Effects of artificial liver support system on patients with acute or chronic liver failure

AIMS

Acute on chronic liver failure (AoCLF) is associated with a high mortality rate. Artificial liver support system (ALSS) is useful to bridge patients with liver failure to liver transplantation or to regenerate their own livers. The aims of this prospective study were to investigate the effects of ALSS on clinical manifestations, liver function, and 30-day survival to probe the factors related to mortality in patients with AoCLF.

METHODS

In this study, 338 enrolled patients with AoCLF who received ALSS treatment for 1 to 8 sessions, were compared with 312 patients treated with conventional medications.

RESULTS

Clinical manifestations and liver functions were significantly improved, namely, decreased levels of serum transaminases, total bilirubin, and bile acid, as well as increased levels of serum albumin following ALSS treatment. The 30-day survival rates of the patients who received ALSS versus controls were 47.9% versus 34.6%, respectively (P = .01). The MELD score and the stage of hepatic encephalopathy were highly associated with mortality (P < .001), but the sessions of ALSS showed a positive relation to the 30-day survival (P < .05).

CONCLUSIONS

ALSS appears to be efficacious and safe for the treatment of patients with AoCLF. Both model for end-stage liver disease (MELD) score and hepatic encephalopathy are useful to predict the mortality of patients.

Chalcones: an update on cytotoxic and chemoprotective properties

Chalcone is a unique template that is associated with several biological activities. In this review, an update of the cytotoxic and chemoprotective activities of chalcones is provided. Cytotoxicity against tumour cell lines may be the result of disruption of the cell cycle, inhibition of angiogenesis, interference with p53-MDM2 interaction, mitochondrial uncoupling or induction of apoptosis. Structural requirements for cytotoxic activity vary according to the mechanisms of action. For anti-mitotic activity, the presence of methoxy substituents, alpha-methylation of the enone moiety and the presence of 2' oxygenated substituents are favourable features. Conformational restraint of the chalcone template generally leads to a decrease in cytotoxic activity. Chemoprotection by chalcones may be a consequence of their antioxidant properties, mediated via inhibition or induction of metabolic enzymes, by an anti-invasive effect or a reduction in nitric oxide production. Hydroxyl and prenyl substituents are associated with antioxidant properties and induction of quinone reductase activities. The thiol reactivity of chalcones is likely to contribute to both cytotoxic and chemoprotective properties of these compounds.

Biodegradation and detoxification of nicotine in tobacco solid waste by a Pseudomonas sp

A Pseudomonas sp. grew with nicotine optimally 3 g l(-1) and at 30 degrees C and pH 7. Nicotine was fully degraded within 10 h. The resting cells degraded nicotine in tobacco solid waste completely within 6 h in 0.02 m sodium phosphate buffer (pH 7) at maximally 56 mg nicotine h(-1) g dry cell(-1).

Oestrogen influence on myogenic satellite cells following downhill running in male rats: a preliminary study

AIM

This study examined the effect of oestrogen supplementation in rats on myogenic satellite cell quantities in type I and II muscles following eccentric exercise.

METHODS

Gonad intact adult male rats divided into four groups, oestrogen supplemented (25 mg oestrogen pellet) control (EC), oestrogen supplemented, exercised (EE), sham (no oestrogen) control (SC) and sham, exercised (SE). After 1 week of oestrogen exposure the EE and SE animals performed 90 min of intermittent downhill running (5 min running/2 min rest @-13.5 degrees incline and 17 m min(-1) speed). Seventy-two hours later exercised (EE and SE) and control (EC and SC) animals were killed and blood samples taken and soleus and white (superficial) vastus muscles surgically removed. Histochemical sections of soleus and white vastus muscles were examined for myogenic satellite cell content by use of Pax7 antibody and for neutrophil content by use of haematoxylin and eosin (H and E) staining procedures.

RESULTS

Downhill running resulted in significant elevations in satellite cells and neutrophils detected in both soleus and white vastus muscle samples (P < 0.01). Interestingly, oestrogen supplementation resulted in significantly greater (P < 0.01) post-exercise elevations in satellite cells detected in both soleus and white vastus muscle samples compared with sham (no oestrogen) rats. Increases in neutrophils were significantly (P < 0.05) attenuated in oestrogen supplemented rats relative to sham in soleus but not in white vastus muscles.

CONCLUSIONS

Oestrogen supplementation in male rats may have accentuated the 72 h post-downhill running increase in Pax7 detected myogenic satellite cell number in both soleus and white vastus muscles relative to unsupplemented rats. The mechanisms and physiological consequences of this effect are yet to be determined.

Electron microscopic studies on the occurrence of activated neutrophils in peripheral blood of children with acute leukemias

Peripheral blood (PB) cells are examined to assess cellular maturity and the degree of bone marrow abnormality in children with acute leukemias. During the ultrastructural assessments of PB cells in these children, we noted a frequent occurrence of activated neutrophils. This phenomenon had not been reported previously. We here report for the first time the identification of activated neutrophils in PB of children with acute leukemias. To examine the impact of activated neutrophils, we compared two groups of children including 18 with acute lymphoblastic leukemia (ALL) and 7 with acute myelogenous leukemia (AML) by an ultrastructural leukocyte count method. Many cases (50%) showed more than 30% activated neutrophils per total neutrophil count in PB. Activated neutrophils were elongated or amoeboid-shaped cells ranging from 13-18 microns in greater diameter with a decreased number of granules in the cytoplasm. A significantly higher rate of activated neutrophils was observed in ALL as compared with AML (median: 42.97% vs. 10.64%). Non-leukemic hospitalized (n =3) and healthy (n = 3) control cases showed a median rate of 3.32% activated neutrophils in PB. These findings reveal that a significantly high rate of activated neutrophils occurs in PB of children with ALL which may be exploited in the diagnostic assessment of children with acute leukemias.

Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China

A novel coronavirus (SCoV) is the etiological agent of severe acute respiratory syndrome (SARS). SCoV-like viruses were isolated from Himalayan palm civets found in a live-animal market in Guangdong, China. Evidence of virus infection was also detected in other animals (including a raccoon dog, Nyctereutes procyonoides) and in humans working at the same market. All the animal isolates retain a 29-nucleotide sequence that is not found in most human isolates. The detection of SCoV-like viruses in small, live wild mammals in a retail market indicates a route of interspecies transmission, although the natural reservoir is not known.

Differences in cerebral reperfusion and oxidative injury after cardiac arrest in pigs

BACKGROUND

An investigation of the free radical scavenger sodium 2-sulfophenyl-N-tert-butyl nitrone (S-PBN) and the weak vasodilatator Tris buffer mixture (TBM) on cerebral cortical blood flow (CCBF) and the jugular bulb concentration of two eicosanoids, indicators of oxidative stress and inflammation, was undertaken in 30 anaesthetized piglets during cardiopulmonary resuscitation (CPR) and after restoration of spontaneous circulation (ROSC).

METHODS

Thirty animals were subjected to 8 min of untreated circulatory arrest followed by 8 min of closed-chest CPR. During CPR, the animals were randomized to receive 60 mg/kg S-PBN, 1 mmol/kg TBM or 2 ml/kg normal saline (n = 10 in each group). Systemic haemodynamic variables, CCBF and jugular bulb plasma concentrations of 8-iso-PGF2alpha and 15-keto-dihydro-PGF2alpha were measured.

RESULTS

The CCBF during reperfusion after ROSC was greater in the TBM group than in the S-PBN group, the regression coefficient between CCBF and mean arterial blood pressure being lower in the S-PBN group than in the TBM group. The jugular bulb plasma concentration of 8-iso-PGF2alpha during the first 30 min after ROSC was greater in the TBM group than in the S-PBN group. Administration of TBM after vasopressin did not attenuate the pressor effect of vasopressin.

CONCLUSION

Administration of S-PBN during CPR results in less cerebral oxidative stress, possibly by promoting normal distribution of cerebral blood flow.

Photodegradation of 17alpha-ethynylestradiol in aqueous solution exposed to a high-pressure mercury lamp (250 W)

The photodegradation of 17alpha-ethynylestradiol (EE(2)) induced by high-pressure mercury lamp (lambda> or =313, 250 W) in aqueous solution of EE(2) was investigated initially. The affecting factors on the photodegradation were studied and described in details, such as EE(2) initial concentration, Fe(3+), algae, exposure time, and so on. The concentration of EE(2) in distilled water was mainly determined using fluorescence spectrophotometer. The photodegradation of EE(2) in aqueous solution exposed to high-pressure mercury lamp was evident and could be accelerated by Fe(3+) or algae (e.g. Anabaena cylindrica) in general. With the algae concentration increasing, photodegradation rate increased. In this paper, the mechanism of photocatalytic degradation of EE(2) by Fe(3+) or algae is discussed primarily.

Endoplasmic reticulum Ca(2+) signaling and calpains mediate renal cell death

The goal of the current study was to determine the roles of ATP content, endoplasmic reticulum (ER) Ca(2+) stores, cytosolic free Ca(2+) (Ca(2+)(f)) and calpain activity in the signaling of rabbit renal proximal tubular (RPT) cell death (oncosis). Increasing concentrations (0.3-10 microM) of the mitochondrial inhibitor antimycin A produced rapid ATP depletion that correlated to a rapid and sustained increase in Ca(2+)(f), but not phospholipase C activation. The ER Ca(2+)-ATPase inhibitors thapsigargin (5 microM) or cyclopiazonic acid (100 microM) alone produced similar but transient increases in Ca(2+)(f). Pretreatment with thapsigargin prevented antimycin A-induced increases in Ca(2+)(f) and antimycin A pretreatment prevented thapsigargin-induced increases in Ca(2+)(f). Calpain activity increased in conjunction with ER Ca(2+) release. Pretreatment, but not post-treatment, with thapsigargin or cyclopiazonic acid prevented antimycin A-induced cell death. These data demonstrate that extensive ATP depletion signals oncosis through ER Ca(2+) release, a sustained increase in Ca(2+)(f) and calpain activation. Depletion of ER Ca(2+) stores prior to toxicant exposure prevents increases in Ca(2+)(f) and oncosis.

Neurological outcome after experimental cardiopulmonary resuscitation: a result of delayed and potentially treatable neuronal injury?

BACKGROUND

In experimental cardiopulmonary resuscitation (CPR) aortic balloon occlusion, vasopressin, and hypertonic saline dextran administration improve cerebral blood flow. Free radical scavenger alpha-phenyl-N-tert-butyl-nitrone (PBN) and cyclosporine-A (CsA) alleviate neuronal damage after global ischemia. Combining these treatments, we investigated neurological outcome after experimental cardiac arrest.

METHODS

: Thirty anesthetized piglets, randomly allocated into three groups, were subjected to 8 min of ventricular fibrillation followed by 5 min of closed-chest CPR. The combined treatment (CT) group received all the above-mentioned modalities; group B was treated with balloon occlusion and epinephrine; and group C had sham balloon occlusion with epinephrine. Indicators of oxidative stress (8-iso-PGF(2 alpha)), inflammation (15-keto-dihydro-PGF(2 alpha)), energy crisis (hypoxanthine and xanthine), and anoxia/hypoxia (lactate) were monitored in jugular bulb venous blood. Neurological outcome was evaluated 24 h after CPR.

RESULTS

: Restoration of spontaneous circulation (ROSC) was more rapidly achieved and neurological outcome was significantly better in the CT group, although there was no difference in coronary perfusion pressure between groups. The jugular venous PCO2 and cerebral oxygen extraction ratio were lower in the CT group at 5-15 min after ROSC. Jugular venous 8-iso-PGF(2 alpha) and hypoxanthine after ROSC were correlated to 24 h neurological outcome

CONCLUSIONS

: A combination of cerebral blood flow promoting measures and administration of alpha-phenyl-N-tert-butyl-nitrone and cyclosporine-A improved 24 h neurological outcome after 8 min of experimental normothermic cardiac arrest, indicating an ongoing neuronal injury in the reperfusion phase.

Use of chemically extracted muscle grafts to repair extended nerve defects in rats

Nerve regeneration, measured as axonal outgrowth, Schwann cell migration, macrophage invasion, and neovascularisation, was compared after repair of a 15 mm gap in rats' sciatic nerves using autologous muscle grafts made acellular either by freezing and thawing or by chemical extraction. Both extracted and freeze-thawed acellular muscle grafts could be used to bridge the defect. However, axons and Schwann cells, as shown by immunohistochemical staining for neurofilaments and S-100 protein, respectively, grew faster into the extracted muscle grafts than into the freeze-thawed acellular muscle grafts and somewhat more axons were observed in the former graft. There were no significant differences between the two graft types with respect to neovascularisation as showed by staining for endothelial alkaline phosphatase, and limited differences concerning invasion of macrophages (ED1 and ED2) as detected by immunocytochemistry. The results showed that chemically extracted muscle grafts could be used to bridge an extended nerve defect and that such grafts in some aspects were superior to freeze-thawed muscle grafts for extended gaps.

[Preparation and evaluation of alkyl ether-bonded phase for reversed-phase high performance liquid chromatography]

A new silane coupling agent, beta-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, was for the firsty time used to react with octanol, then the intermediate product was coupled onto porous silica to obtain a novel bonded phase for reversed-phase high performance liquid chromatography (RP-HPLC). Characterization of prepared packing was carried out with elemental analysis, solid-state 13C nuclear magnetic resonance spectrometry (NMR), Fourier transform infrared(FT-IR) spectroscopy. Chromatographic evaluations were carried out by using a mixture of organic compounds and methanol-water as the binary mobile phase. The results showed that the stationary phase has excellent chromatographic properties and resist to hydrolysis at a pH value between 2.5 and 7.5. The silanophilic activity of the OEBP was weakened because of the existence of the cyclohexyl group in the packing. It can be efficiently used for the separation of basic compounds.

Effect of scopoletin on PC3 cell proliferation and apoptosis

AIM

To investigate the effect of scopoletin on cell proliferation and apoptosis of PC3 cells.

METHODS

Cell growth curve, MTT assay, and acid phosphatase activity (ACP) were used to determine cell proliferation. Coomassie brilliant blue assay was used to measure the content of protein in cells. Light microscope, transmission electronmicroscope, and fluorescence microscope were used to observe scopoletin-induced morphological changes. Apoptosis rate and cell cycle distribution were determined by flow cytometry.

RESULTS

The IC50 of scopoletin for inhibiting PC3, PAA, and Hela cell proliferation was (157 +/- 25), (154 +/- 51), and (294 +/- 100) mg/L, respectively. Scopoletin induced a marked time- and concentration-dependent inhibition of PC3 cell proliferation. Scopoletin reduced the protein content and decreased the ACP level in PC3 cells in a concentration-dependent manner. Cells treated by scopoletin showed typical morphologic changes of apoptosis by light microscope, fluorescence microscope, and transmission electronmicroscope. Apoptosis rate was 0.3 %, 2.1 %, 9.3 % and 35 % for scopoletin 0, 100, 200, and 400 mg/L, respectively, and cells in G2 phase decreased markedly after being treated with scopoletin.

CONCLUSION

Scopoletin inhibited PC3 proliferation by inducing apoptosis of PC3 cells.

Activated Notch2 signaling inhibits differentiation of cerebellar granule neuron precursors by maintaining proliferation

In the developing cerebellar cortex, granule neuron precursors (GNPs) proliferate and commence differentiation in a superficial zone, the external granule layer (EGL). The molecular basis of the transition from proliferating precursors to immature differentiating neurons remains unknown. Notch signaling is an evolutionarily conserved pathway regulating the differentiation of precursor cells of many lineages. Notch2 is specifically expressed in proliferating GNPs in the EGL. Treatment of GNPs with soluble Notch ligand Jagged1, or overexpression of activated Notch2 or its downstream target HES1, maintains precursor proliferation. The addition of GNP mitogens Jagged1 or Sonic Hedgehog (Shh) upregulates the expression of HES1, suggesting a role for HES1 in maintaining precursor proliferation.

[Reversed-phase high performance liquid chromatography used for determination of amino acids of parasites]

The compositions and contents of amino acids of parasites in different areas of China have been determined by precolumn derivatization, reversed-phase high performance liquid chromatography (HPLC) separation and ultra-violet absorption quantitation in order to prevent diseases caused from parasites. The results show that there were some differences in contents of amino acids in B. malayi from seven different areas in China. The contents of amino acids gradually increased from the southern to the northern areas in China. The method is simple and accurate, and the results have important values to investigate the life activities of parasites.

[Preparation and evaluation of amide-octyl-bonded phase for the separation of basic substances in reversed-phase liquid chromatography]

A new bonded-phase, amide-octyl-bonded phase (AOBP), with an internal polar functional group-amide was firstly prepared in domestic by two-step reaction process. The amino phase was formed in the first step and further modified in the second step by attaching an alkyl chain via reaction of an acid chloride with the amino ligand. Characterization of prepared packing was carried out with elemental analysis and Fourier transform infrared (FTIR) spectrometry. Hydrophobicity, selectivity and silanophilic activity of AOBP were evaluated by using organic components including acidic, bascic and neutral analytes and methanol-water as binary mobile phase. The applicable ranges of pH and stability of AOBP were also evaluated. The results showed that AOBP has excellent chromatographic properties and resistance to hydrolysis between pH = 2.5-7.5, It can be used for the separation of basic solutes efficiently.

ELF3 encodes a circadian clock-regulated nuclear protein that functions in an Arabidopsis PHYB signal transduction pathway

Many aspects of plant development are regulated by photoreceptor function and the circadian clock. Loss-of-function mutations in the Arabidopsis EARLY FLOWERING 3 (ELF3) and PHYTOCHROME B (PHYB) genes cause early flowering and influence the activity of circadian clock-regulated processes. We demonstrate here that the relative abundance of the ELF3 protein, which is a novel nucleus-localized protein, displays circadian regulation that follows the pattern of circadian accumulation of ELF3 transcript. Furthermore, the ELF3 protein interacts with PHYB in the yeast two-hybrid assay and in vitro. Genetic analyses show that ELF3 requires PHYB function in early morphogenesis but not for the regulation of flowering time. This suggests that ELF3 is a component of a PHYB signaling complex that controls early events in plant development but that ELF3 and PHYB control flowering via independent signal transduction pathways.

ELF3 encodes a circadian clock-regulated nuclear protein that functions in an Arabidopsis PHYB signal transduction pathway

Many aspects of plant development are regulated by photoreceptor function and the circadian clock. Loss-of-function mutations in the Arabidopsis EARLY FLOWERING 3 (ELF3) and PHYTOCHROME B (PHYB) genes cause early flowering and influence the activity of circadian clock-regulated processes. We demonstrate here that the relative abundance of the ELF3 protein, which is a novel nucleus-localized protein, displays circadian regulation that follows the pattern of circadian accumulation of ELF3 transcript. Furthermore, the ELF3 protein interacts with PHYB in the yeast two-hybrid assay and in vitro. Genetic analyses show that ELF3 requires PHYB function in early morphogenesis but not for the regulation of flowering time. This suggests that ELF3 is a component of a PHYB signaling complex that controls early events in plant development but that ELF3 and PHYB control flowering via independent signal transduction pathways.

ELF3 modulates resetting of the circadian clock in Arabidopsis

The Arabidopsis early flowering 3 (elf3) mutation causes arrhythmic circadian output in continuous light, but there is some evidence of clock function in darkness. Here, we show conclusively that normal circadian function occurs with no alteration of period length in elf3 mutants in dark conditions and that the light-dependent arrhythmia observed in elf3 mutants is pleiotropic on multiple outputs normally expressed at different times of day. Plants overexpressing ELF3 have an increased period length in both constant blue and red light; furthermore, etiolated ELF3-overexpressing seedlings exhibit a decreased acute CAB2 response after a red light pulse, whereas the null mutant is hypersensitive to acute induction. This finding suggests that ELF3 negatively regulates light input to both the clock and its outputs. To determine whether ELF3's action is phase dependent, we examined clock resetting by using light pulses and constructed phase response curves. Absence of ELF3 activity causes a significant alteration of the phase response curve during the subjective night, and constitutive overexpression of ELF3 results in decreased sensitivity to the resetting stimulus, suggesting that ELF3 antagonizes light input to the clock during the night. The phase of ELF3 function correlates with its peak expression levels in the subjective night. ELF3 action, therefore, represents a mechanism by which the oscillator modulates light resetting.

The protective effect of hepatocyte growth-promoting factor (pHGF) against hydrogen peroxide-induced acute lung injury in rats

To examine the protective effect of hepatocyte growth-promoting factor (pHGF) in hydrogen peroxide (H(2)O(2))-induced acute lung injury in rats, we observed the pathological changes in lung tissue by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and by light and electron microscopy. We also measured the serum levels of lipid peroxide (LPO). At 6 to 24 h after H(2)O(2) injection, the level of LPO was significantly higher in the H(2)O(2) group than in the H(2)O(2) + pHGF-treated group. This finding indicated that pHGF protected against cell membrane damage in H2O2-induced acute lung injury. Positive TUNEL signals were found in capillary endothelial cells, alveolar epithelial cells, and inflammatory cells. In the H(2)O(2) + pHGF-treated group, TUNEL-positive signals were reduced compared with those in the H(2)O(2) group. This finding indicated that pHGF acts to suppress apoptosis. In the H(2)O(2) group, severe pulmonary edema was seen 3 h after H(2)O(2) injection, and at 24 h, severe atelectasis was seen. In the H(2)O(2) + pHGF-treated group, pulmonary edema was scarcely seen and severe atelectasis was not found. This finding indicated that pHGF acts to suppress both severe pulmonary edema and atelectasis. In the H(2)O(2) group, the formation of subendothelial blebs and disruption of endothelial cells was observed. Edema and disruption were seen in type I epithelial cells. In type II lung epithelial cells, mitochondria were swollen and microvilli had disappeared. In the H(2)O(2) + pHGF-treated group, the formation of subendothelial blebs was seen, but no severe subendothelial blebs were observed. Disruption of capillary endothelial cells and type I epithelial cells was not evident, nor was there damage to type II lung epithelial cells. These findings indicated that pHGF protects the progression of H(2)O(2)-induced acute lung injury, and showed that pHGF acts to stabilize the cell membrane in capillary endothelial cells and lung epithelial cells.

[Purification of proteins in human plasma with new nylon affinity membranes]

A series of affinity membranes were prepared by using microporous nylon membrane as matrix and activation method with s-triazine and 1,4-butanediol diglycidyl ether, separately. Three proteins with clinic value, gamma-globulin, plasminogen and thrombin, were purified from human plasma by one step with affinity membrane chromatography. The purities of gamma-globulin purified were higher than 83%, and purification folds were higher than 5. The purity of gamma-globulin obtained was higher than that of standard human gamma-globulin. The efficiencies of gamma-globulin purification with affinity membranes prepared by two activation methods were equal. Plasminogen purified with affinity membranes prepared by s-triazine activation was higher than that by 1,4-butanediol diglycidyl ether activation. And SDS-PAGE analysis showed that the purities of gamma-globulin and plasminogen obtained were higher than that of the commercial product. In addition, the purification of thrombin from human plasma by one step with trypsin activation column and affinity membrane was studied. Thrombin with specific activity of 42 NIH unit/mg and 42.5 NIH unit/mg could be obtained from human plasma through affinity membranes prepared by s-triazine and 1,4-butanediol diglycidyl ether methods, respectively.

[Sensitive and rapid analysis of nitrophenols and herbicides by capillary zone electrophoresis (CZE)]

11 Nitrophenols and some acidic herbicides have been separated by modified CZE. Good separation of such compounds can be achieved in less than 10 min by simply modifying the run buffer with organic solvents such as methanol, acetonitrile in a concentration of 40% (V/V). The limits of detection (LODs) for nitrophenols by UV-absorption at 215 nm were 0.5 mg/L-1.1 mg/L. Solid phase extraction was used to preconcentrate nitrophenols and some herbicides to reach an LOD at microgram/L levels. Typical samples have been analyzed.

[Clinical observation on gastrointestinal protective effect of Composite Salviae injection in patients undergoing cardio-pulmonary bypass heart surgery]

OBJECTIVE

To observe the gastrointestinal protective effect of Composite Salviae Injection (CSI) in patients undergoing cardio-pulmonary bypass (CPB) heart surgery.

METHODS

Eighteen patients, who were scheduled to cardiac surgery (either atrial or ventrical septal repairing) undergoing CPB were randomized equally into two groups. Before CPB, the CSI group was treated with CSI 0.5 ml/kg by intravenous dripping and the control group was treated with normal saline in equal volume. The intragastric mucosa pH value (pHi) of patients was monitored by tensiometer.

RESULTS

As compared with the pre-CPB value, pHi lowered significantly during, 1 h and 2 hrs after CPB in the control group (P < 0.05 or P < 0.01), while in the CSI group, pHi lowered significantly only during CPB (P < 0.05), but with insignificant change at 1 h and 2 hrs after CPB. Comparison between the two groups showed that pHi value in the CSI group was higher significantly than that in the control group at all respective monitoring period (P < 0.05).

CONCLUSION

CSI has gastrointestinal protective effect in patients undergoing CPB cardiosurgery to some extent.

[Novel affinity membrane used for bilirubin removal]

Bilirubin is a toxic substance. In order to effectively remove it from the hepatic patients' blood, two novel affinity membranes were prepared. These were prepared by chemically grafting on cellulose and immobilized with different ligands. One kind of ligand was poly-D-lysine, the other one was quaternary ammonium salt. Both affinity membranes were used for removal bilirubin from phosphate buffer and HSA solutions, and the effects of temperature, HSA concentration, adsorption time in static state experiment and flow rate in dynamic state experiment have been investigated. The results indicated that the membranes could remove over 70% bilirubin from phosphate buffer and at least 50% from low concentration HSA solutions. The results also indicated that the removal efficiency was better at higher temperature. In the static state experiment, four hours can be selected as adsorption time. In the dynamic state experiment, the flow rate can be properly increased.

Prostanoids mediate the protective effect of trefoil factor 3 in oxidant-induced intestinal epithelial cell injury: role of cyclooxygenase-2

Trefoil factors are small peptides found in several mammalian tissues including gut, respiratory tract and brain. Their physiological function is not well understood. Among them, trefoil factor 3 (intestinal trefoil factor) is known to be cytoprotective in the gut. However, the molecular mechanism and secondary mediators of trefoil factor 3 action are not known. In the present study, we examined whether the cyclooxygenase pathway is involved in trefoil factor 3 action. We showed that trefoil factor 3 significantly induces the production of prostaglandin E(2) and prostaglandin I(2) in IEC-18 cells (an intestinal epithelial cell line) in a dose dependent manner. Western blot and immunohistochemistry revealed that trefoil factor 3 (2.5 microM) up-regulates the expression of cyclooxygenase-2 but not cyclooxygenase-1 in IEC-18 cells. Treating cells with trefoil factor 3 (10 microM) significantly attenuated reactive oxygen species-induced IEC-18 cell injury. This effect is blocked by NS-398 (10 microM), a selective cyclooxygenase-2 inhibitor. Moreover, we demonstrated that exogenously administered carbacyclin (1 microM, a stable analogue of prostaglandin I(2)) and/or prostaglandin E(2) (1 microM) caused a significant reduction of reactive oxygen species-induced cell injury, mimicking the effect of trefoil factor 3. In summary, our results indicate that trefoil factor 3 activates cyclooxygenase-2 in intestinal epithelium to produce prostaglandin I(2) and prostaglandin E(2), which function as survival factors and mediate the cytoprotective action of trefoil factor 3 against oxidant injury.

[Extraction and isolation of active component for inhibiting PC3 cell proliferation in vitro from the fruit of Lycium barbarum L]

OBJECTIVE

To extract and isolate the active component inhibiting PC3 cell proliferation in vitro from the fruit of Lycium barbarum.

METHOD

The active components of the fruit of L. barbarum were extracted by water, 95% ethanol, 50% ethanol respectively. Then, ethanol extract was extracted with acetone and n-butanol and isolated by SiO2 column and purified by TLC to obtain the active component. The chemical structure of active component was identified by the spectral analysis. MTT assay was used to compare the inhibition activity(IC50) of PC3 cells proliferation of the all extracts.

RESULT

According IC50, the most active component among all extracts isolated from the fruit of L. barbarum isscopoletin.

CONCLUSION

Scopoletin is the active component of the fruit of L. barbarum for inhibiting PC3 cell proliferation.

Prostanoids mediate the protective effect of trefoil factor 3 in oxidant-induced intestinal epithelial cell injury: role of cyclooxygenase-2

Trefoil factors are small peptides found in several mammalian tissues including gut, respiratory tract and brain. Their physiological function is not well understood. Among them, trefoil factor 3 (intestinal trefoil factor) is known to be cytoprotective in the gut. However, the molecular mechanism and secondary mediators of trefoil factor 3 action are not known. In the present study, we examined whether the cyclooxygenase pathway is involved in trefoil factor 3 action. We showed that trefoil factor 3 significantly induces the production of prostaglandin E(2) and prostaglandin I(2) in IEC-18 cells (an intestinal epithelial cell line) in a dose dependent manner. Western blot and immunohistochemistry revealed that trefoil factor 3 (2.5 microM) up-regulates the expression of cyclooxygenase-2 but not cyclooxygenase-1 in IEC-18 cells. Treating cells with trefoil factor 3 (10 microM) significantly attenuated reactive oxygen species-induced IEC-18 cell injury. This effect is blocked by NS-398 (10 microM), a selective cyclooxygenase-2 inhibitor. Moreover, we demonstrated that exogenously administered carbacyclin (1 microM, a stable analogue of prostaglandin I(2)) and/or prostaglandin E(2) (1 microM) caused a significant reduction of reactive oxygen species-induced cell injury, mimicking the effect of trefoil factor 3. In summary, our results indicate that trefoil factor 3 activates cyclooxygenase-2 in intestinal epithelium to produce prostaglandin I(2) and prostaglandin E(2), which function as survival factors and mediate the cytoprotective action of trefoil factor 3 against oxidant injury.

Nuclear assembly of purified Crythecodinium cohnii chromosomes in cell-free extracts of Xenopus laevis eggs

Incubation of dinoflagellate Crythecodinium cohnii chromosomes in cytoplasmic extracts of unfertilized Xenopus laevis eggs resulted in chromosomes decondensation and recondensation, nuclear envelope assembly, and nuclear reconstitution. Dinoflagellate Crythecodinium cohnii is a kind of primitive eukaryote which possesses numerous permanently condensed chromosomes and discontinuous double-layered nuclear membrane throughout the cell cycle. The assembled nuclei, being surrounded by a continuous double membrane containing nuclear pores and the uniformly dispersed chromatin fibers are morphologically distinguishable from that of Dinoflagellate Crythecodinium cohnii. However, incubation of dinoflagellate Crythecodinium cohnii chromosomes in the extracts from dinoflagellate Crythecodinium cohnii cells does not induce nuclear reconstitution.

[A new method for extracting the dinoflagellate crypthecodinium cohnii chromosomes and observation of their ultrastrcture]

In this paper, a new method of extracting the dinoflagellate Crypthecodinium cohnii chromosomes was proposed. The ultrastructure of dinoflagellate Crypthecodinium cohnii chromosome was studied by transmission electron microscope. The chromosome fibres of dinoflagellate fold in a different manner from that of typical eukaryotes.

Development of a novel biomarker of free radical damage in reperfusion injury after cardiac arrest

In a porcine model of cardiopulmonary resuscitation (CPR), we investigated changes in the plasma levels of 8-iso-PGF(2alpha), a marker for oxidative injury, and 15-keto-dihydro-PGF(2alpha), an inflammatory response indicator during the post-resuscitation period after cardiac arrest. Twelve piglets were subjected to either 2 or 5 min (VF2 and VF5 group) of ventricular fibrillation (VF) followed by 5 min of closed-chest CPR. Six piglets without cardiac arrest were used as controls. In VF5 group, 8-iso-PGF(2alpha) in the jugular bulb plasma (draining the brain) increased four-fold. Jugular bulb 8-iso-PGF(2alpha) in the control group remained unchanged. The 15-keto-dihydro-PGF(2alpha) also increased four-fold in the VF5 group. Thus, 8-iso-PGF(2alpha) and 15-keto-dihydro-PGF(2alpha) measurements in jugular bulb plasma may be used as biomarkers for quantification of free radical catalyzed oxidative brain injury and inflammatory response in reperfusion injury.

The protective effect of hepatocyte growth-promoting factor (pHGF) against carbon tetrachloride-induced acute liver injury in rats: an ultrastructural study

The protective effect of hepatocyte growth-promoting factor (pHGF) against CCl4-induced acute hepatitis in rats was examined by light and electron microscopy. Hepatocyte growth-promoting factor, purified from infant pig liver in an active form, has been used clinically in patients with hepatitis in China. Four hours after administration of CCl4, a single dose of pHGF was administered intraperitoneally. Six hours after administration of CCl4, inhibition of CCl4-induced hepatic necrosis and hepatocytes with severely dilated endoplasmic reticula were evident in rats treated with pHGF. At 48 h post administration, most hepatocytes had recovered, and not only mitotic hepatocytes (10-13 mitotic cells/100) but also mitotic Kupffer cells were observed. At 72 h, it was evident that the differentiation of hepatic stellate cells (Ito cell) into myofibroblast-like cells and the development of fibrosis around the central veins was prevented by pHGF. These results suggested that (1) pHGF may stabilize cell membranes, (2) pHGF acts as a mitogen not only for hepatocytes but also for Kupffer cells, and (3) pHGF prevents fibrogenesis in the case of CCl4-induced liver injury by preventing the differentiation of hepatic stellate cells.

Glutathione antagonized cyclophosphamide- and acrolein-induced cytotoxicity of PC3 cells and immunosuppressive actions in mice

AIM

To study the antagonistic effect of glutathione (GSH) on toxicity of PC3 cell induced by cyclophosphamide (Cyc) and acrolein (Acr) and on immunosuppressive actions caused by Cyc.

METHODS

Splenocyte, PC3 cell proliferation and cell protein content were measured by tetrazolium (MTT) assay and Coomassie brilliant blue assay. Serum anti-SRBC hemolysin, agglutinin, and splenocyte proliferation were measured in normal and S-180-bearing mice. Tumors were weighed.

RESULTS

Pretreatment with GSH 2 mmol.L-1 reduced splenocyte proliferation inhibition from 18.64%, 49.72% to 6.78%, 18.36% (induced by Cyc 1, and 5 mmol.L-1), and PC3 cell proliferation inhibition from 27.7%, 45.3%, and 74.6% to 14.6%, 18.8%, and 49.1% (induced by Cyc 1, 3, and 5 mmol.L-1), and from 62.6%, 85.4%, and 90.6% to 41.9%, 57.7%, and 86.4% (induced by Acr 10, 25, and 50 mumol.L-1), respectively. In normal mice, s.c. GSH 75 or 150 mg.kg-1 b.i.d. x 5 d after i.p. Cyc 40 mg.kg-1, the hemolysin and the splenocyte proliferation were higher than those in normal mice i.p. Cyc 40 mg.kg-1 alone. Hemolysin, serum agglutinin, and splenocyte proliferation in S-180-bearing mice given s.c. GSH 150 mg.kg-1 b.i.d. x 10 d after i.p. Cyc 40 mg.kg-1 were also markedly higher than those in S-180-bearing mice given i.p. Cyc alone. But, according to tumor weight, GSH did not interfere the antitumor activity of Cyc in S-180-bearing mice.

CONCLUSION

GSH exhibited protective effects against Cyc and Acr, but had no effect on the antitumor action of Cyc.

Production of recombinant adeno-associated virus vectors using a packaging cell line and a hybrid recombinant adenovirus

Recombinant adeno-associated virus (rAAV) vectors are under consideration for a wide variety of gene therapy applications. One of the limitations of the rAAV vector system has been the difficulty in producing the vector in sufficient quantity for adequate preclinical and clinical evaluation. A common method for vector production involves large-scale transient transfection of multiple plasmids into cultured cells. Because this approach might not be feasible for clinical scale manufacturing, we have sought approaches for rAAV vector production that avoid transient transfection procedures. In previously reported work, we generated an AAV packaging cell line that produces infectious rAAV when the vector genome is transfected into the cell line as plasmid DNA. We have now extended this approach by constructing a hybrid recombinant adenovirus (rAd) that contains a complete rAAV vector genome in the E1 region. This hybrid virus is used to deliver the rAAV genome to the packaging cell line (in the place of plasmid transfection). rAAV is produced when the packaging cell line is infected with the hybrid adenovirus and wild-type adenovirus. This method avoids the need for plasmid transfection and is adaptable to large-scale manufacturing processes.

Diversity of cDNAs encoding phospholipase A2 from Agkistrodon halys pallas venom, and its expression in E. coli

As a step toward understanding the structure and function of phospholipase A2(PLA2), we isolated several novel cDNAs encoding Agkistrodon halys Pallas PLA2 isoenzymes including B-PLA2, Asn49-PLA2, A-PLA2, A'-PLA2 and BA1-PLA2 by polymerase chain reaction with oligonucleotide primers corresponding to the N- and C-terminus of these enzymes. The amino acid sequences of A-PLA2 deduced from cDNA are consistent with that isolated from venom except for four residues. Asn49-PLA2 and B-PLA2 are highly similar (> 95%), but the critical residue Asp49 in the active centre of B-PLA2 is replaced by Asn49 in Asn49-PLA2. The N-terminal residues (1-24) of BA1-PLA2 shows high similarity to that of B-PLA2 which has strong ability to hemolyze erythrocytes, while its C-terminal residues (72-125) are the same as that of A-PLA2 which can inhibit platelet aggregation. The successful cloning of these isoenzymes not only provide excellent native material to study the structure-function relationship of PLA2s, but also to disclose the genesis of structural diversity of PLA2s, namely DNA modification and gene rearrangement. The cloned cDNA for A-PLA2 has been expressed in E. coli. By Q-Sepharose column chromatography, denaturation-renaturation and FPLC, we obtained the active recombinant protein with the initiator Met. This is the first report of the production of an active recombinant PLA2 with the initiator Met.

Effects of metallothionein on action potentials of anoxic and reoxygenated papillary muscles of guinea pigs

AIM

To study anti-arrhythmic effects of metallothionein (MT).

METHODS

Standard microelectrode technique was used to study the effects of MT on action potentials (AP) in anoxic and reoxygenated papillary muscles of guinea pigs.

RESULTS

MT (0.02 mmol.L-1) had no effects on AP of the normal papillary muscles; when the muscles were exposed to ischemic solution without MT, there was a marked shortening of action potential duration (APD) at 20%, 50%, and 90% of repolarization (APD20, APD50, APD90) from 82 +/- 7 to 37 +/- 7, 131 +/- 35 to 63 +/- 11, and 167 +/- 12 to 100 +/- 19 ms, respectively, (P < 0.01); and an obvious reduction of resting potential (RP), action potential amplitude (APA), and the maximal upstroke velocity of phase 0 (Vmax) from -92 +/- 9 to -63 +/- 12 mV, 135 +/- 13 to 80 +/- 8 mV, and 286 +/- 55 to 164 +/- 42 V.s-1, respectively (P < 0.01). However, in the presence of MT, the AP parameters (RP, APA, and Vmax) changed from -63 +/- 2 to -82 +/- 1 mV, 80 +/- 8 to 104 +/- 25 mV, and 164 +/- 42 to 237 +/- 43 V.s-1, respectively, (P < 0.01), except that APD20, APD50, and APD90 shortened further from 37 +/- 7 to 12 +/- 3, 63 +/- 11 to 28 +/- 7, and 100 +/- 19 to 82 +/- 11 mV, respectively (P < 0.01). MT decreased the incidence of automaticity during reoxygenation from 91% to 33%.

CONCLUSION

MT possesses a calcium regulatory property.

Resurgence of vivax malaria in Henan Province, China

Henan Province (population, 90 million) in China has nonstable endemic malaria. After 1970 when 10.2 million cases of malaria were reported in the province, a huge control programme was undertaken, and in the mid-1980s indoor spraying and bednet impregnation with pyrethroids began. By 1992 only 318 cases were reported. In 1992 Henan declared "basic elimination of malaria" and in consequence spraying and bednet impregnation ceased after 1994. Subsequently, malaria broke out again in southern Henan. In 1995 we conducted a household survey for malaria transmission in southern Henan. Blood smears and serum samples for immunofluorescent antibody (IFA) testing were collected from 2329 people and 3.1% (73/2329) were positive for infection with Plasmodium vivax and 13% (301/2329) positive for malaria (titre > or = 1:20). All age groups were affected. Exophilic Anopheles sinensis occurs throughout the province; endo-anthropophilic A. anthropophagus, whose vectorial capacity is 20 times greater than that of A. sinensis, occurs mainly in southern Henan (S of latitude 33 degrees N) and was greatly reduced in numbers during 1985-92. Comparison of 1995 entomological data with historical data showed that A. anthropophagus increased in proportion to other anophelines after spraying activities and impregnation of bednets ceased. Over 10% of 9377 residents reported having malaria. The true number affected among the at-risk population of 700,000 must be larger. We conclude that impregnated bednets and malaria surveillance should continue even after an area is declared to have "basically eliminated" malaria.

[Effect of taozhi zhipo granule on intestinal adhesion in rats and exploration of its therapeutic mechanism]

OBJECTIVE

To explore the therapeutical mechanism of Taozhi Zhipo Granule (TZZPG) on intestinal adhesion.

METHODS

Fed SD male rats of intestinal adhesion model with TZZPG 10, 20 g/kg.d continuously for 12 days.

RESULTS

TZZPG could alleviate the degree and the average length of intestinal adhesion in rats. It also could prolong bleeding time in mice and plasma recuperation time of guinea-pigs, improve the auricular microcirculation in mice, accelerate the removing speed of charcoal powder in mice's intestine and slightly strengthen the contraction of rat intestine in vitro. TZZPG relieved the croton oil topical edema of ear and reduced the capillary permeability of abdominal cavity in mice. TZZPG could enhance the phagocytosis of peritoneal macrophages.

CONCLUSIONS

TZZPG has preventive effect on intestinal adhesion. The action might be due to improve the ischemia in local tissue, strengthen the contraction of intestine and inhibit the inflammation.

Electrophysiologic effect of enalapril on guinea pig papillary muscles in vitro

AIM

To study the direct effect of enalapril on cellular electrophysiology of myocardium.

METHODS

Conventional microelectrodes technique was used to record the action potentials (AP) of guinea pig papillary muscles.

RESULTS

Enalapril caused an increase of the AP amplitude (APA) and the resting potential (RP) in a concentration-dependent manner without any significant change of AP duration, Vmax and overshoot of AP. Superfusion of ouabain 0.5 mumol.L-1 reduced APA and RP, induced stable delayed after-depolarizations (DAD) at different basic cycle lengths (BCL) in a frequency-dependent manner. At BCL 200 ms, the amplitude of DAD was large enough to induce nonsustained triggered activity (TA). In additional presence of enalapril 10 mumol.L-1, the DAD amplitude at 500, 400, 300, and 200 ms were decreased from 5.3 +/- 2.3, 5.9 +/- 2.8, 7.4 +/- 2.1, and 8.9 +/- 1.3 to 2.6 +/- 0.7, 3.1 +/- 1.0, 3.7 +/- 1.5, and 5.3 +/- 1.1 (mV) respectively, all P < 0.01. The compensation intervals were increased in a similar frequency-dependent manner. The number of TA induced at BCL 200 ms was decreased from 3.6 +/- 0.7 to 0.8 +/- 0.2 (P < 0.05).

CONCLUSION

Enalapril directly inhibits DAD and TA induced by ouabain through increasing RP and APA, which may contribute to its anti-arrhythmic effect.

Effects of 17 beta-estradiol on early afterdepolarizations and L-type Ca2+ currents induced by endothelin-1 in guinea pig papillary muscles and ventricular myocytes

By use of standard microelectrodes and whole cell patch clamp, the effects of 17 beta-estradiol on early afterdepolarizations (EADs) and increase of L-type Ca2+ currents (L-Ica) induced by endothelin-1 (ET-1) were studied in guinea pig ventricular papillary muscles and myocytes. The results indicated that superfusion with ET-1 for 30 min resulted in a marked prolongation of the action potential duration (APD) and caused stable EADs leading to triggered activity occurring at the plateau of the action potentials in isolated guinea pig ventricular papillary muscles. With the addition of 17 beta-estradiol (30 mumol/l), APD was shortened and EADs were decreased. In the patch clamp study, ET-1 induced an increase of mean peak L-Ica from 534.46 +/- 46.23 to 1003.15 +/- 39.12 (pA) with the peak voltage-current curve shifting to the left. When 17 beta-estradiol (30 mumol/l) was added, the L-Ica was decreased by up to 33.32% (p < 0.01) with the peak voltage-current curve shifting to the right. In contrast to the steady-state inactivation curve, ET-1 shifted the steady-state activation curve in the depolarization direction. However, with the addition of 17 beta-estradiol, the deviation of the steady-state activation and inactivation curves caused by ET-1 was suppressed. In conclusion, 17 beta-estradiol appears to attenuate the prolongation of APD and reduce EADs induced by ET-1 in guinea pig papillary muscles by its inhibitory effect on L-Ica.

Identification of a novel serine protease-like gene, the expression of which is down-regulated during breast cancer progression

In an effort to isolate genes with down-regulated expression at the mRNA level during oncogenic transformation of human mammary epithelial cells (MECs), we performed subtractive hybridization between normal MEC strain 76N and its radiation-transformed tumorigenic derivative 76R-30. Here, we report the isolation of cDNA clones corresponding to a 1.4-kb mRNA species that is abundantly expressed in 76N cells but is drastically reduced in 76R-30 cells. Based on its selective expression in MECs compared with fibroblasts, the corresponding gene is designated NES1 (normal epithelial cell-specific 1). Sequence analysis of the full-length NES1 cDNA clones revealed it to be a novel gene with a predicted polypeptide of 30.14 kilodaltons; in vitro transcription and translation confirmed this prediction. Database searches revealed a 50-63% similarity and 34-42% identity with several families of serine proteases, in particular the trypsin-like proteases, members of the glandular kallikrein family (including prostate-specific antigen, nerve growth factor gamma, and epidermal growth factor-binding protein) and the activators for the kringle family proteins (including the human tissue plasminogen activator and human hepatocyte growth factor activator). Importantly, all of the residues known to be crucial for substrate binding, specificity, and catalysis by the serine proteases are conserved in the predicted NES1 protein, suggesting that it may be a protease. An antipeptide antibody directed against a unique region of the NES1 protein (amino acids 120-137) detected a specific 30-kilodalton polypeptide almost exclusively in the supernatant of the mRNA-positive MECs, suggesting that NES1 is a secreted protein. The 1.4-kb NES1 mRNA was expressed in several organs (thymus, prostate, testis, ovary, small intestine, colon, heart, lung, and pancreas) with highest levels in the ovary; a 1.1-kb transcript was found in the pancreas. Although expression of the NES1 mRNA was observed in all normal and immortalized nontumorigenic MECs, the majority of human breast cancer cell lines showed a drastic reduction or a complete lack of its expression. The structural similarity of NES1 to polypeptides known to regulate growth factor activity and a negative correlation of NES1 expression with breast oncogenesis suggest a direct or indirect role for this novel protease-like gene product in the suppression of tumorigenesis.

Mutant p53-induced immortalization of primary human mammary epithelial cells

Mutations of the p53 gene are the most frequent genetic lesions in breast cancer, suggesting a critical role for p53 protein in normal mammary cell growth control. Indeed, the p53-targeting human papillomavirus oncogene E6 induces efficient immortalization of normal human mammary epithelial cells (MECs). To assess whether selective loss of p53 is sufficient for MEC immortalization, we introduced seven missense mutants and one single-amino acid deletion mutant (del239) of p53 into the 76N normal MEC strain. Although the missense mutants failed to immortalize MECs, the del239 mutant reproducibly immortalized these cells. The immortal cells were anchorage dependent and nontumorigenic, indicating a preneoplastic transformation. Gamma-irradiation of these cells failed to induce G1 cell cycle arrest and did not lead to an increase in WAF1 and mdm-2 mRNA levels, demonstrating a loss of the endogenous p53 function. These results demonstrate that selective ablation of p53 function by a dominant-negative mutant is sufficient for immortalization of MECs. Availability of an immortalizing as well as several nonimmortalizing p53 mutants should help identify functions critical for cell growth control by p53 in mammary epithelial cells.

Immortalization of distinct human mammary epithelial cell types by human papilloma virus 16 E6 or E7

Multiple mammary epithelial cell (MEC) types are observed both in mammary ducts in vivo and in primary cultures in vitro; however, the oncogenic potential of different cell types remains unknown. Here, we used human papilloma virus 16 E6 and E7 oncogenes, which target p53 and Rb tumor suppressor proteins, respectively, to immortalize MECs present in early or late passages of human mammary tissue-derived cultures or in milk. One MEC subtype was exclusively immortalized by E6; such cells predominated in late-passage cultures but were rare at early passages and apparently absent in milk. Surprisingly, a second cell type, present only in early-passage tissue-derived cultures, was fully immortalized by E7 alone. A third cell type, observed in tissue-derived cultures and in milk, showed a substantial extension of life span with E7 but eventually senesced. Finally, both E6 and E7 were required to fully immortalize milk-derived MECs and a large proportion of MECs in early-passage tissue-derived cultures, suggesting the presence of another discrete subpopulation. Identification of MECs with distinct susceptibilities to p53- and Rb-targeting human papillomavirus oncogenes raises the possibility that these cells may serve as precursors for different forms of breast cancer.

[Application of SRK II formula and measurement of A constant of KM intraocular lens]

The characteristics and distribution of the axial lengths and the results of keratometric measurements of 757 eyes with senile cataracts were reported and their relationship was discussed. The range of the axial lengths was 19.53-33.74 mm, the mean value being 23.81 +/- 2.26 mm (mean +/- SD), the eyes with longer axial lengths accounting for 21.8% and the eyes with axial lengths over 27 mm, 8.59%. The range of the degrees of the corneal curvatures was 39.75-50.50 D, the mean value being 44.47 +/- 0.78 D. The corneal curvatures of the eyes with shorter axial lengths are increased markedly with the shortening of the axial lengths. However, the corneal curvatures of the eyes with longer axial lengths are not decreased significantly with the lengthening of the axes. The A constant of KM intraocular lens we measured is 116.86 and the post-operative mean anterior chamber depth is 3.63 +/- 0.28 mm. If the C value is + 1.5 in eyes with 21-22 mm axial lengths, 0 in eyes with 22-24.5 mm and -0.5 in eyes with > 24.5, > 27, > 28.5 mm, the predictive error seen post-operatively is the smallest.

Tumor cell-specific loss of p53 protein in a unique in vitro model of human breast tumor progression

Mutations of the p53 gene are the most frequent genetic lesion in breast cancer. Here, we examined p53 expression in a unique in vitro model of tumor progression derived from a single breast cancer patient (21T series). While the normal mammary epithelial, fibroblast and mesothelial cells derived from this patient expressed easily detectable functional p53 protein, the primary as well as metastatic tumor cell lines demonstrated a lack of p53 protein synthesis. 21T tumor cells failed to exhibit G1 cell cycle arrest upon exposure to gamma-irradiation, and their growth was suppressed by transfection of a normal p53 cDNA, demonstrating a lack of p53-mediated function in these cells. No p53 gene deletion or rearrangements were detectable. PCR and sequence analysis of the entire coding region of p53 gene revealed a novel mutation, an insertion of a single T within codon 33, which resulted in a frame-shift and early termination. The same mutation was observed in all 21T tumor cell lines. These results demonstrate a tumor cell-specific loss of p53 protein due to a frame-shift mutation, and suggest that p53 loss may occur at a relatively early step in breast tumorigenesis before metastatic seeding or emergence of tumor heterogeneity. In addition, the availability of normal and tumor-derived epithelial cells with known p53 sequences from a single breast cancer patient should facilitate understanding of the p53 regulation in mammary cells.

[Phage typing of Salmonella typhimurium in 20 provinces, autonomous regions and municipalities of China]

Thirty strains of Salmonella bacteriophages were isolated from hospital sewage. Eleven strains selected from them, in combination with Felix Salmonella Phage O-I, were used as a phage typing set for serotyping Salmonella. Thirty-one identified types and 20 undefined types were detected in 2348 strains of Salmonella typhimurium collected from 20 provinces, autonomous regions and municipalities in China. The nine types with higher frequencies were 7774 (accounted for 48.0%), 0774 (17.1%), 6774 (7.7%), 4774 (7.3%), 5774 (3.3%). 3774 (2.2%), 4000(2.1%), 0000 (1.8%) and 7000 (1.7%). Most outbreaks of nosocomial infection and food poisoning were caused by phage types 7774 and 4774. Phage types of Salmonella typhimurium in domestic ducks, pigs, rats, snails, and in sewages were analyzed, and their significance in epidemics was discussed.