[Microsurgical treatment of cranial base meningioma]

OBJECTIVE

To improve the total removal rate of cranial base meningiomas, and to reduce the mortality and morbidity.

METHODS

103 patients with cranial base meningiomas were treated by microsurgery. Tumors of different position were resected by variant transcranial base approaches and the operative methods.

RESULTS

and complications were analyzed retrospectively.

RESULTS

Total removal of Simpson's 1 to 2 grade was performed in 63 patients, subtotal removal in 31 and partial removal in 9. Good postoperative recovery was noted in 75 patients, skull nerve paralysis in 24 and death 4.

CONCLUSION

Using skull base microsurgery to resect cranial base meningiomas could shorten the distance of surgical approach and lessen the damage to brain.

Effects of sodium butyrate on growth, differentiation, and apoptosis in head and neck squamous carcinoma cell lines

BACKGROUND

Biologic agents that reverse early changes in the aerodigestive tract mucosa have potential treatment applications for patients with field cancerization of the upper aerodigestive tract. Sodium butyrate (BA) is a normal dietary constituent that induces differentiation and inhibits growth in several malignant cell types in vitro, but its effect on head and neck squamous cell carcinoma (HNSCC) has not been evaluated.

METHODS

Using five HNSCC cell lines, the effects of BA on cell proliferation and apoptosis were examined by colorimetric and fluorescence-labeling methods, and the expression of differentiation markers and apoptosis-related proteins were analyzed using Western and Northern blotting, flow cytometry, and cell cycle analysis.

RESULTS

BA-induced growth inhibition and apoptosis in HNSCC cells at millimolar concentrations. Apoptosis induction did not depend on the p53 status of the cell lines or on expression of members of the Bcl-2/Bax family.

CONCLUSIONS

These results demonstrate that butyrate has activity against HNSCC in vitro and may have clinical applications for management of HNSCC patients.

Pharmacodynamic assessment of cefprozil against Streptococcus pneumoniae: implications for breakpoint determinations

Cefprozil, an oral semisynthetic cephalosporin, is commonly utilized in the treatment of respiratory-tract infections in children. While this agent has provided acceptable clinical success over a number of years, this study was undertaken to better define its pharmacodynamic profile against Streptococcus pneumoniae. Nineteen clinical isolates of S. pneumoniae were utilized in the neutropenic murine thigh infection model. To simulate the pharmacokinetic profile of cefprozil in children, the renal function of mice was impaired with uranyl nitrate, and a commercially available cefprozil suspension (6 mg/kg of body weight) was administered orally every 12 h. Mice were infected with 10(6) to 10(7) CFU per thigh, and therapy was initiated 2 h later. At 0 and 24 h postinfection, thighs were harvested to determine bacterial density. Survival was assessed during 96 h of therapy. The magnitude of bacterial kill ranged from 0.5 to 4.4 log(10) CFU per thigh over 24 h, and the extent of microbial eradication was dependent on the MIC. Killing of more than 2.6 log(10) CFU per thigh was observed with MICs of < or =3 microg/ml, while either minimal killing or growth was detected with MICs of > or =4 microg/ml. Mortality in untreated control animals was 100%. Animals infected with strains for which the MICs were < or =2 microg/ml survived the infection, whereas MICs exceeding 2 microg/ml resulted in substantial mortality. These studies demonstrate the effectiveness of cefprozil against isolates of the pneumococcus for which the MICs are < or =2 microg/ml using a drug exposure typically observed in children. These data support a susceptibility breakpoint of < or =2 microg/ml for cefprozil.

Inhibitory activity and structural characterization of a C-terminal peptide fragment derived from the prosegment of the proprotein convertase PC7

Mammalian proprotein convertases (PCs) belong to the family of recently discovered serine proteases responsible for the processing of a large number of precursor proteins into their active forms. The enzymatic activities of the convertases have been implicated in a variety of disease states, such as cancer and infectious and inflammatory diseases. Like many other proteases, PCs are also synthesized as inactive proenzymes with N-terminal extensions as their prosegments. Here, we present the inhibitory activities of a number of "putative" interfacial peptide fragments derived from the proregion of PC7. We found that a peptide fragment corresponding to the C-terminal region (residues 81p-104p, or C24: E(1)-A-V-L-A-K-H-E-A-V-R-W-H-S-E-Q-R-L-L-K-R-A-K-R(24)) of the PC7 prosegment displays a strong inhibition (K(i) = 7 nM) of the PC7 enzyme comparable to that of the full-length (104 residue) prosegment. The same 24 residue peptide shows significantly populated helical conformations in an aqueous solution close to the physiological condition. Structure calculations driven by NOE distance restraints revealed a slightly kinked helical conformation for the entire peptide, characterized by many side-chain/side-chain interactions including those involving charged residues E8-R11-E15 and hydrophobic residues W12 and L19. These results suggest that the C-terminal region of the prosegment of PC7 may play a dominant role in conferring the inhibitory potency to the cognate enzyme and this strong inhibitory activity may be a direct consequence of the folded conformation of the peptide fragment in solution. We surmise that such a structure-function correlation for an inhibitory peptide could lead to the design and discovery of molecules mimicking the specific interactions of the PC prosegments for their cognate proteases.

[Changes of serum myocardial enzymes in patients with malignant hematologic diseases]

Myocardial enzymes including aspartate aminotransferase (AST), lactate dehydrogenase (LDH), HBD (LDH1 and LDH2), and creatine kinase (CK) and its isoenzyme were monitored in 106 cases of malignant hematologic diseases. The findings were that average values of LDH and HBD increased. There were 82.4% myocardial enzyme levels of 51 patients with leukemia, lymphoma, and myelodysplastic syndrome (MDS) returning to normal or making an obvious reduction after chemotherapy associated with drugs of heart toxicity, while there were increases of the myocardial enzyme levels before chemotherapy. Patients with the increasing of enzyme levels were only 3.9% after chemotherapy. After several courses of chemotherapy, the positive rates of the increasings of CK and CK-MB were higher than that of pretreatment. The results suggest that the injuries of myocardium are possible.

[The relation between MSI and the clinicopathologic factors of NSCLC.]

BACKGROUND

To explore the relationship between microsatellite instability (MSI) and various clinicopathologic factors in non-small cell lung cancer (NSCLC) .

METHODS

Ninety-four lung cancer specimens resected from patients with NSCLC were investigated. We used a very precise microdissection technique to obtain the genomic DNA from tumor tissue and paired normal tissue , followed by PCR amplification of 4 polymorphic genomic sequences (D3S1067 ,D3S659 ,D3S966 and AR) . MSI and its relationship with clinicopathological factors were analyzed.

RESULTS

Sixty-one of 94 (64. 89 %) NSCLC patients showed MSI at single or multiple loci. Statistically significant correlation was found between MSI and lymph node metastasis (Chi-Square = 9. 945 , P = 0. 002) . MSI-positive patients had significantly shorter survival time than MSI-negative ones had ( P = 0. 0001) . Cox-proportional-hazard-regression-model analysis confirmed that MSI was a very important prognostic indicator for NSCLC patients (Chi-Square = 15. 4126 , P = 0. 0001) , and lymph node metastasis had some prognostic significance in NSCLC patients (Chi-Square = 6. 6108 , P = 0. 0101) .

CONCLUSIONS

MSI closely correlates with lymph node metastasis of NSCLC and it is a crucial factor in predicting the survival time and prognosis of NSCLC patients.

[Studies on pncA gene mutations in M. tuberculosis isolates]

OBJECTIVE

To understand the mutations of pncA gene in M. tuberculosis isolates, and to evaluate their clinical value.

METHODS

Analyzing the pncA genes in 74 M. tuberculosis clinical isolates with PCR-SSCP and PCR-AS. M. tuberculosis strain H37Rv was used as control.

RESULTS

32 drug-sensitive isolates all displayed normal pncA SSCP profile. Of 20 non-pyrazinamide-resistant isolates, 4 had abnormal pncA SSCP profile, in which 2 isolates were sequenced, one was TTC-->TTA mutation at codon 58, another was TGG-->CGG mutation at codon 68. Of 22 pyrazinamide-resistant isolates, 10 displayed abnormal pncA SSCP profile, in which 2 isolates sequenced had TTC-->TTA mutation at codon 58.

CONCLUSIONS

The mutation of pncA gene is a pyrazinamide-resistant molecular mechanism in M. tuberculosis. Detecting the mutations of pncA genes might diagnose pyrazinamide resistance rapidly in some M. tuberculosis isolates.

Phospholipase D and RalA cooperate with the epidermal growth factor receptor to transform 3Y1 rat fibroblasts

3Y1 rat fibroblasts overexpressing the epidermal growth factor (EGF) receptor (EGFR cells) become transformed when treated with EGF. A common response to oncogenic and mitogenic stimuli is elevated phospholipase D (PLD) activity. RalA, a small GTPase that functions as a downstream effector molecule of Ras, exists in a complex with PLD1. In the EGFR cells, EGF induced a Ras-dependent activation of RalA. The activation of PLD by EGF in these cells was dependent upon both Ras and RalA. In contrast, EGF-induced activation of Erk1, Erk2, and Jun kinase was dependent on Ras but independent of RalA, indicating divergent pathways activated by EGF and mediated by Ras. The transformed phenotype induced by EGF in the EGFR cells was dependent upon both Ras and RalA. Importantly, overexpression of wild-type RalA or an activated RalA mutant increased PLD activity in the absence of EGF and transformed the EGFR cells. Although overexpression of PLD1 is generally toxic to cells, the EGFR cells not only tolerated PLD1 overexpression but also became transformed in the absence of EGF. These data demonstrate that either RalA or PLD1 can cooperate with EGF receptor to transform cells.

Efficient synthesis of a porphyrin-N-tripod conjugate with covalently linked proximal ligand: toward new-generation active-site models of cytochrome c oxidase

[formula: see text] A new-generation cytochrome c oxidase active-site model compound (4) featuring both a trisimidazolyl moiety and a proximal base has been designed and efficiently synthesized. During this study, a facile method based on the chemistry of a 4-magnesioimidazole derivative to synthesize 4-imidazolyl-containing tripodal ligands (7) has been developed.

Detection of neuroendocrine feature about salivary adenoid cystic carcinoma

OBJECTIVE

To study the possibility of neuroendocrine feature of salivary adenoid cystic carcinoma (SACC).

METHODS

Immunohistochemical staining was operated in SACC with S-100 protein, neurospecific enolase (NSE), chromogranin A, and synaptophysin, which are specific and correlative with neuroendocrine cells and neoplasias.

RESULTS

The positive expression of S-100, NSE, chromogranin, and synaptophysin were 42, 32, 8, and 7, respectively, in 50 cases of SACC.

CONCLUSION

Neuroendocrine feature in some SACC cells is possibly indicated.

[Gamma delta T cells and their receptor Vdelta gene rearrangement in transitional mucosa of rectal carcinoma]

OBJECTIVE

To observe gamma delta T cells and their receptors Vdelta gene rearrangement expression in the transitional mucosa of rectal carcinoma, and to investigate their relations with local tumor recurrence.

METHODS

In 13 patients with rectal carcinoma, gamma delta T cells in transitional mucosa were measured with two-color immunofluorescent flow cytometric analysis and polymerase chain reaction technique.

RESULTS

The volume of gamma delta T cells in transitional mucosal lymphocytes (TML) were significantly higher than that in tumor infiltrating lymphocytes (TIL), and significantly lower than that in normal intestinal epithelial lymphocytes (IEL) (P < 0.05). The gamma delta T cell receptors delta chain V region (gamma delta-TCR Vdelta1-Vdelta6) gene rearrangement was all expressed in TIL, TML and IEL; but the Vdelta 6 gene expression in both TML and TIL were higher than that in IEL (P < 0.05).

CONCLUSIONS

The decreased volume of gamma delta T cells in TML resulted in decreased local immune function and may be responsible for the local tumor recurrence after resection. The high expression of Vdelta 6 gene rearrangement in both TIL and TML suggests the skewing of gamma delta-TCR receptors and the abtitumor specificity of TIL and TML in local epithelium.

The prosegments of furin and PC7 as potent inhibitors of proprotein convertases. In vitro and ex vivo assessment of their efficacy and selectivity

All proprotein convertases (PCs) of the subtilisin/kexin family contain an N-terminal prosegment that is presumed to act both as an intramolecular chaperone and an inhibitor of its parent enzyme. In this work, we examined inhibition by purified, recombinant bacterial prosegments of furin and PC7 on the in vitro processing of either the fluorogenic peptide pERTKR-MCA or the human immunodeficiency virus envelope glycoprotein gp160. These propeptides are potent inhibitors that display measurable selectivity toward specific proprotein convertases. Small, synthetic decapeptides derived from the C termini of the prosegments are also potent inhibitors, albeit less so than the full-length proteins, and the C-terminal P1 arginine is essential for inhibition. The bacterial, recombinant prosegments were also used to generate specific antisera, allowing us to study the intracellular metabolic fate of the prosegments of furin and PC7 expressed via vaccinia virus constructs. These vaccinia virus recombinants, along with transient transfectants of the preprosegments of furin and PC7, efficiently inhibited the ex vivo processing of the neurotrophins nerve growth factor and brain-derived neurotrophic factor. Thus, we have demonstrated for the first time that PC prosegments, expressed ex vivo as independent domains, can act in trans to inhibit precursor maturation by intracellular PCs.

Antagonistic effects of protein kinase C alpha and delta on both transformation and phospholipase D activity mediated by the epidermal growth factor receptor

Downregulation of protein kinase C delta (PKC delta) by treatment with the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) transforms cells that overexpress the non-receptor class tyrosine kinase c-Src (Z. Lu et al., Mol. Cell. Biol. 17:3418-3428, 1997). We extended these studies to cells overexpressing a receptor class tyrosine kinase, the epidermal growth factor (EGF) receptor (EGFR cells); like c-Src, the EGF receptor is overexpressed in several human tumors. In contrast with expectations, downregulation of PKC isoforms with TPA did not transform the EGFR cells; however, treatment with EGF did transform these cells. Since TPA downregulates all phorbol ester-responsive PKC isoforms, we examined the effects of PKC delta- and PKC alpha-specific inhibitors and the expression of dominant negative mutants for both PKC delta and alpha. Consistent with a tumor-suppressing function for PKC delta, the PKC delta-specific inhibitor rottlerin and a dominant negative PKC delta mutant transformed the EGFR cells in the absence of EGF. In contrast, the PKC alpha-specific inhibitor Go6976 and expression of a dominant negative PKC alpha mutant blocked the transformed phenotype induced by both EGF and PKC delta inhibition. Interestingly, both rottlerin and EGF induced substantial increases in phospholipase D (PLD) activity, which is commonly elevated in response to mitogenic stimuli. The elevation of PLD activity in response to inhibiting PKC delta, like transformation, was dependent upon PKC alpha and restricted to the EGFR cells. These data demonstrate that PKC isoforms alpha and delta have antagonistic effects on both transformation and PLD activity and further support a tumor suppressor role for PKC delta that may be mediated by suppression of tyrosine kinase-dependent increases in PLD activity.

Network construction of first aid for electrical injury in the east China area of China Power

Electrical injury is an area of burn medicine that requires specialized treatment. Injury rates have reached 6.56% in 1990, compared to only 1% prior to 1980. In recent years, the morbidity has steadily increased due to the rapid development of the electrical power industry and the popularization of electrical installations. Electrical accidents cause severe damage to muscle and tissue, which makes treatment of these accident patients quite challenging. Therefore, it is very important to promote the widespread use of a first aid network within the electrical power system while strengthening safety measures within the industry to reduce morbidity and mortality among the electrically injured. To date, similar networks have been established in East China, Central China, North China, and Shandong within the six major electrical power industries. We hope to minimize the injury of workers through appropriate supervision, improved safety measures, and improved safeguarding of equipment.

A general route to 4-imidazolyl-containing multidentate ligands for biomimetic studies

[formula: see text] 4-iodo-1-tritylimidazole undergoes magnesium-iodine exchange with a Grignard reagent to give selectively the 4-magnesioimidazole derivative, which reacts with esters to form a variety of poly-4-imidazolyl carbinol compounds in 40-79% yields. A wide range of bi-, tri-, and pentadentate ligands featuring 4-substituted imidazole units have been efficiently synthesized.

Inhibitory effect of resveratrol on interleukin 6 release by stimulated peritoneal macrophages of mice

In the present investigation, interleukin 6 (IL-6) activity in the supernatant of cultured mouse peritoneal macrophages was monitored using a sensitive bioassay involving the IL-6-dependent murine hybridoma B9 cell line. The effects of resveratrol on Il-6 release by mouse peritoneal macrophages stimulated with calcium ionophore A23187 and fMLP were explored. Resveratrol, at a concentration range from 5 x 10(-6) to 4 x 10(-5) mol.l-1, was found to dose-dependently inhibit IL-6 release by cultured macrophages induced by A23187 and fMLP, and showed no direct cytotoxic effect, but induced proliferation of cultured mouse thymus cells. Resveratrol, at a concentration range from 10(-8) to 10(-5) mol.l-1, was shown to dose-dependently inhibit calcium ion influx into the cells with the stimulation of fMLP (10(-6) mol.l-1). These results suggest that the blocking of calcium ion influx into cells by reveratrol is one of the possible mechanisms of the IL-6 biosynthesis inhibitory action of resveratrol.

[Detection of neuroendocrine feature about salivary adenoid cystic carcinoma]

OBJECTIVE

To study the possibility of neuroendocrine feature of salivary adenoid cystic carcinoma (SACC).

METHODS

Immunohistochemical staining was operated in SACC with S-100 protein, Neuron-specific enolase (NSE), chromagranin A and synaptophysin which are specific and correlative with neuroendocrine and neoplasias.

RESULTS

The positive expression of S-100, NSE, chromogranin and synaptophysin were respectively 42, 32, 8 and 7 in 50 cases of SACC.

CONCLUSION

There is possibility of neuroendocrine feature in some SACC cells.

Decreased proteasome-mediated degradation in T cells from the elderly: A role in immune senescence

Induction of NFkappaB is a highly regulated process requiring phosphorylation, ubiquitination, and proteasome-mediated degradation of the cytosolic inhibitor IkappaBalpha. Analyses of the regulation of IkappaBalpha in TNF-alpha-treated T lymphocytes from young and elderly donors revealed severely compromised degradation of IkappaBalpha in T cells from the elderly. Examination of activation-induced phosphorylation and ubiquitination of IkappaBalpha did not demonstrate any significant age-related alterations. However, examination of proteasome activity in these T cells using fluorogenic peptide assays revealed a significant age-related decline in chymotryptic activity. These results suggest that a decline in proteasome activity results in a failure to fully degrade IkappaBalpha in the elderly. This failure to degrade IkappaBalpha may underlie both the observed decrease in NFkappaB induction and the IL-2 receptor expression in TNF-treated T cells during aging. Thus, decreased proteasome-mediated degradation may be central to immune dysfunction that accompanies aging.

Mammalian subtilisin/kexin isozyme SKI-1: A widely expressed proprotein convertase with a unique cleavage specificity and cellular localization

Using reverse transcriptase-PCR and degenerate oligonucleotides derived from the active-site residues of subtilisin/kexin-like serine proteinases, we have identified a highly conserved and phylogenetically ancestral human, rat, and mouse type I membrane-bound proteinase called subtilisin/kexin-isozyme-1 (SKI-1). Computer databank searches reveal that human SKI-1 was cloned previously but with no identified function. In situ hybridization demonstrates that SKI-1 mRNA is present in most tissues and cells. Cleavage specificity studies show that SKI-1 generates a 28-kDa product from the 32-kDa brain-derived neurotrophic factor precursor, cleaving at an RGLT downward arrowSL bond. In the endoplasmic reticulum of either LoVo or HK293 cells, proSKI-1 is processed into two membrane-bound forms of SKI-1 (120 and 106 kDa) differing by the nature of their N-glycosylation. Late along the secretory pathway some of the membrane-bound enzyme is shed into the medium as a 98-kDa form. Immunocytochemical analysis of stably transfected HK293 cells shows that SKI-1 is present in the Golgi apparatus and within small punctate structures reminiscent of endosomes. In vitro studies suggest that SKI-1 is a Ca2+-dependent serine proteinase exhibiting a wide pH optimum for cleavage of pro-brain-derived neurotrophic factor.

[Simultaneous determination of europium and copper in rare earth oxide by use AAS-PLS method]

Partial least squares regression was used to compensate for spectral "overlap" interference of Eu 324. 753 nm with Cu 324.754 nm in atomic absorption spectrometry. We could only use the copper element hollow-cathode lamp to simultaneous determine Eu and Cu in synthetic samples and rare earth oxide, and obtained satisfactory results.

Sensitivity of Drosophila heat shock transcription factor to low pH

The heat shock transcription factor (HSF) mediates the induction of heat shock gene expression. The activation of HSF involves heat shock-induced trimerization, binding to its cognate DNA sites, and the acquisition of transcriptional competence. In this study, the oligomeric properties of Drosophila HSF were analyzed by equilibrium analytical ultracentrifugation and gel filtration chromatography. Previous findings showed that trimerization of purified Drosophila HSF was directly sensitive to heat and oxidation (1). Here we report that low pH, in the physiological range, also directly induces HSF trimerization and DNA binding in vitro. Furthermore, the induction of HSF trimerization by low pH is synergistic with the actions of heat and oxidation. Since heat or chemical stress leads to a moderate decrease of intracellular pH, we suggest that intracellular acidification may contribute to activating the heat shock response in vivo.

Tubular-wire dual electrode for detection of thiols and disulfides by capillary electrophoresis/electrochemistry

A new dual-electrode detector for capillary electrophoresis is described. The detector consists of an integrated gold tubular electrode as the generator electrode and a gold wire electrode for detection. The detector configuration, including electrode size and position, has been optimized in terms of detection sensitivity and separation efficiency. After amalgamation of the dual electrode with mercury, the capillary electrophoresis/electrochemistry system was employed for simultaneous detection of thiols and disulfides. The response of cystine was found to be linear from 1 microM to 1 mM with a LOD of 0.5 microM (S/N = 3) and sensitivity of 60 pA/microM. The detection limits represent 200-fold improvement over previously reported dual-electrode designs for the detection of disulfides. The use of this detector for identification of thiol- and disulfide-containing peptides was demonstrated with a tryptic digest of ribonuclease A.

[Synthesis of adenine derivatives and their activities against herpes virus in vitro]

A series of 9-(N4-substituted acetaldehyde thiosemicarbazone) adenines were synthesized and evaluated for antiherpes virus activity. Compounds 4a-l were prepared by condensation of 9-(acetaldehyde) adenine(6) and the corresponding N4-substituted thiosemicarbazides (10). The antiviral effects of all compounds 4a-l were tested in vitro in primary rabbit kidney cell cultures infected with herpes simplex virus type 1 (HSV-1) and varicella-herpes zoster virus (VZV), and in primary human embryo cell cultures infected with herpes simplex virus type 2 (HSV-2). The results showed that the minimum inhibitory concentrations (MIC) of 4e and 4f for HSV-1 and VZV were 20, 40, 20 and 20 micrograms.ml-1, respectively, and other compounds were 200 micrograms.ml-1. For HSV-2, the MIC of all tested compounds were 300 micrograms.ml-1. We also evaluated the antiherpetic effect of 4e (and 4f) by combination with acyclovir (ACV) in the ratio of 1:1 in vitro. The MIC of the combined compounds were 2 micrograms.ml-1 for 4e and 6 micrograms.ml-1 for 4f, while their minimum cytotoxicities (MCC) in the cell were markedly reduced compared with the individual compounds.

[Effects of isorhapotigenin and resveratrol on function of peripheral blood polymorphonuclear leukocytes from rabbits]

In effects of isorhapotigenin and resveratrol on chemotaxis and release of beta-glucuronidase from rabbit peripheral blood polymorphonuclear leukocytes stimulated with formylmethionyl-leucyl-phenyl-phenylalanine (fMLPP) were studied. The optimal concentration of fMLPP for the induction of chemotaxis of polymorphonuclear leukocytes was approximately at 5 x 10(-10) mol.L-1. fMLPP, at the concentration range of 10(-10)-10(-6) mol.L-1, dose-dependently increased the release of beta-glucuronidase from polymorphonuclear leukocytes. Isorhapotigenin and resveratrol both inhibited the chemotaxis of polymorphonuclear leukocytes stimulated with fMLPP(5 x 10(-10) mol.L-1). Isorhapotigenin, at the concentration range of 10(-5)-10(-4) mol.L-1, dose-dependently inhibited the release of beta-glucuronidase from polymorphonuclear leukocytes stimulated with fMLPP(10(-8) mol.L-1). Resveratrol, at the concentrations of 1 x 10(-5) and 3 x 10(-5) mol.L-1, was shown to dose-dependently inhibit beta-glucuronidase release from polymorphonuclear leukocytes stimulated with fMLPP(10(-8) mol.L-1).

[A clinical observation on the leukopenia treated with shengbaikuai decoction]

OBJECTIVE

To study the effective orally taken medicine in treating the leukopenia.

METHODS

Ninety cases of leukopenia induced by chemotherapy were divided into 3 groups. They were test group treated with Shengbaikuai Decoction (SBK), control group and blank group. Their efficacies were compared with each other, 25 cases with nonchemotherapy were also observed.

RESULTS

WBC count and absolute neutrophil count (ANC) in test group were higher than those of other groups immediately after treatment and 2 weeks later (P < 0.01). The marked effective rate and total effective rate of test group after 2 weeks were 60.0% and 80.0% (P < 0.001) respectively, which were significantly higher than those of other groups. WBC and ANC count after treatment and 3 weeks later were higher than those before treatment in nonchemotherapy group (P < 0.001). The marked effective rate and total effective rate 3 weeks later were 64.0% and 80.0% respectively.

CONCLUSIONS

SBK could increase WBC count rapidly and definitely without apparent side effect.

Direct sensing of heat and oxidation by Drosophila heat shock transcription factor

The heat shock transcription factor HSF activates expression of its target genes in response to elevated temperatures and chemical or physiological stress. A key step in the activation process involves the formation of HSF homotrimers, leading to high-affinity DNA binding. The mechanism by which HSF trimerization and DNA binding is regulated by stress signals has remained elusive. Here, we report that trimerization and DNA binding of purified Drosophila HSF can be directly and reversibly induced in vitro by heat shock temperatures in the physiological range and by an oxidant, hydrogen peroxide. Other inducers of the heat shock response, including salicylate, dinitrophenol, ethanol, and arsenite, have no effect on HSF trimerization in vitro, indicating that these inducers act by indirect mechanisms.

[Effects of leukotrienes on production of interleukin 6 from mouse peritoneal macrophages]

In the present study, effects of leukotrienes on IL-6 production by mouse resident peritoneal macrophages were explored with a bioassay method involving IL-6 dependent murine hybridoma B9 cell line. The results showed that LTB4, LTC4 and LTD4 can enhance the production of IL-6 from cultured peritoneal macrophages of mice. The optimal concentractions for LTB4, LTC4 and LTD4 were found to be 1.45 x 10(-6), 6.9 x 10(-8) and 8.05 x 10(-8) mol.L-1, respectively. The results suggest that peptide leukotrienes might play important role on IL-6 production in the local milieu of inflammation.

[Simultaneous determination of cobalt and indium by atomic absorption spectrometry]

Present paper describes method which uses solution of simultaneous equations to compensate for spectral "overlap" interference of In 252.137nm with Co 252.136nm. Experimental results show that solution of simultaneous equations is possible method for resolving spectral interference in atomic absorption spectrometry. This method has been applied to determination of Co and In in the samples. Satisfactory results are obtained.

[Production and secretion of interleukin 6 from stimulated peritoneal macrophages of the mouse]

In this paper, a bioassay method involving the interleukin 6 dependent murine hybridoma B9 cell line was used to detect the level of released and cell-associated interleukin 6 in resident peritoneal macrophages from the mouse. The phorbol ester, phorbol 12-myristate 13-acetate (PMA), the calcium ionophores A23187, the chemotactic peptide fMLP and lipopolysaccharide(LPS) were introduced in these experiments as stimulators. PMA, A23187 and fMLP were shown to induce a dose-dependent increase of both released and cell-associated interleukin 6, whereas, LPS caused increase of interleukin 6 activity in supernatants of cultured peritoneal macrophages of the mouse. The effects of PMA and A23187 suggested that the pathway of PKC and calcium is involved in the production and secretion of interleukin 6. The effects of fMLP and LPS provided evidence that they participated in the process of inflammation. The difference between LPS and the other three stimulators in cell-associated interleukin 6 activity might suggest a different mechanism of actions of generation of interleukin 6.

[Human rotavirus infection in perinatal transmission]

OBJECTIVE

To investigate the perinatal infection of human rotavirus (HRV) in pregnant women and the effect on their neonates.

METHODS

HRV was examined by RT-PCR in cervical secretion and feces of 250 pregnant women and fecal samples of their neonates on the third postpartum day.

RESULTS

In pregnant women the HRV prevalence was 26.0% in feces and 8.8% in cervical secration, respectively. The infection rate of the 250 neonates in the first three days after birth was 4.4%, 15.6% and 22.0%, respectively. The HRV infection rate in neonates of infected mothers was 52.31%.

CONCLUSION

The infected mothers may be an important source for HRV infection of neonates. HRV transmitted via the labor tract and intrahospital transmission were the main sources for the neonatal infection.

[Characteristic mass and atomization efficiency of graphite furnace atomic absorption spectrometry]

Measurements of peak height and peak area characteristic masses and atomization efficiency for 7 elements (Ag, Bi, Cd, Cr, Ga, Ge and In) have been studied. The m0(i)(exp) values are compared with theoretical data, m0(i)(cal), to assess the effect of temperature on the correction factor of theorization for characteristic mass value (alpha = m0(i)(cal) m0(i)(exp)), the peak height and the peak area atomization efficiencies (betap and betai). The peak area atomization efficiency (betai) was equal to the correction factor of theorization for characteristic mass value (alpha) times tauD/tauR value. The tauR was value experimentally measured of atomic residence time and the tauD value calculated from rD = l2/8D. The betai value of elements always are smaller than the alpha values because the tauD/tauR values is less than one for most elements in the operating conditions. Past of the analyte vapours is readsorbed by the heated tube wall at high temperature and reevaporation of the adsorbed analyte followed by diffusion account for the larger atomic residence time and it appeared that the tauR value was larger than the tauD in graphite furnace.

Identification of a flexible loop region (297-313) of urokinase-type plasminogen activator, which helps determine its catalytic activity

Pro-urokinase has a much higher intrinsic catalytic activity than other zymogens of the serine protease family. Lys300(c143) in an apparent "flexible loop" region (297-313) was previously shown to be an important determinant of this intrinsic catalytic activity. This was related to the loop allowing the positive charge of Lys300(c143) to transiently interact with Asp355(c194), thereby inducing an active conformation of the protease domain (Liu, J. N., Tang, W., Sun, Z., Kung, W., Pannell, R., Sarmientos, P., and Gurewich, V. (1996) Biochemistry 35, 14070-14076). To further test this hypothesis, the charge at position 300(c143) and the flexibility of the loop were altered using site-directed mutagenesis designed according to a computer model to affect the interaction between Lys300(c143) and Asp355(c194). When the charge at Lys300(c143) but not Lys313(c156) was reduced, a significant reduction in the intrinsic catalytic activity occurred. Similarly, when the flexibility (wobbliness) of the loop was enhanced reducing the size of side chain, the intrinsic catalytic activity was also reduced. By contrast, when the loop was made less flexible, the intrinsic catalytic activity was increased. These findings were consistent with the hypothesis. The effects of these mutations on two-chain activity were less and often discordant with the intrinsic catalytic activity, indicating that they can be modulated independently. This structure-function disparity can be exploited to create a more zymogenic pro-urokinase (lower intrinsic catalytic activity) with a high catalytic activity, as exemplified by two of the mutants. The changes in intrinsic catalytic activity and two-chain activity induced by the mutations were due to changes in kcat rather than Km. Some significant structure-function differences between pro-urokinase and its highly homologous counterpart, tissue plasminogen activator, were also found.

In vitro characterization of the novel proprotein convertase PC7

Biochemical and enzymatic characterization of the novel proprotein convertase rat PC7 (rPC7) was carried out using vaccinia virus recombinants overexpressed in mammalian BSC40 cells. Pro-PC7 is synthesized as a glycosylated zymogen (101 kDa) and processed into mature rPC7 (89 kDa) in the endoplasmic reticulum. No endogenously produced soluble forms of this membrane-anchored protein were detected. A deletion mutant (65 kDa), truncated well beyond the expected C-terminal boundary of the P-domain, produced soluble rPC7 in the culture medium. Enzymatic activity assays of rPC7 using fluorogenic peptidyl substrates indicated that the pH optimum, Ca2+ dependence, and cleavage specificity of this enzyme are largely similar to those of furin. However, with some substrates, cleavage specificity more closely resembled that of yeast kexin, suggesting differential processing of proprotein substrates by this novel convertase. We examined the rPC7- and human furin-mediated cleavage of synthetic peptides containing the processing sites of three proteins known to colocalize in situ with rPC7. Whereas both enzymes correctly processed the pro-parathyroid hormone tridecapeptide and the pro-PC4 heptadecapeptide, neither enzyme cleaved a pro-epidermal growth factor hexadecapeptide. Thus, this study establishes that rPC7 is an enzymatically functional subtilisin/kexin-like serine proteinase with a cleavage specificity resembling that of hfurin. In addition, we have demonstrated that rPC7 can correctly process peptide precursors that contain the processing sites of at least two potential physiological substrates.

[Determination of atomization efficiency in graphite furnace with V-boat]

Based on that the absorbance is proportional to the effective length of the absorbing layer of atoms, a simple foumula is derived by which the atomization efficiency. Two atomization efficiencies were calculated: beta1 and beta2, which gave the fraction of calculated the total number of analytical atoms that enter the analysis volume during each stage of atomization. It is based on two different calculated ways for the mean residence time of atoms, and the beta1 and beta2 values of Ga and Tl in furnace with V-boat in various atomization temperatures were determined. Influence of the loss process of atomic vapor on the atomization efficiency value was discussed.

gamma-Interferon-induced resistance to 1,25-(OH)2 D3 in human monocytes and macrophages: a mechanism for the hypercalcemia of various granulomatoses

The hypercalcemia of various granulomatoses is caused by endogenous 1,25-dihydroxyvitamin D [1,25-(OH)2D3] overproduction by disease-activated macrophages. The inability of 1,25(OH)2D3 to suppress its synthesis in macrophages contrasts with the tight control of its production in macrophage precursors, peripheral blood monocytes (PBM). We examined whether 1,25(OH)2D3 resistance develops as PBM differentiate to macrophages or with macrophage activation. Normal human pulmonary alveolar macrophages (PAM) are less sensitive to 1,25(OH)2D3 than PBM, despite similar vitamin D receptor content; however, both PBM and PAM respond to exogenous 1,25-(OH)2D3 by inhibiting 1,25(OH)2D3 synthesis and inducing 1,25(OH)2D3 degradation through enhancement of 24-hydroxylase mRNA levels and activity. The human monocytic cell line THP-1 mimics PAM in 1,25(OH)2D3 synthesis and sensitivity to exogenous 1,25(OH)2D3. We utilized THP-1 cells to examine the response to 1,25(OH)2D3 with macrophage activation. Activation of THP-1 cells with gamma-interferon (gamma-IFN) enhances 1,25(OH)2D3 synthesis 30-fold, blocks 1,25-(OH)2D3 suppression of its synthesis, and reduces by 42.2% 1,25-(OH)2D3 induction of its degradation. The antagonistic effects of gamma-IFN are not merely restricted to enzymatic activities. In THP-1 cells and in normal PBM, gamma-IFN inhibits 1,25-(OH)2D3 induction of 24-hydroxylase mRNA levels without reducing mRNA stability, suggesting gamma-IFN inhibition of 1,25(OH)2D3 transactivating function. These results explain 1,25(OH)2D3 overproduction in granulomatoses and demonstrate potent inhibition by gamma-IFN of 1,25(OH)2D3 action in immune cells.

State-imposed limits on Medicaid reimbursement for nursing facility care

OBJECTIVES

Nursing cost-center limits were examined, along with their effects on Medicaid.

METHODS

A national survey of Medicaid nursing facility reimbursement provided data on cost centers for nursing, administration, and capital, whether in specific, larger, or multiple cost centers.

RESULTS

Most states impose nursing and administration limits. Far fewer states impose capital limits, but only capital limits may be related to constraint of reimbursement rates.

CONCLUSIONS

Shifting toward limiting capital costs, or simply eliminating cost-center limits, might accommodate cost control while removing negative constraints on direct resident care.

[The expression of proliferating cell nuclear antigen and p53 protein in salivary gland tumours]

The expressions and distributions of PCNA and p53 protein were studied with anti-PCNA and anti-p53 protein MoAbs, using immunohistochemical staining method in salivary gland tumour. The relationship between PCNA and p53 protein was also studied. Results indicated: Malignant mixed tumour (MmT) had a higher proliferating index (PI) of PCNA. The PI could be used as one of adjuvant diagnostic criteria; and as an important parameter for grading mucoepidermoid carcinoma (MEC); The positive expression of p53 might be a good tumour marker for MmT; Tumour tissues with positive expression of p53 had been shown higher PI of PCNA, however there was no significance difference in our group; It remained to be studied later.

[Human parvovirus B19 infection in perinatal transmission and abnormal fetuses]

OBJECTIVE

To investigate the perinatal infection of human parvovirus B19 in pregnant women and their fetuses.

METHODS

350 sera of normal pregnant women and 9 sera of abnormal fetuses were investigated by polymerase chain reaction (PCR) to check the parvovirus B19 DNA.

RESULTS

The prevalence of parvovirus B19 DNA was 1.14% and 0.28% in the sera of normal pregnant women and umbilical cords, respectively. Parvovirus B19 DNA was detected in 6 sera of pregnant women and umbilical cords from 9 abnormal fetuses parvovirus DNA could be detected by in situ hybridization in the nuclei of immature hematopoetic cells within fetal brain or spleen whose PCR tests were positive.

CONCLUSION

The results suggest that parvovirus B19 infection do exist in pregnant women and their neonates as well as fetuses in our country. PCR and in situ hybridization could provide more sensitive, more accurate and specific methods for clinical pathologic diagnosis and epidemic investigation.

Thermodynamics of dT--dT base pair mismatching in linear DNA duplexes and three-arm DNA junctions

We have used a combination of magnetic-suspension densimetry and calorimetry to derive complete thermodynamic profiles, including volume changes, for the formation of linear DNA duplexes and three-arm branched DNA junctions, from their component strands, with and without dT-dT mismatches. The formation of each type of complex at 20 degrees C is accompanied by a favorable free energy, with a favorable enthalpy term partially compensated by an unfavorable entropy. Formation is associated also with net uptake of water molecules. Using the formation of the fully-paired linear duplex or three-arm junction as reference states, we can establish a thermodynamic cycle in which the contribution of the single-strand species cancels. From this cycle, we determine that substitution of dA for dT has a differential free energy of deltadeltaG degrees of +2.4 kcal mol(-1) for mismatched duplex and +2.0 kcal mol(-1) (on the average) for the mismatched junction. These unfavorable differential free energies result from an unfavorable enthalpy, partially compensated by a favorable entropy, and a negative deltadeltaV. The free energies in the two cases have signs opposed to those of deltadeltaV, a situation that implicates hydration changes in creating the mismatch. When the deltadeltaV terms are normalized by the total number of base pairs involved, the immobilization of structural water molecules (and/or substitution of electrostricted for hydrophobic water molecules) is about 7 times greater for junctions than duplexes. This is consistent with more extensive hydrophobic hydration of branched DNA structures than of duplexes.

[Reasons of failure in blocking mother-infant transmission of HBV by using vaccine and related strategies]

We have detected the serum marker of HBV of 32 mothers whose HBsAg present positive and their children whom were given Hepatitis B vaccine immunization throughout duration of their mothers' pregnancy, altogether making up 66 cases. In 3 of these 32 families, Hepatitis B vaccine failed to block transmission between mother and infant. Direct nucleotide sequence analysis of HBV were carried out in 7 HBsAg positive infected persons. To confirm the possibility of HBV transmission between mother and infant on molecular level, we used PCR technique and DNA sequencing method. The reasons of which HBV vaccine failed in blocking transmission were discussed at the point of views of virus variation. Besides, we make and emphasized discussion on how to tighten up the measurement of controlling the course of infection and protecting susceptible population.

Proteolytic mapping of heat shock transcription factor domains

Heat shock transcription factors (HSFs) of higher eukaryotes respond to physical and cellular stress signals by trimerizing, binding to a specific site on DNA, and transactivating genes encoding the heat shock proteins. In this work, limited proteolysis was used as a biochemical probe of the domain organization of Drosophila HSF. Both unshocked monomeric and heat-shocked trimeric HSF possess an internal protease-sensitive region located between the amino-terminal and carboxyl-terminal hydrophobic heatad repeats, suggesting that this is a less structured region compared to those defined for DNA-binding, trimerization, and transactivation. For a few cleavage sites, the heat-shocked form of HSF is more accessible to proteases than the unshocked form, providing an additional diagnostic marker for inducible changes in conformation or modification between the latent and activated forms of HSF.

Functional analysis of human PACE4-A and PACE4-C isoforms: identification of a new PACE4-CS isoform

There are seven known subtilisin/kexin-like proprotein convertases responsible for the processing of numerous precursors at either pairs or specific single basic residues. Three members, PACE4, PC4 and PC5, exhibit alternative splicing of their RNAs resulting in the generation of multiple isoforms differing in their C- or N-terminal segments. In this study we examined the biosynthesis, functional activity and cellular localization of two of these isoforms, namely the full length PACE4-A and the C-terminally truncated PACE4-C which lacks 11 amino acids at the end of its chaperone-like P-domain. We report the existence of a new isoform, termed PACE4-CS, which is a C-terminally shortened version of PACE4-C. Cellular expression results demonstrated that PACE4-A codes for a functional secretable enzyme capable of cleaving pro7B2 into 7B2. In contrast, PACE4-CS is not secreted since it remains in the endoplasmic reticulum as an inactive zymogen form, thereby emphasizing the importance of the integrity of the P-domain. Microsequencing of the intracellular PACE4-CS protein in two cell lines revealed that it is proPACE4-CS with an N-terminal trimming reminiscent of the action of a dipeptidylpeptidase recognizing the motifs X-Ala and X-Pro.

Renal calcitriol synthesis and serum phosphorus in response to dietary phosphorus restriction and anabolic agents

Calcitriol [1,25-(OH)2D3] synthesis by the renal 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-hydroxylase) is induced in rats on a low phosphorus diet, but not in the hypophysectomized (HPX) or diabetic rat. However, the normal response is restored by the administration of growth hormone (GH) or insulin-like growth factor-I (IGF-I), or insulin, respectively. To further characterize this in vivo phenomenon, the acute effects of GH, IGF-I, and insulin were studied in the HPX rat. In the HPX rat the low phosphorus diet alone did not significantly alter serum phosphorus or 1alpha-hydroxylase activity, but treatment with GH resulted in a marked decrease in serum phosphorus that was associated with a fivefold induction of enzyme activity. Time course studies showed that by 6 hours after GH administration, hepatic IGF-I mRNA had increased 10-fold while renal IGF-I mRNA had increased by only 52%. Between 6 and 12 hours, serum phosphorus decreased dramatically and 1alpha-hydroxylase activity increased twofold. Treatment of phosphorus-restricted HPX rats with IGF-I resulted in a decrease in serum phosphorus by 2 hours that preceded a fourfold increase in enzyme activity between 6 and 10 hours. Treatment of phosphorus-restricted HPX rats with insulin produced similar results. This is the first demonstration of hypophosphatemia preceding induction of the 1alpha-hydroxylase after administration of IGF-I or insulin to the HPX rat on a low phosphorus diet. Although these growth factors may have a direct effect on the 1alpha-hydroxylase, these data suggest that the influence of GH, IGF-I, and insulin on transcellular phosphorus flux may have an independent effect on enzyme activity. Furthermore, the much greater induction of hepatic compared with renal IGF-I mRNA in response to GH suggests that systemic, rather than the local, IGF-I may be required for induction of the 1alpha-hydroxylase. This effect may be mediated by either the insulin or the IGF-I receptor.

Expression of the renal 25-hydroxyvitamin D-24-hydroxylase gene: regulation by dietary phosphate

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] plays a key role in phosphate (Pi) homeostasis through its phosphatemic actions on intestine and bone. In turn, dietary Pi restriction increases serum 1,25(OH)2D3 by stimulating its production, but its effect on vitamin D catabolism is less clear. Here we have examined the effects of dietary Pi on the expression of the renal vitamin D-24-hydroxylase (24-OHase), the first enzyme in the catabolic pathway for vitamin D compounds. Rats fed a low Pi (0.02% P) diet showed a fivefold decrease in renal 24-OHase mRNA compared with rats fed a normal Pi (0.67% P) diet. 24-OHase mRNA and 24-OHase activity decreased within 24 h of Pi restriction, reached a minimum by 48 h, and remained low through 14 days. Decreased 24-OHase mRNA was observed with more moderate Pi restriction (0.2% P), but higher Pi (1.2% P) did not increase 24-OHase mRNA over the 0.8% P diet. 24-OHase mRNA correlated well with plasma Pi (r = 0.862, P < 0.001). In conclusion, renal 24-OHase expression is regulated by dietary phosphate at the mRNA level.

Phosphorus restriction prevents parathyroid gland growth. High phosphorus directly stimulates PTH secretion in vitro

Dietary phosphorus (P) restriction is known to ameliorate secondary hyperparathyroidism in renal failure patients. In early renal failure, this effect may be mediated by an increase in 1,25-(OH)2D3, whereas in advanced renal failure, P restriction can act independent of changes in 1,25-(OH)2D3 and serum ionized calcium (ICa). In this study, we examined the effects of dietary P on serum PTH, PTH mRNA, and parathyroid gland (PTG) hyperplasia in uremic rats. Normal and uremic rats were maintained on a low (0.2%) or high (0.8%) P diet for 2 mo. PTG weight and serum PTH were similar in both groups of normal rats and in uremic rats fed the 0.2% P diet. In contrast, there were significant increases in serum PTH (130 +/- 25 vs. 35 +/- 3.5 pg/ml, P < 0.01), PTG weight (1.80 +/- 0.13 vs. 0.88 +/- 0.06 microg/gram of body weight, P < 0.01), and PTG DNA (1.63 +/- 0.24 vs. 0.94 +/- 0.07 microg DNA/gland, P < 0.01) in the uremic rats fed the 0.8% P diet as compared with uremic rats fed the 0.2% P diet. Serum ICa and 1,25-(OH)2D3 were not altered over this range of dietary P, suggesting a direct effect of P on PTG function. We tested this possibility in organ cultures of rat PTGs. While PTH secretion was acutely (30 min) regulated by medium calcium, the effects of medium P were not evident until 3 h. During a 6-h incubation, PTH accumulation was significantly greater in the 2.8 mM P medium than in the 0.2 mM P medium (1,706 +/- 215 vs. 1,033 +/- 209 pg/microg DNA, P < 0.02); the medium ICa was 1.25 mM in both conditions. Medium P did not alter PTH mRNA in this system, but cycloheximide (10 microg/ml) abolished the effect of P on PTH secretion. Thus, the effect of P is posttranscriptional, affecting PTH at a translational or posttranslational step. Collectively, these in vivo and in vitro results demonstrate a direct action of P on PTG function that is independent of ICa and 1,25-(OH)2D3.

Evaluation of a polymerase chain reaction-based assay for diagnosis of Wuchereria bancrofti infection

To assess the utility of a polymerase chain reaction (PCR)-based method for diagnosis of Wuchereria bancrofti infection, blood, plasma, and paraffin-embedded tissue samples were tested using a PCR-based assay that detects a W. bancrofti-specific repetitive DNA sequence. The assay was positive in 100 microL of blood from 40 of 42 microfilaria-positive subjects, the 2 subjects with negative assays having microfilarial counts of 1. Samples from 127 uninfected subjects were PCR-negative. The assay was also positive in 7 of 10 daytime samples in regions where infection is nocturnally periodic; PCR amplification from paraffin-embedded sections established the diagnosis of W. bancrofti infection in another 2 cases. A microtiter ELISA plate-based method was developed for rapid evaluation of large numbers of samples. These results suggest that this PCR-based assay will be useful in diagnosis of W. bancrofti infection in a variety of clinical settings.