[The morphological characteristics of desmoplastic fibroblastoma]

OBJECTIVE

To study the clinical and pathological characteristics of desmoplastic fibroblastoma.

METHODS

Three cases of desmoplastic fibroblastoma were evaluated by light microscopy and immunohistochemistry.

RESULTS

The patients were all adults, 2 males and 1 female, age range 46 - 62 years (mean 53 years). Clinically, the tumors presented as slowly growing painless masses, which were located in the deep soft tissue of the lower extremity, the subcutaneous tissue of the forearm and the ankle respectively. Grossly, they were well-circumscribed neoplasms with a firm consistency. Histologically, the tumors were composed of paucicellular spindle or stellate-shaped fibroblastic cells embedded in a densely fibrous or fibromyxoid stroma. The neoplastic fibroblastic cells resembled the reactive fibroblasts by containing fine chromatin and small distinct nucleoli without cellular atypia or mitotic figures. Immunohistochemically, the neoplastic cells showed diffuse and strong immunoreactivity for vimentin, focal staining for alpha-SMA, MSA and desmin.

CONCLUSION

Desmoplastic fibroblastoma is a benign fibroblastic neoplasm with distinctive clinical and pathological characteristics. It should be differentiated from a variety of reactive or low-grade fibroblastic lesions.

In vitro bioactive behavior of hydroxylapatite-coated porous Al(2)O(3)

To produce bioactive materials for bone substitutes, two major deposition methods, suspension method and thermal deposition method, were employed to develop bioactive, mechanically strong, and porous ceramics. Hydroxylapatite (HA) has been uniformly coated onto inner pore surfaces of reticulated alumina substrates. It has been found that the in vitro bioactivity of HA coatings was affected by both structural crystallinity and specific surface area. Well-crystallized HA heat-treated at high temperatures has resulted in reduced bioactivity. The bio-reaction rate was found to increase with the surface area of HA. We have found that the stability of the well-crystallized HA is associated with the high driving force required for the formation of hydroxy-carbonate apatite (HCA) phase.

Role of frizzled 7 in the regulation of convergent extension movements during gastrulation in Xenopus laevis

Wnt signalling plays a crucial role in the control of morphogenetic movements. We describe the expression and functional analyses of frizzled 7 (Xfz7) during gastrulation in Xenopus. Low levels of Xfz7 transcripts are expressed maternally during cleavage stages; its zygotic expression strongly increases at the beginning of gastrulation and is predominantly localized to the presumptive neuroectoderm and deep cells of the involuting mesoderm. Overexpression of Xfz7 in the dorsal equatorial region affects the movements of convergent extension and delays mesodermal involution. It alters the correct localization, but not the expression, of mesodermal and neural markers. These effects can be rescued by extra-Xfz7, which is a secreted form of the receptor that also weakly inhibits convergent extension when overexpressed. This suggests that the wild-type and truncated receptors have opposing effects when coexpressed and that overexpression of Xfz7 causes an increased signalling activity. Consistent with this, Xfz7 biochemically and functionally interacts with Xwnt11. In addition, Dishevelled, but not (β)-catenin, synergizes with Xfz7 to affect convergent extension. Furthermore, overexpression of Xfz7 and Xwnt11 also affects convergent extension in activin-treated animal caps, and this can be efficiently reversed by coexpression of Cdc42(T17N), a dominant negative mutant of the small GTPase Cdc42 known as a key regulator of actin cytoskeleton. Conversely, Cdc42(G12V), a constitutively active mutant, rescues the effects of extra-Xfz7 on convergent extension in a dose-dependent manner. That both gain-of-function and loss-of-function of both frizzled and dishevelled produce the same phenotype has been well described in Drosophila tissue polarity. Therefore, our results suggest an endogenous role of Xfz7 in the regulation of convergent extension during gastrulation.

[Clinical effect of Xiongshao capsule on preventing restenosis post-PTCA or/and stenting]

OBJECTIVE

To evaluate the effect of Xiongshao capsule (XSC) in preventing clinical and angiographic restenosis after coronary angioplasty or/and stenting.

METHODS

Sixty-five coronary heart disease (CHD) patients with successful angioplasty or and stenting were randomly divided into the control group (37 cases, routine treatment) and the XSC group (28 cases, routine treatment plus XSC). The recurrent of angina, changing of blood stasis syndrome score (BSSS) and coronary angiography within 6 months after coronary angioplasty or/and stenting were observed.

RESULTS

Recurrent angina occurred in 6 out of 28 patients in the XSC group, which was much better than that in the control group, 18 out of 37 patients (P < 0.05). Follow-up angiography was performed in 26 including 10 patients in the XSC group (restenosis was observed in 4 cases), and 16 cases in the control group (restenosis in 13 cases), there was significant difference between the XSC group and the control group (P < 0.05). For BSSS at follow-up, XSC group was much lower than that of the control group (P < 0.01). Logistic regress analysis showed the combination with XSC and the base-line BSSS were important affecting factors on the occurrence of restenosis (P < 0.05). The odds ratio of the occurrence of angiographic restenosis (BSSS > 25 to BSSS < or = 25) was 6.5.

CONCLUSIONS

XSC could markedly reduce the occurrence of restenosis, recurrence of angina and improve the condition of blood stasis after coronary angioplasty or/and stenting. The severity of blood stasis syndrome was an important affecting factor on the occurrence of restenosis. BSSS > 25 can be served as one of the predicting factors of the occurrence of restenosis after coronary angioplasty or/and stenting.

[Measurement of T and DHT contents in normal and diseased human prostate tissues]

OBJECTIVE

To measure T and DHT contents in normal and diseased human prostate tissues.

METHODS

Serum and prostatic T and DHT levels were measured in patients with normal, benign prostatic hyperplasia and prostate cancer.

RESULTS

A decline was observed in serum T level, but no change in DHT concentration with aging. There were no significant differences in both blood T and DHT levels between the patients with BPH or PCA and normal controls. Serum T level remained constant. There were excessive accumulation of DHT in BPH, and cancerous prostate tissues were responsible for the pathogenesis of BPH and PCA. Finasteride treatment did not produce a reduction in prostatic DHT content.

CONCLUSION

More than one form of 5a-reductases is responsible for the high level of DHT in the gland.

Coating of hydroxyapatite on highly porous Al2O3 substrate for bone substitutes

A thin film of hydroxyapatite (HA) was successfully coated onto a highly porous substrate of alumina by using a novel solution technique. The coated HA bonded strongly to the substrate through a glass sintering aid with an intermediate thermal expansion coefficient. The coating was also found to be microstructurally and chemically uniform on the surfaces of the interconnected pores in the matrix of the substrate. Mechanical property testing results showed that the strength of the HA-coated composite was significantly improved, indicating a high potential for structural bone substitutes in hard tissue prosthetics.

Coating of hydroxyapatite on porous alumina substrate through a thermal decomposition method

A thin film of hydroxyapatite (HA) was uniformly coated onto a highly porous substrate of alumina through the thermal decomposition method. Calcium 2-ethyl hexanoate and bis(2-ethyhexyl) phosphite were used as starting materials. Scanning electron microscopy, X-ray diffraction, and infrared spectroscopy were used to characterize the chemical and structural evolution of the coating. In vitro tests were conducted to evaluate the reactivity of the synthetic HA. It was found that the sintering process greatly influenced the in vitro behavior of HA. High temperature sintering may reduce the reactivity of HA, suggesting that the reactivity is structure dependent.

[Association of HLA-DRB1 allele and the susceptibility to alveolar echinococcosis in the west of China]

OBJECTIVE

To investigat the association of HLA-DRB1 alleles and the susceptibility to alveolar echinococcosis (AE).

METHODS

Thirty-five patients with AE in the high prevalence areas in the west of China were investigated for HLA-DRB1 gene by PCR/SSP technique. The results were compared with 104 normal healthy peoples.

RESULTS

Frequency of HLA-DRB1 * 040x was 26% in patient group, which was significantly higher than in control group (9.62%), with a relative risk (RR) of 4.45 (chi(2) = 13.67, P < 0.01), and with an etiological fraction of 0.20. Frequency of HLA-DRB1 * 0701 allele was decreased in patient group (patient 2.86%, control 13.94%; chi(2) = 6.67, P < 0.05), with preventable fraction of 0.30. While the frequencies of other DRB1 alleles were not significantly different.

CONCLUSION

Susceptibility to AE is strongly associated with the HLA-DRB1 * 040x allele. The high prevalence of human AE in this region was associated with genetic factor. HLA-DRB1 * 0701 geners resistant to Echinococcus multilocularis metacestode infection.

Crystal structure of human ornithine transcarbamylase complexed with carbamoyl phosphate and L-norvaline at 1.9 A resolution

The crystal structure of human ornithine transcarbamylase (OTCase) complexed with carbamoyl phosphate (CP) and L-norvaline (NOR) has been determined to 1.9-A resolution. There are significant differences in the interactions of CP with the protein, compared with the interactions of the CP moiety of the bisubstrate analogue N-(phosphonoacetyl)-L-ornithine (PALO). The carbonyl plane of CP rotates about 60 degrees compared with the equivalent plane in PALO complexed with OTCase. This positions the side chain of NOR optimally to interact with the carbonyl carbon of CP. The mixed-anhydride oxygen of CP, which is analogous to the methylene group in PALO, interacts with the guanidinium group of Arg-92; the primary carbamoyl nitrogen interacts with the main-chain carbonyl oxygens of Cys-303 and Leu-304, the side chain carbonyl oxygen of Gln-171, and the side chain of Arg-330. The residues that interact with NOR are similar to the residues that interact with the ornithine (ORN) moiety of PALO. The side chain of NOR is well defined and close to the side chain of Cys-303 with the side chains of Leu-163, Leu-200, Met-268, and Pro-305 forming a hydrophobic wall. C-delta of NOR is close to the carbonyl oxygen of Leu-304 (3.56 A), S-gamma atom of Cys-303 (4.19 A), and carbonyl carbon of CP (3.28 A). Even though the N-epsilon atom of ornithine is absent in this structure, the side chain of NOR is positioned to enable the N-epsilon of ornithine to donate a hydrogen to the S-gamma atom of Cys-303 along the reaction pathway. Binding of CP and NOR promotes domain closure to the same degree as PALO, and the active site structure of CP-NOR-enzyme complex is similar to that of the PALO-enzyme complex. The structures of the active sites in the complexes of aspartate transcarbamylase (ATCase) with various substrates or inhibitors are similar to this OTCase structure, consistent with their common evolutionary origin.

Cryoatomic force microscopy of filamentous actin

Cryoatomic force microscopy (cryo-AFM) was used to image phalloidin-stabilized actin filaments adsorbed to mica. The single filaments are clearly shown to be right-handed helical structures with a periodicity of approximately 38 nm. Even at a moderate concentration ( approximately 10 microg/ml), narrow, branched rafts of actin filaments and larger aggregates have been observed. The resolution achieved is sufficient to resolve actin monomers within the filaments. A closer examination of the images shows that the branched rafts are composed of up to three individual filaments with a highly regular lateral registration with a fixed axial shift of approximately 13 nm. The implications of these higher-order structures are discussed in terms of x-ray fiber diffraction and rheology of actin gels. The cryo-AFM images also indicate that the recently proposed model of left-handed F-actin is likely to be an artifact of preparation and/or low-resolution AFM imaging.

[A diagnostic analysis of imaging in ocular cysticercosis]

OBJECTIVE

To discuss B-ultrasonography, CT and MRI appearances and image diagnostic value for ocular cysticercosis.

METHOD

In the 29 cases with ocular cysticercosis, 21 cases were examined by B-ultrasonography, 19 cases by X-ray computed tomography (CT) and 6 cases by magnetic resonance imaging (MRI).

RESULTS

At the living stage of the cysticercus, B-ultrasound might detect parasitic cyst and its movement in the eyeball and orbit, extraocular muscle irregular hyperplasia; CT might detect parasitic cyst in the orbit and the pathologic extraocular muscle; MRI might detect the parasitic cyst in the eyeball and the orbit and the pathologic extraocular muscle. At the non-living stage of the cysticercus, B-ultrasonography and CT might discover calcification focus in the eyeball and extraocular muscle.

CONCLUSION

Image appearances of ocular cysticercosis depend on the parasitic site and living status of cysticercus in the eye region. For diagnosis, B-ultrasonography may first be selected, MRI secondly selected for living stage and CT secondly selected for non-living stage of the ocular cysticercosis.

Chronic effects of xanthines on levels of central receptors in mice

1. Chronic ingestion of caffeine causes a significant increase in levels of A1-adenosine, nicotinic and muscarinic receptors, serotonergic receptors, GABAA receptors and L-type calcium channels in cerebral cortical membranes from mice NIH Swiss strain mice. 2. Chronic theophylline and paraxanthine had effects similar to those of caffeine except that levels of L-type channels were unchanged. Chronic theobromine, a weak adenosine antagonist, and 1-isobutyl-3-methylxanthine (IBMX), a potent adenosine antagonist and phosphodiesterase inhibitor, caused only an increase in levels of A1-adenosine receptors. A combination of chronic caffeine and IBMX had the same effects on receptors as caffeine alone. Chronic 3,7-dimethyl-1-propargylxanthine (DMPX), a somewhat selective A2A-antagonist, caused only an increase in levels of A1-adenosine receptors. Pentoxifylline, an adenosine-uptake inhibitor inactive at adenosine receptors, had no effect on receptor levels or calcium channels. 3. A comparison of plasma and brain levels of xanthines indicated that caffeine penetrated more readily and attained somewhat higher brain levels than theophylline or theobromine. Penetration and levels were even lower for IBMX, paraxanthine, DMPX, and pentoxyfylline. 4. The results suggest that effective blockade of both A1 and A2A-adenosine receptors is necessary for the full spectrum of biochemical changes elicited by chronic ingestion of xanthines, such as caffeine, theophylline, and paraxanthine.

Neocognitron's parameter tuning by genetic algorithms

The further study on the sensitivity analysis of Neocognitron is discussed in this paper. Fukushima's Neocognitron is capable of recognizing distorted patterns as well as tolerating positional shift. Supervised learning of the Neocognitron is fulfilled by training patterns layer by layer. However, many parameters, such as selectivity and receptive fields are set manually. Furthermore, in Fukushima's original Neocognitron, all the training patterns are designed empirically. In this paper, we use Genetic Algorithms (GAs) to tune the parameters of Neocognitron and search its reasonable training pattern sets. Four contributions are claimed: first, by analyzing the learning mechanism of Fukushima's original Neocognitron, the correlations amongst the training patterns are claimed to affect the performance of Neocognitron, tuning the Neocognitron's number of planes is equivalent to searching reasonable training patterns for its supervised learning; second, a GA-based supervised learning of the Neocognitron is carried out in this way, searching the parameters and training patterns by GAs but specifying the connection weights by training the Neocognitron; third, other than traditional GAs which are unsuitable for the large searching space of training patterns set, the cooperative coevolution is incorporated to play this role; fourth, an effective fitness function is given out when applying the above methodology into numeral recognition. The evolutionary computation in our initial experiments is implemented based on the original training pattern set, e.g. the individuals of the population are generated from Fukushima's original training patterns during initialization of GAs. The results prove that our correlation analysis is reasonable, and show that the performance of a Neocognitron is sensitive to its training patterns, selectivity and receptive fields, especially, the performance is not monotonically increasing with respect to the number of training patterns, and this GA-based supervised learning is able to improve Neocognitron's performance.

[The association of radiation-induced apoptosis with radiosensitivity of cervical carcinoma]

OBJECTIVE

To study the relationship between apoptosis, radiation-induced apoptosis and radiosensitivity of cervical carcinoma and find new markers for predicting radiosensitivity.

METHODS

TdT-mediated bio-dUTP nick end labeling (TUNEL) method was used to check apoptosis cells. The association of radiation-induced apoptosis with tumor volume shrinkage, radiation damage grade and local control rate was analysed.

RESULTS

There was no relationship between apoptosis before radiation and tumor volume shrinkage(P > 0.05); Radiation-induced apoptosis had a significant association with tumor volume shrinkage (P < 0.01); In patients with radiation-induced apoptosis 10 or more, the grade of radiation damage IIb-III accounted for 76% (13/17), while for less than 10, it was 39% (5/13, P < 0.05); After 6 months of radiotherapy, local control rate was 88% (15/17) in the former, 69% (9/13) in the latter, respectively (P > 0.05).

CONCLUSION

Radiation-induced apoptosis has some reference value for predicting radiosensitivity of cervical carcinoma.

[Histological grading in ductal carcinoma in situ of the breast]

OBJECTIVE

To study the significance of histological grading as a prognostic factor in ductal carcinoma in situ of the breast.

METHODS

According to Van Nuy's classification, 32 cases of ductal carcinoma in situ (DCIS) of the breast were divided into three grades.

RESULTS

Low grade (well differentiated, low grade DCIS) 12 patients (37.5%); Intermediate grade, 9 patients (28.1%); High grade (poorly differentiated DCIS) 11 patients (34.4%). Among the high grade DCIS, the histological subtypes were comedo (9 patients), micto papillary (1 patient) and solid (1 patient). The positive expression of c-erbB-2, p53 and MIB-1 in high grade DCIS was higher than that in intermediate and low grade DCIS. The difference between high grade and low grade DCIS was significant (P < 0.05). The expression of ER in high grade DCIS was lower than that in intermediate and low grade DCIS.

CONCLUSIONS

Histological grading of breast ductal carcinoma in situ may be a good prognostic factor.

Images of oligomeric Kv beta 2, a modulatory subunit of potassium channels

The Shaker type voltage-gated potassium (K+) channel consists of four pore-forming Kv alpha subunits. The channel expression and kinetic properties can be modulated by auxiliary hydrophilic Kv beta subunits via formation of heteromultimeric Kv alpha-Kv beta complexes. Because each (Kv alpha)4 could recruit more than one Kv beta subunit and different Kv beta subunits could potentially interact, the stoichiometry of alpha-beta and beta-beta complexes is therefore critical for understanding the functional regulation of Shaker type potassium channels. We expressed and purified Kv beta 2 subunit in Sf9 insect cells. The purified Kv beta 2, examined by atomic force and electron microscopy techniques, is found predominately as a square-shaped tetrameric complex with side dimensions of 100 x 100 A2 and height of 51 A. Thus, Kv beta 2 is capable of forming a tetramer in the absence of pore-forming alpha subunits. The center of the Kv beta 2 complex was observed to be the most heavily stained region, suggesting that this region could be part of an extended tubular structure connecting the inner mouth of the ion permeation pathway to the cytoplasmic environment.

[Prognostic value of cell proliferation and apoptosis in uterine cervical cancer treated with radiation]

OBJECTIVE

To study the prognostic value of cell proliferation and apoptosis in cervical cancer patients treated with radiation.

METHODS

A retrospective study was done in 40 radiotherapy-uncontrolled cases of squamous-cell carcinoma of the cervix uteri and an equal number of cases, matched in age, clinical stage, tumor size and histologic grade, which had been cured by radiotherapy. Cell proliferation was judged by the proliferating cell nuclear antigen (PCNA)-positively stained cell number x intensity of staining, and number of cells in mitosis per 10 high-power microscopic fields (HPF). Apoptotic cells were identified by TUNEL method and the result was expressed as the number of cells undergone apoptosis per 10 HPF.

RESULTS

The average level of PCNA expression was 5.38 +/- 3.21 in the cured patients and 7.50 +/- 3.16 in the radiotherapy-uncontrolled patients (P < 0.01). The number of mitotic cells/10 HPF was 6.33 +/- 5.15 in the cured patients and 11.33 +/- 7.50 in the uncontrolled patients (P < 0.001). The number of apoptotic cells/10 HPF was 20.90 +/- 8.19 in the cured patients and 27.13 +/- 17.28 in the uncontrolled patients (P < 0.05). The ratio of number of apoptotic cells to that of mitotic cells (A/M) was 4.97 +/- 3.31 in the cured and 3.36 +/- 2.83 in the uncontrolled (P < 0.05).

CONCLUSION

In cervical cancer, PCNA expression, the number of cells in mitosis and that of cells in apoptosis are significantly increased while the A/M ratio is significantly decreased in radiotherapy-uncontrolled patients compared to those of patients cured by radiotherapy. These parameters may be of value of predict response to radiotherapy and prognosis of patients with cervical cancer.

Crystal structure of bullfrog M ferritin at 2.8 A resolution: analysis of subunit interactions and the binuclear metal center

Ferritins concentrate and store iron as a mineral in all bacterial, plant, and animal cells. The two ferritin subunit types, H or M (fast) and L (slow), differ in rates of iron uptake and mineralization and assemble in vivo to form heteropolymeric protein shells made up of 24 subunits; H/L subunit ratios reflect cell specificity of H and L subunit gene expression. A diferric peroxo species that is the initial reaction product of Fe(II) in H-type ferritins, as well as in ribonucleotide reductase (R2) and methane monooxygenase hydroxylase (MMOH), has recently been characterized, exploiting the relatively high accumulation of the peroxo intermediate in frog H-subunit type recombinant ferritin with the M sequence. The stability of the diferric reaction centers in R2 and MMOH contrasts with the instability of diferric centers in ferritin, which are precursors of the ferric mineral. We have determined the crystal structure of the homopolymer of recombinant frog M ferritin in two crystal forms: P4(1)2(1)2, a = b = 170.0 A and c = 481.5 A; and P3(1)21, a = b = 210.8 A and c = 328.1 A. The structural model for the trigonal form was refined to a crystallographic R value of 19.0% (Rfree = 19.4%); the two structures have an r.m.s.d. of approximately 0.22 A for all C alpha atoms. Comparison with the previously determined crystal structure of frog L ferritin indicates that the subunit interface at the molecular twofold axes is most variable, which may relate to the presence of the ferroxidase site in H-type ferritin subunits. Two metal ions (Mg) from the crystallization buffer were found in the ferroxidase site of the M ferritin crystals and interact with Glu23, Glu58, His61, Glu103, Gln137 and, unique to the M subunit, Asp140. The data suggest that Gln137 and Asp140 are a vestige of the second GluxxHis site, resulting from single nucleotide mutations of Glu and His codons and giving rise to Ala140 or Ser140 present in other eukaryotic H-type ferritins, by additional single nucleotide mutations. The observation of the Gln137xxAsp140 site in the frog M ferritin accounts for both the instability of the diferric oxy complexes in ferritin compared to MMOH and R2 and the observed kinetic variability of the diferric peroxo species in different H-type ferritin sequences.

Karyological and dental identification of Microtus limnophilus in a large focus of alveolar echinococcosis (Gansu, China)

A study of voles (Arvicolidae, Rodentia) from Gansu (China) designed to identify a potential host of Echinococcus multilocularis, responsible for human alveolar echinococcosis, leads to a general analysis of Microtus limnophilus population karyotypes, M1 of M. oeconomus populations from all of Eurasia and of M. limnophilus of Mongolia. The Microtus of Gansu belonging to the nominal subspecies M. limnophilus limnophilus (2n = 38; NF = 58) differs markedly in size and shape of M1 from the M. limnophilus of Mongolia, which must therefore be considered as a new subspecies M. limnophilus of malygini nov. ssp. (2n = 38; NF = 60) and the M. oeconomus of Mongolia should be ranked as M. oeconomus kharanurensis nov. ssp. (2n = 30; NF = 60).

Expression of gp145trkB in the early stage of Schwann cell tube formation

We investigated the expression of tyrosine kinase receptors (trkBs) and their ligand, brain-derived neurotrophic factor (BDNF), in isolated sciatic nerve segments of rat in a silicone chamber model devoid of axonal contact, using an immunohistochemical technique. The receptor gp 95trkB was not detected during the first 3 weeks but was strongly expressed in the nerve stumps on day 21. In contrast, gp 145trkB immunoreactivity was readily detected in the Schwann cells in the nerve stumps between days 1 and 7 after isolation. Immunohistochemical analysis using anti-S-100 antibody demonstrated that Schwann cell tube formation within the silicone chamber had been completed by the third week, which suggested that gp 95trkB began to be produced by Schwann cells after completion of Schwann cell tube formation. Considering the low level of BDNF production during the first week, molecules other than BDNF may be ligands for gp 145trkB in the silicone chamber model devoid of axonal contact.

1.85-A resolution crystal structure of human ornithine transcarbamoylase complexed with N-phosphonacetyl-L-ornithine. Catalytic mechanism and correlation with inherited deficiency

The crystal structure of human ornithine transcarbamoylase complexed with the bisubstrate analog N-phosphonacetyl-L-ornithine has been solved at 1.85-A resolution by molecular replacement. Deleterious mutations produce clinical hyperammonia that, if untreated, results in neurological symptoms or death (ornithine transcarbamylase deficiency). The holoenzyme is trimeric, and as in other transcarbamoylases, each subunit contains an N-terminal domain that binds carbamoyl phosphate and a C-terminal domain that binds L-ornithine. The active site is located in the cleft between domains and contains additional residues from an adjacent subunit. Binding of N-phosphonacetyl-L-ornithine promotes domain closure. The resolution of the structure enables the role of active site residues in the catalytic mechanism to be critically examined. The side chain of Cys-303 is positioned so as to be able to interact with the delta-amino group of L-ornithine which attacks the carbonyl carbon of carbamoyl phosphate in the enzyme-catalyzed reaction. This sulfhydryl group forms a charge relay system with Asp-263 and the alpha-amino group of L-ornithine, instead of with His-302 and Glu-310, as previously proposed. In common with other ureotelic ornithine transcarbamoylases, the human enzyme lacks a loop of approximately 20 residues between helix H10 and beta-strand B10 which is present in prokaryotic ornithine transcarbamoylases but has a C-terminal extension of 10 residues that interacts with the body of the protein but is exposed. The sequence of this C-terminal extension is homologous to an interhelical loop found in several membrane proteins, including mitochondrial transport proteins, suggesting a possible mode of interaction with the inner mitochondrial membrane.

Three-dimensional crystals of Ca2+-ATPase from sarcoplasmic reticulum: merging electron diffraction tilt series and imaging the (h, k, 0) projection

Electron crystallography offers an increasingly viable alternative to X-ray crystallography for structure determination, especially for membrane proteins. The methodology has been developed and successfully applied to 2D crystals; however, well-ordered thin, 3D crystals are often produced during crystallization trials and generally discarded due to complexities in structure analysis. To cope with these complexities, we have developed a general method for determining unit cell geometry and for merging electron diffraction data from tilt series. We have applied this method to thin, monoclinic crystals of Ca2+-ATPase from sarcoplasmic reticulum, thus characterizing the unit cell and generating a 3D set of electron diffraction amplitudes to 8 A resolution with tilt angles up to 30 degrees. The indexing of data from the tilt series has been verified by an analysis of Laue zones near the (h, k, 0) projection and the unit cell geometry is consistent with low-angle X-ray scattering from these crystals. Based on this unit cell geometry, we have systematically tilted crystals to record images of the (h, k, 0) projection. After averaging the corresponding phases to 8 A resolution, an (h, k, 0) projection map has been calculated by combining image phases with electron diffraction amplitudes. This map contains discrete densities that most likely correspond to Ca2+-ATPase dimers, unlike previous maps of untilted crystals in which molecules from successive layers are not aligned. Comparison with a projection structure from tubular crystals reveals differences that are likely due to the conformational change accompanying calcium binding to Ca2+-ATPase.

Transcription factor AP-2gamma regulates murine adenosine deaminase gene expression during placental development

Trophoblast cells are specialized extra-embryonic cells present only in eutherian mammals. They play a major role in the implantation and placentation processes. To understand better the molecular mechanisms that control the development and function of trophoblast cells, we sought to identify the transcription factors that regulate murine adenosine deaminase (ADA) gene expression in the placenta. Here we report a detailed characterization of a placenta-specific footprinting region (FP1) in the Ada placental regulatory element. The sequence of FP1 was mapped by DNase I footprinting and was found to match a consensus AP-2 transcription factor-binding site. Electrophoretic mobility shift assays demonstrated that FP1 interacted with AP-2-like proteins. Further analysis using AP-2 antibody confirmed that AP-2 protein was indeed present in the placenta and bound to FP1. Mutation at the AP-2 site in FP1 abolished the ability of the Ada placental regulatory element to bind AP-2 proteins and failed to target chloramphenicol acetyltransferase reporter gene expression to placentas in transgenic mice, indicating that AP-2 is required for Ada expression in the placenta. In addition, RNase protection assays demonstrated that AP-2gamma was the predominant AP-2 family member expressed in the placenta. In situ hybridization analysis revealed that AP-2gamma expression was enriched in the trophoblast lineage throughout development, suggesting that AP-2gamma may be critical for trophoblast development and differentiation.

[The comparison of radiosensitivity between uterine cervical squamous carcinoma and adenocarcinoma]

OBJECTIVE

To compare the radiosensitivity of uterine cervical squamous carcinoma and adenocarcinoma.

METHODS

The shrinkage of tumor and the radiation-induced damage were compared between cervical squamous carcinoma and adenocarcinoma after twice afterloading radiotherapy. Proliferating cell nuclear antigen index (PI), detected immunohistochemically, was compared before and after radiotherapy between the two tumors.

RESULTS

Patients of squamous carcinoma with tumor shrinkage 50% or more accounted for 70% (21/30) and patients of adenocarcinoma accounted for 27% (4/15), which was statistically significant (P < 0.01). The radiation-induced damage grade II b-III accounted for 60% (18/30) in squamous carcinoma and for 20% (3/15) in adenocarcinoma, which was statistically significant (P < 0.05); PI decreased from 53.50% +/- 4.34% to 39.30% +/- 4.02% after radiotherapy in squamous carcinoma (P < 0.001), while PI decreased from 35.47% +/- 3.83% to 31.80% +/- 3.06% in adenocarcinoma (P > 0.05).

CONCLUSIONS

The radiosensitivity of cervical squamous carcinoma is higher than that of adenocarcinoma. The decrease of PI after radiotherapy may be a biological basis of radiosensitivity for uterine cervical squamous carcinoma.

[Observation on the surface characteristics of the leaves of Dysosma and its related genus by scanning electronic microscope]

OBJECTIVE

To observe the surface characteristics of leaves of Dysosma and its related genus by SEM for identification.

METHOD

Leaf surface characteristics of seven species of Dysosma and tow species of its related genus were observed by scanning electronic microscopic method.

RESULT

The leaf surface characteristics of upper epidermis and lower epidermis of the nine plants are different from each other. A key and illustrations were listed.

CONCLUSION

The leaf surface characteristics observed by SEM can be used for identification of Dysosma and its related plants.

[Inhibitor of plasminogen activator 1 (PAI-1) in hepatocellular carcinoma]

OBJECTIVE

To study the expression of the type-1 inhibitor of plasminogen activator (PAI-1) on protein and mRNA in hepatocellular carcinoma (HCC), and the relation between PAI-1 and biological behaviour of HCC.

METHOD

The tumor specimens of HCC (n = 48) and benign liver tumor (contorl n = 12) were tested by immunohistochemistry for the expression of PAI-1 protein. The tumor specimens of HCC (n = 20) and normal liver tissue (contorl n = 5) were evaluated by Northern blot analysis for the expression of PAI-1 mRNA.

RESULT

PAI-1 protein and PAI-1 mRNA were higher in tumor cell than in the marginal tissue of tumor and in control (P < 0.01 and P < 0.05). In deaths 2 years after surgery, PAI-1 was increased as compared to the survival group (P < 0.05). When negative PAI-1 conupared with positive urokinase-type plasminogen activator (uPA) and positive uPA receptor (uPAR). The nambeigs invasion case increased, the difference was more significant than that in the group with negative PAI-1, uPA and uPAR (P = 0.039).

CONCLUSION

The expression of PAI-1 protein and PAI-1 mRNA is increased in HCC. PAI-1 contributes to the invasion, metastasis and prognosis of HCC.

Localized unfolding at the junction of three ferritin subunits. A mechanism for iron release?

How and where iron exits from ferritin for cellular use is unknown. Twenty-four protein subunits create a cavity in ferritin where iron is concentrated >10(11)-fold as a mineral. Proline substitution for conserved leucine 134 (L134P) allowed normal assembly but increased iron exit rates. X-ray crystallography of H-L134P ferritin revealed localized unfolding at the 3-fold axis, also iron entry sites, consistent with shared use sites for iron exit and entry. The junction of three ferritin subunits appears to be a dynamic aperture with a "shutter" that cytoplasmic factors might open or close to regulate iron release in vivo.

Deficits in smooth-pursuit eye movements after muscimol inactivation within the primate's frontal eye field

To evaluate smooth-pursuit (SP) function in the primate frontal eye field (FEF), microinjections of muscimol, a gamma-aminobutyric acid (GABA) agonist, were used to reversibly deactivate physiologically characterized sites in FEF. SP was severely impaired by deactivation at sites in the FEF's smooth eye movement region (FEFsem) located in the fundus and posterior bank of the macaque monkey's arcuate sulcus. These SP deficits were apparent immediately after the muscimol injection and persisted for several hours but recovered by the next day. SP was most drastically and consistently impaired for directions similar to the injected site's elicited smooth eye movement direction or to the optimal SP direction for its neuronal responses. Targets moving in these directions, usually ipsilateral to the injected hemisphere, were tracked primarily with saccades after the muscimol injection, the peak SP velocity being only 10-30% of preinjection velocity. SP in other directions, including contralateral, was less strongly affected. Initial SP acceleration in response to target motion onset was also significantly diminished, generally by approximately the same proportion as peak SP velocity. In contrast, saccades were largely unaffected by muscimol injections in FEFsem; nor was there an immediate effect on SP when control sites in the saccadic region of FEF (FEFsac) were deactivated, although a SP deficit often appeared 30-60 min after FEFsac injections, possibly reflecting diffusion of muscimol into neighboring FEFsem. These reversible SP deficits produced by muscimol inactivation within FEFsem are similar to permanent deficits caused by large aspiration lesions of FEF and indicate that inclusion of FEFsem is the critical factor determining whether FEF lesions impair SP. The severity of the reversible deficits found here indicates how extremely critical FEFsem is for normal highgain SP.

Clinical observation on 84 cases of ventricular premature beat with deficiency syndrome treated by qi lu tang

From August 1989 to May 1994, 84 cases of ventricular premature beat (VPB) with deficiency syndrome were treated with our empirical prescription called Qi Lü Tang Decoction for Improving Abnormal Heart Beat). The total effective rate was 88.10%, being significantly different from that of the control group treated with the Western drug propafenone (P < 0.01). Qi Lü Tang exhibited a better therapeutic effect in cases of VPB with deficiency of qi, deficiency of both qi and blood, and deficiency of both qi and yin.

[Nucleoside diphosphate kinase/nm23H1 expression in ovarian epithelial carcinoma: retroperitoneal lymphatic metastasis and survival]

OBJECTIVE

To determine the relationship between NDPK(A) expression and retroperitoneal lymph node metastasis (LNM) and the significance of the prognosis in epithelial ovarian carcinoma.

METHODS

NDPK(A) expression of formalin-fixed parafin-beded samples, which included 74 primary, 31 intraperitoneal and 18 retroperitoneal lymph node metastatic tumors, were examined by ABC immunohistochemisty in 74 patients with primary ovarian cancer.

RESULTS

In the 74 primary lesions, 22 samples showed positive staining of NDPK(A) (30%). Positive staining was higher in patients without LNM(46%) than those with LNM (17%, P = 0.008); it was lower in menopausal patients (19%) than in menstruant (44%, P = 0.022). Compared with primary tumor, NDPK(A) expression appeared to decrease in lymph-node lesion(28% vs 39%, P > 0.1) but to increase in intraperitoneal metastastic tumor (32% vs. 19%, P > 0.5). Multivariance analysis confirmed that the important risk factors for LNM were lower expression of NDPK(A), more large residual tumor and poor differentiation. But there was no any corelation between NDPK(A) expression and survia.

CONCLUSION

The study suggested that increased expression of NDPK(A)/nm23H1 is inversely related to LNM in epithelial ovarian carcinoma, but it can not confirm the prognostic significance of NDPK(A).

[Perilunate progressive instability of the wrist: a study of wrist dynamics]

OBJECTIVE

To study the changes in dynamics of wrist motor tendons after perilunate instability of the wrist.

METHODS

14 cadaver upper extremities were used. Excursions of the principle wrist and finger motor tendons were measured during wrist flexion-extension and radiolunar deviation was determined. Data were collected in the intact wrist, then in the wrist with stage I, II and III perilunate instability. The average moment arms of the tendons during wrist motion were calculated.

RESULTS

The moment arms of the wrist flexors increased and those of the finger flexors decreased after instability. Increase in the moment arms dominated changes of radial side wrist motors, while decrease in the moment arms dominated ulnar wrist motors. Moment arms of the flexor carpi radialis tendon showed a consistent increase during wrist motion.

CONCLUSION

The changes in wrist dynamics play an important role in clinical manifestations of perilunate instability. The significance of kinetic information on principle of treatment of the instability is discussed.

Expression of the mouse metallothionein-I gene conferring cadmium resistance in a transgenic cyanobacterium

This paper reports the construction of a transgenic strain of cyanobacterium aimed at removing heavy metal pollution in waters. The mouse metallothionein-I (mMT-I) gene was inserted in the vector pRL-439 downstream of the strong psbA promoter. The resulting plasmid pRL-MT was ligated at the EcoRI site of the shuttle vector pKT-210 to generate the shuttle expression vector pKT-MT. This recombinant plasmid was introduced into Anabaena sp. PCC 7120 by triparental conjugative transfer. After selection on streptomycin, a stable transgenic Anabaena strain was obtained. The presence of the mMT-I gene was confirmed by DNA/DNA hybridization and its expression was demonstrated by immunodetection with specific antibodies. A metal tolerance experiment showed that this transgenic Anabaena strain had acquired higher metal resistance.

Fast road classification and orientation estimation using omni-view images and neural networks

This paper presents the results of integrating omnidirectional view image analysis and a set of adaptive backpropagation networks to understand the outdoor road scene by a mobile robot. Both the road orientations used for robot heading and the road categories used for robot localization are determined by the integrated system, the road understanding neural networks (RUNN). Classification is performed before orientation estimation so that the system can deal with road images with different types effectively and efficiently. An omni-view image (OVI) sensor captures images with 360 degree view around the robot in real-time. The rotation-invariant image features are extracted by a series of image transformations, and serve as the inputs of a road classification network (RCN). Each road category has its own road orientation network (RON), and the classification result (the road category) activates the corresponding RON to estimate the road orientation of the input image. Several design issues, including the network model, the selection of input data, the number of the hidden units, and learning problems are studied. The internal representations of the networks are carefully analyzed. Experimental results with real scene images show that the method is fast and robust.

[Effect of purified Xuefu capsule on cardiac haemodynamics and oxygen consumption in acute myocardial ischemia of experimental dogs]

OBJECTIVE

To investigate the effect of Purified Xuefu Capsule (PXC) on cardiac haemodynamic and oxygen consumption in acute myocardial ischemia of experimental dogs.

METHODS

The coronary arteries was ligated to create the myocardial ischemic modle and gave them PXC through the duodenum. The effect of PXC on the systolic and diastolic function, volume of blood flow in coronary arteries and cardiac output of acute ischemic heart of experimental dogs were examined.

RESULTS

After ligation of the coronary artery the myocardial ischemia was formed, the systolic and diastolic function, volume of blood flow in coronary arteries and cardiac output were decreased significantly in the control group, whereas these indexes in high-dose and low-dose PXC group were improved to some extent, the effect of high-dose PXC group was better than that of the low-dose PXC group. Furthermore high-dose PXC could reduce the oxygen consumption.

CONCLUSIONS

PXC could prevent the cardiac pump function from acute myocardial ischemia of experimental dogs. The mechanism may be related to reduce the oxygen consumption and increase the blood supplement to myocardium.

[The preparation of poly (DL-lactide) hollow fiber and the release of drug in vitro]

The biodegradable hollow fibers of DL-PLA were prepared by a dry-wet phase inversion spinning process. By using four different spinning systems, DL-PLA hollow fibers with varying asymmetric membrane structure were obtained. The structure of hollow fiber wall was examined by SEM. In vitro release of norethisterone from the DL-PLA hollow fibers was also investigated. The hollow fibers were filled with a 50 wt% NET in castor oil. The DL-PLA hollow fibers NET release was found to be dependent on the membrane structure of the hollow fiber wall. Possible release mechanisms were discussed.

[Preliminary observation of MRI manifestations of adult pulmonary tuberculosis]

OBJECTIVE

To study the role of MRI in diagnosis of adult pulmonary tuberculosis.

METHODS

MRI and X-ray appearance of 55 adult pulmonary tuberculosis cases were reviewed.

RESULTS

No obvious difference was found between the images of MRI and chest radiography which reflect infiltrative and proliferative pathologic changes of pulmonary tuberculosis (including cavity, tuberculoma and caserous pneumonitis). Infiltrative, proliferative lesions and caserous pneumonitis showed middle signal on the T1 and T2 weighted images. Cavity showed low signal. Tuberculoma showed generally hyterogenous signal on the T2 weighted images.

CONCLUSION

It is unnecessary to use MRI as a routine tool for diagnosis of pulmonary tuberculosis.

Diverse genetic regulatory motifs required for murine adenosine deaminase gene expression in the placenta

Murine adenosine deaminase (ADA) is a ubiquitous purine catabolic enzyme whose expression is subject to developmental and tissue-specific regulation. ADA is enriched in trophoblast cells of the chorioallantoic placenta and is essential for embryonic and fetal development. To begin to understand the genetic pathway controlling Ada gene expression in the placenta, we have identified and characterized a 770-base pair fragment located 5.4 kilobase pairs upstream of the Ada transcription initiation site, which directs reporter gene expression to the placenta of transgenic mice. The expression pattern of the reporter gene reflected that of the endogenous Ada gene in the placenta. Sequence analysis revealed potential binding sites for bHLH and GATA transcription factors. DNase I footprinting defined three protein binding regions, one of which was placenta-specific. Mutations in the potential protein binding sites and footprinting regions resulted in loss of placental expression in transgenic mice. These findings indicate that multiple protein binding motifs are necessary for Ada expression in the placenta.

[Relationship between c-erbB2 oncoprotein expression and biologic behavior of cervical squamous cell cancer]

OBJECTIVE

To investigate the relationship between c-erbB2 oncoprotein expression and biologic behavior and prognosis of cervical squamous cell cancer.

METHOD

Immunohistochemistry was used to examine the c-erbB2 oncoprotein expression in 62 cases of cervical sequamous cell cancer, 9 cases of cervical iutraepithelical neoplasia (CIN) and 10 cases of normal epidermal tissues section of the cervix.

RESULTS

Nineteen of 62 cancers and 1 of 9 cases of CIN showed positive staining. None of normal epithelium showed positive. In cervical cancer the positive staining rate of c-erbB2 oncoprotein in grade 1, 2 and 3 was 12.5%, 27.6% and 52.9% respectively. There was a significant difference between grade 1 + 2 and grade 3 (P = 0.019). In 20 cases operated on, 3 of 6 cases with positive staining had pelvic lymph node metastasis, while only 1 of 14 cases with negative staining had metastasis (P = 0.032). The 5-year survival rate of positive staining group was significantly lower than that of negative group (31.5% Vs 74.4%, P < 0.001).

CONCLUSION

The c-erbB2 oncoprotein expression on cervical sequamous cell cancer was related to agressive biologic behavior and poor prognosis.

Spiropyrrolizidines: a new class of blockers of nicotinic receptors

The spiropyrrolizidine oximes 236 and 222 and a related spiropyrrolizidine alkaloid, nitropolyzonamine, block nicotinic receptor channels in rat pheochromocytoma PC12 cells and in human medulloblastoma TE671 cells. In PC12 cells with an alpha 3 beta 4(5)-nicotinic receptor, both the spiropyrrolizidine oxime 236 and nitropolyzonamine had IC50 values of about 1.5 microM, while spiropyrrolizidine oxime 222 had an IC50 value of 2.6 microM versus carbamylcholine-elicited sodium-22 influx. In TE671 cells with an alpha 1 beta 1 gamma delta nicotinic receptor, the spiropyrrolizidine oximes 236, 222, and nitropolyzonamine had IC50 values of 9.5, 14, and 67 microM, respectively. The inhibitions by the spiropyrrolizidine oxime 236 and nitropolyzonamine appeared to be noncompetitive in nature in both cell lines. In rat cerebral cortical membranes, binding of [3H]nicotine to alpha 4 beta 2 nicotinic receptors was not inhibited significantly by 10 microM concentrations of the spiropyrrolizidine oxime 236, or by nitropolyzonamine, as expected for a noncompetitive blocker. Both compounds at 10 microM had marginal effects on a variety of central receptors, but did inhibit binding of [3H]1,3-di(2-tolyl) guanidine to sigma receptors in mouse brain membranes with IC50 values of about 0.5 microM. The spiropyrrolizidine oxime 236 at 10 microM had no effect on batrachotoxin-elicited sodium influx in guinea pig cerebral cortical synaptoneurosomes or on ATP-elicited calcium influx in PC12 cells. Such spiropyrrolizidines represent a new structural class of blockers of nicotinic receptor channels with selectivity for ganglionic-type receptors.

Biomechanical and histologic evaluation of tendon sheath management

The effect of changes in diameter of the flexor sheath after tendon repair on tendon function was studied using the long toes of 64 white leghorn chickens. Biomechanical studies of gliding excursion, toe flexion, and ultimate load were carried out at 6 and 12 weeks after tendon repair to determine functions of the tendons healed in narrowed, directly closed, partially excised, and enlarged flexor sheath experimental groups. Histologic examination was used to evaluate the extent of adhesions, healing status of the tendons, and status of the managed sheath. At 6 weeks, gliding excursions and range of toe flexion were statistically the smallest in the group with sheath narrowing, statistically larger in the groups with direct sheath closure or sheath excision, and statistically the largest in the sheath enlargement group (p < .01). These differences in gliding excursions and range of toe flexion were persistently observed at 12 weeks. The ultimate load of the repaired tendons was statistically the weakest in the group with sheath narrowing at either 6 or 12 weeks (p < .01). However, the ultimate load of the groups with sheath enlargement, direct sheath closure, and partial sheath excision was statistically the same. Results of histologic examination demonstrated more severe adhesions and worsened tendon healing in specimens with sheath narrowing. The repaired tendons in the group with sheath enlargement healed better and had less severe peritendinous adhesions than those in the group with sheath narrowing. The extent of adhesions and tendon healing were similar in the groups with sheath enlargement and direct sheath closure. This study demonstrates that the diameter of the repaired sheath exerts significant influence on flexor tendon function. Enlargement of the digital flexor sheath may provide an additional way to improve function of repaired tendons.

Can cast immobilization successfully treat scapholunate dissociation associated with distal radius fractures?

During a 3.5-year period, 20 of 424 consecutive patients with fractures of the distal radius presented with evidence of scapholunate dissociation upon x-ray films and traction view fluoroscopy. The sequential changes of x-ray abnormalities of the scapholunate joint were consistently observed over a 1-year period, and wrist functions were evaluated 1 year after injury. The scapholunate gaps were 3.5 +/- 0.5 mm at the time of injury, 3.2 +/- 0.4 mm immediately after closed reduction of the fracture, 3.4 +/- 0.5 mm at the time after removal of fixation, and 3.8 +/- 0.4 mm 1 year after injury. By the modified clinical scoring system of Green and O'Brien, of these 20 patients, none had excellent, 2 had good, 14 had fair, and 4 had poor wrist function 1 year after injury. The wrists with scapholunate dissociation had significantly worse function as compared to a selected subgroup of 228 wrists with no signs of intercarpal ligament disruption. All 20 patients with signs of scapholunate dissociation on x-ray examination at the time of injury had clinical signs in the scapholunate joint and positive x-rays findings of dissociation 1 year later. After 1 year, 8 of the 20 patients underwent surgery for relief of symptoms and to stabilize the joint. Arthrography in the patients with persistent symptoms showed disruption in scapholunate interosseous ligaments. This study indicates that scapholunate dissociation with concomitant fractures of the distal radius cannot be cured by cast immobilization of the fracture. Early operative treatment should be instituted for the concomitant scapholunate dissociation.

Vasoactive intestinal peptide: mediator of laminin synthesis in cultured Schwann cells

To learn more about neuropeptide-induced glial responses which accompany axon regeneration, we studied effects of VIP on laminin production by cultured Schwann cells. Schwann cells were isolated from sciatic nerves of neonatal mice, purified, and incubated for 5 days in either control medium (DMEM + 15% FCS) or control medium containing 10-7 -10-11 M VIP. At 10-7 and 10-8 M VIP, laminin levels measured by enzyme-linked immunosorbent assay were significantly higher (55% and 35%) than those in control cultures. Lower VIP concentrations (10-9 -10-11 M) produced smaller increases which were not significant. Low-affinity VIP receptors which mediated this effect were demonstrated on Schwann cells by radioligand binding studies. The increased Schwann cell synthesis of laminin induced by VIP was blocked when either a VIP antagonist or a VIP receptor antagonist was added to the VIP-containing incubation medium. In contrast to astrocytes, when Schwann cells were loaded with fura-2, VIP did not increase cytosolic Ca2+. This indicates that Schwann cells and astrocytes may have different intracellular transduction pathways; their receptor subtypes also may differ. We suggest that the VIP-induced increase in laminin synthesis which we have observed in cultured Schwann cells may also occur in vivo and might be an important component of axon-Schwann cell interactions during nerve regeneration.