[Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing]

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

[Association between different treatment timings and adverse neonatal outcomes in pregnant women with syphilis during pregnancy]

Objective: To analyze the association between different treatment timings and adverse neonatal outcomes (premature birth, death, congenital syphilis) in syphilis-infected pregnant women. Methods: The National Management Information System for Prevention of HIV, Syphilis and HBV Mother-to-Child Transmission was used to collect information on the detection and treatment of syphilis-infected pregnant women and their newborns in Guangdong Province from October 2011 to December 2021. According to the gestational weeks of syphilis-infected pregnant women receiving penicillin treatment for the first time, they were divided into four groups: treatment in the first trimester, treatment in the second trimester, treatment in the third trimester, and no treatment during pregnancy. Multivariate logistic regression was used to analyze the association between different treatment timings and adverse neonatal outcomes in syphilis-infected pregnant women. Results: A total of 22 483 syphilis-infected pregnant women were included. The number of pregnant women who started treatment in the first trimester, second trimester, and third trimester and did not receive treatment during pregnancy were 4 549 (20.23%), 8 719 (38.78%), 2 235 (9.94%) and 6 980 (31.05%), respectively. Compared with pregnant women who started treatment in the first trimester, pregnant women who did not receive anti-syphilis treatment during pregnancy had increased risks of neonatal preterm birth (OR=1.42, 95%CI: 1.24-1.62), death (OR=4.27, 95%CI: 1.64-14.69) and congenital syphilis (OR=12.26, 95%CI: 6.35-27.45). At the same time, the risk of congenital syphilis in the newborns of pregnant women who started anti-syphilis treatment in the second trimester (OR=2.68, 95%CI: 1.34-6.16) and third trimester (OR=6.27, 95%CI: 2.99-14.80) also increased. Conclusion: Early initiation of anti-syphilis treatment during pregnancy in patients with syphilis can improve neonatal outcomes.

Dual-channel compressed ultrafast photography for Z-pinch dynamic imaging

The compressed ultrafast photography (CUP) can capture non-repetitive time-evolving events at 7 × 10¹³ fps, which is anticipated to find a diverse range of applications in physics, biomedical imaging, and materials science. The feasibility of diagnosing ultrafast phenomenon of Z-pinch by using the CUP has been analyzed in this article. Specifically, a dual-channel CUP design has been adopted for acquiring high quality reconstructed images and the strategies of identical masks, uncorrelated masks, and complementary masks have been compared. Furthermore, the image of the first channel was rotated by 90° to balance the spatial resolution between the sweep direction and the non-sweep direction. Both five synthetic videos and two simulated Z-pinch videos were chosen as the ground truth to validate this approach. The average peak signal to noise ratio of the reconstruction results is 50.55 dB for the self-emission visible light video and 32.53 dB for the laser shadowgraph video with unrelated masks (rotated channel 1). The simulation results show that the time-space-evolving process of plasma distribution can be well retold, and the phenomenon of plasma instability can be accurately diagnosed by the dual-channel CUP with unrelated masks (rotated channel 1). This study may promote the practical applications of the CUP in the field of accelerator physics.

[Evaluation of the effect of free fibular flap transplantation in repairing mandibular osteoradionecrosis defect in 151 cases]

Objective: To investigate the clinical effect of free fibula flap transplantation in repairing the defect of mandibular osteoradionecrosis (ORN). Methods: A total of 151 mandibular ORN patients undergoing free fibular flap transplantation were selected from August 2005 to September 2020 in the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University. Among them, 109 patients were males and 42 patients were females, aged (54.1±10.1) (ranged 31-85) years old. The clinical data of the patients was collected and the survival rate of the flaps and postoperative function were calculated to evaluate the surgical efficacy. The χ² test was used for difference analysis. Results: Among the 151 patients, mandibular ORN caused by radiotherapy for nasopharyngeal carcinoma accounted for 79.5% (120/151). The average time for mandibular ORN appeared was 5(6) years after radiotherapy. Facial artery [57.2%(87/152)] and superior thyroid artery (50/152, 32.9%) were the main anastomotic arteries in the recipient area. There was no significant difference in the necrosis rates of the two flaps [10.3%(9/87) and 12.5%(5/50), respectively, P=0.949]. The main anastomotic veins in the recipient area were the external jugular vein [48.4%(135/279)] and the common facial vein [26.5%(74/279)]. Twenty-five cases (16.6%) had one vein anastomosed, and 126 cases (83.44%) had two veins anastomosed. There was no significant difference in the flap necrosis rate between the two conditions [20.0%(5/25) and 7.1%(9/126), respectively, P=0.100]. Ninety-seven cases (64.2%) used the peroneal musculocutaneous-fascia composite flap to repair the maxillofacial soft and hard tissue defects. Thirteen cases (8.6%) underwent the restorations with digital virtual surgery design, of which 5 cases were repaired with dental implants at the same time. After the operations, lower respiratory tract infection occurred in 17 patients (11.3%), and upper respiratory tract obstruction occurred in 3 cases (2.0%). The survival rate of the flap after operation was 90.7% (136/151), and 21 patients (13.9%) had flap vascular crisis. Delayed healing of maxillofacial wounds occurred in 33 cases (21.9%). After 3 to 24 months of follow-ups, 110 patients (76.9%) had no fistula inside/outside the oral cavity, 118 patients (82.5%) had an improvement in opening mouth of increasing (≥0.5 cm) after surgery, 135 patients (94.4%) had pain relief, 97 cases (67.8%) could eat normal diet, semi-liquid or soft food, and 137 cases (95.8%) were satisfied or basically satisfied with the treatment effects. Conclusions: The free fibular flap transplantation is an effective method to repair mandibular ORN defects. Preoperative vascular assessment is helpful for the selection of recipient vessels. Facial artery, superior thyroid artery, external jugular vein and common facial vein can be used as the main recipient vessels. The repair of the peroneal musculocutaneous-fascia composite flap facilitates the closure of internal and external fistulas. Digital technology can help to restore the maxillofacial shape more accurately, improve the patient's occlusal and chewing function and enhance the quality of life of mandibular ORN patients.

Monitoring oxidative stress, immune response, Nrf2/NF-κB signaling molecules of Rhynchocypris lagowski living in BFT system and exposed to waterborne ammonia

The present study was implemented to evaluate oxidative stress, immune response, Nrf2 and NF-κB signaling molecules related genes expression of Rhynchocypris lagowski living in biofloc technology (BFT) system and exposed to waterborne ammonia. According to the differences of C:N ratios, the experiment was divided into four groups: C:N 10.8:1 (control group), C:N 15:1, C:N 20: 1 and C:N 25:1. The results demonstrated that BFT can effectively regulate water quality and promote growth, and the C:N 20:1 group has the most significant effect (P < 0.05). Besides, significant increases in immune enzymes (lysozyme, complement C3, C4, immunoglobulin M and nitric oxide synthase) and anti-inflammatory factor (IL-2) activity of R. lagowski were emerged in the treatment C:N 20:1 after the 56-d growth experiment and the challenging trial (P < 0.05). Comparing the antioxidant status of R. lagowski in liver and gut before and after ammonia stress: superoxide dismutase, total antioxidant capacity and catalase activity in treatments C:N 20:1 were significant increased (P < 0.05), while the level of malondialdehyde was marked lower than that in control. Meanwhile, treatment C:N 20:1 considerably upregulated Nrf2 signaling molecules related genes and significantly down-regulated the expression of pro-inflammatory factor gene in NF-κB signaling pathway compared with the control (P < 0.05). These results indicated that BFT could enhance growth, antioxidant and immune response and regulate Nrf2 and NF-κB related genes expression in R. lagowski, with most excellent effects in fish given C:N 20:1 group.

Involvement of PKA signalling in anti-inflammatory effects of chitosan oligosaccharides in IPEC-J2 porcine epithelial cells

Weaning is characterized by intestinal inflammation, which is a big challenge in pig industry. Control of intestinal inflammation is important for improvement of growth performance and health. Therefore, the study was focused on the anti-inflammatory activity of low-molecular-weight chitosan oligosaccharide (LCOS) in a porcine small intestinal epithelial cell line (IPEC-J2). The results showed that TNF-α, as inflammation inducer, significantly upregulated the mRNA expression of IL-8 and MCP-1. Afterwards, LCOS significantly attenuated mRNA expression of IL-8 and MCP-1 induced by TNF-α in the cells. Mannose (MAN), as ligand of mannose receptor, had no effect on the anti-inflammatory activity of LCOS, which suggested that mannose receptor may not involve in the anti-inflammatory activity of LCOS in IPEC-J2 cells. Interestingly, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide 2HCl hydrate (H89), as PKA (protein kinase A)-specific inhibitor, reversed the mRNA expression of IL-8 when co-cultured with LCOS. Furthermore, LCOS concentration dependent downregulated the mRNA expression of claudin-1 compared with TNF-α treatment. However, the trans-epithelial electric resistance (TEER) was not affected by LCOS when co-cultured with TNF-α in 3 hr. In conclusion, LCOS have a potent anti-inflammatory activity, and as a feed additives, may be useful for the inhibition of inflammatory process in weaning period of pigs with intestinal inflammation occurring.

Benzoic acid beneficially affects growth performance of weaned pigs which was associated with changes in gut bacterial populations, morphology indices and growth factor gene expression

This study was conducted to investigate the effects of benzoic acid (BA) on growth performance, intestinal development and intestinal barrier function in weaned pigs. Ninety weaned pigs were randomly assigned to one of three treatments: a basal diet (CON), the basal diet supplemented with 2000 mg/kg benzoic acid (BA1) and 5000 mg/kg benzoic acid (BA2). At the end of days 14 and 42, six pigs per treatment were randomly selected to collect plasma and intestinal samples. Results showed that BA supplementation not only improved final body weight, daily growth and feed conversion ratio from days 15 to 42 and days 1 to 42, but also decreased the activity of plasma diamine oxidase (day 42) and the pH values of jejunal contents (day 14) (p < 0.05). Ileal Bacillus populations (day 14) were increased by BA, while Escherichia coli counts in the ileum and caecum (day 42) were decreased (p < 0.05). Higher Lactobacillus counts occurred in the ileum (day 14, 42) of BA1-fed piglets as compared to CON and BA2-fed piglets (p < 0.05). In addition, BA supplementation increased the ratio of villus height to crypt depth (day 14, 42) and decreased the crypt depth (day 14) (p < 0.05). Growth-stimulating factors (insulin-like growth factor-1, day 42; insulin-like growth factor-1 receptor, day 14, 42) and tight junction protein (occludin, day 14, 42; zonula occludens-1, day 42)-related gene mRNA levels were upregulated in the jejunum of piglets fed BA diets (p < 0.05). In conclusion, this study provides the first evidence that BA has beneficial effects on intestinal development and intestinal barrier function of weaned pigs, which can partly explain why growth performance of pigs was improved by dietary BA supplementation.

Systematic tracking of altered modules identifies disrupted pathways in teratozoospermia

The objective of this study was to identify disrupted pathways in teratozoospermia by systematically tracking dysregulated modules in reweighted protein-protein interaction (PPI) networks. We inferred and reweighted the PPI networks of normal and teratozoospermia groups based on Spearman correlation coefficients. Modules in the PPI networks were explored via a clique-merging algorithm and altered modules were identified based on maximum weight bipartite matching. Furthermore, pathway-enrichment analyses of genes in altered modules were performed by Database for Annotation, Visualization, and Integrated Discovery (DAVID) to illuminate the biological pathways in teratozoospermia. A total of 20,102 genes were screened from the expression profile. We explored 2406 and 2101 modules in normal and disease PPI networks, respectively. Moreover, we obtained 875 altered modules by comparing modules in normal and teratozoospermia PPI networks. At P < 0.01, the genes involved in 2855 interactions with score changes >1 were mainly enriched in 66 pathways and the genes in altered modules were enriched in 71 pathways. The activity genes (missed and added genes in the disrupted modules) were enriched in 41 common pathways. There were 36 mutual enriched pathways under the five different conditions. Moreover, the cell cycle pathway was disrupted in the first 10 pathways of each condition. This study provides a powerful biomarker discovery platform to better understand the progression of teratozoospermia by systematically tracking dysregulated modules. This method uncovered potential diagnostic and therapeutic targets of teratozoospermia. This information might lead to improved monitoring and treatment of teratozoospermia.

Transgenic Expression of Human IGF1 in Intervertebral Degenerative Discs

This study investigated the role of human insulin-like growth factor-1 (hIGF-1; encoded by the hIGF1 gene) on intervertebral disc degeneration. A total of 24 male New Zealand rabbits of an intervertebral disc degeneration (IVDD) model were randomly divided into three groups where the following were injected into the lumbar 4 – 5 and 5 – 6 discs: second generation adenovirus containing cytomegalovirus hIGF1 (Ad/CMV- hIGF1); 100 μg/l hIGF-1 protein; or phosphate-buffered saline. At 1, 2, 4 and 8 weeks post-injection, intervertebral disc samples were harvested. Human IGF-1 protein was detected using Western blot analysis, and aggrecan and collagen type II gene fragments were quantified using reverse transcription—polymerase chain reaction. At week 1 post-injection, hIGF-1 protein levels were similar in the Ad/CMV- hIGF1 and hIGF-1 groups. By week 2 the level had decreased substantially in the hIGF-1 group. At week 4 it was still present in the Ad/CMV- hIGF1 group and, by week 8, no protein was detected in any of the three groups. Aggrecan and collagen type II mRNA levels increased in the Ad/CMV- hIGF1 group 1 – 4 weeks post-injection, but declined by week 8, while both decreased steadily over 8 weeks in the other two groups. In conclusion, hIGF1 gene expression lasted for 4 weeks and stimulated the synthesis of aggrecan and collagen type II in the Ad/CMV- hIGF1 group.

Bimetallic structure fabricated by laser interference lithography for tuning surface plasmon resonance

Tuning of surface plasmon resonance by gold and silver bimetallic thin film and bimetallic dot array is investigated. Laser interference lithography is applied to fabricate the nanostructures. A bimetallic dot structure is obtained by a lift-off procedure after gold and silver thin film deposition by an electron beam evaporator. Surface plasmon behaviors of these films and nanostructures are studied using UV-Vis spectroscopy. It is observed that for gold thin film on quartz substrate, the optical spectral peak is blue shifted when a silver thin film is coated over it. Compared to the plasmon band in single metal gold dot array, the bimetallic nanodot array shows a similar blue shift in its spectral peak. These shifts are both attributed to the interaction between gold and silver atoms. Electromagnetic interaction between gold and silver nanostructures is discussed using a simplified spring model.

TECA hybrid artificial liver support system in treatment of acute liver failure

AIM: To assess the efficacy and safety of TECA type hybr id artificial liver support system (TECA-HALSS) in providing liver function of detoxification, metabolism and physiology by treating the patients with acute liv er failure (ALF).

METHODS: The porcine liver cells (1-2) × 10¹⁰ were separated from the Chinese small swine and cultured in the bioreactor of TECA-BALSS at 37.0 °C and circulated through the outer space of the hollow fiber tubes in BALSS. The six liver failure patients with various degree of hepatic coma were treated by TECA-HALSS and with conventional medicines. The venous plasma of the patients was separated by a plasma separator and treated by charcoal adsorbent or plasma exchange. The plasma circulated through the inner space of the hollow fiber tubes of BALSS and mixed with the patients’ blood cells and flew back to their blood circulation. Some small molecular weight substances were exchanged between the plasma and porcine liver cells. Each treatment lasted 6.0-7.0 h. Physiological and biochemical parameters were measured before, during and after the treatment.

RESULTS: The average of porcine liver cells was (1.0-3.0) × 10¹⁰ obtained from each swine liver using our modified enzymatic digestion method. The survival rate of the cells was 85%-93% by trypan blue stain and AO/PI fluorescent stain. After cultured in TECA-BALSS bioreactor for 6 h, the survival rate of cells still remained 70%-85%. At the end of TECA-HALSS treatment, the levels of plasma NH₃, ALT, TB and DB were significantly decreased. The patients who were in the state of drowsiness or coma before the treatment improved their appetite significantly and regained consciousness, some patients resumed light physical work on a short period after the treatment. One to two days after the treatment, the ratio of PTA increased warkedly. During the treatment, the heart rates, blood pressure, respiration condition and serum electrolytes (K⁺, Na⁺ and Cl^-) were stable without thrombosis and bleeding in all the six patients.

CONCLUSION: TECA-HALSS treatment could be a rapid, safe and efficacious method to provide temporary liver support for patients with ALF.

Experimental research on TECA-I bioartificial liver support system to treat canines with acute liver failure

AIM: To evaluate the efficacy and safety of the TECA-I bioartificial liver support system (BALSS) in treating canines with acute liver failure (ALF).

METHODS: Ten canines with ALF induced by 80% liver resection received BALSS treatment (BALSS group). Blood was perfused through a hollow fiber tube containing 1 × 10¹⁰ porcine hepatocytes. Four canines with ALF were treated with BALSS without porcine hepatocytes (control group), and five canines with ALF received drug treatment (drug group). Each treatment lasted 6 h.

RESULTS: BALSS treatment yielded beneficial effects for partial liver resection-induced ALF canines with survival and decreased plasma ammonia, ALT, AST and BIL. There was an obvious decrease in PT level and increase in PA level, and there were no changes in the count of lymphocytes, immunoglobulins (IgA, IgG and IgM) and complement (C3 and C4) levels after BALSS treatment. In contrast, for the canines with ALF in non-hepatocyte BALSS group (control group) and drug group, there were no significant changes in ammonia, ALT, AST, BIL, PT and PA levels. ALF canines in BALSS group, control group and drug group lived respectively an average time of 108.0 h ± 12.0 h, 24.0 h ± 6.0 h and 20.4 h ± 6.4 h, and three canines with ALF survived in BALSS group.

CONCLUSION: TECA-I BALSS is efficacious and safe for ALF canines induced by parcial liver resection.

Methylation of histone H4 at arginine 3 facilitating transcriptional activation by nuclear hormone receptor

Acetylation of core histone tails plays a fundamental role in transcription regulation. In addition to acetylation, other posttranslational modifications, such as phosphorylation and methylation, occur in core histone tails. Here, we report the purification, molecular identification, and functional characterization of a histone H4-specific methyltransferase PRMT1, a protein arginine methyltransferase. PRMT1 specifically methylates arginine 3 (Arg 3) of H4 in vitro and in vivo. Methylation of Arg 3 by PRMT1 facilitates subsequent acetylation of H4 tails by p300. However, acetylation of H4 inhibits its methylation by PRMT1. Most important, a mutation in the S-adenosyl-l-methionine-binding site of PRMT1 substantially crippled its nuclear receptor coactivator activity. Our finding reveals Arg 3 of H4 as a novel methylation site by PRMT1 and indicates that Arg 3 methylation plays an important role in transcriptional regulation.

[Determination of organophosphorus pesticide multi-residues in tea by gas chromatography]

An efficient gas chromatographic method for the determination of 14 organophosphorus pesticide residues in tea by gas chromatography using micro-chemical and solid phase extraction technique has been established. The organophosphorus pesticides were extracted from tea samples with ethyl acetate and mixture of ethyl acetate-hexane(1:1, V/V). The extracts were cleaned up with a column of 3 mL Supelclean Envl-carb by GILSON ASPEC XL. The 14 organophosphorus pesticides were separated from each other through SPB-1701 capillary column(30 m x 0.53 mm i.d. x 1.0 micron) and determined by flame photometric detector. The recoveries ranged 70.8%-120% when the added levels were from 0.100 mg/kg to 1.00 mg/kg, the RSD was 2%-7% and the limits of detection were 0.01 mg/kg-0.08 mg/kg. This method is rapid, sensitive and suitable for the analysis of pesticide residues. It can also be applied to the determination of organophosphorus pesticide multi-residues in other plant samples such as vegetables, fruits and so on.

Apoptosis induced by 5-flucytosine in human pancreatic cancer cells genetically modified to express cytosine deaminase

AIM

To elucidate the pattern of 5-flucytosine (5-FC)-induced apoptosis and its role in gene therapy of human pancreatic cancer.

METHODS

The human pancreatic cancer SW1990 cells (CEA-producing) were infected with recombinant adenoviruses (Adex1CEA-prCD or Adex1CEA-prZ). Expression of CD gene protein was examined by western blot. Apoptosis induced by 5-FC in human pancreatic cancer SW1990 cells genetically modified to express cytosine deaminase was observed by means of electron microscopy, DNA electrophoresis, and flow cytometry analysis techniques.

RESULTS

The SW1990 cells infected with Adex1CEA-prCD were treated with 5-FC at 100 mumol.L-1 for 48 h, and cell apoptosis was observed. Typical apoptosis morphological feature appeared and DNA ladder could be demonstrated on DNA electrophoresis. Apoptosis peak was also showed by flow cytometry. Apoptotic cells accounted for 34.6% of the cell population. Cells in G1, S, and G2/M phase of cell cycle were 64%, 11%, and 7%, respectively.

CONCLUSION

The apoptosis induced by 5-FC may be a primary mechanism in CD gene therapy of pancreatic cancer.

Preclinical studies of allograft tolerance in rhesus monkeys: a novel anti-CD3-immunotoxin given peritransplant with donor bone marrow induces operational tolerance to kidney allografts

A major challenge in clinical transplantation today is to design a practical and effective protocol for tolerance induction compatible with cadaver organ transplantation. A preclinical rhesus monkey kidney allograft model using immediate peritransplant anti-CD3 immunotoxin (anti-CD3-IT) and donor bone marrow (DBM) is shown here to induce operational tolerance with prolonged graft survival in the absence of chronic immunosuppressive drugs. Bone marrow harvested from the kidney donor was depleted of mature alloantigen-presenting cells and T cells by removing DR(bright) cells and CD3(bright) cells, respectively. In outbred, major histocompatibility complex-incompatible donor-recipient pairs with high pretransplant mixed lymphocyte response and cytotoxic T lymphocyte precursor activity, four of six allografts survived for periods of 120 days to >1.5 years. Graft acceptance after peritransplant treatment followed robust elimination of both peripheral blood T cells and lymph node T cells. In most recipients given anti-CD3-IT and DBM infusion, anti-donor immunoglobulin G responses were completely inhibited. Microchimerism was observed in all recipients studied, including those not given DBM, but levels of microchimerism did not correlate with graft survival. Anti-CD3-IT induction in combination with modified DBM protocols such as the depletion of mature T cells and DR(bright) antigen-presenting cells may offer new opportunities to improve clinical tolerance protocols beyond those attempted in the clinic to date. Overall, these results with anti-CD3-IT show promise for development of cadaver transplant tolerance induction.

Localization of a single binding site for immunoglobulin light chains on human Tamm-Horsfall glycoprotein

Cast nephropathy is a severe complication of multiple myeloma. Binding of filtered monoclonal light chains (LC) with Tamm-Horsfall glycoprotein (THP) triggers heterotypic aggregation of these two proteins to form casts in the distal nephron of the kidney. To localize the LC binding site on THP, human THP was deglycosylated and underwent limited trypsin digestion in the presence or absence of a nephrotoxic LC known to bind THP. A 29.6-kD band was protected from trypsin digestion by the addition of LC. NH2-terminal amino acid sequence and amino acid analyses revealed this band was located between the 6th and 287th amino acid residues of THP. Six peptides located within this 29.6-kD fragment were synthesized and used as potential inhibitors of binding or aggregation of five different nephrotoxic LCs with THP. Peptide AHWSGHCCL (from amino acid 225 to 233) completely inhibited binding and aggregation of these proteins. Optimal inhibition required a cystine residue in this peptide. Truncation experiments demonstrated the entire sequence was necessary for ideal inhibition and the histidine residue explained the effects of pH on binding. These studies provided a basis for further study of LC-THP interaction and a potential approach toward the prevention of cast nephropathy.

[Effect of hemin in treating hemorrhagic anemia and toxicity]

AIM

To study the effect of hemin in treating hemorrhagic anemia and toxicity.

METHODS

Fifty rats with hemorrhagic anemia were randomly divided into 5 groups with different dosage of hemin (93, 168, 300 mg.kg-1.d-1), ferrous gluconate (FG 300 mg.kg-1.d-1), and water, ig for 7 d. Twenty mice fed with hemin (6.0 g.kg-1.d-1) in 24 h for observing acute toxicity effects. Long-term toxicity were observed in 80 rats given hemin (0.65, 1.3, 2.6 g.kg-1.d-1) in 3 months.

RESULTS

Hb of the rats of corresponding groups were 66-->121, 71-->141, 66-->148, 69-->140, and 67-->112 g.L-1. There were no adverse effects observed on acute toxicity test. No abnormalitis were found in hemogram, liver renal function test, and autopsy.

CONCLUSION

Hemin had a better effect than FG and no adverse effect was found in hemin.

Biochemical interaction between Tamm-Horsfall glycoprotein and Ig light chains in the pathogenesis of cast nephropathy

BACKGROUND

Cast nephropathy in multiple myeloma patients is caused by heterotypic aggregation of Tamm-Horsfall glycoprotein (THP) with monoclonal light chains (Bence Jones protein, BJP). Co-aggregation of these proteins is triggered by the binding of BJP to a specific peptide portion of THP. Defining those factors that alter the interaction between BJP and THP may help to understand further the pathogenesis of cast nephropathy and serve to decrease the morbidity and mortality of cast nephropathy. We hypothesized that pH, calcium, furosemide, and the carbohydrate moiety of THP all modulate the protein-protein interaction between BJP and THP.

EXPERIMENTAL DESIGN

Binding affinity and aggregation rate of human THP with two human nephrotoxic BJP were tested at pH 8.5, 7.4, and 5.0. The effects of calcium, furosemide, and free sialic acid were also evaluated. Binding and aggregation of BJP with THP purified from normal volunteers treated with oral colchicine were observed. The carbohydrate components of THP were also analyzed.

RESULTS

An acidic environment increased initial binding rate and produced a parallel increase in the aggregation rate of THP with BJP. Calcium and furosemide enhanced aggregation rates without interfering with binding. Colchicine treatment decreased the amount of sialic acid linked alpha(2-6) to galactose (NeuAc alpha 2-6Gal) and sialic acid linked alpha(2-3) to galactose (NeuAc alpha 2-3Gal) on THP and thereby decreased the aggregation rate with BJP without altering binding. Addition of free sialic acid did not alter binding but did decrease aggregation rates of the two proteins.

CONCLUSIONS

Environmental conditions modulate BJP-THP interactions and may be responsible for inducing case nephropathy in multiple myeloma. Modification of carbohydrate components of THP or use of oligosaccharides may decrease or prevent cast nephropathy.

Pathogenesis of glomerulosclerosis in light chain deposition disease. Role for transforming growth factor-beta

The glomerulopathy of monoclonal immunoglobulin light chain deposition disease is a progressive disorder characterized by accumulation of monoclonal light chains and matrix proteins in the mesangium. To define the role of light chains in this process, cultured rat mesangial cells were exposed to different light chains and human albumin. Two light chains were purified from the urine of patients who had biopsy-proven light chain deposition disease. These proteins inhibited mesangial cell proliferation and increased production of matrix proteins, including type IV collagen, laminin, and fibronectin. By immunocytochemistry and bioassay, transforming growth factor-beta (TGF-beta) production and activity increased when mesangial cells were exposed to these proteins. Furthermore, anti-TGF-beta antibody abolished the inhibition of cell proliferation and the increase of extracellular matrix protein production caused by these light chains. These findings were not observed in mesangial cells exposed to human albumin and two other light chains previously characterized to be tubulopathic. We concluded that the glomerulopathic light chains increased TGF-beta, which inhibited mesangial cell proliferation and increased matrix protein production. Together with overexpression of TGF-beta in affected glomeruli of light chain deposition disease, light chain-mediated stimulation of mesangial cells to produce TGF-beta appears to be a key pathological mechanism of this disease.

[Effect of Astragalus membranaceus on T-lymphocyte subsets in patients with viral myocarditis]

The efficacy of Astragalus membranaceus (AM) oral liquor combined with routine therapy and routine therapy alone on T-lymphocyte subsets of peripheral blood in viral myocarditis patients have been studied. The results showed that the T-lymphocyte subsets profile and OKT4/OKT8 ratio of peripheral blood were significantly lower in viral myocarditis patients than that in healthy control (P < 0.05, 0.01). Routine therapy combined with AM could significantly enhance OKT3, OKT4 and OKT4/OKT8 ratio in the above-mentioned patients (P < 0.05, 0.01). The possible pharmacodynamic mechanism of improved cell immunity in viral myocarditis patients by combining routine therapy with AM was discussed.

[Effects of selective hepatic duct embolization on normal, cirrhotic livers and hepatocellular carcinomas]

Variant gross and pathology features were observed on effects of selective hepatic duct embolization (SHDE) in contrast to selective hepatic duct ligation (SHDL). Glue TH was used in SHDE that performed on normal liver, induced cirrhotic liver and hepatocellular, carcinoma. The results demonstrated that SHDL has weak effected, while SHDE causes the embolized liver lobes to acute ischemic necrosis, followed by atrophy and fibrosis, accompanied by quickly hypertrophy of the uninvolved lobes. All tumors on the embolized liver lobes also showed acute tumors on the embolized liver lobes also showed acute tumor ischemic necrosis, atrophy and fibrosis. The reason for the above variations is that pressure and tension of SHDE expand the embolized bile duct tree, especially the Hering duct, which will continuously obstruct the dual blood supply to the liver tumor. Effectively and thoroughly annihilating or restricting the tumor, SHDE may lead the tumors to "spontaneous excision", with the unoperated lobes hypertrophy to compensate liver functions simultaneously. These studies indicated that SHDE will be a new method in liver cancer clinic.

[Antitumor activity of thevetoside alone and in combination with chlormethine in vivo]

Thevetoside (TS) is one of the cardiac glycosides. A study of antitumor activity was carried out in 6 types of murine tumors in vivo, such as the ascitic tumors H22, EAC, P388, and solid tumors S180, U14, Lewis lung carcinoma, which were treated with i.p. TS 1.5 mg.kg-1.d-1 alone or in combination with chlormethine (Chl) 0.3, 0.5, or 1.0 mg.kg-1.d-1. TS only showed a remarkable inhibition on the growth of 3 types of solid tumors with inhibition rates of 48.7%-56.7%. The effect of the combination therapy was much pronounced than that of independent administration. The life span under combined therapy was increased 82.4% to > 122.1%. For solid tumors, the combined administration gave inhibition rates of 65.6%-72.5%.

Bence Jones proteins bind to a common peptide segment of Tamm-Horsfall glycoprotein to promote heterotypic aggregation

Bence Jones proteins (BJPs) are the major pathogenic factor causing cast nephropathy ("myeloma kidney") by coaggregation with Tamm-Horsfall glycoprotein (THP). Understanding the interaction between these proteins is therefore important in developing treatment strategies to prevent renal failure from cast formation in multiple myeloma. We developed an enzyme-linked immunoassay to examine this phenomenon. Five different human BJPs (four kappa and one lambda immunoglobulin light chains) were used in this assay that demonstrated these proteins bound THP with different affinity. BJPs competed among themselves for binding to THP. The binding site was a peptide portion of THP since these proteins also bound deglycosylated THP. Also, one monoclonal antibody directed against a peptide segment of human THP prevented binding of THP to BJPs. By altering the conformation of THP, reducing agents decreased binding between these two proteins in concentration-dependent fashion. In turbidity studies, the monoclonal antibody that prevented binding and a reducing agent, dithiothreitol, decreased coaggregation. Deglycosylated THP did not coaggregate with BJPs. We concluded that ionic interaction between BJPs and a specific peptide binding site on THP promoted heterotypic coaggregation. The carbohydrate moiety of THP was also essential for coaggregation, perhaps by facilitating homotypic aggregation of THP.

Surgical treatment of hilar bile duct carcinoma. Clinical and pathological studies

Resection of the extrahepatic bile tract for hilar bile duct carcinoma was performed at the PLA General Hospital, with a resectability rate of 62% (31/50) and no operative mortality. Hepatic lobectomy was performed at the same time in 16 cases (51.6%). Reoperative resections were successfully done in 5 cases; 4 cases are still living 1-4 years after the second operation. The cause of late death was mainly biliary infection due to local recurrence and bile duct obstruction. The median survival period was 15 months. 32 cases were studied pathologically, of which 27 were resected surgical specimens and 5 autopsies. The tumors were histologically classified into 4 types: papillary adenocarcinoma (6 cases); well differentiated adenocarcinoma (21); poorly differentiated adenocarcinoma (3); and simple carcinoma (2). The importance of early diagnosis of hilar bile duct carcinoma at its subclinical stage before appearance of clinical jaundice is stressed.

[Research of the relation between the type of asthenia of the spleen and kidney and platelet associated antibodies and T-lymphocyte subsets in idiopathic thrombocytopenic purpura]

Idiopathic thrombocytopenic purpura (ITP) is a kind of disease associated with immunity. At present a great quantity of study on ITP has been made on humoral and cellular immunity. But there are few reports about the relationship between the types based on the differential diagnosis of TCM and immune rationale of ITP. In order to deeply explore the relationship between the types based on differential diagnosis of TCM and immune rationale of ITP., the authors measured PAIg and T lymphocyte subsets of 34 ITP patients of asthenia of both Spleen and Kidney. The value of PAIgG increased in both types of Spleen failing to control blood (SFCB) and deficiency of Spleen-yin and Kidney -yin (DSYKY), and the value of PAIgG of the type of DSYKY was significantly higher than that of SFCB (P less than 0.01). OKT3, OKT4/OKT8 of the type of SFCB remarkably decreased (P less than 0.05), OKT4, OKT4/OKT8 of DSYKY also remarkably decreased (P less than 0.001), while OKT8 significantly increased (P less than 0.001). The above results suggested that the type of DSYKY has more serious immune dysfunction than the type of SFCB, and the types of SFCB and DSYKY has close relationship with PAIg T lymphocyte subsets.

Parallel stranded DNA under the scanning tunnelling microscope

Using scanning tunnelling microscopy, we have directly observed parallel stranded DNA helixes of 43 nucleotides in length. The double helix is right-handed and has an average spacing, 17.43 A (+/- 1 S.D.: 2.30 A), and an average apparent depth, 4.79 A (+/- 1 S.D.: 1.04 A) for each groove. The average pitch of the helical turn is 34 A (+/- 1 S.D.: 3.35 A) and consists of no more than ten base pairs. The diameter of the helix is approx. 17-20 A. Our results provide direct evidence for the existence of a parallel structure of DNA in vitro and some details of its fine structure.

Treatment of hypercholesterolemia: comparison of younger versus older patients using wax-matrix sustained-release niacin

OBJECTIVE

Compare lipid response, side effect profile and toxicity of younger (less than 50 years) versus older (50 to 70 years) hypercholesterolemic subjects taking wax-matrix sustained-release niacin (Endur-acin).

STUDY DESIGN

An 8-week randomized double-blind placebo controlled trial.

SETTING

General community.

PARTICIPANTS

Volunteers from community cholesterol screening programs and chart review of patients at family practice clinics. Male and female subjects, age 20 to 70, with baseline low density lipoprotein cholesterol level within the 75th to 95th percentile, excluded if on medications that affect lipids or if a history of diabetes, gout, peptic disease, or liver disease is present.

INTERVENTION

Nicotinic acid dosage schedules were 1,000 mg/day, 1,250 mg/day, 1,500 mg/day, or 2,000 mg/day for 8 weeks.

MAIN OUTCOME MEASURES

Change in blood lipids and blood chemistries, side effects, and pill compliance.

RESULTS

158 subjects (79%) completed the study. Higher dose groups (1,500 mg and 2,000 mg) demonstrated improvements in total cholesterol, LDL-cholesterol, HDL cholesterol, and total-to-HDL-cholesterol ratio (P less than 0.05) compared to baseline and controls. Higher-dose older subjects demonstrated significantly greater improvements than younger subjects on comparable doses for total cholesterol, HDL cholesterol, total-to-HDL-cholesterol ratio, and triglycerides, P less than 0.02). Adherence to medication schedules was better and incidence of side effects and toxicity no greater in older subjects compared to younger.

CONCLUSION

Wax-matrix niacin (Endur-acin) was shown to be effective and well tolerated for the pharmacological treatment of hypercholesterolemia. Older persons, ages 50 to 70, appear to experience greater benefits with no greater side effects when compared to younger subjects on similar doses.

[Risk factors of acute pancreatitis]

A total of 689 operative cases of acute necrotic pancreatitis (ANP) were collected from 42 hospitals all over the country by the ANP Cooperative Study Group in the years of 1987 to 1989. General data, laboratory findings, pathology of the pancreas and the type of surgical treatment were analysed according to the outcome of the patient. The results showed that 37% of the cases were related to cholelithiasis, the highest incidence was in age above 60, and female patients were predominant and with higher mortality. Laboratory findings at admission, WBC greater than 20,000/mm3, Hb greater than 15 g%, blood sugar greater than 200 mg%, serum bilirubin greater than 5 mg%, BUN greater than 20 mg%, and serum calcium less than 7 mg% were related to the markedly elevated mortality rate. Operative findings noted in patients with bloody or cloudy peritoneal fluid, necrotic changes up to 75% of the pancreas, more than 2 areas of extrapancreatic involvements and resection of a large portion of the pancreas was found to be necessary were all related to a higher mortality. And emergency operations performed within 24 hours after the onset of the disease was also related with a highest mortality rate.

Niacin revisited. A randomized, controlled trial of wax-matrix sustained-release niacin in hypercholesterolemia

Two hundred one male and female subjects, aged 20 to 70 years, with elevated low-density lipoprotein cholesterol values (in the 75th to 95th percentiles), participated in a randomized, controlled, double-blind study using a new form of niacin (Enduracin), which employs a wax-matrix vehicle for sustained release. Four niacin treatment groups (daily doses of 2000, 1500, 1250, and 1000 mg) were compared with placebo- and diet-treated controls to determine side-effect profile and optimal range of efficacy. The groups given 2000 and 1500 mg demonstrated significant reductions in values of low-density lipoprotein cholesterol (-26% and -19.3%, respectively), total cholesterol (-18.4% and -13.3%), and total cholesterol-high-density lipoprotein cholesterol ratio (-20.4% and -19.4%) when compared with diet- and placebo-treated controls. Smaller improvements were seen in high-density lipoprotein cholesterol and triglyceride levels. Blood chemistry monitoring indicated that reduction in low-density lipoprotein cholesterol level strongly correlated with an increase in baseline levels of some enzymes for niacin-treated subjects. The improved side-effect profile of the wax-matrix form of niacin was particularly notable. The dropout rate due to side effects was only 3.4% and was coupled with good medication compliance.

[In vitro effect of shen-xue-ling on megakaryocytopoiesis in patients with idiopathic thrombocytopenic purpura]

This paper, used an improved methylcellulose-agar double layer method in vitro to culture megakaryocyte progenitors (CFU-meg) of 15 normal bone marrow donors and 20 idiopathic thrombocytopenic purpura (ITP) patients bone marrow cells in order to observe the action of Shen-Xue-Ling (SXL). The results showed that the colony efficiency of CFU-meg of ITP group (13.75 +/- 6.93/10(5) MNC) was obviously lower than that of the control group (21.22 +/- 9.06/10(3) MNC, P less than 0.01). The serum of the patients whose PAIgG was markedly higher than normal value inhibited growth of CFU.meg derived from normal bone marrow cells (P less than 0.01). SXL could increase the colony efficiency of CFU-meg for ITP patients at several doses. The average colonies were 15.77 +/- 6.31/10(5) MNC (at 100 mg/ml, P greater than 0.05), 18.72 +/- 5.54/10(5) MNC (at 200 mg/ml, P less than 0.05), 21.60 +/- 7.35/10(5) MNC (at 300 mg/ml, P less than 0.01) and 21.84 +/- 7.15/10(5) MNC (at 500 mg/ml, P less than 0.01) as compared with the group of ITP patients. Incubated with patient's serum (1%) and SXL (at 300 mg/ml), the number of CFU-meg extracted from normal bone marrow cells was significantly higher than that from patients (P less than 0.01) and was close to normal group (P greater than 0.05). The results suggested that SXL might inhibit the antiplatelet antibodies, facilitate reproduction, division and maturity of CFU-meg.

[Surgical treatment of hilar bile duct carcinoma]

Carcinoma of the bile duct at the hepatic hilar region is not a rare condition but with a low resectability rate. The incidence of this disease seems to be on increasing. In a previous report, 60 cases were explored surgically from 1975 to 1985, but resection was only possible in 5 cases (9.1%); while in the recent years from June, 1986 to June 1989, 24 cases were explored in the Surgical Department of General Hospital of PLA, 16 cases were resected, with a resectability rate of 66%. The increase of resectability rate was due to earlier recognition of this condition and the extension of surgery, including major resection of liver as well as radical dissection of the hepato-duodenal ligament and reparative operations on the blood vessels. Among these 16 cases, major hepatic resection was performed in 10 cases, in which, 3 cases of resections of the middle lobe of the liver were done instead of right or extended right lobectomy. No operative mortality in the 30 days' postoperative period, but the postoperative morbidity rate was still high and most of the complications were related to biliary leakage and infect ion. Three patients died in the postoperative follow up period at 6.14 and 15 months respectively. All of them died from biliary infection. The remaining 13 patients were still living, the longest being 40 months and the average living time was 16.1 months. Probably, lowering of the operative mortality rate and morbidity rate are still the most important considerations in the surgical treatment of hilar carcinoma at the present time.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of the pineal body and melatonin on sensitivity to pain in mice]

Sensitivity to painful stimuli was measured by hot plate, writhing tests and electric caudal stimulation in mice. The mice were kept under light-dark 12/12 cycle with light out at 18:00 for at least 2 wk. Both basal analgesia and meperidine (pethidine)-induced analgesic effect exhibited parallel circadian rhythms, with the marked peak and through occurring at mid-dark and mid-light phases, respectively. The day-night differences in pain threshold 10 d after pinealectomy were not evident, especially in the loss of dark time augmentation of analgesic responses, but persisted in sham operated mice. Melatonin (MT) 50-200 mg/kg ip during light phase produced analgesic activity. MT 250 mg/kg ip resulted in a loss of the righting reflex. In pinealectomized mice, the pre-treatment of MT 5 mg/kg potentiated levels of analgesia induced by meperidine 10 mg/kg or morphine 5 mg/kg. It is possible that MT is one of the endogenous nocifensor inhibitors in CNS.

Observation of molecular vibrations in the time domain with incoherent laser pulses

With the method of self-diffraction of incoherent light, molecular vibrations were observed in real time in various dye molecules pumped near the absorption edge. In Rhodamine 560, 35-fsec oscillations in the signal were measured, which corresponds to a vibrational frequency of 1000 cm(-1). Simultaneously, this technique can be used to deduce the ultrafast dephasing times in the molecular vibrational quasi-continuum. Dephasing times of 20 and 150 fsec were observed in Rhodamine 590 and Rhodamine 560, respectively.

[Effect of triptolide on cytokinetics of HeLa cells]

The cytostatic effects of triptolide on HeLa cells in different proliferation stages and cell cycle phases were studied by colony-forming units assay. An exposure of exponential-phase cells to triptolide 0.02-4.00 micrograms/ml for 0.5 h resulted in a biphasic-exponential dose-survival curve (n = 1, D0 = 0.3 micrograms/ml in the most sensitive population; D0 = 2.8 micrograms/ml in the more resistant population). The plateau-phase cells in the same conditions seemed to have lower sensitivity to the drug. The synchronized cells caused by excess TdR double block and the selective detachment of mitotic cells from monolayer were exposed to triptolide 0.06 micrograms/ml for 0.5 h. The sensitivity of cell cycle phases to the drug ranked as follows: S greater than G2, M greater than G1. The result showed that triptolide is one of the cell cycle phase non-specific agents, but more sensitive to S phase cells.