A thermodynamic model for receptor clustering

Intracellular signaling often arises from ligand-induced oligomerization of cell surface receptors. This oligomerization or clustering process is fundamentally a cooperative behavior between near-neighbor receptor molecules; the properties of this cooperative process clearly affect the signal transduction. Recent investigations have revealed the molecular basis of receptor-receptor interactions, but a simple theoretical framework for using these data to predict cluster formation has been lacking. Here, we propose a simple, coarse-grained, phenomenological model for ligand-modulated receptor interactions and discuss its equilibrium properties via mean-field theory. The existence of a first-order transition for this model has immediate implications for the robustness of the cellular signaling response.

Activation of extracellular signal-regulated kinase in human prostate cancer

PURPOSE

To investigate the level of expression, activation state, and functional significance of extracellular signal regulated kinase (ERK) in prostate cancer.

MATERIALS AND METHODS

Human prostate tissue samples (n = 22) were obtained from patients undergoing radical prostatectomy for localized adenocarcinoma of the prostate (n = 16, age range 44 to 72 years) or normal prostate specimens (n = 6, age ranges 19 to 47 years) obtained from rapid autopsy. Immunoblots, in vitro kinase assays, and immunohistochemistry were used to determine the expression and activation state of ERK in human prostate cancer.

RESULTS

Immunoblot and in vitro kinase assays demonstrated a 15-fold increase in ERK activation in prostate cancer specimens compared with normal human prostate tissue; however, ERK expression levels were only 1.3-fold higher in cancer. Immunohistochemical analysis demonstrated similar expression of ERK in cancer and normal tissues; however, phosphorylated ERK demonstrated greater intensity in the cancer specimens. Experiments conducted on a prostate cancer cell line demonstrated that EGF induced activation of ERK and cellular proliferation was partially inhibited by PD98059, a chemical inhibitor of the immediate upstream signaling component responsible of activation of ERK.

CONCLUSIONS

Collectively, these data demonstrate a dramatic increase in ERK activation in prostate cancer compared with normal prostate tissue and suggest that inhibitors designed to target this signal transduction cascade might have therapeutic benefit in the treatment of prostate cancer.

[Mapping the gene responsible for Smith-Fineman-Myers syndrome to Xq25]

OBJECTIVE

To map and eventually identify the gene responsible for Smith-Fineman-Myers syndrome.

METHODS

The short tandem repeat markers(STRs) distributed on X chromosome at 8-10cM interval were used in the initial mapping to look for the candidate region for Smith-Fineman-Myers syndrome locus and the linked marker. The additional STRs flanking the linked marker were tested to confirm the candidate region and decide the interval of disease gene.

RESULTS

Thirteen DNA samples from a Chinese family with Smith-Fineman-Myers syndrome were genotyped using 20 polymorphic STRs which cover the whole X chromosome. Of 20 STRs, DXS1001 on Xq25 suggested linkage and yielded a lod score of 3.01 at straight theta = 0 additional STRs flanking DXS1001 were tested. Fourteen polymorphic STRs out of 27 confirmed that Smith-Fineman-Myers syndrome locus is linked to several markers on Xq25. Haplotype analysis placed the disease locus within a 14.6cM interval bounded by DXS8064 and DXS8050.

CONCLUSION

The gene responsible for Smith-Fineman-Myers syndrome is mapped to a 14.6cM interval between DXS8064 and DXS8050 on Xq25. This result will be helpful for the identification of disease gene.

Genetic variants in the epithelial sodium channel in relation to aldosterone and potassium excretion and risk for hypertension

Renin and aldosterone secretion is often lower in blacks than in whites, characteristics that resemble a milder form of Liddle syndrome in which a mutation in the amiloride-sensitive epithelial sodium channel (ENaC) of the kidney results in enhanced resorption of sodium. In the present study, we looked for evidence that the intrinsic level of ENaC activity is indeed higher in blacks than in whites. In overnight urine samples collected from young people (249 white and 181 black subjects, mean age 13.4 years), the urinary aldosterone/potassium ratio, which is typically very low in Liddle syndrome, was lower in blacks than in whites: 0.421+/-0.024 (mean+/-SE) versus 0.582+/-0.016 nmol/mmol (P<0.0001). In addition, all but 1 of 5 molecular variants in ENaC were much more common in blacks than in whites. G442V in the beta-subunit, present in 16% of the blacks and in only 1 white, was associated with parameters reflective of a greater Na retention and potentially a higher ENaC activity: a lower plasma aldosterone concentration (P=0.070), a lower urinary aldosterone excretion rate (P=0.052), a higher potassium excretion rate (P=0.048), and a lower urinary aldosterone/potassium ratio (P=0.027). In a second cohort consisting of 126 black and 161 white normotensive subjects and 232 black and 188 white hypertensive subjects, betaG442V did not show a significant association with hypertension (P=0.089). On the other hand, a variant that was twice as common in whites, alphaT663A, was associated with being normotensive both in blacks (P=0.018) and in whites (P=0.034). Expression of either betaG442V or alphaT663A in Xenopus oocytes did not result in a change in basal Na current, consistent with the variants being in linkage disequilibrium with alleles at active loci. In conclusion, several lines of evidence are presented to suggest that ENaC activity is higher in blacks than in whites, which could contribute to racial differences in Na retention and the risk for hypertension.

Myeloablative chemotherapy with autologous peripheral blood stem cell transplantation for metastatic breast cancer: immunologic consequences affecting clinical outcome

Autologous peripheral blood stem cell transplantation following myeloablative chemotherapy is being increasingly utilized in the treatment of a variety of malignancies. We administered busulfan 16 mg/kg orally, thiotepa 500-700 mg/m2 i.v., and carboplatin 800-1000 mg/m2 i.v. to 56 women with metastatic carcinoma of the breast. Autologous peripheral blood stem cells, which had been collected after a combination of chemotherapy and granulocyte colony-stimulating factor, were infused on day 0. The major toxicities of the conditioning regimen included severe pancytopenia, stomatitis, nausea, emesis, diarrhea, fever, and infection. Transplant-related mortality was 1.8%. The incidence of opportunistic viral infections was 42.9%. Fourteen individuals achieved a complete response. The actuarial survival at 1223 days was 13.7% for the entire group of patients; the actuarial survival at 1009 days was 39.3% among complete responders. The functional status of the immune system was determined following transplantation in a subset of patients. Peripheral blood mononuclear cells were obtained before and after stem cell infusion, and were analyzed phenotypically and functionally. Proliferative and interleukin-2 synthetic ability of these cells was assessed following stimulation with phytohemagglutinin and anti-CD3 antibody. The response to influenza peptides was also ascertained. Proliferative and interleukin-2 synthetic capacity was markedly impaired for over a year. Memory response was virtually absent for up to 2 years following transplantation. The prolonged and marked immunosuppression following this myeloablative regimen was associated with a high incidence of opportunistic viral infections, and may have contributed to disease relapse and progression especially in patients who failed to achieve a complete response following transplantation.

On topography and functionality in the B-D rings of cephalostatin cytotoxins

Analogues 12'beta-hydroxycephalostatin 1 (9), 7'-deoxyritterazine G (10), and 14-epi-7'-deoxyritterazine B (11) were prepared via our protocol for unsymmetrical pyrazine synthesis. Cytotoxicity against human tumors was also determined for the first time for ritterazines, with femtomolar potency and a high correlation to cephalostatins observed. The SAR of these and related compounds provide insight into the importance of topography and certain chemical functionality in the B-D and B'-D' rings of cephalostatin type antineoplastics.

Allelic deletion at 11q23 is common in MYCN single copy neuroblastomas

Deletions of the long arm of chromosome 11 (11q) have been noted in primary neuroblastomas, but a comprehensive analysis has not been performed. Therefore, we analysed 331 neuroblastomas (295 sporadic, 15 familial and 21 tumor-derived cell lines) to determine the prevalence of 11q allelic deletions, to map the location of a putative tumor suppressor gene and to perform clinical correlative studies. Assays for loss of heterozygosity (LOH) were performed at 24 microsatellite loci spanning 11q. LOH was observed at multiple 11q loci in 129/295 (44%) sporadic neuroblastomas, 5/15 (33%) familial neuroblastomas, and 5/21 (24%) neuroblastoma cell lines. A single region of 2.1 cM within 11q23.3, flanked by markers D11S1340 and D11S1299, was deleted in all specimens with 11q LOH. Allelic loss at 11q23 was inversely related to MYCN amplification (P<0.001). Within the subset of cases with a single copy of MYCN, 11q LOH was associated with advanced stage disease (P=0.008), unfavorable histopathology (P=0.042), and decreased overall survival probability (P=0.008). However, 11q LOH was not independently prognostic in multivariate analyses. These data support the hypothesis that a tumor suppressor gene mapping within 11q23.3 is commonly inactivated during the malignant evolution of a large subset of neuroblastomas, especially those with unamplified MYCN.

Dispersion-free transient-grating frequency-resolved optical gating

We have developed a compact dispersion-free TG (transient-grating) FROG (frequency-resolved optical gating) by utilizing a mask that separates the input beam into three distinct beams focused into fused silica to create the FROG signal. Two of the beams are reflected off the same set of mirrors to ensure identical optical paths, eliminating the difficulty in establishing zero time delay between the beams. In addition, the use of only reflective optics avoids material dispersion in the FROG except for the mixing crystal. This TG FROG is capable of operating with an intensity of 1 x 10(11) W/cm(2) and has resolutions less than 0.5 and 1.3 fs for 25- and 10-fs input pulses, respectively.

[The expression of nm23-H1 genes with clinical prognosis in endometrial carcinoma]

OBJECTIVE

To study the expression of nm23-H1 gene in endometrial carcinoma and its relationships between the clinicopathological parameter and prognosis of endometrial carcinoma.

METHODS

The endometrial specimens of 60 cases with endometrial carcinoma were studied retrospectively by immunohistochemical stainings.

RESULTS

The positive expression rate of nm23-H1 gene in endometrial carcinoma was 55.0% (33/60). The positive rate of nm23-H1 in early endometrial carcinoma was significantly higher than that in advanced cases (65.9% and 25.0%, respectively, P < 0.05). Positive rates in the well and moderately differentiated endometrial carcinoma were also higher than those of poorly differentiated (66.7%, 63.6%, 29.4%, P < 0.05). 20.0% of the cases with and 64.9% of the cases without lymph node metastasis showed positive for nm23-H1 (P < 0.05). The expression of nm23-H1 was not correlated with histological type, myometrial invasion, estrogen receptor and progesterone receptor. The survival rate of patients with nm23-H1 expression was significantly higher than that of patients without nm23-H1 expression. The 5-year survival rate was 90.5% and 55.3% respectively (P < 0.05).

CONCLUSION

nm23-H1 gene may play a role in the inhibitory effect on the development and the lymph node metastasis of endometrial carcinoma, and may be related to be prognosis of endometrial carcinoma.

[Studies on extracting procedure for huoxue jiangzhi capsules by orthogonal analysis]

The contents of tanshinone IIA, protocatechuic aldehyde and anthraquinone were used to evaluate the extracting procedure for Huoxue Jingzhi capsules by orthogonal analysis. The best one can be described as: the drug powder is reflowed 2 times, 3 hours each, percolated by 80% alcohol with the 4 times weight of powder.

Differential targeting of protein kinase CK2 to the nuclear matrix upon transient overexpression of its subunits

Modest dysregulation of CK2 has been shown to enhance the oncogenic potential in transgenic models of cancer. Since nuclear matrix serves as an anchor for CK2 and plays a key role in growth-related activities, we examined the effects of CK2 overexpression on its signaling to the nuclear matrix. Expression plasmids pCI-CK2alpha, pCI-CK2beta, and the bicistronic pCI-CK2alphabeta containing full length cDNAs encoding the various subunits were employed to transiently transfect two cell lines, BPH-1 and COS-1. Cytosol from transfected BPH-1 cells containing alpha or beta or alpha + beta or alphabeta showed a modest increase in CK2 activity by 26%, 1%, 20%, and 17%, respectively, over that in the controls transfected with pCI vector. However, the corresponding increase in CK2 activity in the NM fraction was 156%, 8%, 147%, and 152%, respectively. Immunoblot analysis of the CK2 in the NM accorded with these data. Similar results were obtained with COS-1 cells or other expression vectors. The results suggest that moderate overexpression of CK2 in the cells evokes a differential several-fold enhancement in NM associated CK2 relative to that in the cytosol. This process may have a bearing on the functional signaling of this kinase in relation to its possible role in oncogenesis.

[Determination of stilbene in radix Polygoni multiflori by HPLC and its stability study]

OBJECTIVE

To develop a HPLC method for determining stilbene in Radix Polygoni Multiflori and studying its stability.

METHOD

HPLC conditions: An Econosphere C18 column, a mixture of methanol-water(30:70) as mobile phase, and UV detection at 310 nm. In addition, the stability of stilbene was studied at high temperature and in acidic solution.

RESULT

The linear range of calibration curve was 2.24 x 10(-2)-1.12 x 10(-1) micrograms(n = 6) with a correlation coefficient of 0.99998, the average recovery with RSD being 99.96% +/- 1.54%.

CONCLUSION

The method is sensitive, accurate and speedy. Stilbene in aqueous solution is stable, but high temperature(80 degrees C) tends to affect the stability. In acidic solution no stability can be found.

Prevalence and risk factors of behavioral and emotional problems among Chinese children aged 6 through 11 years

OBJECTIVE

To examine the prevalence and risk factors of behavioral and emotional problems in Chinese children.

METHOD

A sample of 2,940 children aged 6 through 11 years was randomly drawn from household registers in Shandong Province of China. Parents completed the Child Behavior Checklist (CBCL) and a structured self-rating questionnaire.

RESULTS

The mean CBCL Total Problems score was 16.1 (SD = 14.0). There was no significant age effect on the Total Problems score; boys scored significantly higher than girls (17.2 versus 15.0; F = 24.94, p < .01). The overall prevalence rates of behavioral problems were 12.5% for boys and 8.3% for girls (chi 2 = 14.23, p < .01). Logistic regression analysis showed that a number of parental, prenatal, perinatal, and postnatal factors were significantly associated with increased risk of children's behavioral problems.

CONCLUSIONS

The prevalence of parent-reported behavioral problems in Chinese children is lower than those found in other countries. Of multiple psychosocial and biological factors associated with children's behavioral problems, separation or divorce of parents is the most significant factor.

[Neural cluster structure with single component prediction in multiple variable systems for X-ray fluorescence spectrometry]

A neural cluster structure with single component prediction (NCSCP) was proposed for X-ray fluorescence spectrometry in a multivariable system. The neural cluster structure is built by the collection of a group of neurons which have close relationships among one another. In X-ray fluorescence analysis, the structure is constructed by choosing the elements in which there exist serious matrix effects, and deleting the components containing large noise. The predictability of the neural cluster structure was compared with that of the classical backward error propagation algorithm with single component prediction. The results show that the neural cluster structure is significantly superior to the classical algorithm in prediction accuracy, antidisturbance and the predictabilty to outliers.

Mechanisms of internalization of Staphylococcus aureus by cultured human osteoblasts

Staphylococcus aureus is an important bone pathogen, and evidence shows that this organism is internalized by chick osteoblasts. Here we report that S. aureus is internalized by human osteoblasts. Internalization was inhibited by monodansylcadaverine and cytochalasin D and to a lesser extent by ouabain, monensin, colchicine, and nocodazole. We propose that internalization occurs via a receptor-mediated pathway, requiring the participation of cytoskeletal elements, principally actin.

[A case-control study on the dietary risk factors of upper digestive tract cancer]

OBJECTIVE

To understand the effect of dietary factors in Yangzhong, Jiangsu Province-a high prevalence area in China.

METHODS

A case-control study on 209 cases of upper digestive tract cancer was conducted. There were 68 cases of esophageal cancer, 69 cases of cardiac cancer and 72 cases of other gastric cancers including 129 males and 80 females aged 35-79 under the study.

RESULTS

It is revealed that intake of pickled vegetables increases the ORs of esophageal, cardiac and other gastric cancers (OR = 2.82, OR = 5.17, OR = 2.92, respectively). It is also concluded that the intake of leftovers can elevate the ORs of esophageal and cardiac gastric cancer (OR = 1.88 and OR = 1.90) and over consumption of salt also elevates the OR of cardiac cancer (OR = 1.87). However, drinking green tea may decrease the ORs of esophageal and other gastric cancers (OR = 0.20 and OR = 0.28) while fruits consumption may reduce the OR of esophageal cancers (OR = 0.51).

CONCLUSION

Tumors from upper digestive tract have some relations with diet factors but the effects vary with the differences of tumor sites, dose of exposure and area, etc.

Nuclear matrix targeting of the protein kinase CK2 signal as a common downstream response to androgen or growth factor stimulation of prostate cancer cells

Protein kinase CK2, a messenger-independent serine/threonine kinase, has been implicated in cell growth. Androgenic stimulus in rat prostate modulates its association with nuclear matrix (NM) and chromatin. Because the growth of human prostate carcinoma cells is influenced by androgens and/or growth factors, we determined the nature of CK2 signaling in the NM in response to androgen and growth factor stimuli. Androgen-sensitive LNCaP and androgen-insensitive PC-3 cells were cultured in media to regulate their growth in the presence of 5alpha-dihydrotestosterone (5alpha-DHT) or growth factors (epidermal growth factor, keratinocyte growth factor, and transforming growth factor alpha). The activity of CK2 was measured in the cytosolic and NM fractions isolated from these cells after treatment with growth stimuli. The changes in CK2 in various fractions were also confirmed by immunoblotting with a specific antibody. LNCaP cells responded to both 5alpha-DHT and growth factors for growth. The presence of these agents in the culture medium evoked a translocation of CK2 to the NM from the cytosol. The PC-3 cells did not respond to 5alpha-DHT for growth but did respond to growth factors. Under these conditions, there was also a translocation of CK2 to the NM concomitant with a decrease in the cytosolic fraction. These results suggest that CK2 translocation to the NM occurs in response to various growth stimuli in cells in culture. Thus, CK2 is a common downstream signal transducer in response to diverse growth stimuli that may relate to the pathobiology of prostate cancer cells.

[Isolating the ends of yeast artificial chromosome by inverse polymerase chain reaction]

OBJECTIVE

To establish a highly efficient method for isolating yeast artificial chromosome(YAC) ends.

METHODS

Based on the sequence of TAC vector, the frequent cutting enzymes were used to cleave within the vector and the genomic insert to generate relatively small fragments,which were ligated and subsequently amplified using vector primers that are in inverse orientation. The PCR products were purified and sequenced. RESULTS 8 YAC termini were isolated from YAC 776E2,964C5,11D8 and 8D1.

CONCLUSION

The results suggest that inverse PCR be an efficient method for isolating YAC termini.

On the relationship of OSW-1 to the cephalostatins

Antineoplastic bis-steroidal (cephalostatin-type) analogues of the saponin OSW-1 were produced from a dihydroaglycone of OSW-1. The key aglycone 6H was obtained from 5alpha-androstan-3beta-ol-17-one in 8 steps (38% yield). The SAR of the aglycones, intermediates, and hybrid analogues provide insights regarding the proposed common role of C22-oxocarbenium ions in the bioactivity of both OSW-1 and cephalostatins.

Interleukin 1 (IL-1) causes changes in lateral and rotational mobilities of IL-1 type I receptors

To investigate IL-1-dependent interactions of IL-1 type I (IL-1 RI) receptors on intact cells, lateral and rotational mobilities and detergent insolubility were investigated. Lateral mobility was measured by fluorescence photobleaching recovery, using a Cy3-modified, noncompetitive mAb specific for IL-1RI (M5) bound to wild-type IL-1 RI or mutant IL-1 RI with a truncated cytoplasmic tail. Addition of IL-1 causes significant reduction in the mobile fraction of wild-type IL-1 RI for two different transfected cell lines. For the mutant IL-1 RI, no significant decrease in response to IL-1 is observed, indicating that the missing cytoplasmic segment is involved in IL-1-dependent interactions of IL-1 RI that lead to reduced lateral mobility on the cell surface. The rotational mobility of IL-1 RI was assessed with phosphorescence anisotropy decay measurements using erythrosin-labeled M5. IL-1 decreases the rotational mobility of cell surface IL-1 RI on the microsecond time scale and also increases the initial anisotropy, indicating loss in segmental motion. Measurements of resistance to solubilization by Triton X-100 showed that IL-1 binding increases the fraction of IL-1 RI sedimenting with cytoskeletal residues. The IL-1 receptor antagonist protein (IL-1ra) causes partial effects in reducing rotational mobility and increasing detergent insolubility of M5-lableled IL-1 RI, indicating that this ligand causes structural changes in the presence of the dimerizing M5 mAb. These ligand-dependent physical interactions of IL-1 RI on the cell surface may be related to signal initiation by this receptor.

[Trace analysis of Zn-doped compound semiconductor material by resonant ionization mass spectrometry]

An experimental setup and the procedure for the laser resonant ionization mass spectrometry (RIMS) have been described. Both an optical spectrum and a mass spectum have been shown. The detection limit that can be reached by using this procedure has been estimated.

Conformational Structure of Triblock Copolymers by FT-Raman and FTIR Spectroscopy

Fourier transform Raman (FT-Raman) and Fourier transform infrared (FTIR) spectra of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers as pure solids or liquids and in aqueous solutions have been examined. The qualitative features in Raman and FTIR spectra of these copolymers have been presented. The Raman and FTIR spectra of PEO-PPO-PEO triblock copolymers are very sensitive to the structural and conformational changes. It shows that the relative intensities of several peaks in Raman spectra are dependent on the PPO/PEO ratios and the conformation of the copolymers. From Raman and FTIR spectra, Pluronic F68 and F88 assume helical structures with a few trans conformers. Other block copolymers exhibit that the disordered structure increases with increasing PPO/PEO ratio. Comparison of Raman spectra of PEO-PPO-PEO triblock copolymers as pure solids or liquids with those in aqueous solutions has been presented. Copyright 1999 Academic Press.

Role of protein kinase CK2 in phosphorylation nucleosomal proteins in relation to transcriptional activity

Protein kinase CK2 undergoes rapid translocation to nuclear matrix and nucleosomes on androgenic stimulation of growth in prostatic epithelial cells. Further, CK2 appears to be regulated differentially in the transcriptionally active and inactive nucleosomes. We have investigated the role of CK2 in phosphorylation of nucleosome-associated proteins in the transcriptionally active and inactive nucleosomes that were isolated from ventral prostate subjected to different androgenic status in vivo. Proteins associated with these nucleosomes were phosphorylated via the intrinsic protein kinase activity, using [gamma-32P]ATP in the absence and presence of GTP. Several proteins appear to be potential substrates for CK2 associated with the nucleosomes. Among them are proteins that are differentially associated with the transcriptionally active and inactive nucleosomes. Phosphorylation of several of these proteins is modulated depending not only on their sites of association (i.e., active vs. inactive nucleosomes) but also on the state of transcriptional activity. Differential phosphorylation of specific proteins by CK2 associated with the active and inactive nucleosomes may be pertinent to the process of transcription regulation.

[Carcinoma of the lips developing in discoid lupus erythematosus]

OBJECTIVE

This clinical study was designed to learn the diagnosis and treatment of lip carcinoma developing in discoid lupus erythematosus.

METHODS

One hundred and eighty-one of squamous cell carcinoma of the lips treated in our department from 1980 to 1995 were retrospectively studied.

RESULTS

Ten cases of the 181 lip carcinoma (5.5%) had concomitant discoid lupus erythematosus (DLE) of the vermilion border of the lower lip.

CONCLUSION

Bleomycin or radiotherapy is the best treatment for the disease.

[A preliminary study on the relationship between nutritional status and postoperative complications in patients with head and neck malignancies]

OBJECTIVES

To study the role of nutritional factor in the development of postoperative complications in patients with head and neck malignancies.

METHODS

Postoperative complications of 96 patients with head and neck malignancies who were operated on were surveyed. Twenty-seven developed postoperative complications; the remaining 69 went uneventful. Comparisons of nutritional status and clinical variables between these two groups were made.

RESULTS

1. The prevalence of poor preoperative nutritional status in the complication group (56%) was higher as compared with that in the noncomplication group (20%) (P < 0.001); 2. values of body weight, triceps skin fold thickness, arm circumference, arm muscle circumference, and creatinine-height index in the complication group decreased much more significantly than in the noncomplication group (P < 0.001); 3. the nitrogen and calorie intake within the first postoperative week was lower in the complication group than in the non-complication group (P < 0.001).

CONCLUSIONS

Nutritional factor plays a very important role in the development of postoperative complication and the perioperative nutritional support for head and neck surgical patients should not be ignored.

Differential stimulation of proline-rich tyrosine kinase 2 and mitogen-activated protein kinase by sphingosine 1-phosphate

Sphingosine 1-phosphate (SphP), a metabolite of cellular sphingolipids, has been shown to induce cell proliferation by activating the mitogen-activated protein kinase (MAPK) pathway. Proline-rich tyrosine kinase 2 (Pyk2) is a novel cytosolic tyrosine kinase which mediates activation of the MAPK or c-Jun N-terminal kinase (JNK) signaling pathways in response to a variety of stimuli that elevate intracellular calcium. In this report, we show that SphP stimulates both tyrosine phosphorylation of Pyk2 and MAPK activation in a transient and dose-dependent manner in rat aortic smooth muscle cells. Further studies indicate that Pyk2 phosphorylation, but not MAPK activation, is dependent on a pertussis toxin-sensitive G-protein-coupled receptor as well as partially on actin cytoskeleton. In addition, both intracellular calcium mobilization and protein kinase C (PKC) are required for optimal Pyk2 phosphorylation while either calcium increase or PKC activation is sufficient for MAPK activation in response to SphP. Finally, we show that a tyrosine kinase(s) other than Pyk2 is necessary for MAPK activation by SphP. Together, these results suggest that SphP stimulates tyrosine phosphorylation of Pyk2 through a G-protein coupled receptor, which is dissociated from its activation of the MAPK pathway in these cells.

[Genetic analysis of varicose vein of lower extremities]

OBJECTIVE

To make a hereditary analysis of varicose vein of lower extremities(VVLE), including hereditary pattern, sex ratio and the transmitted expression male and female of varicose vein of lower extremities.

METHODS

The ascertainment probability was estimated according to Weinberg's proband method. The value of segregation ratio P and proportion of sporadic cases X were estimated by the maximum likelihood score method. The calculations were performed using computer program of segregation analysis. The VVLE cases were random samples from inpatients and outpatients of the authors' hospital from 1991 to 1996.

RESULTS

There were 68 pedigrees including 80 nuclear families in 3 different mating types:UAU, UAA and AAA. UAU, UAA and AAA were analysed together. UAA and UAU (multiplex families) were analysed respectively. All the values were compatible with autosomal dominant inheritance of incomplete penetrance; the penetrance frequencies were 91.94%, 78.14% and 69. 92% respectively. The proportion of X was 24.32%. The UAU was compatible with autosomal recessive inheritance; the proportion of sporadic cases was 36.75%.

CONCLUSION

VVLE is compatible with autosomal dominant and recessive inheritance. The sex ratio of male:female is 2.39:1. The transmission is possible from male and female to male and female both.

[Effect of dietary calcium on serum calcium and calmodulin activity of brain and hypothalamus in rats]

The effect of low calcium (LC) diet supplemented with various amount of calcium on serum calcium and calmodulin of rats was studied. The LC diet was mainly composed of corn low in calcium. The calcium content of LC diet was only half of that of the stock diet. Seventy Wistar rats were divided into 7 groups by weight and sex. Results showed that serum calcium in LC group was low and calmodulin activity was also low. These parameters were improved while calcium was supplemented in LC diet. There is a significant dose-response relationship among diet calcium, serum calcium and growth. When the total calcium in diet was increased up to 1000 mg/kg, serum calcium level was closed to that of normal and higher than the serum calcium in LC group significantly. The study demonstrated that low dietary calcium, hypocalcemia and low calmodulin are associated. When total dietary calcium was up to 1000 mg/kg, the growth retardation was attenuated.

[An experimental study on promoting reconstruction of microcirculation of the ischemic skin flap with basic fibroblast growth factor]

OBJECTIVE

This study was to determine whether the basic fibroblast growth factor (bFGF) could promote reconstruction of microcirculation in the ischemic portion of a random skin flap.

METHODS

Five methods were used in the experiment: measurement of the survival area of the skin flap; light and electron microscopic studies; immunohistochemical observation of the endothelial cell and microvessel image analysis technology (IAT).

RESULT

The survival area and microvessels in the skin flap were significantly increased in the treated group. The results indicate that bFGF can stimulate the proliferation and differentiation of endothelial cells in vivo and promote the microcirculation of the ischemic flap.

CONCLUSION

bFGF could promote reconstruction of microcirculation of the ischemic skin flap.

Dynamics of protein kinase CK2 association with nucleosomes in relation to transcriptional activity

Protein kinase CK2 has been implicated in control of cell growth and proliferation. Since growth stimuli evoke its preferential association with chromatin and nuclear matrix, we examined the dynamics of CK2 in nucleosomes fractionated on the basis of their transcriptional activity in the rat prostate. In this model, androgens induce expression of androgen-dependent genes but inhibit the androgen-repressed genes, whereas absence of androgens has the reverse effect. The level of CK2 was higher in the active than in inactive nucleosomes from normal prostate. Differential alterations in the levels of CK2 activity in the transcriptionally active versus inactive nucleosomes were evoked by androgen deprivation or administration. Comparison of the distribution of CK2 in active and inactive nucleosomes under varying androgenic conditions showed that the relative CK2 activity intrinsic to the transcriptionally active nucleosomes remained fairly stable, concordant with gene activity specific to the androgenic status. However, CK2 associated with inactive nucleosomes declined to a minimal level on androgen deprivation but increased rapidly on androgen administration (reflecting expression of multiple androgen-dependent genes). We suggest a role for CK2 in promoting the conformational transition of inactive nucleosomes to the active form and in the function of transcriptionally active nucleosomes.

[Polymorphism analysis of 4 loci of X-chromosome in a Chinese population of the Han nationality]

OBJECTIVE

To investigate the polymorphism of 4 loci of X-chromosome in the Hans.

METHODS

Using PCR-SSLP, the authors analysed the polymorphism of DXS1068, DXS7132, DXS6804 and DXS6799 in the X-chromosome in 70 randomly selected female Hans.

RESULTS

The number of alleles in the 4 loci were 5,5,5 and 6 respectively; there were no significant differences between the observed and estimated and genotype probabilities of the 4 loci; the estimates of heterozygosity of 4 loci were 0.6819, 0.6895, 0.7659 and 0.6483 respectively and there were no significant differences between the observed and estimated heterozygosity of the 4 loci.

CONCLUSION

The distribution of alleles and genotype probabilities of 4 loci all observe the Hardy-Weinberg equilibrium.

[Determination of adenosine and 3'-deoxyadenosine in Cordyceps militaris (L.) Link. by HPLC]

The establishment of a quantitative determination method by HPLC for adenosine and 3'-deoxyadenosine in Cordyceps militaris is reported. The sample was extracted with water under ultrasonic management for 2 hours. Chromatographic conditions: YWG C18 10 microns 5 mm x 200 mm; mobile phase consisted of NaH2PO4-NaOH buffer solution (pH 6.8); UV detection at 260 nm. The recoveries of adenosine and 3'-deoxyadenosine were 95.8% +/- 0.64% and 100.6% +/- 0.65% (n = 5) respectively.

[A study of genetic patterns of idiopathic epilepsy]

OBJECTIVE

To explore genetic patterns of idiopathic epilepsy (IEP).

METHODS

Using familial analysis, tests for multifactorial inheritance and segregation analysis, we studied 210 pedigrees with IEP found in a population survey in Shangdong province.

RESULTS

The genetic pattern of IEP is not polygenic but is mainly influenced by autosomal recessive disorders. The results of segregation analysis indicate that the genetic pattern of U*U multiplex families and U*A group is autosomal recessive. Only a few cases in U*U group may accept the assumption of autosomal recessive inheritance while the other are sporadic cases. The frequency of sporadic cases is approximately 78.5%. Genetic heterogeneity may influence U*U(f) group and U*U group.

CONCLUSION

Further and careful empirical scrutiny of U*U(f) group and the sporadic cases in U*U group offers the best hope for getting a clear understanding of genetic patterns and mechanisms in IEP.

Relationship between lung function and blood pressure in Chinese men and women of Beijing and Guangzhou. PRC-USA Cardiovascular and Cardiopulmonary Epidemiology Research Group

BACKGROUND

Previous studies of western populations have shown an inverse association between lung function and blood pressure.

METHODS

As part of a People's Republic of China-United States cardiopulmonary epidemiology study, we investigated the cross-sectional relationship between lung function and blood pressure in 6757 Chinese men and women, aged 35-54, from Beijing and Guangzhou, China. We also evaluated the longitudinal association between lung function and incident hypertension among 4818 initially normotensive subjects followed up between 2 and 4 years later.

RESULTS

In our cross-sectional analyses of baseline data, lung function varied inversely with baseline systolic (SBP) and diastolic blood pressure (DBP) in all women and in Beijing men. This association held for absolute and height-standardized forced vital capacity (FVC) and one-second forced expiratory volume (FEV1) (correlations: 0.10, -0.18, P < 0.0001), but was weaker after adjustment for age (correlations: -0.02, -0.11). The longitudinal follow-up showed that lower initial lung function levels were associated with a higher incidence of hypertension (SBP > or = 140 mmHg or DBP > or = 90 mmHg or currently using antihypertensive medications), but only among women in Guangzhou. Relative risks for hypertension incidence for those in the two lowest quintiles for FEV1 and FVC, compared to those in the two highest quintiles, ranged from 1.9 to 2.3 for Guangzhou women and from 0.9 to 1.4 for all other gender-city subgroups. Logistic regression analyses adjusting for age, baseline SBP, body mass index, smoking, education, and urban versus rural setting generally confirmed these patterns.

CONCLUSIONS

These results suggest a statistically significant, though weak, inverse relationship between lung function and blood pressure in Chinese men and women. This association is largely attributable to age and is present prospectively only in women.

Differential regulation of Pyk2 and focal adhesion kinase (FAK). The C-terminal domain of FAK confers response to cell adhesion

Pyk2 is a recently described cytoplasmic tyrosine kinase that is related to focal adhesion kinase (FAK) and can be activated by a variety of stimuli that elevate intracellular calcium. In this report, we showed that Pyk2 and FAK tyrosine phosphorylation are regulated differentially by integrin-mediated cell adhesion and soluble factors both in rat aortic smooth muscle cells, which express endogenous Pyk2 and FAK, and in transfected Chinese hamster ovary cells. We also found that Pyk2 is diffusely present throughout the cytoplasm, while FAK is localized in focal contacts as expected, suggesting that the different localization may account for their differential regulation. By analyzing a chimeric protein contain N-terminal and kinase domains of Pyk2 and C-terminal domain of FAK, we provided evidence that the distinctive C-terminal domains of Pyk2 and FAK were responsible for their differential regulation by integrins and soluble stimuli as well as their subcellular localization. Finally, we correlated FAK, Pyk2, and the chimeric protein binding to talin, but not paxillin, with their regulation by integrins and focal contact localization. These results demonstrate that the distinctive C-terminal domain of Pyk2 and FAK confer their differential regulation by different subcellular localization and association with the cytoskeletal protein talin.

Factors influencing survival rate in adenoid cystic carcinoma of the salivary glands

Ninety-one cases of adenoid cystic carcinoma (ACC) of the salivary glands with more than ten years' follow up were studied to investigate factors influencing the survival rate of patients, which vary according to site, histological type, clinical stage and nature of therapy. The data were statistically analysed for survival curves. Log rank tests were employed to assess the statistical significance of various groups. As a result, it may be concluded that tumour site, clinical stage and histological type are the important factors influencing the prognosis. ACC of the palate and parotid, early clinical stage, glandular/tubular histological type, and tumour without nerve involvement had the best prognosis. ACC in the submandibular gland, maxillary antrum and tongue, advanced clinical stage (stage III and IV), solid histological type, and tumour with nerve involvement had a poor prognosis.

[Cellular immunity in childhood iron deficiency anemia with recurrent respiratory infections]

OBJECTIVE

To examine interleukin-2 (IL-2) activity,serum soluble IL-2 receptor (sIL-2R) level and T lymphocyte subsets in peripheral blood from 63 childhood iron deficiency anemia (IDA) patients with recurrent respiratory infections(RRI).

METHODS

IL-2 activity, sIL-2R level and T lymphocyte subsets were assayed by MTT, ELISA and APAAP, respectively.

RESULTS

IL-2 activity, percentages of CD3+ and CD4+ cells as well as the ratio of CD4+/ CD8+ cells in the patients were significantly lower ( P < 0.01),while sIL-2R levels were higher than that in normal controls (P < 0.01). No significant change was found in the percentage of CD8+ cells.

CONCLUSION

Cellular immunity was impaired in childhood IDA with RRI.

A new nutritional assessment in patients with oral and maxillofacial malignancies

Combined subjective and objective nutritional assessment was performed on admission in 127 patients with oral and maxillofacial malignancies. On the basis of the nutritional assessment result, three typical nutritional parameters-body weight (BW) (X1), mid-upper-arm circumference (MAC) (X2), and hand grip strength (HGS) (X3) were used to establish a new nutritional assessment method that was developed by a computer-based discriminant analysis. The established model was as follows: Y1 = -126 + 1.09X1 + 1.34X2 + 0.23X3; Y2 = -95.63 + 0.96X1 + 1.17X2 + 0.19X3. In the model Y1 was regarded as good nutrition and Y2 as malnutrition. The larger value of Y stood for the patient's nutritional status (i.e. Y1 > Y2, well nourished; Y1 < Y2 malnourished). The new nutritional assessment correlates well with the combined subjective and objective nutritional assessment with a total agreement rate of 88.2%. With its simplicity and accuracy, the new nutritional assessment deserves a wide application in clinical situation.

[Epidemic trend of tuberculous meningitis in children of Heilongjiang province]

OBJECTIVE

To investigate the epidemic trend of tuberculous meningitis in children of Heilongjiang province in recent ten years, and to provide scientific evidence for control of the disease.

METHODS

The data, registered by 82 counties' antituberculosis institute, of tuberculous meningitis patients under 14 years were analyzed, and the epidemic trend of the disease was also discussed.

RESULTS

The incidence of tuberculous meningitis was 9.58 per 10,0000 populations in 1982, 2.17 per 10,0000 populations in 1992. The rate of annual decrease was 13.8%.

CONCLUSION

Participation of the government, improvement of pelple's life standard, control of sources of infection, and vaccination of BCG are effective measures for decreasing the incidence of this disease.

Responses of plasma fibronectin to the changes of dietary protein levels in rats

In this study, the plasma fibronectin was evaluated as a nutritional marker in protein- and protein-energy malnourished rats in comparison with plasma prealbumin, albumin, and total protein. The plasma fibronectin was determined by nephelometric assay based on the interaction of an antigen and antibody. The rats were subjected to three diets, containing 20, 5, and 0% casein, respectively, for 5 wk except in the last 2 wk, the rats on the 0% casein diet were re-fed on a 20% casein diet. The results showed that in the rats on a 5% casein diet (protein malnourished), the plasma fibronectin concentration rose significantly in the early stage and normalized thereafter. In the rats subjected to a 0% casein diet (protein-energy malnourished), the plasma fibronectin concentration did not decline quickly in response to protein depletion, compared with the plasma prealbumin, albumin, and total protein concentrations. Following the re-feeding of a 20% casein diet in the last 2 wk, the plasma fibronectin concentration was restored earlier than other plasma protein concentrations. No significant change in plasma fibronectin concentration was found in the rats receiving a 20% casein diet (control) over the 5 wk feeding period. It is concluded that plasma fibronectin may not be a suitable marker for protein or protein-energy malnutrition, though it is a sensitive index for nutritional rehabilitation.

[Production of anti-enteric adenovirus monoclonal antibody by electrofusion and semi-solid medium culture]

Ten million splenocytes from the enteric adenovirus (Ad40/41) immunized mice were fused with 3 x 10(6) myeloma cells by electrofusion. Then, the cells were selectively cultured in methyl cellulose semi-solid medium. Eighteen clones of hybridoma were directely picked out from the culture plates and 7 of them could secret high level specific antibodies to enteric adenovirus. So far, the anti-Ad40/41 virus monoclonal antibodies were successfully generated by the protocal of electrofusion accompanied with selective culture in methyl cellulose semi-solid medium.