Unifying characteristics of sites of anesthetic action revealed by combined use of anesthetics and non-anesthetics

1. The usefulness of nonanesthetics in the study of mechanisms of general anesthesia lies in the possibility to identify the unifying characteristics of molecular sites that are shared by the anesthetics but not by the structurally similar nonanesthetics. 2. In model membranes, pairs of structurally similar anesthetics and nonanesthetics showed distinctly different submolecular distributions. 3. This difference may be the underlying cause for the different anesthetic and nonanesthetic interaction with gramicidin A, a model transmembrane cation channel. 4. Generalization of our findings suggests that the nature of the sites, whether in lipids or proteins, must be neither extremely hydrophilic nor extremely lipophilic, but amphiphilic.

Supraglottic carcinoma: does preoperative radiotherapy reduce the incidence of cervical metastasis?

OBJECTIVE

To compare surgery (S) alone with combined radiotherapy and surgery (R + S) in the management of patients with supraglottic laryngeal cancer.

METHODS

Between 1981 and 1994, patients were stratified according to stage and randomised to either surgery (S) or 4000cGy of radiotherapy and surgery. There were 102 patients in the S group and 99 in the R + S group who completed at least 3-year follow-up.

RESULTS

Using Kaplan-Meier survival method showed no significant difference between the two groups. When the patients were grouped according to tumour stage, a significant reduction in the regional recurrence was noted in the R + S group for stage I-III disease (Cox multivariate analysis, P < 0.02). They had an increased relative risk of 1.8 (95% confidence 1.1-2.9) for neck recurrence. There was no significant difference in neck recurrence rates in the two groups for stage IV disease. When Cox proportional hazard model was used, only TNM stage (P < 0.02) and histological nodal status (positive lymph nodes, P < 0.01) were found to be independent risk factors for regional control.

CONCLUSION

Preoperative radiotherapy can improve regional cervical control of stage I-III supraglottic cancer as compared with surgery alone.

[Prevention and management of chylous fistula after neck dissection]

OBJECTIVE

To evaluate the effect of treatment for chylous fistulas after neck dissection, as a means of reasonable option of therapeutic measures.

METHODS

Of 37 chylous fistulas, 30 were left-sided and 7 were right-sided. Conservative therapy which included closed-wound drainage and local pressure dressing and/or low-fat nutritional support was employed in 26 cases, and 50% glucose was injected into the neck basic wound bed in 2 cases, to promoto the chylous fistula healing up. Operative ligation was performed in 7 cases. Open-wound and packing in 4 cases.

RESULTS

Eighty-six percent chylous fistula occured from 1 to 3 postoperative days. Of 26 chylous fistulas with conservative management, 15 cases were successfully treated, the mean duration for healing was 9.7 (4-30) days, the remaining 11 cases failed to had and were further treated surgically. Seven cases with operative ligation were successful, and the other 4 cases with open-wound and packing had delayed healing, the mean duration was 8.5 (7-10) days.

CONCLUSION

The majority of patients with chylous fistulas could be treated reasonablly without increasing the hospital days. The conservative therapy should be employed in cases with a maximal production of chyle below 500 ml a day. Operative ligation should be done early in cases with a maximal production exceeding 500 ml a day and with conservative treatment failure for a few days. The open-wound and packing should be used in chylous fistulas persisting for more then 7 days.

[Supraglottic horizontal laryngectomy for supraglottic carcinoma]

OBJECTIVE

To evaluate the therapeutic results of supraglottic horizontal laryngectomy (SHL) for T1 and selected T2, T3 and T4 supraglottic carcinoma.

METHODS

One hundred and seven patients undergone SHL during the period of 1979 through 1991 were reviewed retrospectively. All patients were followed up for at least 5 years.

RESULTS

The 5 year-survival rate of 6 cases in stage I, 24 cases in stage II, 53 cases in stage III, and 24 cases in stage IV was 100.0%, 83.3%, 71.7% and 41.7%, respectively. Of the 102 patients, 92.2% were decannulated, and 91.6% of all patients achieved satisfactory recovery of phonation.

CONCLUSION

SHL is a reliable surgical approach for selected supraglottic carcinoma, even for some advanced lesions, provided the tumor has not extended below the ventricle. The upper neck dissection can be used as an exploratory measure. For N0 neck patients with supraglottic cancer, comprehensive neck dissection is not invariably performed to avoid overtreatment.

[31P]/[1H] nuclear magnetic resonance study of mitigating effects of GYKI 52466 on kainate-induced metabolic impairment in perfused rat cerebrocortical slices

PURPOSE

Kainic acid (KA) has long been used in experimental animals to induce status epilepticus (SE). A mechanistic implication of this is the association between excitotoxicity and brain damage during or after SE. We evaluated KA-induced metabolic impairment and the potential mitigating effects of GYKI 52466 [1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine] in superfused rat cerebral cortical slices.

METHODS

Interleaved [31P]/[1H] magnetic resonance spectroscopy (MRS) was used to assess energy metabolism, intracellular pH (pHi), N-acetyl-L-aspartate (NAA) level, and lactate (Lac) formation before, during, and after a 56-min exposure to 4 mM KA in freshly oxygenated artificial cerebrospinal fluid (oxy-ACSF).

RESULTS

In the absence of GYKI 52466 and during the KA exposure, NAA, PCr, and ATP levels were decreased to 91.1 +/- 0.8, 62.4 +/- 3.9, and 59.1 +/- 4.3% of the control, respectively; Lac was increased to 118.2 +/- 2.1 %, and pH, was reduced from 7.27 +/- 0.02 to 7.13 +/- 0.02. During 4-h recovery with KA-free ACSF, pHi rapidly and Lac gradually recovered, NAA decreased further to 85.5 +/- 0.3%, and PCr and ATP showed little recovery. Removal of Mg2+ from ACSF during KA exposure caused a more profound Lac increase (to 147.1 +/- 4.0%) during KA exposure and a further NAA decrease (to 80.4 +/- 0.5%) during reperfusion, but did not exacerbate PCr, ATP, and pHi changes. Inclusion of 100 microM GYKI 52466 during KA exposure significantly improved energy metabolism: the PCr and ATP levels were above 76.6 +/- 2.1 and 82.0 +/- 2.9% of the control, respectively, during KA exposure and recovered to 101.4 +/- 2.4 and 95.0 +/- 2.4%, respectively, during reperfusion. NAA level remained at 99.8 +/- 0.6% during exposure and decreased only slightly at a later stage of reperfusion.

CONCLUSIONS

Our finding supports the notion that KA-induced SE causes metabolic disturbance and neuronal injury mainly by overexcitation through non-N-methyl-D-aspartate (NMDA) receptor functions.

A reproducible model of circulatory arrest and remote resuscitation in rats for NMR investigation

BACKGROUND AND PURPOSE

Because noninvasive physiological monitoring of cerebral blood flow, metabolic integrity, and brain ion and water homeostasis can now be accomplished with new, state-of-the-art MR spectroscopy and imaging techniques, it is appropriate to develop controllable and reproducible animal models that permit prolonged circulatory arrest and resuscitation in the magnet and also allow for studies of long-term survival and outcome. We have developed such a model in rats that involves minimal surgical preparations and can achieve resuscitation remotely within precisely controlled time.

METHODS

Cardiac arrest was induced by asphyxiation, the duration of which ranged from 8 to 24 minutes. Resuscitation was achieved remotely by a slow, intra-aortic infusion of oxygenated blood (withdrawn either from the same rat before asphyxia or from a healthy donor rat) along with a resuscitation cocktail containing heparin (50 U/100 g), sodium bicarbonate (0.1 mEq/100 g), and epinephrine (4 micrograms/100 g). The body temperature was measured by a tympanic thermocouple probe and was controlled either by a heating pad (constant tympanic temperature = 37 degrees C) or by warm ambient air (constant air temperature = 37 degrees C). Interleaved 31P/1H nuclear magnetic resonance (NMR) spectroscopy was used in a selected group of rats to measure the cerebral metabolism before and during approximately 20 minutes of circulatory arrest and after resuscitation.

RESULTS

The overall success rate of resuscitation, irrespective of the duration of cardiac arrest, was 82% (51 of 62). With a programmed infusion pump, the success rate was even higher (95%). The survival time for rats subjected to 15 and 19 minutes of asphyxia with core temperature tightly controlled was significantly lower than that with ambient temperature control (P < 0.001 and P < 0.04, respectively). High-quality NMR spectra can be obtained continuously without interference from the resuscitation effort. Final histological examinations taken 5 days after resuscitation showed typical neuronal damages, similar to those found in other global ischemia models.

CONCLUSIONS

Because the no-flow time and resuscitation time can be precisely controlled, this outcome model is ideally suited for studies of ischemic and reperfusion injuries in the brain and possibly in other critical organs, permitting continuous assessment of long-term recovery and follow-up in the same animals.

[The extended indications of near-total laryngectomy]

OBJECTIVE

To evaluate near-total laryngectomy in treatment of laryngeal cancers.

METHODS

Fifty-seven near-total laryngectomies were reviewed, among them 40 were T3 or T4 laryngeal cancers due to tumor invasion to the base of tongue or subglottic region.

RESULTS

In these patients, there were 11 cases of T3 pyriform sinus cancers, 5 cervical esophageal cancers, 1 case with adenoid cystic carcinoma involving the base of the tongue and oropharynx. Speech function had been preserved in 93% of cases with normal swallowing. Three year survival rates were 67.5% in laryngeal cancer and 50% in hypopharyngeal cancer. Local recurrence rate was only 3.5%.

CONCLUSION

The authors believed that near-total laryngectomy is safe and beneficial to the patients with the above types of cancers. The quality of life may improve if speech function is preserved.

Identification of an allosteric binding site on the transcription factor p53 using a phage-displayed peptide library

Monoclonal antibody PAb1620 recognizes a conformational epitope on the transcription factor p53 and, upon binding, allosterically inhibits p53 binding to DNA. A highly diverse (1.5 x 10(10) members) phage-displayed library of peptides containing 40 random amino acids was used to identify the PAb1620 binding site on p53. Panning this library against PAb1620 resulted in three unique peptides which have statistically significant sequence identities with p53 sufficient to identify the binding site as being composed of amino acids 106-113 and 146-156. Based on these results, we propose a mechanism by which PAb1620 can allosterically inhibit p53 binding to DNA through an indirect interaction between the antibody binding site and the L1 loop (amino acids 112-124) of p53, which is a component of the DNA binding region.

[Salvage surgery for nasopharyngeal carcinoma after irradiation failure]

OBJECTIVE

To study the salvage surgery for nasopharyngeal carcinoma after irradiation failure.

METHODS

One hundred and twenty-one full-dose-irradiation-uncontrolled cases of nasopharyngeal carcinoma had undergone salvage surgery since 1965 till 1992, in which 41 had primary lesion and 80 neck lesion. All patients received radiation before surgery with the dose of 60Gy-145Gy. The patient selection for this report limited to those with recurrent tumors at the primary sites with no apparent bony involvement and no cranial nerve palsy, or cases with resectable neck recurrences.

RESULTS

It showed that palatal fenestration was the best choice of approach for recurrent tumors located at the vault of the nasopharyngeal cavity. When the tumor invaded the parapharyngeal space or, owing to the after-effect of radiotherapy, the patient presented with severe occlusion of the mandible, we preferred the lateral approach through partial mandi-bulectomy. The lateral rhinotomy was only indicated for cases with tumor remnant at the posterior nares. Lymph node excision was performed for cases with single movable node on the neck, and RND for the cases with multiple nodes. The complication rate of after surgery was low (10%), considering the heavy dose of irradiation. The three- and five-year survival rate were 49% (59/121) and 38% (38/100) respectively.

CONCLUSION

It suggests that the surgery should be considered as a salvage procedure for cases of nasopharyngeal cancer after irradiation failure. Because of high rate of distant metastasis (62 cases or 45% died after surgery), chemotherapy or other measures should be adopted after local treatment.

[Application of pectoralis major myocutaneous flap in the reconstruction of tongue: an analysis of 86 cases]

OBJECTIVE

To analyze the results of the use of pectoralis major myocutaneous (PMM) flap in the reconstruction of tongue.

METHODS

From 1984 to 1995, PMM flap was applied in 86 cases with cancer of tongue after radical resection for the immediate reconstruction of the lingual defect.

RESULTS

Notwithstanding the advanced lesions in stages T3 and T4, patients had good survival and functional results. The 1-, 3- and 5-year survival rate was 86.0%, 51.2% and 23.3%, respectively. There was complete flap necrosis in one case and partial necrosis in fifteen cases, but the latter spontaneously regressed. The swallowing and speech rehabilitations following surgical treatment for tongue cancer were acceptable, considering the advanced disease status.

CONCLUSION

The PMM flap with its abundant tissue and excellent blood supply and anatomic proximity provides a reliable method of primary reconstruction of the substance of the tongue. The surgical procedure is simple, easy to perform. Reconstruction of the tongue with PMM flap meets the clinical requirements in the shape, communication and swallowing rehabilitations. The PMM flap is a reliable material for the reconstruction of tongue with major defect following subtotal glossectomy.

Comparison of anaesthetic and non-anaesthetic effects on depolarization-evoked glutamate and GABA release from mouse cerebrocortical slices

1. Investigation with substances that are similar in structure, but different in anaesthetic properties, may lead to further understanding of the mechanisms of general anaesthesia. 2. We have studied the effects of two cyclobutane derivatives, the anaesthetic, 1-chloro-1,2,2-trifluorocyclobutane (F3), and the non-anaesthetic, 1,2-dichlorohexafluorocyclobutane (F6), on K+-evoked glutamate and gamma-aminobutyric acid (GABA) release from isolated, superfused, cerebrocortical slices from mice, by use of h.p.l.c. with fluorescence detection for quantitative analysis. 3. At clinically relevant concentrations, the anaesthetic, F3, inhibited 40 mM K+-evoked glutamate and GABA release by 72% and 47%, respectively, whereas the structurally similar non-anaesthetic, F6, suppressed evoked glutamate release by 70% but had no significant effects on evoked GABA release. A second exposure to 40 mM KCl after a approximately 30 min washout of F3 or F6 showed recovery of K+-evoked release, suggesting that F3 and F6 did not cause any non-specific or irreversible changes in the brain slices. 4. Our findings suggest that suppression of excitatory neurotransmitter release may not be directly relevant to the primary action of general anaesthetics. A mechanism involving inhibitory postsynaptic action is implicated, in which a moderate suppression of depolarization-evoked GABA release by the anaesthetic may be consistent with the enhancement of postsynaptic GABAergic activities.

Listeria monocytogenes invasion of epithelial cells requires the MEK-1/ERK-2 mitogen-activated protein kinase pathway

PD98059, a specific inhibitor of MEK-1 mitogen-activated protein (MAP) kinase kinase, blocked Listeria monocytogenes invasion into HeLa epithelial cells. The effects of PD98059 were reversible, as adherent extracellular bacteria were internalized upon removal of the drug. Previously, we reported that L. monocytogenes could activate ERK-1 and ERK-2 MAP kinases through the action of listeriolysin O (LLO) on the host cell (P. Tang, I. Rosenshine, P. Cossart, and B. B. Finlay, Infect. Immun. 64:2359-2361, 1996). We have now found that two other MAP kinase pathways, those of p38 MAP kinase and c-Jun N-terminal kinase, are also activated by wild-type L. monocytogenes. Mutants lacking functional LLO (hly mutants) were still invasive but only activated ERK-2 and only activated it at later (90-min) postinfection times. Two inhibitors of L. monocytogenes invasion, cytochalasin D, which disrupts actin polymerization, and wortmannin, which blocks phosphatidylinositol (PI) 3-kinase activity, did not block ERK-2 activation by wild-type L. monocytogenes and hly mutants. However, genistein, an inhibitor of tyrosine kinases, and PD98059 both blocked invasion and decreased ERK-2 activation. These results suggest that MEK-1 and ERK-2 activities are essential for L. monocytogenes invasion into host epithelial cells. This is the first report to show that a MAP kinase pathway is required for bacterial invasion.

[Preoperative radiotherapy reduces cervical metastasis of supraglottic carcinoma: a prospective randomized trial in 201 patients]

OBJECTIVE

To evaluate the effectiveness of preoperative radiotherapy in the control of overall cervical lymph node metastasis from supraglottic carcinoma.

METHODS

A prospective randomized study on 210 patients with supraglottic carcinoma was performed. Nine patients were lost from follow-up and therefore excluded. The analysis was based on the remained 201 patients including fifteen who did not complete the treatment protocol. Surgery alone(S) was carried out in 102 patients and radiotherapy(40 Gy) followed by surgery (R + S) in 99 patients. All the patients were followed up for more than three years.

RESULTS

No statistically significant difference in survival rates between S and R + S groups was found by using the Kaplan-Meier analysis. However, relative risk of overall cervical recurrence had a trend of reduction for patients in R + S group, versus patients in S group. There was a statistically significant reduction of lymph node metastasis in R + S group compared to S group in stage I-III(P = 0.0198) while in stage IV no such difference was observed. Patients with stage I-III disease who did not receive preoperative radiation were 1.766 times more likely to develop neck recurrence compared to patients who did. Among all the factors, only TNM stage and histological nodal status were found to be independent risk factors for regional control. Contralateral neck failure occurred more frequently in patients with advanced lesion(P = 0.020) and in patients without preoperative radiation(P = 0.018).

CONCLUSION

There may be a trend towards improved control of cervical lymph node metastasis with preoperative radiation of 40 Gy dose in patients with supraglottic cancer in stage I-III of the disease.

The autocrine loop of TGF-alpha/EGFR and brain tumors

Malignant human gliomas are the most common forms of primary tumors in the central nerve system. Due to their location and invasive nature, treatment so far has been mainly palliative. Thus, understanding the molecular detail of tumor transformation and progression is crucial for developing effective therapeutic strategy for this fetal tumor. Among the genetic alternations found in these tumors, p53 inactivation and PDGF/PDGFR activation represent the early events, and the loss of chromosome 10 and gene amplification and rearrangement of EGFR represent the late events. Studies with both glioma cell lines and primary tumor tissues have strongly suggested that TGF-alpha and EGFR function as an important autocrine loop in supporting proliferation of human glioma, especially in high grade glioma, since elevated TGF-alpha expression is also found in these high grade tumors. Furthermore, down regulation of the expression of TGF-alpha by antisense constructs has been shown to inhibit several types of human tumor cell growth including glioma. Other means of therapeutic approaches using this autocrine loop as a target also include the use of monoclonal antibodies and their cytotoxic conjugated. Considerable understanding of the EGFR-mediated signal transduction pathways has become available recently, which including GRB2/mSOS1 mediated MAP kinase activation; JAK/STATs pathway; PLC-gamma pathway. However, much work still needs to be done before a specific component of these pathways can be applied for effective control of tumor growth in the clinic.

Easy fabrication of a tunable high-pass birdcage resonator

A practical design for a high-pass birdcage resonator is presented. Precision seamless telescoping tubes were used for easy tuning of resonant frequency by adjusting the length of the coils. Three probes, of 4.4, 5.0, and 25.0 cm in diameter, respectively, were constructed and tested. An empirical formula is given that can be used to calculate the capacitance needed for a given frequency when the desired physical dimension and the number of elements of the coll are specified. A simple three-step procedure is suggested for easy fabrication of resonators that are routinely tunable over tens of megahertz.

Different distribution of fluorinated anesthetics and nonanesthetics in model membrane: a 19F NMR study

Despite their structural resemblance, a pair of cyclic halogenated compounds, 1-chloro-1,2,2-trifluorocyclobutane (F3) and 1,2-dichlorohexafluorocyclobutane (F6), exhibit completely different anesthetic properties. Whereas the former is a potent general anesthetic, the latter produces no anesthesia. Two linear compounds, isoflurane and 2,3-dichlorooctofluorobutane (F8), although not a structural pair, also show the same anesthetic discrepancy. Using 19F nuclear magnetic spectroscopy, we investigated the time-averaged submolecular distribution of these compounds in a vesicle suspension of phosphatidylcholine lipids. A two-site exchange model was used to interpret the observed changes in resonance frequencies as a function of the solubilization of these compounds in membrane and in water. At clinically relevant concentrations, the anesthetics F3 and isoflurane distributed preferentially to regions of the membrane that permit easy contact with water. The frequency changes of these two anesthetics can be well characterized by the two-site exchange model. In contrast, the nonanesthetics F6 and F8 solubilized deeply into the lipid core, and their frequency change significantly deviated from the prediction of the model. It is concluded that although anesthetics and nonanesthetics may show similar hydrophobicity in bulk solvents such as olive oil, their distributions in various regions in biomembranes, and hence their effective concentrations at different submolecular sites, may differ significantly.

[The effect of interleukin (IL) 12 on hemopoiesis in irradiated mice]

OBJECTIVE

To investigate the regulating effect of IL-12 on hemopoiesis.

METHODS

cDNA coding for the two subunits of murine IL-12 were cloned into two different eukaryotic expression vectors and transduced into a same NIH3T3 cell line, resulting in two engineered fibroblast clones secreting IL-12. Cells were mixed with collagens and inoculated into the peritoneal cavities of whole-body-irradiated mice.

RESULTS

On day 10 after treatment, endogenous splenic colony-forming-unit (CFU-S) counts in mice treated with IL-12-secreting NIH3T3 cells were higher than those of mice accepting parental cells or untreated irradiated mice. This difference was statistically significant in both 6.0 Gy irradiated mice and 7.0 Gy group mice. Histopathological studies showed that NIH3T3-secreted IL-12 alleviates the injuries caused by irradiation in both bone marrow and spleen, activates hemopoietic cells, increases the number and scale of hemopoietic clusters, hence enhancing hemopoietic function including erythropoiesis, granulopoiesis, and megakaryocytopoiesis.

CONCLUSION

IL-12 up-regulates and promotes the recovery of hemopoietic function in irradiated mice.

[Morphological and cytochemitry features of CD34+ hematopoietic cells isolated from human bone marrow]

OBJECTIVE

To explore the cytomorphological and cytochemitry features of CD34+ hematopoietic cells.

METHODS

Highly purified CD34+ hematopoietic cells isolated from human bone marrow by a two-step method of immunomagnetic beads-FACS sorting were comprehensively examined.

RESULTS AND CONCLUSION

CD34+ hematopoietic cells could be sorted into three types in light of morphology and cytochemical staining. Type I was considered as candidates for stem cells,which were most blastlike in morphology and slightly larger than lymphocytes in size with negative reactions to all cytochemical stainings. Type II was considered as multipotent progenitor cells, with sizes similar to small lymphocytes and negative reactions to all cytochemical stainings. Type III was identified as committed progenitor cells whose sizes were heterogeneous and whose reactions to cytochemical stainings ranged from +/- to + +.

[RU486 reverses dexamethasone-mediated suppression of IL-2 receptor expressions in lymphocytes of rat spleen]

Experiments were designed to investigate whether glucocorticoid-mediated immunosuppression are involved in glucocorticoid receptor activation. It was shown that RU486, a blocker of glucocorticoid, reversed dexamethasone (DEX)-mediated suppression of CD25 antigen expressions on ConA-stimulated lymphocytes, as determined with anti-CD25 monoclonal antibody. By means of radioligand binding assay, changes in high affinity IL-2 receptor were examined. The data indicated that RU486 alone was unable to affect high affinity IL-2 receptor expressions, but antagonized DEX-mediated down regulation of high affinity IL-2 receptor on cellular surface. The maximal binding capacities of IL-receptor were 10.0 +/- 0.7, 10.4 +/- 2.1, 6.5 +/- 0.8 and 12.1 +/- 2.7 fmol/10(7) cell respectively in four groups of the normal, RU486, DEX, and DEX plus RU486. The results suggest that such effects of DEX may be mediated through glucocorticoid receptor in lymphocytes.

Amphiphilic sites for general anesthetic action? Evidence from 129Xe-[1H] intermolecular nuclear Overhauser effects

Because a strong correlation exists between the potency of general anesthetics and their ability to dissolve in oil, a lipophilic site of action is often assumed. We show here that a lipophilic molecule may preferentially target less lipophilic sites after interaction with a membrane takes place. Xenon, a chemically inert and structureless general anesthetic, was chosen as an unbiased molecular probe for assessment of its dynamic distribution. Site-selective intermolecular 129Xe-[1H] nuclear Overhauser effects were used to measure the specific interaction between xenon and protons in different regions in a phosphatidylcholine lipid membrane. It was evident that xenon-membrane interaction was directed toward the amphiphilic head region, with significant involvement of interfacial water, despite xenon's apolar and highly lipophilic nature in the gas phase. This result may suggest the importance of amphiphilicity in association with anesthetic action.

[Antiproliferative effects on Ph+ leukemic cells transfected with antisense bcr/abl fusion gene]

To investigate the possible roles that bcr/abl fusion gene plays in Ph-chromosome positive leukemia cells, in this study the recombinant plasmids expressing antisense transcripts to bcr/abl fusion gene were transfected into K562 and BV173 cell lines by lipofectin reagent. Southern and Northern bilot hybridizations proved the integration and expression of exogenous DNA in target cells. Antisense transcripts to bcr/abl inhibited proliferation and colony-forming ability of target cells. Through flow cytometric cell cycle analysis it was found that during the early period of transfection decrease of cells in G0/G1 and S phases and increase in G2 phase were observed, suggesting block of G2 progression. Later, cells in G0/G1 phase decreased further and retardation of S and G2 progressions was obvious. The results also indicated that proliferative inhibition of target cells was accompanied by genomic DNA degradation.

[Research on IgE responsiveness in asthma patients]

OBJECTIVE

To understand the relationship between IgE and asthma, and the genetic background of IgE.

METHODS

The authors measured serum total IgE in 121 healty subjects and 100 asthmatic children (CAC-IRMA) and investigated three AA families with total IgE evaluation and genetic linkage analysis between IgE and D11S533.

RESULTS

The IgE cutoff point between low and high was defined at 150 kU/L. There were 33.1% population with high level of total IgE. Of the 100 asthmatic children 96% had higher IgE level than controls, the difference was significant (P < 0.001). The IgE level of 22 asthmatic children in their releases had no significant difference compared with that in their attacks. In 40 members of three atopic asthma families, there were 23 persons with high IgE and 15 with asthma. In these families high IgE level were found both in male and female and the affected person occured in consecutive three generations, which fit to AD inheritance. Family 1 and 3 generally showed a high level of IgE, while family 2 showed low level of IgE. Two point linkage analysis between IgE and D11S533 showed that there were two recombinants from 22 meioses in the two families with a maximum lod score 1.074 at a recombination fraction of 0.05.

CONCLUSIONS

Most of asthma children have high IgE, which seems obtained from birth. About 1/3 population have high level IgE who are potential atopic persons. IgE level in human beings in inherited by AD mode. IgE gene may be close to 11q13.3-13.4.

Human pro-tumor necrosis factor is a homotrimer

The structure of human transmembrane pro-TNF-alpha was studied both in intact cell systems and in an in vitro translation system. In intact cell systems (LPS-induced THP-1 and TNF cDNA-transfected COS-7), a trimer of pro-TNF was detected after chemical cross-linking based on its molecular weight in Western blotting analysis. The trimer was shown to be a TNF-specific protein and could be partially cleaved to 26-kDa pro-TNF monomers by cleaving the cross-linkers. The trimeric structure was assembled intracellularly, because it could be detected in both the in vitro microsomal translation system and in THP-1 cells coincident with the appearance of pro-TNF in the cell lysate, prior to secretion of mature TNF. To further analyze the relationship between the trimeric structure and the biological activity of pro-TNF, we characterized several noncleavable pro-TNF deletion mutants. We observed a correlation between expression of TNF cytotoxicity in a juxtacrine fashion and detection of trimer. Thus, human pro-TNF-alpha, like the secreted mature TNF-alpha, has trimeric structure which is assembled intracellularly before transport to the cell surface and is apparently required for mediating its biologic activity.