Inactivation of monomeric sarcosine oxidase by reaction with N-(cyclopropyl)glycine

Monomeric sarcosine oxidase (MSOX) catalyzes the oxidative demethylation of sarcosine (N-methylglycine) and contains covalently bound flavin adenine dinucleotide (FAD). The present study demonstrates that N-(cyclopropyl)glycine (CPG) is a mechanism-based inhibitor. CPG forms a charge transfer complex with MSOX that reacts under aerobic conditions to yield a covalently modified, reduced flavin (lambda(max) = 422 nm, epsilon(422) = 3.9 mM(-1) cm(-1)), accompanied by a loss of enzyme activity. The CPG-modified flavin is converted at an 8-fold slower rate to 1,5-dihydro-FAD (EFADH(2)), which reacts rapidly with oxygen to regenerate unmodified, oxidized enzyme. As a result, CPG-modified MSOX reaches a CPG-dependent steady-state concentration under aerobic conditions and reverts back to unmodified enzyme upon removal of excess reagent. No loss of activity is observed under anaerobic conditions where EFADH(2) is formed in a reaction that goes to completion at low CPG concentrations. Aerobic denaturation of CPG-modified enzyme yields unmodified, oxidized flavin at a rate similar to the anaerobic denaturation reaction, which yields 1,5-dihydro-FAD. The CPG-modified flavin can be reduced with borohydride, a reaction that blocks conversion to unmodified flavin upon removal of excess CPG or enzyme denaturation. The possible chemical mechanism of inactivation and structure of the CPG-modified flavin are discussed.

[Influence of the subglottic secretion drainage on the morbidity of ventilator associated pneumonia in mechanically ventilated patients]

OBJECTIVE

To assess the influence of the subglottic secretion drainage on the morbidity of ventilator associated pneumonia in mechanically ventilated patients.

METHODS

All cases requiring intubation in SICU were intubated with a special type endotracheal tube which has a small-bore cannula in its wall for subglottic secretion drainage. They were randomly divided into two groups received subglottic secretion drainage(SSD) and usual care(NON-SSD) respectively. Bacterial culture of samples from the oropharynx, subglottic secretions and lower respiratory tract were obtained periodically. The amount of subglottic secretion aspirated daily, ventilated days and the number of cases with VAP were recorded. Etiologic diagnosis of VAP was based on the quantitative bacterial culture of secretions obtained by protected specimen brush(PSB).

RESULTS

The morbidity of VAP in the SSD group (n = 35) (23%) was lower than that in the NON-SSD group (n = 33) (45%) (P < 0.05). The difference was due to the significant reduction of VAP caused by gram-positive cocci and Haemophilus influenzae organisms. However, no difference was observed in the incidence of VAP caused by non-fermental bacteria. After intubation the onset of VAP was delayed in SSD group (14 +/- 8 day) as compared with the NON-SSD group (6 +/- 4 day) (P < 0.05). The same organisms were isolated by PSB among 61% (14/23) patients with VAP as what were previously isolated from the subglottic secretions.

CONCLUSIONS

The presence of subglottic secretion may be an origin of the pathogenetic organisms of VAP. The morbidity of VAP in mechanically ventilated patients can be reduced by SSD, especially for VAP caused by gram-positive cocci and Haemophilus influenzae organisms. SSD may be a simple and effective method for prevention of VAP.

[G-protein modulates the inhibition of angiotensin II on BKCa in ECV304]

OBJECTIVE

To investigate the effect of angiotensin II (A II) on maxi-conductance calcium-activated potassium channel(BKCa) activity in ECV304 cell membrane, and the possible involvement of G-protein.

METHODS

Cell-attached configuration of patch clamp technique was employed to record the current of BKCa in ECV304.

RESULTS

10(-7) mol/L angiotensin II inhibited the BKCa activity. Current amplitude and open probability were decreased, open time was shortened and close time was increased. G-protein activation could eliminate the inhibition of A II.

CONCLUSIONS

A II significantly decreased the activity of BKCa in ECV304, which might depolarize the membrane, and the stability of membrane might change. Thus endothelial cell dysfunction might be induced. G-protein activation was involved in the regulation of the above A II inhibition process.

Sympathetic innervation alters activation of pacemaker current (If) in rat ventricle

Pacemaker current (If) exists in both neonatal and adult ventricles, but activates at more negative voltages in the adult. This study uses whole-cell patch clamp to investigate the factors that may contribute to the maturational shift of If, comparing neonatal rat ventricular myocytes that were cultured for 4-6 days either alone, in co-culture with sympathetic nerves, or with neurotransmitters chronically present in culture. If recorded from nerve-muscle co-cultures had a significantly more negative and shallower activation-voltage relation than that from control muscle cultures, which was reflected in the midpoint potential (V50) and slope factor (K) of activation. This effect of innervation was prevented by the sustained presence in the culture of the alpha1-adrenergic antagonist prazosin (Pz) at 10(-7) M. In parallel experiments, myocytes treated with noradrenaline (NA) at 10(-7) M or neuropeptide Y (NPY) at 10(-7) M during culture had the same If activation as control cells, but cells treated with NA and NPY together had a significantly more negative and shallower activation curve. Maximum conductance and reversal potential were unchanged. The effect of chronic exposure to NA + NPY was prevented by the sustained presence of either Pz or the NPY Y2 selective antagonist T4-[NPY(33-36)]4 (3.5 x 10(-7) M) in the culture, indicating a requirement for both alpha1-adrenergic and NPY Y2 activation. Substituting NA with the alpha1A-adrenergic selective agonist A61603 (5(-10) x 10(-9) M), in the presence of NPY, did not alter If, suggesting the involvement of alpha1B- rather than alpha1A-adrenoceptors. Further, sequential exposure to NPY followed by NA was effective in reproducing the action of chronic simultaneous exposure to these agonists, but sequential exposure to NA followed by NPY was ineffective. The results are consistent with past studies indicating that NPY affects the functional expression of the alpha1B-adrenergic cascade and suggest that sympathetic innervation induces a negative shift of If in ventricle via a combined action at alpha1B-adrenergic and NPY Y2 receptors. This effect of innervation probably contributes to the developmental maturation of If activation.

Investigation of the SERS behaviour of porphyrins with different surface concentrations on electrochemically prepared Ag-surface

Surface-enhanced Raman scattering (SERS) spectra, taken with 632.8 nm excitation are reported for the water-soluble tetrakis(3-N-methylpyridyl)porphyrin chloride (TMPyP(3)), tetrakis(4-N-methylpyridyl)porphyrin chloride (TMPyP(4)) and Sn(IV)tetrakis(4-N-methylpyridyl)porphyrin chloride (Sn(IV)TMPyP(4)) using an electrochemically prepared Ag surface with an area ca. 12.56 mm2. It was found that the spectra vary as increasing amounts of the compounds are placed on the surface, with surface concentrations in the approximate range 1000-5 pmol/12.56 mm2. We suggest that the reasons for the changes be that the reaction means between porphyrin molecules and Ag surface is different and the porphyrin macrocyclic molecules adopt different orientation as the surface concentrations decrease.

[Early arthroscopic reconstruction in treatment of acute complete rupture of anterior cruciate ligament]

OBJECTIVE

To early reconstruct acute and complete rupture of anterior cruciate ligament (ACL) and treat combined injuries for the recovery of knee joint stability.

METHODS

Ten cases of acute complete rupture of anterior cruciate ligament and medial collateral ligament were treated arthroscopically by anterior cruciate ligament reconstruction using patellar tendon autograft fixed with interference screw from February 1998 to March 1999.

RESULTS

Follow-up ranged from 5 months to 1 year and 3 months (average 10 months). Clinical results showed that the stability of knee joint was satisfactory in the early stage.

CONCLUSIONS

Acute the ACL rupture can be reconstructed arthroscopically in the early stage and the injuries were moderate, combined injuries could be treated at the same time, and the stability of knee joint could recover in the early stage after operation.

Expression of transforming growth factor-alpha, epidermal growth factor, and epidermal growth factor receptor in follicles of human ovarian tissue before and after cryopreservation

OBJECTIVE

To study the expression of transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), and EGF receptor in follicles of human ovarian tissue.

DESIGN

A retrospective, controlled comparative study.

SETTING

In vitro fertilization laboratory of a university hospital.

PATIENT(S)

Fifteen women with regular menstrual cycles who underwent laparoscopy and the biopsy of ovarian tissue.

INTERVENTION(S)

Paraffin sections were prepared from ovarian tissues, followed by immunohistochemical staining of TGF-alpha, EGF, and EGF receptor.

MAIN OUTCOME MEASURE(S)

Immunostaining for TGF-alpha, EGF, and EGF receptor in follicles of fresh and frozen ovarian tissues.

RESULT(S)

Immunoreactivities for TGF-alpha and EGF receptor were observed simultaneously in the oocytes of primordial, primary, preantral, and antral follicles. Strong staining for TGF-alpha and EGF receptor was present in thecal cells. The TGF-alpha and EGF receptor was also expressed in some granulosa cells of primary to antral follicles. The EGF only stained weakly in the oocytes of primordial and primary follicles and in thecal cells. There was no difference in staining patterns for TGF-alpha, EGF, and EGF receptor between fresh and frozen ovarian tissues.

CONCLUSION(S)

The TGF-alpha and EGF receptor was expressed in primordial to antral follicles, indicating a role of TGF-alpha in regulating follicular development through binding to the EGF receptor. Freeze-thawing did not substantially alter immunoreactivites for TGF-alpha, EGF, and EGF receptor in frozen ovarian tissue.

Histologic and ultrastructural evaluation of fresh and frozen-thawed human ovarian xenografts in nude mice

OBJECTIVE

To compare histologic and ultrastructural characteristics of fresh and frozen-thawed human ovarian cortical tissue grafted into nude mice.

DESIGN

Experimental prospective study.

SETTING

An academic research environment.

PATIENT(S)

Ovarian biopsy specimens were obtained from 13 women undergoing laparoscopy for tubal ligation or infertility.

ANIMAL(S)

Forty nude mice.

INTERVENTION(S)

A minilaparotomy was performed to place fresh and frozen-thawed ovarian grafts subcutaneously (sc) or intraperitoneally (ip). Removal of the ovarian grafts was performed at 24 days.

MAIN OUTCOME MEASURE(S)

[1] the follicular population, [2] fibrosis, [3] vascularization of the grafted tissue, and [4] ultrastructural evaluation.

RESULT(S)

A greater fibrosis relative surface area was noted in frozen-thawed transplanted tissue than in fresh transplants. Regardless of this fibrosis, a similar follicular density was observed in fresh and frozen-thawed ovarian tissue 24 days after transplantation. Active angiogenesis was proved by both immunohistochemical study of the vascular endothelial growth factor and morphometric study of the vascular network. Normal ultrastructural characteristics were noted in frozen-thawed ovarian biopsies.

CONCLUSION(S)

Angiogenesis allows implantation of the graft even if it has been cryopreserved and thawed similarly to implantation of fresh tissue. The greater fibrosis observed in grafts after cryopreservation and implantation does not seem to affect the primordial and primary ovocyte population and their ultrastructural characteristics, but further studies must be conducted to prove that after cryopreservation and transplantation, ovocytes may achieve full maturation and fertilization.

Phosphatidylserine-dependent adhesion of T cells to endothelial cells

Phosphatidylserine (PS) was exposed at the surface of human umbilical vein endothelial cells (HUVECs) and cultured cell lines by agonists that increase cytosolic Ca(2+), and factors governing the adhesion of T cells to the treated cells were investigated. Thrombin, ionophore A23187 and the Ca(2+)-ATPase inhibitor 2, 5-di-tert-butyl-1,4-benzohydroquinone each induced a PS-dependent adhesion of Jurkat T cells. A23187, which was the most effective agonist in releasing PS-bearing microvesicles, was the least effective in inducing the PS-dependent adhesion of Jurkat cells. Treatment of ECV304 and EA.hy926 cells with EGTA, followed by a return to normal medium, resulted in an influx of Ca(2+) and an increase in adhering Jurkat cells. Oxidised low-density lipoprotein induced a procoagulant response in cultured ECV304 cells and increased the number of adhering Jurkat cells, but adhesion was not inhibited by pretreating ECV304 cells with annexin V. PS was not significantly exposed on untreated Jurkat cells, as determined by flow cytometry with annexin V-FITC. However, after adhesion to thrombin-treated ECV304 cells for 10 min followed by detachment in 1 mM EDTA, there was a marked exposure of PS on the Jurkat cells. Binding of annexin V-FITC to the detached cells was inhibited by pretreating them with unlabelled annexin V. Contact with thrombin-treated ECV304 cells thus induced the exposure of PS on Jurkat cells and, as Jurkat cells were unable to adhere to thrombin-treated ECV304 cells in the presence of EGTA, the adhesion of the two cell types may involve a Ca(2+) bridge between PS on both cell surfaces. The number of T cells from normal, human peripheral blood that adhered to ECV304 cells was not increased by treating the latter with thrombin. However, findings made with several T cell lines were generally, but not completely, consistent with the possibility that adhesion to surface PS on endothelial cells may be a feature of T cells that express both CD4(+) and CD8(+) antigens. Possible implications for PS-dependent adhesion of T cells to endothelial cells in metastasis, and early in atherogenesis, are discussed.

[G-protein potentiates the activation of TNF-alpha on calcium-activated potassium channel in ECV304]

OBJECTIVE

Observe the effect of tumor necrosis factor-alpha (TNF-alpha) on calcium-activated potassium channel in ECV304 and the possible involvement of G-protein mediation in the action of TNF-alpha.

METHOD

Using the cell-attached configuration of patch clamp technique.

RESULTS

(1) the activity of high-conductance calcium-activated potassium channel (BKca) was recorded. Its conductance is (202.54 +/- 16.62) pS; (2) the activity of BKca was potentiated by 200 U/ml TNF-alpha; (3) G-protein would intensify this TNF-alpha activation.

CONCLUSIONS

TNF-alpha acted on vascular endothelial cell ECV304 could rapidly activate the activity of BKca. Opening of BKca resulted in membrane hyper-polarization which could increase electro-chemical gradient for the resting Ca2+ influx and open leakage calcium channel, thus resting cytoplasmic free Ca2+ concentration could be elevated. G-protein may exert an important regulation in this process.

[The effect of temperature on the behavior of aminobenzoic acid on silver surface]

SERS spectra of p-Aminobenzoic Acid (PABA) and o-Aminobenzoic Acid (OABA) absorbed on a silver surface, roughened by nitric acid, have been measured with a Renishaw Raman microprobe spectrometer(lambda = 632.8 nm) at different temperature, which ranged from 30 degrees C to -190 degrees C and from -190 degrees C to 30 degrees C. Some reversible changes in some band positions have been observed. The results indicated that if the adsorbates were enhanced by chemical mechanism and the molecules lie flat on surface, e.g. p-Aminobenzoic Acid molecule, temperature had no effect on their orientation. However, the vibrational frequencies enhanced by electromagnetic mechanism shifted as temperature changed, e.g. the vibration of NH2 in o-Aminobenzoic. The fact was that temperature had effect on the orientation of the molecules.

[Observation of biofilms inside tracheal tubes by electron microscopy and the relationship between biofilms and VAP]

OBJECTIVE

To observe the formation of biofilms inside tracheal tubes and to evaluate the effect of biofilm on the development of ventilator associated pneumonia (VAP).

METHODS

Biofilms inside tracheal tubes from intubated patients were observed by scanning electron microscopy and transmission electron microscopy, meanwhile bacteria were detected in the specimens from the lower respiratory tract and the inside of tracheal tubes.

RESULTS

76% (19/25) of inner surface of tracheal tubes was coated with a confluent amorphous matrix by scanning electron microscopy. The average duration of trach-intubation in this group [(10.7 +/- 7.9) days] was longer than that in the other group [(2.1 +/- 0.8) days] in which tracheal tubes were not coated with the confluent amorphous matrix (P < 0.05). The presence of many bacteria(14/18) within these amorphous matrix was confirmed by transmission electron microscopy. Of the sixteen tracheal tubes, eleven tubes grew the same organisms that had been isolated from the secretions of the lower respiratory tract before extubation. In some VAP patients (7/8), organisms isolated from tracheal tubes were the same organisms which were pathogenic organisms of VAP.

CONCLUSIONS

There was a close connection between the formation of bacterial BF and the long-term indwelling tracheal tubes. The presence of bacterial BF in the inner of tracheal tubes might be associated with the pathogenic organisms of VAP.

Gonadal cryopreservation in the young patient with gynaecological malignancy

For patients who are planning to have chemotherapy, radiotherapy or to undergo bilateral oophorectomy, the loss of ovarian function will result in premature ovarian menopause and loss of fertility. Embryo preservation is not an option for single women or married women because delaying treatment for at least 2 months of in-vitro fertilization cycles is inappropriate and may be life-threatening. This study reports on the indications for ovarian tissue cryobanking and the state of the art of this method in preserving fertility in women with iatrogenic premature menopause.

Distribution and epidermal growth factor receptor expression of primordial follicles in human ovarian tissue before and after cryopreservation

The freezing of ovarian tissue and the growth of immature oocytes from primordial follicles is an interesting concept in ovarian tissue transplantation and in-vitro fertilization. In this study, the morphology and distribution of primordial follicles were studied in ovarian tissue from 24 women before and after cryopreservation. Cryopreservation did not significantly change either the morphology or number per unit volume of morphologically normal follicles in frozen ovarian tissue. Primordial follicles were predominant, accounting for 78.6% and 82.6% of total follicles in fresh and frozen ovarian tissues respectively. The distribution of follicles was extremely uneven in ovarian tissue. A large variation in follicle numbers was observed in ovarian tissue samples from patient to patient, and even in the same patient, indicating that the number of follicles counted in one sample of ovarian tissue may not represent the number of follicles in other tissue samples. Ovarian tissue could be frozen in the form of strips instead of fragments for fast processing and better viability of ovarian tissue in cryopreservation. The number of follicles in ovarian tissue declined with the increasing age of the patients. An immunohistochemical study showed that immunoreactivity for the epidermal growth factor (EGF) receptor was detected in primordial follicles of adult ovarian tissue. EGF receptor staining was most intense in the oocytes of primordial follicles. Weak staining for EGF receptor was observed in some surrounding pregranulosa cells. Immunohistochemical staining for EGF receptor was also present in the stromal cells of ovarian tissue, but to a much lesser degree. There was no significant difference in the immunohistochemical staining for EGF receptor in ovarian tissue before and after cryopreservation.

Expression of receptors for insulin-like growth factor-I and transforming growth factor-beta in human follicles

The in-vitro growth of immature oocytes in early follicles from cryopreserved human ovarian tissues is a new concept in in-vitro fertilization programmes for the treatment of infertile and cancer patients. To better understand the regulatory mechanism of follicular development, immunohistochemistry was used to study the expression of insulin-like growth factor (IGF) type I receptor (IGF-IR) and transforming growth factor-beta (TGFbeta) type I (TbetaR-I) and type II (TbetaR-II) receptors in fresh and frozen ovarian tissues from 14 women. Immunoreactivities for IGF-IR and TbetaR-I were present simultaneously in the oocytes of primordial, pre-antral and antral follicles. Staining for both IGF-IR and TbetaR-I was also observed in granulosa cells of primordial, pre-antral and antral follicles. IGF-IR and TbetaR-I also stained in thecal cells of pre-antral and antral follicles. Stromal cells in surrounding ovarian tissue expressed IGF-IR and TbetaR-I at various follicular stages. Unlike TbetaR-I, TbetaR-II was expressed only in the oocytes of primordial and primary follicles, and with weak staining intensity in thecal cells. No significant staining for TbetaR-II was found in oocytes and granulosa cells of antral follicles. There was no difference in staining patterns for IGF-IR, TbetaR-I and TbetaR-II between fresh and frozen ovarian tissues, indicating that cryopreservation might not significantly alter the immunoreactivities of these receptors in frozen ovarian tissue. The results suggest that IGF-I and TGFbeta may participate in the regulation of follicular growth by binding to their receptors through an autocrine or paracrine mechanism. IGF-I and TGFbeta may be useful in regulating the in-vitro or in-vivo maturation of oocytes not only in later follicles but also very early follicles, from cryopreserved ovarian tissues for clinical use in the future.

[Expression and characterization of two outer capsid proteins VP2 and VP5 of bluetongue virus in insect cells]

OBJECTIVE

To study the biological characteristics of the outer capsid proteins VP2 and VP5 of bluetongue virus (BTV) expressed in insect cells and their potential use in the assembly of BTV and genetic engineering vaccine.

METHODS

The genes which encode the two outer capsid proteins VP2 and VP5 of bluetongue virus (BTV) 10 were separately cloned into pFastBac1 vector and the corresponding recombinant baculoviruses were obtained.

RESULTS

BTV VP2 could be expressed in Sf-9 cells better than VP5. Further works indicated that VP2 could elicit neutralizing antibodies to BTV10(1:64), and also could partially neutralize BTV1(1:16), but could not neutralize BTV13. The co-immunizing of VP2 and VP5 could induce higher neutralizing antibodies to BTV10 and BTV1. VP2 also showed a hemagglutination activity.

CONCLUSION

VP2 expressed in insect cells could induce neutralizing antibodies to BTV and had the biological activity of hemagglutination, VP5 could enhance the ability of neutralizing antibody induction of VP2, they can be used for the assembly of virus-like particles and for the development of genetic engineering vaccine.

[Study on inflammatory response and alteration of biochemical components in BALF from Pneumocystis carinii pneumonia]

OBJECTIVE

To study the cellular and biochemical changes in airways in pneumocystis carinii pneumonia (PCP).

METHODS

The cellular and biochemical changes in bronchoalveolar lavage fluid (BALF) between PCP and bacterial pneumonia in rat models induced by cortisone acetate(GC) injections were compared. The activities of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and type IV collagenase(matrix metalloproteinases, MMP-2, MMP-9) in BALF were measured. The rats were divided into four groups: (1) normal controls: 6 healthy SD rats; (2) negative control: 6 rats with GC injection over 8 weeks without lung infection; (3) bacterial pneumonia: 11 rats with GC injection over 8 weeks complicating bacterial pneumonia without other pathogens isolated; (4) PCP: 14 rats with GC injection during 8-12 weeks complicating PCP without other pathogens isolated.

RESULTS

In PCP the total cell counts (6.9 +/- 2.6) x 10(6)/L and the percentage of PMNs (18.6 +/- 6.0)% in BALF were increased compared with negative control(P < 0.01), but were lower than those in bacterial pneumonia group(P < 0.01). ALB in BALF in PCP (623 +/- 484) g/L was increased compared with negative control (36 +/- 16) g/L(P < 0.05) and bacterial pneumonia(91 +/- 43) g/L(P < 0.05). The activities of ALP and LDH in PCP [(217 +/- 81) U/L, (208 +/- 82) U/L respectively] were higher than those in negative control [(75 +/- 37) U/L, (86 +/- 61) U/L, P < 0.05)] and bacterial pneumonia [(90 +/- 45) U/L, (130 +/- 75) U/L, P < 0.05]. The activities of Type IV collagenase, including MMP-2, MMP-9, were increased in PCP compared with negative control (P < 0.001) and bacterial pneumonia (P < 0.001, P < 0.01), and the activities of MMP-2 and MMP-9 had positive correlations with total cell counts in BALF (r = 0.652, P < 0.05; r = 0.803, P < 0.001).

CONCLUSIONS

It suggests that there are differences in the cellular and biochemical aspects of lung inflammation and injury between PCP and bacterial pneumonia.

[Preoperative arterial infusion chemotherapy of colorectal carcinoma pathological and clinical effects]

OBJECTIVE

To investigate the pathological and clinical effects of preoperative selective intra-arterial infusion chemotherapy on colorectal carcinoma.

METHODS

30 patients with colorectal carcinoma underwent selective regional arterial angiography by Seldinger's method followed by intra-arterial infusion chemotherapy.

RESULTS

changes of karyopyknosis, karyorrhexis, coagulation and necrosis of cytoplasm in cancer cells around vascular vessels were found in all cases. Interstitial edema, invasion of inflammatory cells, fibroelastosis around cancer cells, proliferous intima, thrombus and inflammation of vessels were also found at the same sites.

CONCLUSIONS

Histological changes are significant after preoperative selective intra-arterial infusion chemotherapy for colorectal carcinoma. This therapy can relieve symptoms.

[Experimental study on carotid artery resection with vascular replacement by an autogenous vein graft]

OBJECTIVE

In order to observe the survival rate and the histologic changes of the reestablished common carotid artery system.

METHOD

A planned resection of the carotid artery was done and the common carotid artery system was reestablished by interposing an autogenous external jugular vein graft in 15 white rabbits.

RESULT

12 survived, the other 3 rabbits died from graft thrombosis, the survival rate was 80%. Histologic examination demonstrated the smooth internal tunic in the anastomotic part of the carotid-jugular and no graft thrombosis. Angiography demonstrated the free circulation of the blood and no aneurysm in the anastomotic vein.

CONCLUSION

It is concluded that it is possible that in selected patients, a planned resection of the carotid artery with replacement by interposing an autogenous external jugular vein graft will be done.

[The level of expression of adhesion molecules CD44v6 and E-cadherin in colorectal cancer and analysis of correlates with metastasis]

OBJECTIVE

To determine the expression of adhesion molecules CD44v6 and E cadherin in colorectal cancer and its relation with metastasis.

METHODS

The expression of CD44v6 and E-cadherin in 32 patients with colorectal carcinoma was investigated using immunohistochemical staining, which was performed on surgical specimens.

RESULTS

No significant correlation with CD44v6 and histologic type, TNM and Dukes staging was noted, but it was significantly correlated with lymph node and hematogenous metastasis. E-cadherin was strongly expressed in normal epithelium examined. However, E-cadherin expression in colorectal carcinoma was reduced (positive rate 46.9%). Metastatic colorectal carcinoma showed significant reduction (positive rate 20%).

CONCLUSION

CD44v6, E-cadherin immunoreactivity are significantly correlated with lymph node and hematogenous metastasis.

Advance in the study of inhibin, activin and follistatin production in pregnant women

This review summarizes the new information on the studies of inhibin, activin, and follistatin production in the placenta during human pregnancy. Inhibin and activin exert suppressive and stimulatory effects, respectively, on the release of FSH in the pituitary. Follistatin is bound to inhibin and activin and indirectly modulates the FSH release. The placenta produces these three proteins. The serum levels of inhibin, activin, and follistatin are elevated in pregnant women and decrease after delivery. The trophoblast cells from term placenta secrete inhibin and activin in the primary cultures. The production and mRNA expression of inhibin and activin are regulated by several stimulatory and suppressive hormones and growth factors in placental tissues. cAMP, Ca2+, and protein kinase-C may be involved in intracellular signal transduction in trophoblasts. Activin receptors are present on placental cells. Follistatin inhibits the binding of activin to ActRII receptor. Abnormal levels of inhibin and activin in maternal serum are observed in problem pregnancies and gestational diseases. Inhibin, activin, and follistatin may play roles in the regulation of reproductive endocrinology in pregnant women and the embryo/fetal development.

PAK4, a novel effector for Cdc42Hs, is implicated in the reorganization of the actin cytoskeleton and in the formation of filopodia

The GTPases Rac and Cdc42Hs control diverse cellular functions. In addition to being mediators of intracellular signaling cascades, they have important roles in cell morphogenesis and mitogenesis. We have identified a novel PAK-related kinase, PAK4, as a new effector molecule for Cdc42Hs. PAK4 interacts only with the activated form of Cdc42Hs through its GTPase-binding domain (GBD). Co-expression of PAK4 and the constitutively active Cdc42HsV12 causes the redistribution of PAK4 to the brefeldin A-sensitive compartment of the Golgi membrane and the subsequent induction of filopodia and actin polymerization. Importantly, the reorganization of the actin cytoskeleton is dependent on PAK4 kinase activity and on its interaction with Cdc42Hs. Thus, unlike other members of the PAK family, PAK4 provides a novel link between Cdc42Hs and the actin cytoskeleton. The cellular locations of PAK4 and Cdc42Hs suggest a role for the Golgi in cell morphogenesis.

[Analysis of etiological agents and death-relating factors of pulmonary infections in immunocompromised patients]

OBJECTIVE

To explore the distribution of etiological agents and death-relating factors of pulmonary infections in immunocompromised hosts(ICH).

METHOD

80 patients of pulmonary infections in ICH confirmed by etiological and(or) pathological diagnosis were retrospectively analyzed.

RESULT

The distribution of etiological agents of pulmonary infections (except for cytomegalovirus, CMV): common bacteria 56%, mycobacterium tuberculosis 29%, fungus 11%, pneumocystis carinii 4%. Mortality of pulmonary infections in ICH showed significant difference between age 67% (> or = 60 years): 48% (< 60 years), bacteremia 86% (yes): 45% (no), white blood cell count 67%, 87% (> 10 x 10(9)/L, < 4.0 x 10(9)/L): 23% (4.0-10) x 10(9)/L, extent of lesions in x-ray film 65% (diffuse): 23% (local) (P < 0.05, P < 0.01), however, there was no obvious difference in sex, underlying diseases, types of etiological agents, mixed infections.

CONCLUSION

Bacteria was one of the most common etiological agents of pulmonary infections in ICH, the latent reactivation and relapse of pulmonary tuberculosis in ICH should be emphasized sufficiently. The preliminary analysis of death-relating factors showed: age, bacteremia, white blood cell count, extent of lesions in x-ray film were related to the prognosis of pulmonary infections in ICH.