that the average HCHO concentrations have significantly decreased to 2-5 ppb in the LC valley in comparison to its levels (10-20 ppb) observed in July 2006. This discovery with surface measurements deserves attention given that satellite retrievals showed an increasing long-term trend from 2005 to 2014 in total vertical column density of HCHO in the region, suggesting that satellite instruments may not adequately resolve small valleys in the mountainous region. Our PMF modeling identified four major sources of HCHO in the valley: (1) emissions from a local paper mill, (2) secondary formation and background, (3) biogenic sources, and (4) traffic. This study reveals that the emissions from the paper mill cause high HCHO spikes (6-19 ppb) in the early morning. It is found that biogenic volatile organic compounds (VOCs) in the area are influenced by national forests surrounding the region (e.g., Nez Perce-Clearwater, Umatilla, Wallowa-Whitman, and Idaho Panhandle National Forests). The results provide useful information for developing strategies to control HCHO levels and have implications for future HCHO studies in atmospheric chemistry, which affects secondary aerosols and ozone formation.

Harnessing a real-time location system for contact tracing in a busy emergency department

BACKGROUND

With the persistent threat of emerging infectious diseases (EIDs), digital contact tracing (CT) tools can augment conventional CT for the prevention of healthcare-associated infectious disease transmission. However, their performance has yet to be evaluated comprehensively in the fast-paced emergency department (ED) setting.

OBJECTIVE

This study compared the CT performance of a radiofrequency identification (RFID)-based real-time location system (RTLS) with conventional electronic medical record (EMR) review against continuous direct observation of close contacts ('gold standard') in a busy ED during the coronavirus disease 2019 pandemic period.

METHODS

This cross-sectional study was conducted at the ED of a large tertiary care hospital in Singapore from December 2020 to April 2021. CT performance [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and kappa] of the RTLS, EMR review and a combination of the two approaches (hybrid CT) was compared with direct observation. Finally, the mean absolute error (MAE) in the duration of each contact episode found via the RTLS and direct observation was calculated.

RESULTS

In comparison with EMR review, both the RTLS and the hybrid CT approach had higher sensitivity (0.955 vs 0.455 for EMR review) and a higher NPV (0.997 vs 0.968 for EMR review). The RTLS had the highest PPV (0.777 vs 0.714 for EMR review vs 0.712 for hybrid CT). The RTLS had the strongest agreement with direct observation (kappa=0.848). The MAE between contact durations of 80 direct observations and their respective RTLS contact times was 1.81 min.

CONCLUSION

The RTLS was validated to be a high-performing CT tool, with significantly higher sensitivity than conventional CT via EMR review. The RTLS can be used with confidence in time-strapped EDs for time-sensitive CT for the prevention of healthcare-associated transmission of EIDs.

LED-pumped eye-safe pulse laser with an extracavity optical parametric oscillator

An LED-side-pumped Nd:YAG/Cr⁴⁺:YAG passively Q-switched (PQS) laser containing an extracavity optical parametric oscillator (EOPO) is demonstrated. As far as we know, it is the first LED-pumped eye-safe laser. The Nd:YAG pump module is optimized to increase the PQS pulse energy to 24 mJ at 1064 nm. By using a single-pass EOPO design, the output energy of the signal pulse at 1573 nm is 7.44 mJ with a pulse width of 16 ns, the peak power is 434 kW, and the pump-to-signal conversion efficiency is 31%. For double-pass EOPO operation, the pump-to-signal conversion efficiency increases to 45.8%, the output energy of signal pulse is up to 10.98 mJ with a pulse width of 23.5 ns, and the peak power is 459 kW.

Harnessing enhanced CRISPR/Cas12a trans-cleavage activity with extended reporters and reductants for early diagnosis of Helicobacter pylori, the causative agent of peptic ulcers and stomach cancer

Developing rapid and non-invasive diagnostics for Helicobacter pylori (HP) is imperative to prevent associated diseases such as stomach gastritis, ulcers, and cancers. Owing to HP strain heterogeneity, not all HP-infected individuals incur side effects. Cytotoxin-associated gene A (CagA), and vacuolating cytotoxin A (VacA) genes predominantly drive HP pathogenicity. Therefore, diagnosing CagA and VacA genotypes could alert active infection and decide suitable therapeutics. We report an enhanced LbCas12a trans-cleavage activity with extended reporters and reductants (CEXTRAR) for early detection of HP. We demonstrate that extended ssDNA reporter acts as an excellent signal amplifier, making it a potential alternative substrate for LbCas12a collateral activity. Through a systematic investigation of various buffer components, we demonstrate that reductants improve LbCas12a trans-cleavage activity. Overall, our novel reporter and optimal buffer increased the trans-cleavage activity to an order of 16-fold, achieving picomolar sensitivity (171 pM) without target pre-amplification. Integrated with loop-mediated isothermal amplification (LAMP), CEXTRAR successfully attained attomolar sensitivity for HP detection using real-time fluorescence (43 and 96 aM), in-tube fluorescence readouts (430 and 960 aM), and lateral flow (4.3 and 9.6 aM) for CagA and VacA, respectively. We also demonstrate a rapid 2-min Triton X-100 lysis for clinical sample analysis, which could provide clinicians with actionable information for rapid diagnosis. CEXTRAR could potentially spot the ¹³C urea breath test false-negatives. For the first time, our study unveils an experimental outlook to manipulate reporters and reconsider precise cysteine substitution via protein engineering for Cas variants with enhanced catalytic activities for use in diagnostics and genetic engineering.

Predictions of arrhythmic, heart failure and mortality outcomes in pericarditis using automatic electrocardiogram analysis: a retrospective cohort study

Funding Acknowledgements

Type of funding sources: None.

Introduction

 Pericarditis is a relatively rare disease with a global burden. Despite its strong association with adverse cardiovascular outcomes, identification of patients at risk of future heart failure or arrhythmic events is difficult. In the following study, automated electrocardiogram (ECG) variables were used to predict new onset ventricular tachycardia/fibrillation (VT/VF), atrial fibrillation (AF) and heart failure with reduced ejection fraction (HF) in an Asian cohort of pericarditis patients.

Purpose

Assessing the use of automated ECG parameters to predict prognosis in pericarditis patients.

Methods

Consecutive patients admitted to a single tertiary center in China, for a diagnosis of pericarditis between 1st January 2005 and 31st December 2019, were included. Patients with existing AF or HF were excluded. The follow-up period was until the 31st December 2020, or death. Cox regression was applied to identify significant predictors of the incident VT/VF, AF or HFrEF.

Results

A total of 874 patients were included. The cohort was 57% male and had a median age of 59 (IQR: 50-70) years old. During follow-up, 57 patients (6.5%), 156 (17.8%) and 168 (19.2%) suffered from VT/VF, AF and HF, respectively. Cox regression identified baseline VT/VF, terminal angle of the QRS vector in the transverse plane, mean QRS duration and mean QTc intervals as significant predictors of incident VT/VF events, with only the foremost maintaining significance in multivariate analysis. In contrast, baseline age, prior diagnoses of hypertension, malignancy and atrial flutter, initial angle and magnitude of the QRS vector in the transverse plane, P-wave and QRS axis in the frontal plane, ST segment axis in the frontal and horizontal planes, mean PT interval, mean PR segment duration and QTc intervals were all univariate predictors of incident AF, albeit only baseline age and initial angle of the QRS vector in the transverse plane retained significance after multivariate adjustment. As it pertains to new-onset HFrEF, several clinical and electrocardiographic parameters demonstrated an association in univariate analysis, with history of hypertension, history of sudden cardiac death (SCD), initial QRS angle in transverse plane, initial 40ms QRS complex axis, ST-segment axis in the horizontal plane, T-wave frontal axis and atrial rate all showcasing significant relationships in multivariate analysis.

Conclusions

AF and HFrEF are relatively common complications, whilst VT/VF occurs less frequently in the context of pericarditis. Different clinical and ECG predictors of these outcomes were identified. Future studies are still needed to evaluate their use for risk stratification in the clinical setting.

[Detection of right-to-left shunt with transthoracic contrast echocardiography in patients with pulmonary hypertension]

Objective: To explore the value of right heart contrast echocardiography in etiological diagnosis and severity assessment of pulmonary hypertension (PH). Methods: A retrospective analysis was conducted on 74 patients who underwent transthoracic contrast echocardiography in China-Japan Friendship Hospital from May 2015 to July 2018, all of whom were diagnosed as PH by right heart catheterization. Patients were divided into three groups according to contrast echocardiography: the intra-cardiac shunt group (<4 cardiac cycles with microbubbles in the left heart); Intrapulmonary shunt group (>4 cardiac cycles with microbubbles in the left heart); non-shunt group. The etiology, partial arterial oxygen pressure (PO(2)), N-terminal pro-brain natriuretic peptide (NT-proBNP), mean pulmonary artery pressure (mPAP), right atrial pressure (RAP), pulmonary vascular resistance (PVR) and cardiac output (CO) were analyzed. Central nervous system complications were also compared among the three groups. Results: Among the 74 patients, right-to-left shunt was found in 28 cases (37.8%) by contrast echocardiography, including 11 cases (14.9%) of intra-cardiac shunt and 17 cases (23.0%) of intrapulmonary shunt. In the 11 cases of intra-cardiac shunt, 7 were diagnosed with congenital heart disease and 4 were patent foramen. Two with hereditary hemorrhagic telangiectasia (HHT) and 1 with pulmonary arteriovenous malformation (PAVM) were included in the 16 cases of intrapulmonary shunt. There was no statistical difference in PO(2), mPAP, PVR, NT-proBNP, RAP, CO and functional class among the three groups (all P>0.05). A total of 5 cases (6.8%) were found with nervous system comorbidities, 4 cases (5.4%) with cerebral infarction and 1 cases epilepsy, and 2 cases of cerebral infarction were diagnosed as paradoxical embolism. Nervous system complications were more common in patients with intra-cardiac shunt than in other groups. Conclusion: While right-to-left shunt detected by contrast echocardiography has no relationship with disease severity, it has complementary value in the etiological diagnosis of PH, and intra-cardiac shunt may increase the risk of nervous system complications.

[Brain protection strategy and effectivity in pulmonary thromboendarterectomy]

Objective: To summarize the experience and effectivity of brain protection in 25 patients who suffered from chronic thromboembolic pulmonary hypertension (CTEPH) and received pulmonary thromboendarterectomy (PTE) under deep hypothermic circulatory arrest. Methods: Retrospective analysis of 25 PTE surgeries in our center from December 2016 to August 2018. All cases were completed underdeep hypothermic circulatory arrest. Standard brain protections were strictly executed, including: balanced and controlled extracorporeal circulation cooling, cerebral oxygen saturation (rSO(2)) monitoring, strictly control of circulatory arrest time, and etc. The neurological adverse events during the perioperative period were recorded and statistically analyzed, and the intelligence level and cognitive function of the patients were evaluated by MMSE scale and MoCA scale before surgery and discharge. Results: All the 25 patients successfully completed the surgery, and 1 patient (4%) died of postoperative infection. The mean pulmonary arterial pressure decreased from (52.9±16.7) mmHg before surgery to (23.6±8.1) mmHg immediately after surgery (t=10.01, P<0.01), and(20.7±7.9) mmHg at 3 months follow-up (t=10.73, P<0.01). Pulmonary vascular resistance decreased from 975.4 (788.6-1 292.8) dyn·s·cm(-5) to 376.1 (283.6-565.5) dyn·s·cm(-5) (Z=5.34, P<0.01). Neurological complications occurred in 3 patients during the perioperative period, including 2 patients with hypoxic encephalopathy, and 1 patient with cerebral hemorrhage. All 3 patients fully recovered before discharge. Univariate analysis showed that the duration of rSO(2)<40% and the maximum decrease rate of rSO(2) from baseline were significantly correlated with postoperative neurological damage. Multivariate analysis showed only time of rSO(2)<40% was significantly correlated with postoperative neurological damage. There was no significant difference in MMSE and MoCA score before and after surgery (P>0.05). Conclusions: Adequate brain protection measures are essential to reduce the neurological complications of PTE surgery. Real-time intraoperative monitoring of rSO(2) and strict control of circulatory arrest time can further reduce the occurrence of neurological damage.

Enhanced matrix metalloproteinases-2 activates aortic endothelial hypermeability, apoptosis and vascular rarefaction in spontaneously hypertensive rat

Microvascular rarefaction with endothelial cells apoptosis is a common characteristic of various microvascular complications in the spontaneously hypertensive rat (SHR). Elevated levels of proteolytic (e.g. matrix metalloproteinase, MMPs) activity and apoptosis in aortic endothelial cells of SHR were found when compared to its normotensive control. However, the exact mechanisms of microvascular rarefaction and the role of MMPs in this process remain poorly understood. Besides cleavage of VEGFR2 via unbalanced MMPs, we hypothesize that selected cleavage of Beta-Catenin and VE-cadherin by MMPs could induce apoptosis of rat aortic endothelial cells (RAECs) and rarefaction. Primary RAECs were isolated, identified and used in a in-vitro model. Transwell system was used to analyze the permeability of Wistar RAECs, SHR RAECs and SHR RAECs with pretreatment by doxycycline. Qualitative and semi-quantitative analysis of major endothelial adhesion molecules were detected by immunofluorescence technique and Western blot, respectively. MMP-2 activity of SHR RAECs was increased significantly and doxycycline (50 μM) effectively reduced the level of MMP-2 and hyper-permeability in SHR RAECs. SHR RAECs showed enhanced cleavage of VEGFR2, VE-cadherin and B-catenin, which could be prevented by doxycycline (50 μM). Doxycycline (50 μM) attenuated hyper-permeability via decreased MMP-2 by protecting VEGFR2, VE-cadherin, Beta-catenin from cleavage and inhibited the reduction of mitochondrial transmembrane potential (MTP), thus prevented mitochondria-mediated apoptotic signaling and capillary rarefaction in the SHR. It might be a novel insight into the mechanisms of SHR microvascular rarefaction that is independent of pressure but relevant to MMP-2.

Effects of hypoxia on biofilms and subsequently larval settlement of benthic invertebrates

Biofilms on submerged surfaces are important in determining larval settlement of most marine benthic invertebrates. We investigated if exposure of biofilms to hypoxia would alter the larval settlement pattern and result in a shift in benthic invertebrate community structure in the field. Biofilms were first exposed to hypoxia or normoxia in laboratory microcosms for 7 days, and then deployed in the field for another 7 days to allow for larval settlement and recruitment to occur. Using terminal-restriction fragment length polymorphism of the 16S rRNA gene, this study showed that hypoxia altered the biofilm bacterial community composition, and the difference between the hypoxic and normoxic treatments increased with the time of exposure period. This study also demonstrated significantly different benthic invertebrate community structures as a result of biofilm exposure to hypoxia and that the hypoxic and normoxic treatments were dominated by Hydroides sp. and Folliculina sp., respectively.

Blockade of Both CD28/B7 and OX40/OX40L Co-Stimulatory Signal Pathways Prolongs the Survival of Islet Xenografts

CTLA4Ig, a recombinant fusion protein composed of the extracellular domain of human CTLA4 and the constant region of human IgG1, inhibits the interaction of CD28/B7 pathway by binding the B7 molecule. OX40Ig, a recombinant fusion protein composed of the extracellular domain of human OX40 and the constant region of human IgG1, abrogates the interaction of OX40/OX40L pathway by binding the OX40L on APCs. So blockade of CD28/B7 or OX40/OX40L co-stimulatory pathways alone in mice with CTLA4Ig or OX40Ig can result in finitely prolonging the survival of islet grafts (43.2 +/- 4.81 and 67.7 +/- 7.74 days, respectively). In this study, a novel replication-defective adenovirus containing both of the CTLA4Ig and OX40Ig genes, AdCTLA4Ig-IRES-OX40Ig, was constructed by homologous recombination and injected into the streptozocin-rendered diabetic BalB/c mouse recipients (H-2d) through the tail vein, at the same day, the freshly isolated islets from Lewis rats (RT-1) were transplanted under the left kidney capsule of the recipients. The results showed that the mean survival time of the islet xenografts in the AdCTLA4Ig-IRES-OX40Ig-treated diabetic mice was significantly prolonged (100.3 +/- 14.94 days), while those in the untreated or AdEGFP-treated mice were rejected in normal fashion (6.7 +/- 0.94 and 7.0 +/- 1.0 days, respectively). In conclusion, utilizing AdCTLA4Ig-IRES-OX40Ig in vivo which can simultaneously express CTLA4Ig and OX40Ig proteins can improve the survival of Lewis-->BalB/c islet xenografts.

Antileukemic Effect of Interleukin-7-Transduced Bone Marrow Stromal Cells in Mice Following Allogeneic T-Cell-Depleted Bone Marrow Transplantation

Impaired immune reconstitution following allogeneic bone marrow transplantation (BMT) remains a major obstacle to its clinical application. In this study, interleukin (IL)-7-transduced bone marrow stromal cells (MSC-IL7, 1 x 10(6)/mouse) were transfused into lethally irradiated C57BL/6 recipient mice. By day 40 after transplantation, the recipient mice were challenged with the lymphoma cell line EL4. MSC-IL7 co-transplantation protected recipient mice from leukemic mortality (MST >120 days after BMT vs mean survival time (MST) 70 days in the PBS group) It enhance the PFC count and DTH responses of recipients after transplantation. In conclusion, MSC mediated IL-7 gene therapy and may be a more feasible strategy to restore immune function following allo-TCD-BMT.

Semiquantitative evaluation of mRNAs for the membranous form of immunoglobulin heavy chain is useful for investigating the etiology in CVID

Common variable immunodeficiency (CVID) is a primary antibody deficiency syndrome characterized by defective B-cell maturation and antibody formation resulting in low serum antibody levels of all immunoglobulin (Ig) isotypes. To investigate the pathogenesis of CVID, we developed a set of competitive polymerase chain reaction for membrane-bound Ig heavy chain (mHC) mRNAs for IgM, IgG and IgA. Data on three children with CVID in group A of Bryant's classification were analysed. All the three mHC mRNA levels in Patient 1 were almost same as those in healthy controls. In Patient 2, mHC mRNA for IgM was detected at a level similar to that in controls, but mHC mRNAs for IgG and IgA heavy chains were not detected. In Patient 3, all the three mHC mRNAs were undetectable. Our data suggest that a different molecular basis exists in these patients with CVID even though all belong to group A of Bryant's classification. Use of our method facilitates a better understanding of molecular events in CVID patients and may be useful for precise classifications of CVID.

Analysis of Ig subclass deficiency: First reported case of IgG2, IgG4, and IgA deficiency caused by deletion of C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon in a Mongoloid patient

BACKGROUND

The cause of Ig class or subclass deficiencies has been unclear except for IgH gene deletions and a homozygous 1-base insertion (1793insG) in C gamma 2 exon 4 of IgG2 deficiency. In addition, there are no reports that IgH gene deletions are found in patients who are Mongoloid (a category that includes most of the people of Asia, such as the Japanese, Chinese, Indonesians and Malaysians).

OBJECTIVE

To investigate the cause of Ig subclass deficiency, we extensively investigated 4 Japanese patients with low serum IgG2 levels. Patient 1 was a 23-month-old girl whose serum IgG2, IgG4, and IgA levels were under the detection limits; she also had idiopathic thrombocytopenic purpura. Patient 2 was a 5-year-old boy whose serum IgG2 level was under the detection limit. Patient 3 was a 14-month-old boy whose serum IgG2 and IgG4 levels were under the detection limits. Patient 4 was 3-year-old girl whose IgG2 level was low and whose IgA level was under the detection limit.

METHODS

DNA was extracted from neutrophils, and Southern blot analysis was performed.

RESULTS

Southern blot analysis revealed that patient 1 had lost the C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon genes and was a homozygous carrier of the deletion described above. Her mother was of the heterozygous genotype. DNA from patients 2, 3, and 4 revealed no deletions in comparison with control DNA.

CONCLUSION

This is a report of the first case of a Mongoloid in whom IgG2, IgG4, and IgA deficiency was caused by deletion of C alpha 1, psi C gamma, C gamma 2, C gamma 4, and C epsilon. Our finding contributes to investigations of Ig subclass deficiency.

Growth hormone interferes with the progression of myocarditis in rats

In this study, we investigated whether recombinant human growth hormone (rhGH) influences the progression of myocarditis. We induced experimental autoimmune myocarditis in F344 rats by subcutaneous injection of cardiac myosin, and divided the rats into three groups: (1) control group, saline injection; (2) pre-treated group, subcutaneous injection of rhGH (100 mIU/rat/day for 10 days) before induction of experimental autoimmune myocarditis; and (3) post-treated group, subcutaneous injection of rhGH (100 mIU/rat/day for 10 days) after induction of experimental autoimmune myocarditis. On the 35th day after induction of experimental autoimmune myocarditis, all rats were sacrificed and the hearts were examined. The increase in body weight was smaller in the control group than the pre-treated group and the rate of heart weight/body weight was larger in the control group than in the two treated groups. Histopathologically, rats in the control group showed multifocal infiltration by inflammatory cells, mainly neutrophils, lymphocytes and macrophages, extensive fibrosis, and a higher proportion of mast cells in the inflamed region. In contrast, rats in the two treated groups showed only minor changes. We found that rhGH did not influence the distribution of lymphocytes in peripheral blood in the three groups, and that rhGH induced G1 checkpoint dysfunction, thereby arresting the cell cycle in G1 and inhibiting the proliferation of mast cells in vitro. These findings suggest a possible role for mast cells in the progression of myocarditis and the rhGH may be a candidate for use as a new tool to treat myocarditis.

[Treating cicatricial baldness with scalp expanding and hair autografting]

OBJECTIVE

To investigate the effective method to treat cicatricial baldness.

METHODS

From 1993 to 1998, 21 cases with multi-region or great-dimensional cicatricial baldness were treated with scalp expanding and hair autografting. Among them, there were 17 males and 4 females, aged from 14 to 49 years old. The operation was divided into two stages, stage one meaned to embed the expander under the scalp and stage two meaned to sow the autogenous hair.

RESULTS

All cases, no matter what the position and area, were repaired successfully. The biggest dimension of repaired baldness was 340 cm2, one expander exposed and one failed in expanding after operation and be corrected immediately. The normal hair direction changed in two cases.

CONCLUSION

Combined use of scalp expanding and hair autografting is an effective method to treat multi-region or great dimensional cicarticial baldness.

Fate of the mutated IgG2 heavy chain: lack of expression of mutated membrane-bound IgG2 on the B cell surface in selective IgG2 deficiency

IgG2 deficiency is clinically characterized by sinopulmonary infections caused by pneumococcus and Hemophilus. We reported homozygous one-base insertion (1793insG) in the C(gamma)2 gene in two Japanese siblings in whom serum IgG2 levels were under detection limits. The 1793insG was present in exon 4, just upstream from the alternative splice site for M exons; the result being a complete amino acid change in transmembrane and cytosolic parts of membrane-bound gamma2 heavy chain (m gamma 2HC). To determine why this mutation caused selective and complete IgG2 deficiency, we constructed expression vectors of normal and mutant membrane-bound chimeric IgG heavy chain cDNAs. Stable transformants, Ag8N-L and Ag8M-L, expressing either normal and mutant chimeric IgG heavy chain with light chain respectively were obtained using P3X63Ag8653 as recipient cells. Of the Ag8N-L, 22.1% were surface IgG+; however, none of the Ag8M-L were surface IgG+. Addition of an anti-human IgG antibody induced cell death of Ag8N-L and we considered that the expressed chimeric IgG protein on Ag8N-L might function as the Ig receptor for signal transduction. However, Ag8M-L did not express mutant IgG on its surface nor did it secrete this mutant into culture medium. The mutant chimeric IgG protein was rapidly degraded within Ag8M-L. Thus, the mutated IgG2 heavy chain in our patient could not be expressed on the cell surface because of loss of the transmembrane domain and the evolutionally conserved cytoplasmic domain. In humans, B cells expressing surface IgG are indispensable for secretion of IgG.

[Effect of gradient magnetic field on growth of stem pearls of Dioscorea opposita during seedling stage]

OBJECTIVE

To probe into the bioeffect of gradient magnetic field on the growth and development of medicinal plants.

METHODS

Gradient magnetic field with transmission belt was applied to treat the stem pearis of Dioscorea opposita before sowing and an evaluation of the pearl growth during the seedling stage was made.

RESULT

Treated with twice gradient magnetic field, the stem pearls grew the best in the seedling stage. Compared with the control, the rate of emergence increased by 38.60%, root number increased by 8%, and the average root length increased by 2.62 cm. By F Test, the average root length was F = 19.98, F0.05 = 6.94 and F0.01 = 18.00.

CONCLUSION

Proper magnetic field intensities can promote the growth of medicinal plants.

Involvement of protein kinase C in taxol-induced polyploidization in a cultured sarcoma cell line

Taxol was found to inhibit the proliferation and to induce the polyploidization of cultured methylcholanthrene-induced sarcoma cells (Meth-A cells). To investigate whether protein kinase C is involved in taxol-induced polyploidization, phorbol 12-myristate 13-acetate (PMA), which regulates the activity of protein kinase C, was used along with taxol to treat the cells. We found that PMA did not interfere with the proliferation and did not induce polyploidization by itself. However, at low concentration, taxol, which by itself did not induce polyploidization, clearly induced polyploidization in the presence of PMA. To explore the mechanism by which PMA potentiates polyploidization, the levels of the G1 checkpoint-related proteins cyclin E and cdk2, and those of the G2 checkpoint-related proteins cyclin B and cdc2 were determined by flow cytometry. We found that both G1 and G2 checkpoint-related proteins increased during the induction of polyploidization. To verify the relationship between protein kinase C and tubulin polymerization, flow cytometry was used to determine the total content of tubulin protein, and morphological observation was used to examine spindle organization. PMA did not affect the taxol-induced increase in tubulin protein, but markedly potentiated taxol-induced spindle disorganization. These findings suggest that protein kinase C plays an important role in regulating the induction of polyploidization in Meth-A cells.

Both low and high concentrations of staurosporine induce G1 arrest through down-regulation of cyclin E and cdk2 expression

Staurosporine has been reported to cause arrest of cells in G1 phase at low concentration and in G2 phase at high concentration. This raises the question of why the effects of staurosporine on the cell cycle depend on the applied concentration. In order to verify these multiple functions of staurosporine in Meth-A cells, we used cyclin E as a landmark of G1/S transition, cyclin B as a landmark of G2/M transition and MPM2 as a hallmark of M phase. We found that staurosporine arrested cells in G1 phase at a low concentration (20 nM) and in G2/M phase at a high concentration (200 nM). However, 200 nM staurosporine increased the expression of cyclin B and cdc2 proteins, suggesting that the cells progressed through the G2/M transition, and increased the expression of MPM2 protein, indicating that the cells entered M phase. Moreover, 200 nM staurosporine increased the expression of p53 and p21 proteins and inhibited the expression of cyclin E and cdk2 proteins, suggesting that the cells were arrested in the G1 phase of the next cycle. Morphological observation showed similar results as well. These data suggest that the G2/M accumulation induced by 200 nM staurosporine does not reflect G2 arrest, but rather results from M phase arrest, followed by progression from M phase to the G1 phase of the next cycle without cytokinesis, and finally arrest of the cells in G1 phase.

Protection of branched-chain amino acids against ischemic myocardial injury in rats

The protective effects of Branched-Chain Amino Acids (BCAA) on ischemic myocardium in rats were studied. Thirty Wistar rats (15 female and 15 male) were randomly divided into 3 groups of 10 animals each. Group A: control; group B: isoproternol (ISO); group C: ISO + BCAA. The rats in groups A and B received normal synthetic rat chow while those in group C received BCAA as supplement. After two weeks of dietary treatment, the rats in group A were injected with saline while those of groups B and C were injected with ISO which induced acute ischemic myocardial injury. After 4 days of injections with either saline or ISO, the rats were sacrificed. The activities of lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), creatine kinase (CK), pyruvate kinase (PK) in the serum and in the myocardium, and the concentrations of potassium (K+), magnesium (Mg2+), calcium (Ca2+) in the myocardium were measured. The results showed that the activities of LDH, GOT, alpha-HBDH, CK, PK in the serum and in the myocardium were significantly increased in group B. In addition, the concentrations of Ca2+ in the myocardium were significantly increased. However, the concentrations of Mg2+ in the myocardium were substantially decreased while those of K+ in group B were slightly lowered. In the group C animals both the activities of LDH, alpha-HBDH, PK, CK in the serum and the activities of LDH, GOT, alpha-HBDH, CK in the myocardium were significantly lower than those of the rats in group B, and were not significantly different from those of the control group. More significant was the concentrations of Ca2+ in the myocardium of the rats in group C were comparable to those of the control rats but were significantly lower than those of the rats in group B. It appeared that BCAA was effectively blocking the increase of Ca2+ in the myocardium without raising the level of Mg2+. It was concluded that dietary supplement with BCAA provided some protective effects against ischemic myocardium in rats.

Hemorheology and walking of peripheral arterial occlusive diseases patients during treatment with Ginkgo biloba extract

AIM

To study the effects of Ginkgo biloba extract 761 (GbE) from the points of view of hemorheology for patients of peripheral arterial occlusive diseases (PAOD).

METHODS

The treatment with GbE (240 mg.d-1, po) and the pain-free walking distance (PFWD) were carried out for 24 PAOD patients (12 nondiabetic, ND and 12 diabetic, D) over 48 wk. The parameters erythrocyte stiffness (ES) and relaxation time (RT), the blood plasma viscosity (eta), the plasma fibrinogen concentration (Cf) and the blood sedimentation rate (BSR), the PFWD, and maximal walking distance (MWD) were determined at 6 wk before treatment (-6), at the beginning of the treatment (0), and after 6, 11, 16, and 48 wk of treatment.

RESULTS

At wk -6, ES and RT of both the ND- and D-group were not significantly different from a healthy control group. At wk 0, stiffness and RT were significantly higher than healthy control, and the mean PFWD was only 111 m. The eta value was significantly elevated and Cf and BSR were enhanced. Throughout 11 wk of treatment ES, RT, eta, and Cf decreased gradually and PFWD improved. Between 16 and 48 wk, ES, and RT were no longer significantly different from the controls, whereas eta and Cf decreased gradually but remained higher than normal, BSR decreased, and the PFWD improved by a factor of 3.8 times (D) and 3.3 times (ND).

CONCLUSION

GbE gives therapeutic effects in PAOD patients.

Apoptotic cell death of high polyploid cells in a cultured sarcoma cell line

It is well known that DNA-ploidy is useful independent prognosticator of malignancy. However, the biological significance of polyploid cells and the relation between polyploidy and prognosis is not well understood. We analyzed DNA ploidy by flow cytometry in Meth-A cells (a cultured sarcoma cell line) after treatment with K252a, a protein kinase inhibitor, and showed induction of polyploidization. Apoptotic cell death of the high polyploid cells was verified by flow cytometry, morphological observation and gel analysis of DNA integrity. Expression of tumor-suppressor nuclear protein p53 investigated by immunohistochemistry was increased 10-fold or more in cells with 16C (C = haploid DNA content) relative to cells with 2C, suggesting that the overexpression of p53 was involved in the apoptosis. These results may be of clinical relevance since it has been known that both DNA ploidy and p53 expression have prognostic significance.

[The effect of herbal medicines on the immunodeficient animals by injecting cancer chemotherapeutic agent-special reference to age related recovery of the function]

The acquired immunodeficiency of the host plays an essential role in the occurrence of infections even with low pathogenic bacteria. The increase of cases with MRSA and/or pseudomonas infection is one of the serious problems in hospital management in Japan for the elderly as well as pediatric patients. In the present study, mitomycin C (MMC)-treated hosts were prepared in young, adult and old mice to test the immunopotentiating action of the promising Chinese herbal medicine, Tohki-Rikuoh-Toh (TRT), Hotyu-Ekki-Toh (HET) and Juzen-Taiho-Toh (JTT). The effect of these herbal medicines on organ structure and its function in the MMC-treated hosts is clarified and discussed for medical use. 4-5, 8-10 and over 50 week old male C57BL/6 (Clea Japan Inc.) were injected with MMC at a dosage of 3 to 5 mg/kg to inhibit the bone marrow, thus creating a mouse model with reduced immunopotential. A powder extract of TRT, HET and JTT was administrated orally at a dosage of 500 mg/kg/day for seven consecutive days. The white cell number and the subset analysis were carried out by the FACS method. The bactericidal effect of the host was monitored by NBT reduction test. Peritoneal macrophages were prepared by the adherence technique. The macrophage phagocytic activity was examined by an ACAS system. After the administration of TRT, HET and JTT, the body weights recovered as much as 90%, especially in young animals which had been reduced to 75% of their normal values. After MMC-treatment, with the herbal medicines, HET was good for young mice while JTT was effective for the old ones. As for the effect on B cells, the plaque-forming cells (PFC) of spleen cells were compared among the groups. As a result, PFC in the HET group was 184% and the other two were 80 approximately 95% as compared to 76% in the MMC-treated ones. The number of white blood cells in the MMC-treated mice returned to 80% of their normal value. In addition, the phagocytic activity of macrophages increased to 50% although that of the non-treated group was only 20%. The phagocytic activity also recovered in the JTT and TRT of 131% to 95%, respectively compared to 11% in the MMC-treated control. When TRT, HET and JTT were administered orally to mouse models whose immunopotential had been inhibited, the herbal medicines activated both quantitatively and qualitatively, showing themselves to be effective interstitial medicines. In addition, the data from the animal models showed no side effects, confirming the complete efficacy of the drug. Moreover, there was no direct anti-bactericidal effect from these medicines, suggesting that the immunomodulating action of this medicine is host-mediated. It is interesting that quantitative and qualitative recovery were seen when HET was administered to MMC-treated young hosts while JTT was good for the old. With this investigation, the effective components are still unknown for different generations, and we need to clarify this aspect for better understanding of the efficacy of herbal medicines.

[Preliminary analysis of factors causing mental retardation in China]

Analysis of the data collected from national sampling survey of the mental retarded in 1987 showed: (1) prevalence of mental retardation in China was 12.68/1,000, (2) its causes mainly included hereditary diseases, cerebral diseases, malnutrition, pregnant infection and birth trauma for children and senile dementia for the elderly aged 60 or over, (3) severe mental retardation was mainly caused by cerebral diseases and developmental deformity in the country, and (4) the causes for 40.1% of the mental retarded persons remained unknown. Based on the researches at home and abroad, a series of major preventive measures for mental retardation have been put forward, they included: (1) to promote better birth and better rearing, vaccination, proper nutrition for pregnant mothers and infants, and safety education as focuses in primary prevention, (2) to detect early and timely treat cerebral diseases and nutritional deficiency, to strengthen antenatal diagnosis and early screening for inborn metabolic diseases as secondary prevention, and (3) to strengthen education, behavioral training and psychological rehabilitation, and to provide community-based rehabilitation service for the mental retarded as tertiary prevention.

Major histocompatibility complex restriction of maternally induced suppression in young adult mice

This study focused on the mode in which maternal T cells induce suppression of plaque-forming cell (PFC) response in offspring. The maternal T cells of C57BL/6J pregnant mice, which had been intraperitoneally injected with 2 x 10(8) of sheep red blood cells (SRBC) on day 12 of gestation, were transferred, 5 days after immunization, into (C3H/HeJ x C57BL/6J)F1 normal pregnant mice on day 12 of gestation. The (C3H/HeJ x C57BL/6J)F1 x C3H/HeJ offspring of (C3H/HeJ x C57BL/6J)F1 recipient pregnant mice were reared to more than 6 weeks of age, and their anti-SRBC PFC responses were examined. Suppression of anti-SRBC PFC response was observed in H-2bxk but not H-2k offspring. Thus, maternal T cells of SRBC-immunized pregnant mice induce suppression of anti-SRBC PFC in offspring with restriction to major histocompatibility complex (MHC) haplotype utilized in maternal T-cell responses during pregnancy. Maternal CD4+ T cells are responsible for the MHC-restricted induction of PFC suppression in offspring. Furthermore we demonstrated, in this report, using adoptive transfer of maternal T cells from SRBC-immunized pregnant mice and in vitro secondary PFC assay in the offspring, that maternal T-cell-mediated suppression results from the development of CD4+ suppressor T cells in offspring. Moreover, the activation of suppressor T cells in offspring depends on the recognition of SRBC antigens presented in association with the same MHC haplotype as that utilized in the maternal T-cell response during pregnancy. Thus, the maternal T cells of SRBC-immunized pregnant mice generate a repertoire of suppressor T cells in their offspring.

[Report on 114 primary vaginal carcinomas]

114 patients with primary carcinoma of the vagina were treated in our hospital from 1958 to 1978. It accounted for 0.83% of all gynecological malignant tumors in the same period. The youngest was 26 years of age, the oldest 75. Patients 40-59 years comprised 61.4%. 33% of patients had wedding age under 17. 63.4% had more than 4 pregnancies and 58.4% gave more than 4 births. 89.69% was diagnosed as squamous cell carcinoma, 7.2% as adenocarcinoma, 2.06% as undifferentiated carcinoma and 1 as embryonic carcinoma. The tumor occurred frequently in the upper third and posterior wall of the vagina (60% and 68%). In this series, there were 21 stage I, 29 stage II, 61 stage III and 3 stage IV lesions. 110 patients were treated by radiotherapy in different schemes. Intracavitary radium or caesium plus 60Co external irradiation by four fields gave better result with a 5 year survival rate of 66.1%. Only 2 out of 12 patients were cured by 60Co rotation alone but if supplemented by intracavitary radium or caesium, the cure rate was increased. The 5 year survival rate was 71.4% for stage I, 62.1% for stage II, 42.6% for stage III and O for stage IV. After the radiotherapy, rectovaginal fistula developed in 1 patient, vesicovaginal fistula in 1. 14% was complicated with rectal bleeding and 8.18% with hematuria.

The effect of upstream sequences to initiator on the expression of gene coding for hepatitis B core antigen

The nucleotide sequences of cloned adw hepatitis B core antigens (HBcAg) which have different levels of expression have been determined by dideoxy chain-terminating method. The results indicate that the different levels of gene expression is primarily due to the different structures of upstream sequences before the initiator of HBcAg genes. The hepatitis B core gene in the low-expressed clone forms a secondary structure before the initiator. This secondary structure has been removed by Bal-31 exonuclease in the high-expressed clone and half of the structure removed in the mid-expressed clone. It is apparent that the transcription/translation of the hepatitis B core gene is somehow blocked because of the secondary structure. Therefore, the amount of HBcAg synthesized in E. coli is dramatically reduced.

[Intracavitary afterloading radiotherapy--preliminary clinical report on 44 patients]

This report describes the 2 year results of the treatment of 44 patients (1 vaginal carcinoma, 3 endometrial carcinoma and 40 cervical carcinoma) by Buchler afterloading equipment. One patient with vaginal carcinoma and two with endometrial carcinoma are live without disease over 2 years. There were 40 patients with cervical carcinoma: 1 stage I, 21 stage II (52.8%) and 18 stage III (45%). The dose-rate of the source is 10-25 cGy/min. A total dose of 41-55 Gy was given at point A in 87.5% of cases. The measurement of the bladder and the rectum were made in all the 40 patients during the treatment. The dose at the bladder was less than 30 Gy and only 10% of patients had a dose of over 30 Gy at the rectum. A dose of 40-45 Gy external irradiation by 8MV X-rays was delivered to the parametrium in each patient. One died of cancer, 2 were lost in follow up and 3 had local recurrence and metastasis. The two year survival rate was 92.5%. Only 4 had mild rectal reactions during the treatment and 2 had mild rectal bleeding after treatment.