[The experiment of pegylated liposomal doxorubicin to therapy tongue cancer and metastases lymph nodes]

OBJECTIVE

To investigate the effects of pegylated liposmal doxorubicin (PLD) in treating animal model of tongue cancer.

METHODS

The tongue cancer model was established in 70 goldn hamsters, and PLD was injected. The free doxorubicin and its concentration in circulating blood and lymph nodes, the weight of animals, volume of tumor, were defected.

RESULTS

Tumor inhibition effect of the PLD group was higher than controls.

CONCLUSIONS

PLD can be regarded as a valuable drug system to treat oral cancer.

[The influence of palatoplasty and tympanotomy on middle ear function in cleft palate patients]

OBJECTIVE

The aim of this study is to explore the influence of palatoplasty and tympanotomy on middle ear function or hearing condition in cleft palate patients.

METHODS

A total of 22 ears with otitis media with effusion in cleft palate patients were inserted with PE tubes, and Pre- and post-operative hearing level and middle ear function in these patients were tested and compared respectively, in order to demonstrate the action of tympanotomy and PE insertion on hearing and middle ear function. Another 38 patients with cleft palate were operated in their early age with the proper operation method, and pre- and post-operative middle ear function were examined and compared to show the influence of the operation on the middle ear function.

RESULTS

PE Tube insertion and tympanotomy changed the pressure condition of middle ear cavity and raised the hearing level about 17 dB in the middle-ear-diseased cleft palate patients, and patients with palatoplasty did not show obvious changes in middle ear function in the short-term trail.

CONCLUSION

Early and active tympanotomy do help in improving the function of the middle ear, and it is suggested to improve patients' hearing and middle ear function as early as possible. Palatoplasty did not affect the function of middle ear.

Outcome prediction in severe traumatic brain injury with transcranial Doppler ultrasonography

OBJECTIVE

To investigate the value of transcranial Doppler (TCD) ultrasonography in evaluating the outcome of severe traumatic brain injury and to correlate the TCD values with intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring.

METHODS

A prospective study was conducted to evaluate the contribution of TCD ultrasonography to neurological outcome in a series of 96 severe traumatic brain injury patients. The quantitative variables of TCD ultrasonography included the mean blood flow velocity of the middle cerebral artery (MCA) and pulsatility index within the first 24 hours of admission. The ICP and CPP values were a lso recorded. Outcome in 6 months postinjury was evaluated using the Glasgow Outcome Scale (GOS 4-5 was considered as "good" and GOS 1-3 as "poor").

RESULTS

The mean blood flow velocity of the MCA was larger than 40 cm/s in 30 (51%) patients with good outcome whereas it was less than 40 cm/s in 27 (73%) patients with poor outcome (P<0.025). The mean PI in cases of good outcome (34 patients, 57%) was lower than 1.5 whereas in poor outcome (30 patients, 83%) was higher than 1.5 (P<0.001). The correlations of ICP and CPP to pulsatility index were statistically significant (P<0.01).

CONCLUSIONS

TCD ultrasonography is valid in predicting the patient's outcome of 6 months and correlates significantly with ICP and CPP values when it is performed in the first 24 hours of severe traumatic brain injury.

[Cell proliferation in odontogenic jaw cyst epithelium]

OBJECTIVE

The aim of the study is to investigate the epithelial cell proliferation in the lining of odontogenic cysts with Ki-67 monoclonal antibody.

METHODS

Ki-67 expression was studied in 30 odontogenic cysts (odontogenic keratocysts, n = 10; dentigerous cyst, n = 10; radicular cysts, n = 10), and normal oral epithelium (n = 10) by using a biotin streptavidin method on routinely processed paraffin sections after microwave treatment. Ki-67+ cells were counted manually and related to the area of epithelial lining as determined by computer image analyzer. The result was analyzed by using a computer image analyzer to calculate positive cells per square millimeter of the epithelial lining of odontogenic lesions. Data were analyzed by using student test.

RESULTS

The epithelial lining of odontogenic keratocysts contained the highest number of Ki-67+ cells, most of which were located in the suprabasal layers. The mean value of Ki-67+ cells in odontogenic keratocysts linings (1812.29 +/- 606.47 cells/mm2) were significantly higher than that of dentigerous (944.43 +/- 58.98 cells/mm2) and radicular cysts (610 +/- 26.4 cells/mm2) (P < 0.01). Negative reactions were obtained in the normal oral epithelium.

CONCLUSION

The results demonstrate that there are differences in Ki-67 expression between epithelial linings of the major odontogenic cysts, which were consistent with odontogenic keratocysts having a greater proliferative capability than dentigerous and radicular cysts. It also indicates differences in proliferation and differentiation processes within these lesions.

[The mutation of anti-CD3 antibody (HIT3a) gene and its expression]

OBJECTIVE

To improve the expression of anti-CD(3) single chain Fv (scFv) by site mutation and identify its biological activity.

METHODS

Anti-CD(3) scFv gene was mutated by PCR, the target clones were screened by both the fingerprints of DNA restriction endonuclease digestion and Western blot, the antigen-binding activity of scFv was examined by FACS, competitive inhibition was performed with (125)I-labeled HIT3a and the cytotoxic effect mediated by the anti-CD(3) scFv-activated T lymphocytes was analyzed by (51)Cr-released assays.

RESULTS

The DNA sequencing showed that the 6th amino acid of the anti-CD(3) antibody (HIT3a) heavy chain gene was mutated from E (GAG) to Q (CAG). The expression of mutated anti-CD(3) scFv (m2) was increased by 100 times higher than that of the parent scFv, and there was no difference in the Jurkat cell (CD(3)(+))-binding activity between the (m2) and parent scFv. The preliminary results of competitive assays showed that m2 could partially block the sites of CD(3)(+) Jurkat cells where the parent antibody bound to. Cytotoxicity assays demonstrated that CD(3)AK cells induced by IL-2 and m2 showed stronger cytotoxic effect than that of LAK cells induced by IL-2 alone in vitro.

CONCLUSION

By site mutation, a high expression fragment m2 of anti-CD(3) scFv antibody was obtained. The results of some experiments indicated that m2 could bind to CD(3)(+) Jurkat cells, furthermore, by co-stimulated with IL-2, it could activate peripheral T lymphocytes and induce CD(3)AK cytotoxic effect.

Heteronuclear nuclear magnetic resonance assignments, structure and dynamics of SUMO-1, a human ubiquitin-like protein

The structure of a ubiquitin-like protein, small ubiquitin-related modifier-1 (SUMO-1), was earlier determined using homonuclear nuclear magnetic resonance (NMR) spectroscopy, since the spectral quality of the protein was not suitable for heteronuclear NMR data collection. In this study, a slightly different construct of the SUMO-1 gene was used for protein over-expression. The protein purified from this construct showed high spectral qualities, therefore, multi-dimensional heteronuclear NMR data for a dynamic study and structural determination were acquired. The structure of SUMO-1 obtained in this study differs in several respects from the structure obtained from homonuclear NMR data. Furthermore, structural differences were observed between the new SUMO-1 and ubiquitin structures. These differences may be important for SUMO-1-specific recognition in cells. Additionally, relaxation parameters indicate that SUMO-1 undergoes highly anisotropic tumbling in solution and that the long amino (N)-terminal sequence of SUMO-1 is highly dynamic with increasing flexibility towards the end.

[Effect of shenfukang on nephropathy rats induced by adriamycin]

Adriamycin-induced nephropathy (AIN) model in rats (mainlining 7.5 mg/kg avoirdupois adiramycine) was adopted to explore the effect of Shenfukang (SFK). The results showed that SFK could remarkably reduce the content of urine protein, cholesterol, creatinine and urinary nitrogen in serum, MDA in serum and renal cortex of AIN model rats. And SFK also could increase the content of album and golbulin in serum, the activities of SOD in serum and renal cortex of AIN model rats.

CONCLUSION

SFK played an important role on AIN.

[Preliminary study of closing cleft of soft palate at an early age for complete cleft palate]

OBJECTIVE

The aim is to introduce the method closing the soft palate at an early age in order to produce better speech and lessen interruption to the development of maxilla.

METHODS

Clinical data of 37 cases with treated cleft were preliminarily analyzed. Some dental casts were measured.

RESULTS

1. No complications of anaesthesia and surgery. Except 2 cases whose soft palates were split after surgery were observed as they were coughing. 2. A reduction in the width of the hard palate cleft was noticed.

CONCLUSION

Closing the soft palate at an early age is possible and safe. It shows that the Langebeck method could be used to close the hard palate of patients at an early age.

[Influences of age and gender on dose-response and recovery time-course of atracurium]

OBJECTIVES

To evaluate the influences of age and sex on dose-response and recovery time course of atracurium.

METHODS

Seventy-two patients (38 men and 34 women), ASA grade I, aged 15-59 years, scheduled for elective surgery were included in the study. All patients were divided into three groups according to their ages: Group 1, 32 patients aged 15-29 years; Group 2, 21 patients aged 30-40 years, and Group 3, 19 patients aged 41-59 years. General anesthesia was maintained with 60% nitrous oxide in oxygen, thiopentone and fentanyl. Neuromuscular function was assessed by train-of-four(TOF) stimulation of accelerometry and the percentage depression of the first response (T1) of the TOF stimulus was used as the study parameter. The dose-response relations of atracurium were determined by the cumulative dose-response technique.

RESULTS

As compared to older and female patients, dose-response curves of atracurium in young and male patients were shifted in a parallel fashion to the left. The dose-response relation of atracurium correlated closely with patients' ages and sexes by multiple linear regression analysis. There were significant differences of ED50, ED90 and ED95, and clinical duration and total duration of action following administration of atracurium of same doses between the three age groups as well as men and women.

CONCLUSIONS

Age and gender could significantly affect the pharmacodynamics of atracurium.

Dielectric properties of supersaturated alpha-D-glucose aqueous solutions at 2450 MHz

Dielectric properties of supersaturated alpha-D-glucose aqueous solutions (45-56% w/w) at 2.45 GHz were investigated at temperatures ranging from 25 degrees C to 85 degrees C. Penetration depth was calculated as well. At each temperature tested, there exists a concentration range at which the dielectric constants or loss factors for supersaturated glucose solutions are independent of concentration. These results will be helpful in studies of the Maillard reaction as it occurs in a microwave field.

Analysis of cytadherence-deficient, GapA-negative Mycoplasma gallisepticum strain R

Comparison of the phenotypic expression of Mycoplasma gallisepticum strain R low (passage 15) to that of strain R high (passage 164) revealed that three proteins, i.e., the cytadhesin molecule GapA, a 116-kDa protein (p116), and a 45-kDa protein (p45), are missing in strain R high. Sequence analysis confirmed that the insertion of an adenine 105 bp downstream of the gapA translational start codon resulted in premature termination of translation in R high. A second adenine insertion had also occurred at position 907. Restoration of expression of wild-type gapA in R high (clone designated GT5) allowed us to evaluate the extent to which the diminished cytadherence capacity could be attributed to GapA alone. The results indicated that GT5 attached to the same limited extent as the parental R high, from which it was derived. The cytadherence capability of the parental R high was not restored solely by gapA complementation alone, indicating that either p116 or p45 or both may play a role in the overall cytadherence process. The gene encoding p116 was found to be immediately downstream of gapA in the same operon and was designated crmA. This gene exhibited striking homology to genes encoding molecules with cytadhesin-related functions in both Mycoplasma pneumoniae and Mycoplasma genitalium. Transcriptional analysis revealed that crmA is not transcribed in R high. We are currently constructing a shuttle vector containing both the wild-type gapA and crmA for transformation into R high to assess the role of CrmA in the cytadherence process.

A comparative study of the dose-response and time course of recovery of atracurium and rocuronium

OBJECTIVE

To compare the characteristics of the dose-response relationship and the time course of action between atracurium and rocuronium in adult patients anesthetized with N2O-O2-fentanyl-thiopene.

METHODS

Sixty patients, ASA grade I, aged 18-50 years, scheduled for elective plastic surgery were studied. All patients were randomly divided into either the atracurium or rocuronium group. General anesthesia was maintained with 60% nitrous oxide and 40% oxygen, thiopentone, and fentanyl. Neuromuscular function was assessed using an accelograph with train-of-four (TOF) stimulation at the wrist every 12 seconds. The percentage depression of the first twitch (T1) was used as the study parameter. The dose-response relationship of atracurium and rocuronium was determined by the cumulative dose-response technique.

RESULTS

According to the dose-response curves established by a least squares linear regression, the potency ratio of atracurium to rocuronium was 1:1.2. There were significant differences in the ED50, ED90, and ED95 between the two drugs. After the intravenous administration of equipotent doses of both drugs (1.5 x ED95), the duration of peak effect, clinical duration, and total duration were significantly different between the two drugs, but their recovery indexes were similar.

CONCLUSIONS

Atracurium and rocuronium are low-potency nondepolarizing relaxants with intermediate duration. As compared to atracurium, the neuromuscular blocking effect of rocuronium was about 20% less potent and its duration of action was shorter.

[New triterpenoid saponins from Anemone begoniifolia]

AIM

To study the triterpenoid saponins in the whole plants of Anemone begoniifolia Lévl. et Vant.

METHODS

Methanol extraction, normal and reversed phase silica gel column chromatography and various spectral analysis were used to isolate and determine the structures of the triterpenoid saponins.

RESULTS

Four triterpenoid saponins were idenetified as: 3-O-beta-D-glucopyranosyl(1-->2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (1), 3-O-beta-D-glucopyranosyl (1-->3)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (2), 23-O-methyl malonyl hederagenin 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (3) and 3-O-methyl malonyl hederagenin 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranoside (4).

CONCLUSION

Compunds 2, 3 and 4 are new compounds and named as begoniifolides A, B and C, respectively.

Lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions

OBJECTIVE

To investigate lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions.

METHODS

5'-Nase and Aplase expressions and the morphology of lymphatics in gastric carcinoma tissues were observed with enzyme histochemistry. Flt-4 and Flk-1 expression in gastric carcinoma and sarcoma tissues was studied by immunohistochemistry. CNE-2z cells were implanted into the subdermal layer of nude mice and hyaluronic acid was injected at the same sites. After 4 or 5 weeks, nasopharyngeal carcinoma (NPC) xenograft tissues were cut for immunohistochemistry and enzyme histochemistry, and lymphangiogenesis, 5'-Nase, Alpase, Flt-4 and Flk-1 expression in NPC tissues was studied. Hyaluronic acid contents in sera of the patients with NPC and mice with NPC xenografts were measured by radioimmunoassay.

RESULTS

There were a lot of lymphatics and solid strip-like tissues in gastric carcinoma and NPC xenograft treated with hyaluronic acid. The total number of lymphatics (26.9 +/- 14.2/HP) increased significantly in gastric carcinoma tissues. Flt-4 and Flk-1 positive expression was found in gastric carcinoma, sarcoma tissues and NPC xenograft. Most of the vessels with positive Flt-4 were lymphatics. Flk-1 expression was only found in the walls of blood vessels. Hyaluronic acid content (363.52 +/- 98.15 ng/ml) in sera of patients with NPC was higher than that of the patients with chronic nasopharyngeal inflammation (306.29 +/- 27.15 ng/ml), with a significant difference (P = 0.039). The hyaluronic acid content in sera of nude mice with NPC (2120.59 +/- 490.22 ng/ml) was markedly higher than that in normal mice (1588.99 +/- 502.12 ng/ml), with a significant difference between them (P = 0.007).

CONCLUSION

There are a lot of lymph capillaries with positive 5'-Nase in gastric carcinoma and NPC xenograft treated with hyaluronic acid. Flt-4 positive expression is shown in gastric carcinoma, sarcoma tissues and NPC xenografts. The results suggest there is lymphangiogenesis in these malignant tumor tissues. Hyaluronic acid contents in sera of patients with NPC and nude mice with NPC increase, which may promote the formation of lymphatics.

Molecular characterization of a parasitic tapeworm (Ligula) based on DNA sequences from formalin-fixed specimens

Museum specimens of Ligula (Pseudophyllidea, Ligulidae), a fish parasite tapeworm, that have been preserved in ethanol or fixed permanently in formalin up to 24 years were used for DNA extraction and molecular characterization. DNA was amplified via PCR from samples collected from different fish hosts that lived in both salt and fresh water bodies in the Chinese Qinghai-Tibet Plateau, Russia, and England. Phylogenetic analyses based on partial nucleotide sequences of the 5'-end of nuclear 28S rRNA gene and the mitochondrial cytochrome c oxidase subunit I (COI) gene support the morphologically based taxonomy that groups the Chinese Ligula within the same species as their Europe counterpart: Lingula intestinalis. No nucleotide variation was detected in either the 28S rRNA gene or the COI gene among the seven plerocercoid samples, suggesting a considerable genetic homogeneity among Ligula from different regions. Our results show that geographic isolation, affinity of hosts, and host habitats are not reliable taxonomic criteria for Ligula classification. Our data also indicate a low genetic diversity in the Ligula prevalent in China and in Europe. Our experiments demonstrate that endogenous DNA from specimens that were subjected to permanent formalin fixation can be routinely amplified from parasitic tapeworms, suggesting that fixation time in formalin may not be a critical factor affecting DNA degradation in such museum specimens.

[In vitro induction of autologous T cell killing by heat treated human chronic myelogenous leukemia cells]

OBJECTIVE

To investigate the potential of autologous T cell killing of heat treated chronic myelogenous leukemia (CML) cells (autologous tumor killing, ATK).

METHODS

(51)Cr release assay was used to measure the ATK activity of autologous T cells against CML cells treated with 42 degrees C for 30 minutes (heat) or 37 degrees C for 30 minutes (non-heat). The phenotypes of T cells and heat shock protein 70 (HSP70) expression of CML cells were measured by flow cytometry (FCM). T cells from the CML patients were stimulated and expanded by autologous mixed lymphocyte/tumor cell cultures (MLTC).

RESULTS

ATK activity of autologous T cells to the non-heated and heated CML cells were found in 4 (19.05%) and 10 (47.62%) of the 21 cases, respectively. The ATK activity of interleukin-2 (IL-2) stimulated autologous T cells against heated CML cells was markedly higher than that of unstimulated autologous T cells against non-heated CML cells (P < 0.001). FCM analysis showed that no HSP70 was expressed on the CML cell membranes whether heated or non-heated, but intracellular HSP70 expressions were (83.42 +/- 5.65)% and (78.34 +/- 6.32)% pre- and post-heated, respectively. The phenotypes of T cells stimulated and expanded in MLTC were TCRgammadelta - CD(3)(+), mostly CD(8)(+), with some activation markers (CD(25) and HLA-DR) expression. The ATK activities of these T cells against the heated and non-heated CML cells and K562 cells were (51.25 +/- 4.26)%, (36.52 +/- 3.83)% and (2.92 +/- 1.19)%, respectively.

CONCLUSIONS

ATK activity of autologous T cells against CML cells could be induced or enhanced by heat treatment of the CML cells particularly of T cells stimulated with IL-2. This ATK activity was not associated with gammadelta T cells or HSP70 expression of CML cells.

[Classification of eyelid and designs of the double-eyelid operation]

OBJECTIVE

To discuss the morphological characters of eyelids and the designs of double-eyelid operation on various eyelids.

METHODS

The classification of eyelids was named according to morphological characters of eyelids from 6847 cases. A survey of 92 cases treated by double-eyelid operation was carried out to compare the external eye morphology of pre-operation with that of post-operation.

RESULTS

There were several types of eyelids, which were morphologically classified according to eyes' length and height, eyelid skin thickness, eyeball protrusion and eye shape, including eyelids with long and narrow eyes, eyelids with thin and soft skin, eyelids with thick subcutaneous tissue, eyelids with small and round eyes, eyelids with protruding eyeball, and eyelids with triangle eyes. The aesthetic effects of double-eyelid operation on all these types of eyelids were evaluated.

CONCLUSION

The indication of double-eyelid operation should be considered correctly, and the design should be made according to classification of the morphological characters of eyelids. Double-eyelid operation may be not appropriate for the eyelids with small, round and protruding eyes.

t(1) noise and sensitivity in pulsed field gradient experiments

In this paper, a calculation routine based on product operator formalism and coherence pathway is presented, which describes t(1) noise and sensitivity in pulsed field gradient experiments. Several examples including the absolute value mode pulsed field gradient COSY, MQF-COSY, MQC, HMQC, and NOESY sequences are investigated to study the t(1) noise stemming from the phase errors of radiofrequency (RF) pulses and the sensitivity affected by RF pulse rotation angles. Our theoretical results indicate that the t(1) noises in P-type COSY, multiple-quantum-filtered (MQF)-COSY, and multiple-quantum coherence (MQC) are lower than those in the N-type corresponding experiments, while in HMQC and NOESY there is no difference in t(1) noise effects between P-type and N-type spectra. Meanwhile, from the calculations, we obtained the optimized RF pulse rotation angles in those sequences. In MQF-COSY, an increase in sensitivity of about 4(cos(2)&theta; sin(q-1)2&theta;)(2) - 1 (&theta; = arc cot can be achieved by using the optimized angles. In MQC, the increase is 2 cos(2)&theta; sin(q-1)2&theta; - 1 (&theta; = arc cot. MQF-COSY experiments are also carried out to support our corresponding theoretical results.

A winged helix protein from yeast Saccharomyces cerevisiae recognizes centromere sequences

The winged helix-turn-helix motif was initially identified in the mammalian hepatocyte-enriched transcription factor HNF-3 and the Drosophila forkhead homeotic protein. Proteins containing the winged helix motif have been shown to play important roles in tissue-specific developmental regulation. In this report, by using a genomic binding site selection method, we demonstrate that the winged helix protein YFKH-1 from the yeast Saccharomyces cerevisiae recognizes conserved sequence in yeast centromeres. Thus, our data suggest that the winged helix proteins of the yeast may be involved in centromeric functions of the yeast.

Influence of acute normovolaemic haemodilution on the dose-response and time-course of action of atracurium

BACKGROUND

Acute normovolaemic haemodilution is a common method to save and avoid homologous blood transfusion during surgery. The aim of this study was to evaluate the influence of acute isovolaemic haemodilution on the dose-response and time-course of action of atracurium.

METHODS

We studied 25 patients undergoing acute isovolaemic haemodilution during surgery and 25 patients not receiving haemodilution as a control group. All patients were ASA grade I and aged 18-54 yr. The haemodilution patients underwent major elective plastic surgery with an anticipated surgical blood loss of more than 600 ml, and the control patients underwent elective superficial plastic surgery with an anticipated surgical blood loss of less than 200 ml. Anaesthesia was induced with thiopental 4-6 mg/kg and fentanyl 2-4 microg/kg i.v., and maintained with 60% nitrous oxide in oxygen. After stabilization of anaesthesia, acute isovolaemic haemodilution in the haemodilution group was achieved by drainage of venous blood and an i.v. infusion of lactated Ringer's solution, and 6% dextran, during which haematocrit and haemoglobin decreased from 45.1% to 25.8% and from 147.2 g/l to 91.2 g/l, respectively. When anaesthesia was stable in the control group and haemodilution was completed in the haemodilution group, neuromuscular function was assessed by measuring with accelerography the response of the adductor pollicis muscle to supramaximal train-of-four (TOF) stimuli every 12 s to the ulnar nerve at the wrist via surface electrodes. The dose-response relationships of atracurium in the two groups were determined by the cumulative dose-response technique.

RESULTS

The results showed that during haemodilution, the dose-response curve of atracurium was shifted to the left in a parallel fashion and the potency of atracurium was increased. In patients undergoing haemodilution, ED50, ED90 and ED95 of atracurium were decreased by 25-33%, and duration of action was increased by 21-48% following administration of the same dose (mg/kg), as compared with patients not undergoing haemodilution.

CONCLUSION

We concluded that the patients undergoing acute isovolaemic haemodilution were about 30% more sensitive to neuromuscular blockade of atracurium and had a longer duration after administration of the same dose (microg/kg) than the control patients. Care must be taken with this problem when atracurium is used as a muscle relaxant during acute haemodilution.

NMR solution structure of the receptor binding domain of human alpha(2)-macroglobulin

Human alpha(2)-macroglobulin-proteinase complexes bind to their receptor, the low density lipoprotein receptor-related protein (LRP), through a discrete 138-residue C-terminal receptor binding domain (RBD), which also binds to the beta-amyloid peptide. We have used NMR spectroscopy on recombinantly expressed uniformly (13)C/(15)N-labeled human RBD to determine its three-dimensional structure in solution. Human RBD is a sandwich of two antiparallel beta-sheets, one four-strand and one five-strand, and also contains one alpha-helix of 2.5 turns and an additional 1-turn helical region. The principal alpha-helix contains two lysine residues on the outer face that are known to be essential for receptor binding. A calcium binding site (K(d) approximately 11 mM) is present in the loop region at one end of the beta-sandwich. Calcium binding principally affects this loop region and does not significantly perturb the stable core structure of the domain. The structure and NMR assignments will enable us to examine in solution specific binding of RBD to domains of the receptor and to beta-amyloid peptide.

[B7 and DC vaccines induced anti-tumor immunity against murine T-lymphocyte leukemia L615]

OBJECTIVE

To study the effect of B7 and DC vaccines in inducing anti-tumor immunity in murine T-lymphocyte leukemia L615.

METHODS

In vivo, murine mortality and survival were observed to compare the difference between B7 and DC vaccine in inducing immunoprotection against the subsequent challenge of live L615 cells;in vitro, specific cytotoxic assay and MLR were performed to test the specific cytotoxicity and proliferative activity of effective T cells.

RESULTS

Both vaccines could efficiently improve T cell mediated anti-leukemic immunity in syngenic hosts, and DC vaccine was revealed to be more efficient. In vitro observations showed that both vaccines could induce tumor specific cytotoxicity and proliferative activity of effective T cells.

CONCLUSION

DC vaccine is promising in tumor immunotherapy owing to its safety, efficiency and convenience.

Limited contributions of serotonin to long-term hyperexcitability of Aplysia sensory neurons

Serotonin (5-HT) has provided a useful tool to study plasticity of nociceptive sensory neurons in Aplysia. Because noxious stimulation causes release of 5-HT and long-term hyperexcitability (LTH) of sensory neuron somata and because 5-HT treatment can induce long-term synaptic facilitation of sensory neuron synapses, a plausible hypothesis is that 5-HT also induces LTH of the sensory neuron soma. Prolonged or repeated exposure of excised ganglia to 5-HT produced immediate hyperexcitability of sensory neurons that showed little desensitization, but the hyperexcitability decayed within minutes of washing out the 5-HT. Prolonged or repeated treatment of either excised ganglia or dissociated sensory neurons with various concentrations of 5-HT failed to induce significant LTH even when long-term synaptic facilitation was induced in the same preparations. Use of a high-divalent cation solution to reduce interneuron activity during 5-HT treatment failed to enable the induction of LTH in excised ganglia. Pairing 5-HT application with nerve shock failed to enhance LTH produced by nerve shock or to reveal covert LTH produced by 5-HT. The induction of LTH by nerve stimulation was enhanced rather than inhibited by treatment with methiothepin, a 5-HT antagonist reported to block various 5-HT receptors and 5-HT-induced adenylyl cyclase activation. This suggests that endogenous 5-HT may have inhibitory effects on the induction of LTH by noxious stimulation. Methiothepin blocked immediate hyperexcitability produced by exogenous 5-HT and also inhibited the expression of LTH induced by nerve stimulation when applied during testing 1 day afterward. At higher concentrations, methiothepin reduced basal excitability of sensory neurons by mechanisms that may be independent of its antagonism of 5-HT receptors. Several observations suggest that early release of 5-HT and consequent cAMP synthesis in sensory neurons is not important for the induction of LTH by noxious stimulation, whereas later release of 5-HT from persistently activated modulatory neurons, with consequent elevation of cAMP synthesis, may contribute to the maintenance of LTH.

[Experimental study on apoptosis and Apo-1 expression of buccal carcinoma cell(BCC) induced by cisplatin]

OBJECTIVE

To study apoptotic characteristics and expression of apoptosis molecule Apo-1 (Fas, CD95) on buccal carcinoma cell (BCC) induced by cytotoxic drug cisplatin and exploit the apoptotic mechanisms of oral cancer chemotherapy.

METHODS

Human BCC line BcaCD885 was used as in vitro study object. Morphological features of apoptotic BCC induced by cisplatin were observed by use of lightmicroscopy and electronmicroscopy, meanwhile, apoptotic rates (AR) were analysed by the flow cytometry.

RESULTS

1. Condensation and crack of nucleus and apoptotic bodies appeared in apoptotic BCC; 2. There existed time and dosage dependent AR, and AR were respectively 5.4%, 7.4%, 9.4%, 20.3% and 22.6% after BCC had been acted by 15 micrograms/ml cisplatin for 2, 6, 12 and 24 hours, moreover, there was significantly difference (P < 0.01) among the 12-hour group, the 24-hour group and the control group; 3. Cell cycle of BCC was apparently arrested at G0/G1 by cisplatin (P < 0.05); 4. Apo-1 expression of BCC were enhanced 58% and 62% respectively after it was induced by 25 micrograms/ml cisplatin for 18 and 42 hours (P < 0.05).

CONCLUSION

Apoptosis may be an important mechanism of BCC killed by cisplatin, and Apo-1 may play a role in the process of apoptosis induced by chemotherapy drugs.

Backbone dynamics of a winged helix protein and its DNA complex at different temperatures: changes of internal motions in genesis upon binding to DNA

The dynamic properties of a winged helix protein, Genesis, and its DNA complex at different temperatures were studied. Due to the complexity of motions, the commonly used model-free formalism could not be used to reflect the dynamic properties. The reduced spectral density function mapping approach was proven to be a useful tool to describe the overall and internal motion of molecules on the picosecond to nanosecond time-scale, and conformational exchanges on the microsecond to millisecond time-scale. The local motions in DNA-free Genesis showed strong temperature dependence and the backbone dynamics of each secondary structural element responds to the temperature change differently, while the Genesis-DNA complex showed more stability with changing the temperatures. Furthermore, each DNA contact sequence of Genesis showed distinct dynamic perturbation after Genesis binds to DNA.

Influences of age and gender on dose response and time course of effect of atracurium in anesthetized adult patients

STUDY OBJECTIVE

To determine the influences of age and gender on the dose response and the time course of effect of atracurium.

DESIGN

Prospective, nonrandomized, clinical comparison.

SETTING

Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College.

PATIENTS

72 adult ASA physical status I patients (38 male and 34 female), aged 15 to 59 years, scheduled for elective plastic surgery.

INTERVENTIONS

Patients were divided into the three groups on the basis of age: Group 1, patients aged 15-29 years (n = 32); Group 2, patients aged 30-40 years (n = 21); and Group 3, patients aged 41-59 years (n = 19). Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. The dose-response relationship of atracurium was determined by a cumulative dose-response technique.

MEASUREMENTS AND MAIN RESULTS

Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 seconds and the percentage depression of first twitch (T1) response was used as the study variable. Age and gender significantly affected the dose-response relationship and time course of recovery of atracurium. Advancing age was associated with a reduced effective doses (ED50, ED90, and ED95) of atracurium and a longer duration of action. The effective doses of atracurium were greater, and its duration of action was shorter in men than in women. There were significant differences in the 50%, 90%, and 95% effective dose (ED50, ED90, and ED95) of atracurium, and clinical duration and total duration following administration of atracurium 400 micrograms/kg among the three age groups, and between men and women.

CONCLUSIONS

Age and gender have significant effects on the dose response and time course of effect of atracurium. Older patients and women are more sensitive to atracurium-induced neuromuscular block than are young patients and men.

Dynamic DNA contacts observed in the NMR structure of winged helix protein-DNA complex

Genesis is an HNF-3/fkh homologous protein. By using multi-dimensional NMR techniques, we have obtained the solution structure and backbone dynamics of Genesis complexed with a 17 base-pair DNA. Our results indicate that both the local folding and dynamic properties of Genesis are perturbed when it binds to the DNA site. Our data show that a conserved flexible amino acid sequence (wing 1) makes dynamic contacts to DNA in the complex and a short helix is induced by Genesis-DNA interactions. Our data indicate that, unlike the HNF-3gamma/DNA complex, a magnesium ion is not required in forming the stable Genesis-DNA complex.

The binding interface between an E2 (UBC9) and a ubiquitin homologue (UBL1)

Human UBC9 is a member of the E2 (ubiquitin conjugation enzyme) family of proteins. Instead of conjugating to ubiquitin, it conjugates with a ubiquitin homologue UBL1 (also known as SUMO-1, GMP1, SMTP3, PIC1, and sentrin). UBC9 has been shown to be involved in cell cycle regulation, DNA repair, and p53-dependent processes. The binding interfaces of the UBC9 and UBL1 complex have been determined by chemical shift perturbation using nuclear magnetic resonance spectroscopy. The binding site of UBL1 resides on the ubiquitin domain, and the binding site of UBC9 is located on a structurally conserved region of E2. Because the UBC9-UBL1 system shares many similarities with the ubiquitin system in structures and in conjugation with each other and with target proteins, the observed binding interfaces may be conserved in E2-ubiquitin interactions in general.

[Effects of microwave acute irradiation on biomechanic properties of rabbit tissues]

The rabbit body was irradiated acutely by 2.45 GHz continuous microwave. After irradiation, the values of blood viscosity, blood viscoelasticity, platelet aggregation, erythrocyte fragility, erythrocyte deformation, erythrocyte aggregation, the compressive mechanic property and flexible property of bones were tested. The data of irradiated group and unirradiated group were compared. The results showed: after microwave irradiation, the rabbit blood viscosity and viscoelasticity decreased; the rabbit platelet aggregation rate decreased and the disaggregation rate increased; the erythrocyte fragility increased; the biomechanic properties of bones did not change considerably.

[Study of cleft palate with problems of middle ears and its treatment]

OBJECTIVE

To gain a clear idea of the following: 1. the relationship between the incidence of functional obstruction of middle ear and surgery on cleft palate and patients' age; 2. the bacterial culture of secretion taken from the tympanic cavity with secretory otitis media; 3. the preliminary effects of treatment by inserting a tube into the tympanic cavity of a patient with secretory otitis media.

METHODS

275 middle ears of patients with cleft palate were selected, then acoustic immitence examination and hearing threshold of pure tone were adopted, and bacterial culture was carried out for studying secretion of the middle ear with secretory otitis media.

RESULTS

The tympanograms of 75.5% ears of the patients before cleft palate operation were found to be abnormal, among which patients under 3 years were 81%, and 41.2% ears of those after closure of cleft palate were abnormal. Gram's positive and negative germs of bacterial culture were 20.1% and 24% respectively. The hearing of 6 ears with secretory otitis media has recovered from the moderate hearing loss due to tube insertion. And the tympanograms of 4/8 ears were transformed from type B to type A.

CONCLUSION

It is beneficial to improve function of Eustachian tube if cleft palate can be repaired at an early stage and beneficial to improve the patients' hearing and devlope their speech if a tube is inserted into the typanic cavity in cases of secretory otitis media at an early stage.

Observation of the correlation of postanaesthesia recovery scores with early postoperative hypoxaemia in children

To observe the correlation of the postanaesthesia recovery score (PARS) with the incidence, and severity of early postoperative hypoxaemia in children, 1213 infants and children, ASA physical status I, aged three months to 14 years, scheduled for elective plastic surgery were included in this study. Arterial oxygen saturation (Spo2) levels were recorded while children were breathing room air shortly after arrival in the recovery room (0 min), and 5, 10, 15, 20, 30, 40, 50, 60, 120 and 180 min thereafter. The PARS was also determined on all patients when Spo2 levels were recorded in the recovery room. On the basis of different PARS, children were divided into the three groups: Group 1-children having the PARS of < or = 6; Group 2-children having the PARS of 7-9; and Group 3-children having a PARS of 10. The results showed that during the early postoperative period, the incidence and severity of hypoxaemia correlated closely with the PARS. The lower the children's PARS, the higher the incidences of hypoxaemia (Spo2 = 86-90%) and severe hypoxaemia (Spo2 < or = 85%). The incidences of hypoxaemia and severe hypoxaemia were 12.9% and 15.8%, respectively, in Group 1, 20.9% and 2.9% in Group 2, 0.8% and 0% in Group 3. There were significant differences among the three groups. Of the 91 children who required O2 supplementation in the recovery room because of low measured Spo2, 69 had the PARS of < or = 6, and 22 had the PARS of 7-8. It is concluded that if a patient has a PARS of 10, the patient will not need routine oxygen supplement because hypoxaemia will not occur.

In vivo proliferation and cell cycle kinetics of long-term self-renewing hematopoietic stem cells

A rare set of hematopoietic stem cells (HSC) must undergo a massive expansion to produce mature blood cells. The phenotypic isolation of HSC from mice offers the opportunity to determine directly their proliferation kinetics. We analyzed the proliferation and cell cycle kinetics of long-term self-renewing HSC (LT-HSC) in normal adult mice. At any one time, approximately 5% of LT-HSC were in S/G2/M phases of the cell cycle and another 20% were in G1 phase. BrdUrd incorporation was used to determine the rate at which different cohorts of HSC entered the cell cycle over time. About 50% of LT-HSC incorporated BrdUrd by 6 days and >90% incorporated BrdUrd by 30 days. By 6 months, 99% of LT-HSC had incorporated BrdUrd. We calculated that approximately 8% of LT-HSC asynchronously entered the cell cycle per day. Nested reverse transcription-PCR analysis revealed cyclin D2 expression in a high proportion of LT-HSC. Although approximately 75% of LT-HSC are quiescent in G0 at any one time, all HSC are recruited into cycle regularly such that 99% of LT-HSC divide on average every 57 days.

The dissociation rate of a winged helix protein-DNA complex is influenced by non-DNA contact residues

The dissociation constants and the half-lives of the DNA complexes of winged helix protein Genesis and its mutants were investigated. Our data show that substitutions of non-DNA contact residues in the two highly dynamic wing sequences dramatically change the off rates of the complexes. Thus, our data indicate that the off rate of a DNA complex is encoded in the amino acid sequence of the DNA-binding protein and/or should be a unique property for a protein-DNA complex. Our data also indicate that the local structural transition of a DNA-binding protein in its DNA recognition process is likely to go through a transition state, which can control the on and off rates of a complex.

Activation of protein kinase A contributes to the expression but not the induction of long-term hyperexcitability caused by axotomy of Aplysia sensory neurons

Nociceptive sensory neurons (SNs) in Aplysia provide useful models to study both memory and adaptive responses to nerve injury. Induction of long-term memory in many species, including Aplysia, is thought to depend on activation of cAMP-dependent protein kinase (PKA). Because Aplysia SNs display similar alterations in models of memory and after nerve injury, a plausible hypothesis is that axotomy triggers memory-like modifications by activating PKA in damaged axons. The present study disproves this hypothesis. SN axotomy was produced by (1) dissociation of somata from the ganglion [which is shown to induce long-term hyperexcitability (LTH)], (2) transection of neurites of dissociated SNs growing in vitro, or (3) peripheral nerve crush. Application of the competitive PKA inhibitor Rp-8-CPT-cAMPS at the time of axotomy failed to alter the induction of LTH by each form of axotomy, although the inhibitor antagonized hyperexcitability produced by 5-HT application. Strong activation of PKA in the nerve by coapplication of a membrane-permeant analog of cAMP and a phosphodiesterase inhibitor was not sufficient to induce LTH of either the SN somata or axons. Furthermore, nerve crush failed to activate axonal PKA or stimulate its retrograde transport. Therefore, PKA activation plays little if any role in the induction of LTH by axotomy. However, the expression of LTH was reduced by intracellular injection of the highly specific PKA inhibitor PKI several days after nerve crush. This suggests that long-lasting activation of PKA in or near the soma contributes to the maintenance of long-term modifications produced by nerve injury.

The influence of surgical sites on early postoperative hypoxemia in adults undergoing elective surgery

To determine the influence of the surgical sites on early postoperative hypoxemia, we studied postoperative hypoxemia in 994 patients, ASA physical status I or II, aged 18-68 yr, scheduled for various types of elective surgery. Patients were divided into three groups on the basis of the surgical sites: Group 1 = elective superficial plastic surgery (n = 288); Group 2 = upper abdominal surgery (n = 452); and Group 3 = thoracoabdominal surgery (n = 254). Anesthesia was maintained with 1%-2% enflurane and 67% nitrous oxide in oxygen; thiopental or fentanyl was given IV as required. SpO2 levels were recorded while patients breathed room air shortly after arrival in the recovery room (0 min) and 5, 10, 15, 20, 30, 40, 50, 60, 120, and 180 min thereafter. The results showed that during the early postoperative period, the degree of arterial desaturation and the incidences of hypoxemia (SpO2 86%-90%) and severe hypoxemia (SpO2 85%) were closely related to the operative sites and were greatest for thoracoabdominal operations, less for the upper abdominal operation, and least for the peripheral surgery. The incidence of hypoxemia and severe hypoxemia in the recovery room was 7% and 0.7%, respectively, in Group 1, 38% and 3% in Group 2, and 52% and 20% in Group 3. Mild airway obstruction and hypothermia in the postanesthesia recovery unit (PAR) were the predictive factors of early postoperative hypoxemia. We conclude that during the early postoperative period, there were significant differences in SpO2 levels and incidences of hypoxemia and severe hypoxemia among the three groups.

IMPLICATIONS

We found that the severity of arterial desaturation and the incidence of hypoxemia during the early postoperative period are closely related to the surgical sites and are strongest for thoracoabdominal surgery, less for upper abdominal surgery, and least for peripheral surgery.

Localization of basic residues required for receptor binding to the single alpha-helix of the receptor binding domain of human alpha2-macroglobulin

To better understand the structural basis for the binding of proteinase-transformed human alpha2-macroglobulin (alpha2M) to its receptor, we have used three-dimensional multinuclear NMR spectroscopy to determine the secondary structure of the receptor binding domain (RBD) of human alpha2M. Assignment of the backbone NMR resonances of RBD was made using 13C/15-N and 15N-enriched RBD expressed in Escherichia coli. The secondary structure of RBD was determined using 1H and 13C chemical shift indices and inter- and intrachain nuclear Overhauser enhancements. The secondary structure consists of eight strands in beta-conformation and one alpha-helix, which together comprise 44% of the protein. The beta-strands form three regions of antiparallel beta-sheet. The two lysines previously identified as being critical for receptor binding are located in (Lys1374), and immediately adjacent to (Lys1370) the alpha-helix, which also contains an (Arg1378). Secondary structure predictions of other alpha-macroglobulins show the conservation of this alpha-helix and suggest an important role for this helix and for basic residues within it for receptor binding.

[Clinical observation of yugengongyu decoction in treatment of coronary heart disease with angina pectoris]

OBJECTIVE

To observe the clinical effect of Yugengtongyu Decoction (YGTY) in treatment of coronary heart disease (CHD) with Qi deficiency, Blood stasis and phlegm stagnancy type and Qi deficiency and Blood stasis type.

METHODS

Patients were divided into two groups, 45 cases in the YGTY group and 38 cases in the control group. In alleviating angina pectoris and improving symptom of CHD, the serum total cholesterol (TC), serum triglyceride (TG) were determined before and after treatment.

RESULTS

The total effective rate of spontaneous angina pectoris were significantly better in the treated group than those in the control group (P < 0.005). In improving symptom of CHD were significantly better in the treated group than those in the control group (P < 0.005), and it was better the type of Qi deficiency, Blood stasis and phlegm stagnancy than type of Qi deficiency and Blood stasis in treated group (P < 0.05). TC of the treated group was lowered markedly after treatment, as compared with that before treatment, the difference was significant (P < 0.005).

CONCLUSIONS

YGTY was effective for alleviating angina pectoris and improving symptom of CHD. It is best for the type of Qi deficiency, Blood stasis and phlegm stagnancy. It also has regulatory effect on the blood lipid.

A comparative study of the dose-response and time course of action of rocuronium and vecuronium in anesthetized adult patients

STUDY OBJECTIVES

(1) To compare the dose-response relations of rocuronium and vecuronium in healthy adult patients anesthetized with nitrous oxide-oxygen-fentanyl-thiopental; and (2) to evaluate the time-course of action of two drugs following equipotent doses.

DESIGN

Prospective, randomized, clinical comparison.

SETTING

Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College.

PATIENTS

60 ASA physical status I patients, aged 17-51 years, scheduled for elective plastic surgery.

INTERVENTIONS

All patients were randomly assigned to either the rocuronium or vecuronium group. General anesthesia was induced with thiopental 4 to 6 mg/kg and fentanyl 2 to 4 micrograms/kg intravenously (i.v.), and maintained with 60% nitrous oxide (N2O) in oxygen. Further increments of thiopental or fentanyl were given as required. The dose-response relations of rocuronium and vecuronium were determined by the cumulative dose-response technique.

MEASUREMENTS AND MAIN RESULTS

Neuromuscular function was assessed mechanomyographically with train-of-four (TOF) stimulation at the wrist every 12 seconds. The percentage depression of first twitch (T1) was used as the study parameter. The cumulative dose-response curve of vecuronium was shifted to the left in a parallel fashion compared with that of rocuronium. As assessed by linear regression, the potency ratio of vecuronium: rocuronium was 1:7.2. There were significant differences in the ED50, ED90, and ED95 between the two drugs. After i.v. administration of equipotent doses of both drugs (2 x ED90), the duration of peak effect, clinical duration, recovery index, and total duration were not significantly different between the two drugs.

CONCLUSIONS

Compared with vecuronium, rocuronium is a low-potency, nondepolarizing relaxant, and its neuromuscular blocking potency is approximately 15% that of vecuronium in adult patients anesthetized with N2O and fentanyl. Following equipotent doses, the time-course of recovery for rocuronium is similar to that of vecuronium.

The pharmacokinetics of vecuronium in male and female patients

To evaluate the effect of gender on the pharmacokinetics of vecuronium, we studied 30 patients (15 male and 15 female) undergoing elective plastic surgery with anticipated surgical blood loss of <300 mL under general anesthesia. General anesthesia was induced with thiopental 4-6 mg/kg and fentanyl 2-4 microg/kg and was maintained with 60% nitrous oxide in oxygen and an end-tidal concentration of 1.5%-2% enflurane. After a 2-min infusion of vecuronium 100 microg/kg, a modified fluorometric assay was used to determine the plasma concentrations of vecuronium for 5 h. The results showed that, compared with women, the plasma concentrations of vecuronium in men were significantly lower during the first 20 min and that the disposition kinetics of vecuronium can be best described mathematically by a three-compartment open model in the two groups. The volume of the central compartment and the volume of distribution at steady state were 39.6 +/- 8.6 and 164.8 +/- 29.3 mL/kg, respectively, in women. These values increased significantly to 54.4 +/- 14.4 and 201.4 +/- 75.8 mL/kg in men (P < 0.05). When the data were calculated on the basis of ideal body weight, the volume of distribution of vecuronium was also different between men and women (P < 0.05. The half-lives of fast distribution and distribution, the elimination half-life, mean residual time, area under the plasma-concentration curve, and plasma clearance were not different between the two groups. We conclude that the pharmacokinetics of vecuronium are significantly different between genders and that and men have the greater volume of distribution of vecuronium.

IMPLICATIONS

The authors found that, compared with women, men had lower plasma concentrations of vecuronium after the i.v. administration of vecuronium and a larger volume of distribution of vecuronium. The pharmacokinetic differences may be related to the differences in the sensitivity to vecuronium between genders.

Dose-response curve and time-course of effect of vecuronium in male and female patients

To determine the differences between men and women in the dose-response curve and the time-course of effect of vecuronium, we studied 60 adult patients (30 male and 30 female), ASA I, age 18-51 yr, undergoing elective plastic surgery. Anaesthesia was maintained with nitrous oxide 60% in oxygen; thiopentone and incremental doses of fentanyl were given as required. Neuromuscular function was assessed mechanomyographically using the train-of-four (TOF) stimulation at the wrist every 12 s. The percentage depression of T1 was used as the study variable. The dose-response relationship of vecuronium was determined by a cumulative dose-response technique. The dose-response curve in men was shifted in a parallel fashion to the right, indicating a decrease in the sensitivity to vecuronium-induced neuromuscular block, compared with women. The ED50, ED90 and ED95 of vecuronium were 23.9 (4.7), 45.4 (11.2) and 55.7 (14.3) micrograms kg-1 in men and 18.4 (3.7), 33.5 (7.8) and 39.8 (9.6) micrograms kg-1 in women respectively. There were statistically significant differences in these values between the two groups (P < 0.01 in each instance). After a total dose of vecuronium 80 micrograms kg-1, neuromuscular block was significantly longer in women than in men. The duration of peak effect, clinical duration, and the total duration were 18.7 (7.1), 26.6 (8.8) and 50.6 (16.0) min respectively in men and 26.0 (7.2), 37.1 (11.2) and 65.9 (20.7) min in women. They differed significantly between men and women (P < 0.005 in each case).

Structural changes in the region directly adjacent to the DNA-binding helix highlight a possible mechanism to explain the observed changes in the sequence-specific binding of winged helix proteins

The hepatocyte nuclear factor 3 (HNF-3)/fork head (fkh) family contains a large number of transcription factors and folds into a winged helix motif. Despite having almost invariable amino acid sequences in their principal DNA-binding helices, HNF-3/fkh proteins show a wide diversity of sequence-specific binding. Previous studies of chimeric HNF-3/fkh proteins demonstrated that the binding specificity is primarily influenced by a region directly adjacent to the binding helix. We report our findings of an NMR structural study performed on an HNF-3/fkh family member (Genesis, formerly HFH-2) and compare it to that of another family member (HNF-3gamma) complexed to DNA and determined by X-ray crystallography. It is found that in comparison to HNF-3gamma, Genesis contains an extra small helix directly prior to the N terminus of the primary DNA contact helix. Due to the insertion of this helix, a shorter and slightly re-positioned primary DNA contact helix is observed, which we believe leads to the DNA-binding specificity differences among family members.

[Experimental study of anti-tumor immunity induced by B7 vaccine of a highly malignant murine leukemic T cell line (L615)]

OBJECTIVE

To assess the potential of B7-1 vaccine in inducing immunity to leukemic cells.

METHODS

B7-1 gene was introduced into L615 cells and then the positive clone (L615-B7) highly expressing B7-1 was selected. Tumorigenic and immunoprotective activities of L615-B7 cells were studied in vivo. T cell functions of cytotoxicity, proliferation and growth factor secretion were detected in vitro.

Sequence specific collective motions in a winged helix DNA binding domain detected by 15N relaxation NMR

The recognition between transcription factors and their DNA binding sites is a highly dynamic process. During transcriptional regulation, transcription factors must bind to or dissociate from their cognate DNA binding sites. The winged helix DNA binding motif is one of many highly conserved DNA binding motifs identified in transcription factors. Backbone dynamics has been studied on the 15N- and 2H-enriched winged helix family member Genesis. Our data show that the overall motions of the single domain Genesis are better described by more than two autocorrelation times (taum). Our data also demonstrate that Genesis shows structure specific conformation exchange characterized by Rex. Therefore, our results indicate that the structure of Genesis is highly dynamic and that secondary structure elements in Genesis have collective motions in the nanosecond to millisecond time scale. Since the winged helix DNA binding motif is highly conserved, this unique dynamic property observed in Genesis is also likely to be conserved in other winged helix family members and important in DNA binding.

Influence of surgical technique on early postoperative hypoxaemia in children undergoing elective palatoplasty

We have assessed the influence of different surgical procedures on the incidence, severity and duration of early postoperative hypoxaemia in 312 healthy infants and children undergoing elective palatoplasty. Group 1 patients underwent von Langenbeck palatoplasty (n = 149), group 2 patients underwent push-back palatoplasty (n = 124) and group 3 patients underwent combined push-back palatoplasty and superior pharyngeal flap surgery (n = 39). Arterial oxygen saturation (SpO2) was recorded while patients were breathing air shortly after arrival in the recovery room (0 min), and at 5, 10, 15, 20, 30, 40, 50, 60, 120 and 180 min thereafter. Patients who underwent more complex surgical techniques for palatoplasty had lower postoperative SpO2 values, slower recovery of SpO2 and a higher incidence of hypoxaemia during the early postoperative period. There were significant differences in postoperative SpO2, values and the incidence of hypoxaemia. The incidences of hypoxaemia and severe hypoxaemia were 27% and 1%, respectively, in group 1, 37% and 12% in group 2, and 36% and 33% in group 3. Hypoxaemia occurred most commonly in the first 15 min in children after von Langenbeck palatoplasty, in the first 40 min after push-back palatoplasty and in the 120 min after combined push-back palatoplasty and superior pharyngeal flap surgery. There were significant associations between low SpO2 values, incidence of hypoxaemia on admission to the recovery room and recovery scores.

The influence of acute normovolemic hemodilution on the dose-response and time course of action of vecuronium

To evaluate the influence of acute isovolemic hemodilution on the dose-response and time course of action of vecuronium, we studied 60 adult patients with and without hemodilution during surgery. The patients with hemodilution underwent major elective plastic surgery with an anticipated surgical loss of more than 600 mL. Anesthesia was induced with thiopental 4-6 mg/kg and fentanyl 2-4 microg/kg i.v. and was maintained with 60% nitrous oxide in oxygen. Further increments of thiopental 2 mg/kg or fentanyl 2 microg/kg were given as required. Acute isovolemic hemodilution in the hemodilution group was induced by drainage of venous blood and an i.v. infusion of lactated Ringer's solution and 6% dextran, during which hematocrit and hemoglobin decreased from 45.7% to 26.2% and from 148.5 g/L to 90.2 g/L, respectively. Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 s, and the percent depression of T1 response was used as the study parameter. The dose-response relationships of vecuronium in the two groups were determined by using the cumulative dose-response technique. The results showed that during hemodilution, the dose-response curve of vecuronium was shifted to the left in a parallel fashion, and the potency of vecuronium was increased. There were significant differences in the 50%, 90%, and 95% effective doses between the two groups. After the i.v. administration of vecuronium 80 microg/kg, vecuronium-induced neuromuscular block was significantly longer in the patients with hemodilution than in the control patients. The duration of peak effect, clinical duration, recovery index, and total duration in the hemodilution patients were significantly different from those in the control patients. We conclude that hemodilution induces significant changes in the pharmacodynamics of vecuronium.

IMPLICATIONS

We found that patients with hemodilution were 20% more sensitive to vecuronium and had a longer duration of action after the administration of the same dose than the controls. This should be taken into account when vecuronium is used as a muscle relaxant during acute hemodilution.

[Methodology for designing pathological models of acute renal failure]

This paper reports the methodological study on the following five pathological models of acute renal failure (ARF): 1. glycerine-induced ARF in rats; 2. noradrenaline-induced ARF in dogs; 3. ARF model caused by shutting left renal artery in dogs; 4. hydrargyrism-induced ARF in rabbits; and 5. gentamycin-induced ARF in rats.

Influence of acute normovolaemic haemodilution on the relation between the dose and response of rocuronium bromide

The influence of acute moderate haemodilution on the relation between dose and response for rocuronium was evaluated in 60 adult patients, ASA grade I, undergoing elective plastic surgery. The patients were randomly allocated to either the control or the haemodilution group. Following the induction of general anaesthesia, the status of acute moderate haemodilution in the haemodilution group was achieved by draining venous blood, and intravenous infusion of lactated Ringer's solution, 6% dextran or gelofusine, during which the levels of haemoatocrit and haemoglobin dropped from 44% to 27.5% and from 148.3 to 91.3 g L-1, respectively. Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 s and the percentage depression of T1 response was used as the study parameter. The relation between dose and response for rocuronium in the two groups was determined by the cumulative dose-response technique. The results showed that the dose-response curve for rocuronium during acute moderate haemodilution was shifted in a parallel fashion to the left and the potency of rocuronium was increased. There were significant differences in ED50, ED90 and ED95 between the two groups. The ED50, ED90 and ED95 of rocuronium in the haemodilution group was decreased by 28.2%, 35.4% and 38.8%, respectively, compared with the control group.

Dose-response and time-course of the effect of rocuronium bromide during sevoflurane anaesthesia

To evaluate the influence of sevoflurane on the dose-response relationship and on the time-course of the effect of rocuronium, 60 adult patients undergoing elective plastic surgery were randomly allocated to either the control or the sevoflurane group. Anaesthesia was maintained with 60% nitrous oxide in oxygen and thiopentone in the control group and with 60% nitrous oxide in oxygen and an end-tidal concentration of 1.75% sevoflurane in the sevoflurane group. Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12s and the percentage depression of the first twitch of the train-of-four was used as the study parameter. The dose-response relationship of rocuronium in the two groups was determined by the cumulative dose-response technique. The dose-response curve of rocuronium in the sevoflurane group was shifted to the left compared to the control group, indicating a potentiation of rocuronium-induced neuromuscular block. The effective doses of rocuronium required to produce 50%, 90% and 95% twitch depression in the sevoflurane group were decreased by 30.5%, 26.7% and 25.2%, respectively, compared to the control group. Following the administration of a total dose of rocuronium of 400 micrograms.kg-1, the duration of action of, and the recovery from, rocuronium were both significantly prolonged by sevoflurane. There were significant differences in the duration of peak effect, clinical duration, recovery index and the total duration of action between the control and the sevoflurane groups.