[Distribution of F13A01, FESFPS and vWA loci in Jingpo ethnic group in Yunnan provice]

F13A01 FESFPS and vWA were extracted and amplified using denaturing polyacrylamide gel electrophoresis and silver stain. The distribution of allete frequencies of F13A01, FESFPS and vWA loci in Jingpo ethnic group living in southwestern Yunnan province were investigated. It was observed that there were 8 alleles and 13 genotypes in F13A01 locus; 7 alleles and 18 genotypes in FESFPPS locus; 7 alleles and 21 genotypes in vWA lous.

A study into the variations in the labial reduction of teeth prepared to receive porcelain veneers--a comparison of three clinical techniques

OBJECTIVES

Various techniques have been suggested to enable the operator to produce an even reduction of 0.5 mm of labial tooth enamel during preparation for a porcelain veneer. For example, in addition to the traditional free hand method, longitudinal or horizontal depth orientation grooves and the use of small round burs to produce dimples as depth guides have been suggested. However, there is no published data that compares how effective these techniques are at producing the 'ideal' veneer preparation. In this study three techniques were compared using the technique of co-ordinate metrology.

METHOD

A single operator using the above three techniques prepared 84 extracted teeth. Impressions of the prepared and unprepared teeth were scanned using a co-ordinate measuring machine (CMM). Measurements of maximum labial reduction along the mid-labial plane were taken and analysed.

RESULTS

The study showed that among the three techniques studied the use of small round burs (D001-012), when used side on at an angle of 45 degrees to the tooth surface to produce dimples as depth guides, resulted in the greatest frequency of tooth reductions closer to the 'ideal' depth chosen for this study, ie within the 0.4 mm-0.6 mm range.

CONCLUSION

The study concluded that even after using techniques designed to produce consistent preparations, a single operator still produced preparations with considerable variation from the ideal. The study showed that among the three techniques compared the use of small round burs, when used side on at an angle of 45 degrees to the tooth surface to produce dimples as depth guides, resulted in the greatest frequency of tooth reduction closer to the 'ideal' depth chosen for this study only, ie within the 0.4 mm-0.6 mm range. It is stressed that this range may not be the ideal in all clinical situations.

Effects of intrinsic fluorescence and quenching on fluorescence-based screening of natural products

To evaluate the effects of intrinsic (natural) fluorescence and quenching as confounding variables in fluorescence-based enzyme inhibition assays of natural products, we measured the fluorescence and quenching properties of 25 components of popular herbal products. The analyses were performed under conditions typically employed in drug-drug interaction studies that use c-DNA-derived P450 isoforms and surrogate fluorogenic substrates. Four of the 25 compounds tested (isorhamnetin, quercetin, vitexin, and yangonin) fluoresced or quenched sufficiently to interfere with these assays. Intrinsic fluorescence had a greater effect on these assays than quenching and for one compound, yangonin, was sufficient to mask inhibition and potentially produce a false negative result. Quenching had less of an effect on these assays, but was significant enough for one compound, quercetin, to mimic "weak" inhibition. Therefore, because intrinsic fluorescence or quenching could render some natural products unsuitable for testing in certain fluorometric assays, it would be prudent to include an evaluation of these properties in experimental protocols.

[The development of clinical application of the rejuvenator and a study of its mechanism for the treatment of functional erectile dysfunction]

In this paper, we describe the development and clinical application of the Rejuvenator and report the result of our study on its mechanism for the treatment of functional erectile dysfunction (FED). The Rejuvenator, which can be used both at home and in hospitals to treat patients with FED, was developed on the basis of our clinical practice in the light of the modern theory of traditional Chinese medicine and by integrating multiple techniques of engineering science. It works by means of the paraoral use of the special herbal medicine, electro-magnetic effects, thermal moxibustion and drug-ingression. 2250 patients with FED received the treatment. Using combined electro-neurophysiological techniques, pulsed ultrasound Doppler and microcomputer image-scanning, we further studied the mechanism of the Rejuvenator for the treatment of FED. The total effective rate was 92%. The clinical data and result of study indicate that the Rejuvenator for the patients with functional erectile dysfunction is a safe, effective and scientific new method.

The proteinase-activated receptor 2 is involved in nociception

The proteinase-activated receptor 2 is expressed on a subset of primary afferent neurons and may participate in the neurogenic component of inflammation. We hypothesized that this receptor may also play a role in neuronal sensitization and contribute to the pathogenesis of pain in inflammatory conditions such as pancreatitis. Using a specific proteinase-activated receptor 2 activating peptide, we found evidence of such sensitization in vitro in the form of enhanced capsaicin- and KCl-evoked release of calcitonin gene-related peptide, a marker for nociceptive signaling. We then demonstrated that injection of the proteinase-activated receptor 2 activating peptide into the pancreatic duct can activate and sensitize pancreas-specific afferent neurons in vivo, as measured by Fos expression in the dorsal horn of the spinal cord. These observations suggest that proteinase-activated receptor 2 contributes to nociceptive signaling and may provide a novel link between inflammation and pain.

[Orthokeratology induced infective corneal ulcer]

OBJECTIVE

To investigate the clinical course, treatment and outcome of infective corneal ulcer induced by orthokeratology.

METHODS

Sixteen cases of infective corneal ulcer caused by orthokeratology were reported, including 7 cases of pseudomonas corneal ulcers, 8 cases of acanthamoeba keratitis and 1 case of mycotic keratitis. Smears and cultures from corneal scrapings for bacteria, fungi and amoeba were performed for all of the patients. According to the results of pathogenic microorganisms, different therapeutic approaches were given. Lamellar keratoplasty or penetrating keratoplasty was performed for 9 patients whose corneal lesions were serious and unresponsive to medical therapy.

RESULTS

After medical treatment or keratoplasty, corneal infections of all the patients were controlled. The visual acuity of most cases was improved.

CONCLUSIONS

The infective corneal ulcer is the most serious complication of orthokeratology. The treatment of infective corneal ulcer should be directed toward the elimination of the pathogenic microorganisms from the cornea. Keratoplasty continues to have a central role in the management of some advanced cases. Although the infections can be controlled, the vision of these patients is seriously damaged.

Tooth size and morphology in twins

OBJECTIVE

To assess concordance of tooth size and occlusal morphology in monozygotic (identical) and dizygotic (non-identical) twins compared to unrelated controls in order to determine how much these dental traits are related to inheritance.

METHODS

Mesiodistal and bucco-lingual dimensions of tooth size in 34 pairs of twins were measured with dial calipers. In addition, the occlusal morphology of nine pairs of teeth was assessed using a co-ordinate measuring machine with a non-contact laser probe.

RESULTS

The results showed greater concordance in tooth size for both mesiodistal and bucco-lingual dimensions within twin pairs compared to twin and unrelated controls. Furthermore, monozygotic (MZ) twins showed greater concordance than dizygotic (DZ) twins for all permanent teeth with statistically significant variance for the mesiodistal dimension (P = 0.01) but not bucco-lingual dimension. Superimposed computer models of the digitized occlusal surfaces showed a high degree of similarity for MZ twins compared to DZ twins. The mean intrapair deviation was 147 microm for MZ, 209 microm for DZ and 258 microm for unrelated controls.

CONCLUSIONS

The remarkable similarity in the tooth size and morphology of monozygotic twins suggests a strong inheritability factor to tooth size and shape and that these may be useful as additional tools for zygosity determination along with other dental traits.

Gadolinium inhibits thymidine incorporation and induces apoptosis in chondrocytes

Magnetic resonance arthrography. a procedure where contrast agents containing gadolinium are administered intra-articularly, has become a useful tool in musculoskeletal diagnosis. Although considered safe for systemic use, toxicities in some tissues have been identified for both free gadolinium ion and the gadolinium chelates used as contrast. In this study, the effects of short-term exposure of articular chondrocytes to gadolinium contrast were examined by assaying for proteoglycan synthesis, cell proliferation, and apoptosis. Bovine chondrocytes were grown in monolayer culture and exposed to gadodiamide for 16 h. Proteoglycan synthesis was measured through incorporation of radiolabeled sulfate. Uptake of radiolabeled thymidine assessed cell proliferation. Apoptosis was detected using the TUNEL assay, where DNA strand breaks characteristic of apoptosis are labeled with fluorescent nucleotide. Proteoglycan synthesis was stimulated by lower dose exposure to gadodiamide. At higher doses, proteoglycan synthesis returned to baseline. Cell proliferation decreased following exposure to gadodiamide in a dose-dependent manner. Chondrocyte apoptosis was induced in a dose-dependent manner. Further work is needed to determine if these in vitro effects are present in the intact joint.

[An experimental study on subconjunctival interleukin-1 receptor antagonist for promotion of corneal transplant survival]

OBJECTIVE

To determine whether the subconjunctival application of interleukin-1 receptor antagonist (IL-1ra) can prolong the corneal graft survival in the rat model of orthotopic penetrating keratoplasty.

METHODS

For all experiments, F344 corneas were transplanted into LOU (major histocompatibility-disparate) eyes. Experimental groups received subconjunctival injection of 50, 100 and 200 microg IL-1ra respectively, and the control group received the same volume of 0.9% normal saline instead for consecutive 2 weeks. All transplants were evaluated for 4 weeks after surgery for signs of rejection.

RESULTS

The mean survival time (MST) of the grafts of the experimental groups was increased significantly (t = 0.00, P < 0.01) in comparison with the control group. The MST of the IL-1ra 200 microg group was increased significantly than that of the IL-1ra 50 microg group (t = 0.00, P < 0.01). Furthermore, the IL-1ra-treated grafts had significantly less corneal inflammation, infiltration, lower levels of opacity, edema, neovascularization and rejection index compared with the control group.

CONCLUSIONS

Subconjunctival treatment of IL-1ra has a significantly positive effect on promoting corneal allograft survival. And its effect is dosage-dependent.

[The influence of ecological factors on simultaneous nitrification and denitrification in MBR]

The influence of dissolved oxygen(DO), C/N and pH on simultaneous nitrification and denitrification in the membrane bioreactor was studied. The experimental results showed that only under condition that each ecological factor was maintained relative steady, simultaneous nitrification and denitrification might proceed smoothly. When DO, C/N and pH of feed water was 1 mg/L, 30 and 7.2, the removal rate of COD, NH4+, and TN were 96%, 95% and 92% respectively.

[beta-elemene induces apoptosis of K562 leukemia cells]

OBJECTIVE

To investigate the apoptosis-inducing effect of beta-elemene on K562 leukemia cells.

METHODS

Hoechst 33342 and PI fluorescence staining, DNA fragmentation, electron microscopy, flow cytometry, and immunocytochemistry were used to evaluate the effect of beta-elemene on K562 cells.

RESULTS

beta-elemene heatment induced the formation of apoptotic bodies and DNA ladder. The effect was dose- and time-dependent. The expression of bcl-2 was decreased in beta-elemene treated cells as compared with the untreated control cells.

CONCLUSION

beta-elemene exerts its cytotoxic effect on K562 leukemic cells by the induction of apoptosis.

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) blockade enhances incidence and severity of experimental autoimmune neuritis in resistant mice

Experimental autoimmune neuritis (EAN), an autoimmune inflammatory demyelinating disease of the peripheral nervous system, represents an animal model of the human Guillain-Barré syndrome. EAN can be induced by active immunization in several animals, including Lewis rats. In contrast, most strains of mice including the widely used C57BL/6 (B6) strain are reputedly resistant to the induction of EAN. In the present study, we demonstrate that in B6 mice, anti-CTLA-4 monoclonal antibody administration in conjunction with immunization with the P0 protein derived peptide 180-199 can induce clinical and pathological definite EAN. Upregulating effects of CTLA-4 blockade on initial and ongoing EAN are demonstrated. CTLA-4 blockade augmented cellular infiltration and enhanced demyelination in the target organ sciatic nerves as well as increased T cell proliferation in lymph node cells. Moreover, serum levels of IFN-gamma and IL-4 were increased. Thus, manipulation of CTLA-4/B7 costimulatory pathway by CTLA-4 blockade can promote autoreactivity and break the relative tolerance to peripheral autoantigen P0 in resistant B6 mice.

[Study on the chemosensitivity test of human gastric cancer using the MTT assay]

OBJECTIVE

This study was conducted to investigate the chemosensitivity of gastric carcinoma.

METHODS

112 cases of fresh human gastric cancer samples were obtained for drug sensitivity testing using MTT.

RESULTS

The sensitivity sequence of antitumor agents was 5-Fu, DDP, MMC, etc. On the other hand, the sensitivity was relative to pathology and individual differences.

CONCLUSION

The MTT assay is an accurate system for determination of the chemosensitivity of tumor cells.

Helper-dependent adenoviral vector-mediated gene transfer in aged rat brain

Transfer of the neurotrophin gene into brain can attenuate age-related deficits such as neuronal atrophy and memory loss, but a suitable vector for this procedure has been lacking. The toxicity and immunogenicity of first-generation adenoviral vectors with E1 deletion (fgAdv) prohibit the application of gene transfer in the majority of central nervous system disorders. Here, we report less toxic and persistent gene expression mediated by helper-dependent adenovirus (hdAdv) in aged rat brain. After intrahippocampal or intraventricular inoculation of the vector, transgene expression was monitored by X-Gal staining and compared with fgAdv-mediated expression. Host inflammatory and immune responses against these vectors were evaluated by immunohistochemical detection of microglia, astrocytes, and infiltrating macrophages, as well as by enzyme-linked immunosorbent assay of cytokines TNF-alpha and IL-1beta. Transgene expression mediated by hdAdv persisted for more than 183 days regardless of inoculation site, as compared with 33 and 66 days for fgAdv-mediated expression after intraventricular and intrahippocampal inoculation, respectively. Inoculation with hdAdv was also associated with reduced numbers of activated microglial cells, astrocytes, and infiltrating macrophages in brain tissue. Secretion of the proinflammatory cytokines TNF-alpha and IL-1beta was minimal after hdAdv but not after fgAdv inoculation. These findings indicate that hdAdv would provide a safe and effective means to transfer therapeutic genes into aged brain.

Study on modification of the Misgav Ladach method for cesarean section

172 cases of pregnant women scheduled for delivery by cesarean section were randomly assigned to 59 cases in modification group with modified Misgav Ladach technique, 57 cases in Misgav Ladach group with Misgav Ladach technique and 56 cases in Pfannenstiel group with Pfannenstiel technique from May to Dec. 1999. The modified points included: transversely incising the fascia 2 to 3 cm, then dividing it bluntly; without opening and dissociating the visceral peritoneum; two layers suturing of low transverse uterine incision; closing the skin by continuous suturing. Results showed the average delivery time in the modification group was (3.6 +/- 2.6) min and (5.7 +/- 2.9) min in the Misgav Ladach group (P < 0.05). Median operating time was (28.3 +/- 5.4) min in modification group compared with (27.5 +/- 6.5) min in the Misgav Ladach group (P > 0.05). Average blood loss was (128 +/- 35) ml in modification group compared with (212 +/- 147) ml in the Pfannenstiel group (P < 0.05). It was concluded that the modified Misgav Ladach technique not only preserved all advantages of Misgav Ladach method, but also had additional advantages, such as faster in delivering the fetus, less damage, easier mastering for obstetricians.

[Evaluation of derma and fat combined pedicled superficial temporal fascia flap for reconstruction of facial depression]

OBJECTIVE

To evaluate the curative effect of derma and fat combined pedicled superficial temporal fascia flap for reconstruction of facial depression.

METHOD

Postoperative follow-up and comparative study were performed. 10 cases of facial depression deformities were involved, in which 5 cases were hemifacial atrophy, and 5 cases were branchial arch maldevelopment.

RESULTS

Postoperative follow-up for 1-3 years showed that the method produced better results in branchial arch depression than in hemifacial atrophy. The combined tissue used in plomb of branchial arch maldevelopment had a low ratio of anaphase absorption, maintaining a satisfactory long-term full contour. In plomb of hemifacial atrophy, the anaphase absorption ratio of the was combined tissue approximately 20%-40%.

CONCLUSIONS

The noxa of depression ought to be noticed when this method is used in reconstruction of facial depression. The exorbitant plomb is inadvisable for facial depression of branchial arch maldevelopment. However, in facial depression of hemifacial atrophy, in considering anaphases absorption, the suitable exorbitant plomb is reasonable for better future results.

Human hyaluronidases: electrophoretic multiple forms in somatic tissues and body fluids. Evidence for conserved hyaluronidase potential N-glycosylation sites in different mammalian species

Some properties of the multiple forms of human hyaluronidases in somatic tissues and in body fluids were investigated. Liver and placenta exhibited seven hyaluronidase forms when analyzed electrophoretically on a polyacrylamide-hyaluronan gel. Ovary, breast, myometrium, endometrium, skin, leukocytes and platelets displayed distinct patterns of enzymatic micropolydispersity. The most acidic forms of hyaluronidase were in synovial fluid and serum, some serum exhibited an additional basic form. Following sialidase treatment, the number of forms decreased to two in placenta, three in liver and to a broad basic form in serum. The native serum and placental hyaluronidases remained fully active after thermal inactivation but desialylated hyaluronidase was inactivated slowly in serum, and quickly in placenta suggesting a higher overall glycosylation of the plasma enzyme. Potential N-glycosylation sites were searched in the amino acid sequences of six human hyaluronidases and several hyaluronidases from different mammalian species using the PROSITE motif database. A potential N-glycosylation site (site 1) with similar tripeptide patterns was observed at the same position in human plasma (HYAL1), human lysosomes (HYAL2) and in two newly reported hyaluronidases (HYAL4 and HYALP1). The same site was also present in mouse plasma (HYAL1) and mouse lysosomes (HYAL2), and in rat lysosomes (HYAL2). This site was absent in human HYAL3 and in all sperm hyaluronidases (PH-20) studied (human, macaque, mouse, guinea pig, rabbit and fox). A second potential N-glycosylation site was observed at a location further in the polypeptide chain. This site is present in all mammalian hyaluronidase isoenzymes reported in the present study whatever the species and organ localization. The pattern at site 2 is NVT for all hyaluronidases except for hyaluronidases of lysosomal origin where it is NVS. Such conserved sites strongly suggest that they may represent actual N-glycosylation sites.

The human ARHI tumor suppressor gene inhibits lactation and growth in transgenic mice

ARHI is a novel imprinted tumor suppressor gene. To study its function in vivo, we have developed transgenic mice that overexpress ARHI. Offspring bearing the transgene had significantly lower body weights than did nontransgenic littermates. In addition, strong expression of the ARHI transgene was associated with greatly impaired mammary gland development and lactation, failure of ovarian folliculogenesis resulting in decreased fertility, loss of neurons in the cerebellar cortex, and impaired development of the thymus. Decrease in body size and defects in the mammary glands correlated with the level of transgene expression. Immunohistochemical analysis indicated that expression of prolactin (PRL), but not growth hormone, was lower in the pituitary glands of mice with defective mammary gland development. The defect in pregnancy-associated mammary tissue proliferation was associated with decreased serum PRL and progesterone levels. Moreover, lower levels of estrogen receptor and progesterone receptor were observed in postpartum mammary glands and in the ovaries of mice that overexpressed ARHI. Our data suggest that ARHI can inhibit PRL secretion and act as a negative regulator in murine growth and development.

Prolonged transgene expression mediated by a helper-dependent adenoviral vector (hdAd) in the central nervous system

Conventional adenoviral vectors such as E1-deleted first-generation adenovirus (fgAd) elicit striking host immune response, resulting in limited expression of the transgene. A recently described helper-dependent, or gutless, adenoviral vector (hdAd) can promote stable transgene expression in peripheral organs, including the liver. We therefore investigated the safety and durability of hdAd-mediated gene transfer to the central nervous system (CNS) of rats compared with gene delivery by fgAd. Equal amounts of either fgAd or hdAd carrying the beta geo transgene were stereotactically injected into the right hippocampus of adult rats. Transgene expression was assessed by histochemical staining, transgene stability by PCR analysis, and immune infiltration of T lymphocytes and macrophages by immunocytochemical methods. Strong transgene expression from either vector was detected in brain tissue examined on day 6 postinoculation. Thereafter, fgAd-mediated gene expression rapidly decreased, becoming undetectable by day 66, while expression from the hdAd vector persisted throughout the test period. PCR confirmed the presence of hdAd-associated DNA at 66 days postinoculation. The hdAd injection elicited apparently lower numbers of brain-infiltrating macrophages and T cells than did administration of fgAd. These results indicate improved transgene expression and reduced immunogenicity with use of hdAd to deliver genes to the CNS.

Using electrophoresis to observe the interaction of nitrogenase with ions

The two protein components of nitrogenase from Klebsiella pneumoniae were shown to interact with metal ions and ADP, altering their electrophoretic mobility in polyacrylamide gel electrophoresis. Both Mg+2 and Mn+2 caused reduced mobility of Fe protein relative to other proteins. The effect was about 50% complete at concentrations around 0.2 mM. Other ions including Fe+2, Ni+2 and Co+2 had no observable effect at levels up to 1 _mM. Both Cd+2 and Zn+2 appeared to interact with the protein; Cd+2 at 0.5 mM dramatically destabilized the protein. The effects of more than a dozen different mutations of the Fe protein on Mg+2 interaction were examined. All mutated proteins appeared to interact with Mg+2 similarly to wild-type. Using relative mobility differences of charge-changed mutants it was estimated that two to three Mg+2 interact with each Fe protein monomer. The MoFe protein also showed interaction with metal ions but the alteration of mobility was much smaller than for the Fe protein because it is larger and less acidic, so that it runs much more slowly than the Fe protein in standard gels. The interaction of ADP with Fe protein was examined in the presence of Mg+2. Increasing ADP partially reversed the mobility decrease observed on Mg+2 binding, and produced a more diffuse protein band indicative of a reaction zone of interconverting conformers. No alteration of MoFe protein mobility was observed with ADP added during electrophoresis.

Effect of nitrite on endothelial function in isolated lung

Nitrated tyrosine, implicated in protein dysfunction, is increased in various tissues in association with diverse pathological processes. Angiotensin converting enzyme (ACE) is a luminal vascular endothelial enzyme whose dysfunction is an early sign of endothelial injury. ACE contains a tyrosine critical for its enzymatic activity. Others have shown that nitrite exacerbates the ACE dysfunction of cultured endothelial cells in contact with activated polymorphonuclear neutrophils (PMN). We hypothesized that exogenous nitrite would enhance endothelial ACE dysfunction associated with PMN activation in the isolated lung. Rats received lipopolysaccharide (LPS) 2 h prior to isolated lung perfusion with Ficoll containing buffer. Either formyl-Met-Leu-Phe (fMLP, 10(-7) M) or phorbol myristate acetate (PMA, 10(-7) M) was used to activate PMN in lungs treated or not treated with 300-microM nitrite. A first pass indicator dilution method and first order reaction kinetics were used to determine ACE activity, while lung Ficoll content served as an index of vascular permeability. Both fMLP and PMA decreased endothelial ACE activity and increased pulmonary artery pressure, edema and vascular permeability. Exogenous nitrate did not potentiate the decrease in ACE activity, the lung injury or nitrotyrosine immunoreactivity of lung homogenates. In contrast to observations in cultured endothelial cells, our findings in the whole lung are compatible with the speculation of others that the rat lung has an unidentified factor, which minimizes accumulation of nitrated proteins.

[The relationship of cellular DNA content with clinical stage and biological features of colorectal cancer]

The purpose of this study was to explore the relationship of cellular DNA content with clinical stage and biological features of cancer. Flow cytometry was performed on fresh specimens from 86 patients from 1997 to 1998. Forty-five (53.3%) specimens were found to contain cells with abnormal DNA (DNA nondiploidy). Although none of the sex, age, site, differentiation variables correlated with flow cytometric DNA ploidy, nondiploidy was associated with Dukes' stage and lymph node metastasis. Duke's A stage tumors were more frequently diploid than were more advanced tumors, but no difference between Duke's B, C and D stages were observed. These findings suggest that ploidy is associated with some pathological factors.

Experimental examination of the effects of atmospheric wet deposition on primary production in the Yellow Sea

The effects of atmospheric wet deposition on primary production in the coastal Yellow Sea were examined by in situ incubation experiments in August, 1997. Phytoplankton species flourished in response to nutrient additions and chlorophyll-a (Chl-a) increased significantly when rainwater was added. Concentration of Chl-a increased 2.6 times with the addition of 10% (v/v) rainwater. In a coastal eutrophic region like Jiaozhou Bay, the impact of atmospheric wet deposition is negligible. However, the N/P ratio ranged from 22:1 to 80:1, indicating P limitation of photosynthesis in the Yellow Sea. During field observations, high N and low P rainwater was observed to be transported into the oligotrophic central Yellow Sea. Ammonium was used by phytoplankton in preference to nitrate, and Fe stimulated nutrient uptake by phytoplankton. Rainwater increased the Chl-a growth more than a single nutrient owing to the abundance of both plant and trace nutrients in the rainwater. A negative exponent relationship may exist between the impact of rainwater and total nutrient quality of the water in influencing phytoplankton growth.

Assembly of a complex containing Cdc45p, replication protein A, and Mcm2p at replication origins controlled by S-phase cyclin-dependent kinases and Cdc7p-Dbf4p kinase

In Saccharomyces cerevisiae, replication origins are activated with characteristic timing during S phase. S-phase cyclin-dependent kinases (S-CDKs) and Cdc7p-Dbf4p kinase are required for origin activation throughout S phase. The activation of S-CDKs leads to association of Cdc45p with chromatin, raising the possibility that Cdc45p defines the assembly of a new complex at each origin. Here we show that both Cdc45p and replication protein A (RPA) bind to Mcm2p at the G(1)-S transition in an S-CDK-dependent manner. During S phase, Cdc45p associates with different replication origins at specific times. The origin associations of Cdc45p and RPA are mutually dependent, and both S-CDKs and Cdc7p-Dbf4p are required for efficient binding of Cdc45p to origins. These findings suggest that S-CDKs and Cdc7p-Dbf4p promote loading of Cdc45p and RPA onto a preformed prereplication complex at each origin with preprogrammed timing. The ARS1 association of Mcm2p, but not that of the origin recognition complex, is diminished by disruption of the B2 element of ARS1, a potential origin DNA-unwinding element. Cdc45p is required for recruiting DNA polymerase alpha onto chromatin, and it associates with Mcm2p, RPA, and DNA polymerase epsilon only during S phase. These results suggest that the complex containing Cdc45p, RPA, and MCMs is involved in origin unwinding and assembly of replication forks at each origin.

Pramipexole inhibits lipid peroxidation and reduces injury in the substantia nigra induced by the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in C57BL/6 mice

Pramipexole has been showed to protect cultured dopaminergic (DAergic) cells against free radical-induced cytotoxicity. To test if pramipexole is protective against 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP)-mediated nigral DAergic injury in vivo and if such protection is related to inhibition of lipid peroxidation, DAergic function and lipid peroxidation were determined in MPTP-treated C57BL/6 mice. We reported that MPTP administration induced a 38.1% increase of lipid peroxidation product thiobarbituric acid reactive substance (TBARS) in nigra, a 46.7% decrease of tyrosine hydroxylase -positive nigral DAergic neurons and a 59.4% reduction of striatal DA levels. However, pramipexole treatment significantly inhibited the TBARS production by 76%, and attenuated the MPTP-induced decreases in nigral DAergic neurons and striatal DA levels by about 50%. This study suggests that pramipexole can inhibit free radical-mediated lipid peroxidation and protect MPTP-induced nigral injury.

High frequency color Doppler image of choroidal detachment

PURPOSE

To study the Color Doppler Image (CDI) characteristics of choroidal detachment and the applied value of CDI.

METHODS

Seventy-two cases (74 eyes) of choroidal detachment were studied retrospectively.

RESULTS

The typical ultragraph of chroridal detachment displayed one or several smooth hemispherical or lobuler circular thick bands, with convex side toward vitreous cavity. Most of the choroidal detachments were located before the equator, a few of them were beyond the equator. CDI displayed blood flow singnal in the band. Pulse Doppler showed the frequency spectrum features of retinal detachment band were similar to those of central retinal vessels, whereas the frequency spectum features of choroidal detachment bend resembled those of ciliary artery in some cases of retinal detachment (RD) accompanied by choroidal detachment.

CONCLUSION

CDI could make a correct and precise diagnosis of choroidal detachment.

[Surgical correction of complete atrioventricular septal defect with tetralogy of Fallot]

OBJECTIVE

To report the surgical correction of complete atrioventricular septal defect with tetralogy of Fallot (AVSD-TOF).

METHODS

Six consecutive patients aged 3 - 9 years underwent correction of complete AVSD-TOF. The two-patch technique for atrioventricular septal defect was used. The ventricular septal defect was closed through a right ventriculotomy and right atriotomy in each case. The commissure between the superior and inferior bridging leaflets of the left portion of the common atrioventricular valve was closed in each patient. RVOT obstruction was relieved by a transannular autologous pericardium with monocuspid valve.

RESULTS

Postoperative complications included respiratory failure in 1 patient, low cardiac output syndrome in 1, and MOF in 1. There was one mortality because of MOF in the early postoperative period. Five survivors were followed up from 6 months to 5.5 years (mean 2.3 years). There was no late mortality and only one patient had mild left atrioventricular valve regurgitation. NYHA cardiac function was class I in 4 patients and class II in 1.

CONCLUSIONS

AVSD-TOF can be corrected using the two-patch technique and closure of the ventricular septal defect through a combined approach using a right ventriculotomy and right atriotomy. Routine closure of the commissure of the left portion of the atrioventricular valve results in a low incidence of regurgitation. Good functional result can be achieved in most patients postoperatively.

Interaction with magnesium and ADP stabilizes both components of nitrogenase from Klebsiella pneumoniae against urea denaturation

The nitrogenase enzyme of Klebsiella pneumoniae consists of two separable proteins, each with multiple subunits and one or more oxygen sensitive metallocenters. The wild-type nitrogenase proteins are stable to electrophoresis in high concentrations of urea under anaerobic conditions. Addition of Mg+2 and ADP greatly increases the stability of the smaller Fe protein (from <4 to >6 M for full unfolding), an effect directly analogous to stabilization in p21ras induced by Mg+2 and GDP. Stabilization by Mg+2 is slight for the holo MoFe protein (from approximately 1.5 to approximately 2.4 M) but more dramatic for the apo protein form of the MoFe protein accumulated by certain Fe protein (nifH gene) mutants. The potent product inhibitor of nitrogenase function, MgADP, increases stability of the MoFe protein more than Mg+2 alone, to approximately 3.6 M, showing that nucleotides interact with the MoFe protein. Mutations of the nifM gene result in slower accumulation of less stable Fe protein, indicating that NifM is involved in correct folding of the Fe protein. Mutationally altered proteins are often difficult to purify for study because of their inherent instability, low expression level, or oxygen lability. Crude extracts of 11 different mutants of Fe protein (nifH gene) were examined by transverse urea gradient gels to rapidly screen for stabilizing interactions in the presence or absence of substrate or inhibitor analogs. Amino acid alterations D44N and R188C, at the interface of the dimer, in the vicinity of the nucleotide binding site(s), have significantly lower stability than the wild-type enzyme in the absence of Mg+2 but comparable stability in its presence, showing the importance of Mg+2 in the subunit interactions. Mutations N163S and E266K, in which residues normally involved in hydrogen bonding far from the active site were altered, are more labile than the wild-type even with Mg+2 added. Seven other mutants, though nonfunctional, did not appear altered in stability compared to the wild-type.

[Evaluation of the results of therapeutic lamellar keratoplasty and penetrating keratoplasty for fungal corneal ulcer]

OBJECTIVE

To evaluate the effects of therapeutic lamellar and penetrating keratoplasty for fungal corneal ulcer.

METHODS

Donor corneas preserved in pure glycerine or water-free calcium chloride were used in corneal transplantation for fungal corneal ulcers that were poorly responsive to the anti-fungal medical treatment, 5% iodine was used in lamellar keratoplasty to kill the fungi in the recipient bed, and diluted or original solution of fluconazole was used in penetrating keratoplasty to wash the anterior chamber.

RESULTS

In the lamellar keratoplasty group, there were 23 cases; 18 cases were cured with one surgery and 3 cases were cured after second surgery, the success rate being 91.3%. There were 2 cases with recurrence of corneal inflammation, and the lesion was controlled by penetrating keratoplasty. The penetrating keratoplasty group included 31 cases, of them, 27 cases were cured with one surgery and 4 eyes were enucleated due to recurrent corneal inflammation or refractive glaucoma. In the total 54 cases, the inflammation was controlled in 50 cases after therapeutic corneal transplantation, success rate being 92.6%.

CONCLUSIONS

For those fungal corneal ulcers that are poorly responsive to anti-fungus eye drops, it is recommended to perform lamellar keratoplasty if the ulcer is located in the anterior 1/2 stroma, the key points of surgery are to remove the affected tissue completely and cauterize the recipient bed with 5% iodine. For deep ulcers or nearly perforative or perforated ulcers, diluted or original solution of diflucan is used to wash the anterior chamber during penetrating keratoplasty, that can help to improve the success rate.

Assessing the quality of shoulder preparations for metal ceramic crowns

Previous work by the authors indicates a tendency for academic clinicians to under prepare and over angle shoulder preparations for metal ceramic crowns. This has implications for the final restoration in terms of contour, appearance and strength. This study analysed ninety six preparations, forty eight in vitro and forty eight in vivo, performed by six clinicians. The results show a mean shoulder width of 0.804 +/- 0.274 mm and a mean shoulder angle of 116 +/- 18 degrees for preparations performed in vitro; and 0.892 +/- 0.337 mm and 121 +/- 24 degrees for preparations performed in vivo. Thus, despite recommendations that such crowns should have 1-1.5 mm, 90 degrees shoulders, many of the preparations studied here fell short of this, indicating a lack of consistency in preparation geometry and adherence to the perceived 'ideal' preparation for a metal ceramic crown.

[A SEM observation on taxonomic and pharmacognostical identification of genus murraya produced in China]

OBJECTIVE

To Observe the morphological characteristics of the leaf epidermis of 9 Chinese species of genus Murraya and prepare and index for their differentiation.

METHOD

SEM(scanning electron microscope).

RESULT

Sect. Murraya was found having with blurred dividing lines on epidermis without ropy emblazonry, while sect. Bergera appeared the other way round.

CONCLUSION

M. kwangsiensis var. macrophylla should be ground under Sect. Murraya as a new species, while M. tetramera should be separated from M. euchrestifolia; SEM has been proved very useful in the identification, taxonomic and pharmacognostical study of Murraya.

Selective agenesis of mesencephalic dopaminergic neurons in Nurr1-deficient mice

Nurr1, a member of the nuclear receptor superfamily of transcription factors, has been found to be essential for the development of ventral midbrain dopamine (DA)ergic neurons. To study the regional selectivity and phenotypic specificity of regulation by Nurr1 of the genesis of DAergic neurons, we examined DAergic, serotonin (5-HT)ergic, norepinephrine (NE)ergic, cholinergic, glutamate (GLU)ergic, and gamma-aminobutyric acid (GABA)ergic neurons in the brains of Nurr1-deficient mice by immunohistochemistry and biochemistry. We demonstrated that in homozygous Nurr1-deficient mice (Nurr1-/-), DAergic neurons were totally absent in substantia nigra and ventral tegmental area, but preserved in other regions including diencephalon and hypothalamus, olfactory bulb (OB). Levels of DA in Nurr1-/- mice were decreased by 98% in striatum (Str) and 65% in OB. NEergic neurons in locus ceruleus, 5-HTergic neurons in raphe nuclei, and cholinergic neurons in basal forebrain and other regions were not changed. A 30% reduction of NE was found in the Str of Nurr1-/- mice. The levels of GLU and GABA and the activity of choline acetyl transferase in the brains of Nurr1-/- mice were not significantly altered. Our results demonstrate a selective and specific deficit of DA and absence of DAergic neurons in the mesencephalic structures of Nurr1-deficient mice, which resembles the pattern similar to that seen in patients with Parkinson's disease (PD). This model may contribute to our understanding of the mechanisms influencing DAergic cell survival in PD.

[The genotype-based haplotype relative risk and transmission disequilibrium test analyses of familial febrile convulsions]

OBJECTIVE

To confirm the linkage of familial febrile convulsions to the short arm of chromosome 6(6p) or the long arm of chromosome 8(8q).

METHODS

The authors finished genotyping of Pst I locus on the coding region of heat shock protein (HSP) 70, 5'untranslated region of HSP70-1, 3' untranslated region of HSP70-2, D8S84 and D8S85. The data were processed by the genotype-based haplotype relative risk(GHRR) and transmission disequilibrium test(TDT) methods in PPAP.

RESULTS

Some signs of association and disequilibrium between D8S85 and FC were shown by GHRR and TDT.

CONCLUSION

A suspect linkage of familial febrile convulsions to the long arm of chromosome 8 has been proposed.

Quantification of root surface plaque using a new 3-D laser scanning method

There are no published reports in the literature objectively quantifying thickness of plaque on teeth. The aim of this study was to quantify plaque on a tooth surface and assess if this quantification correlates with a clinical index of plaque from each of 51 patients. Patients were instructed not to perform any oral hygiene on the day of the assessment. The Silness and Löe plaque index was scored and replicas were scanned using a co-ordinate measuring machine (CMM) and laser scanning probe. A replica was obtained from this surface before and after toothbrushing. Plaque adjacent to the gingival margin had a mean thickness of 0.106+/-0.118 mm (mean+/-SD) whilst mean plaque thickness 250 microm from the gingival margin was 0.053+/-0.052 mm (mean+/-SD). There was a significant correlation between the plaque index and the plaque thickness (p < or = 0.002). The finding that plaque is present in the greatest amount adjacent to the gingival margin supports a previously reported hypothesis that primary root carious lesions (PRCL's) may initiate adjacent to the gingival margin. This method quantifies plaque thickness on exposed root surfaces which correlates with the plaque index as well as illustrating how the morphological characteristics of teeth, gingivae and plaque can be studied in vivo from replicas recorded.

[Study on carbazole alkaloids of Murraya microphylla]

Four carbazole alkaloids were isolated from the methanol extract of Murraya microphylla. Their structures were identified by spectral analysis and chemical evidence, which were identified as koenigine, bis-6-hydroxy-7-methoxygirinimbine, girinimbine and mukonicine. All the compounds were discovered from this plant for the first time, and bis-6-hydroxy-7-methoxygirinimbine was a new compound.

[High voltage transmission electron microscope and X-ray double-crystal diffractometer observation of pure titanium implant-bone interface]

OBJECTIVE

To examine the integration of pure titanium implant and bone tissue.

METHODS

Using low temperature dualion mill technique, the interface of titanium implant and bone was examined with high voltage transmission electron microscope and X-ray double crystal diffractometer.

RESULTS

It was shown that calium globules of various electron density or sheets of calcified osseous tissue blended with titanium at the interface. The bone had grown in two directions.

CONCLUSION

The integration of pure titanium implant and bone tissue is good, leaving no gap at their interface.

[Distribution of six STR loci in Bai ethnic group in Yunnan province of China]

OBJECTIVE

This study was conducted to make known the distribution of six STR loci in Bai ethnic group in Yunnan province.

METHODS

DAN extraction from blood samples (126 in number ) and multiplex amplification of CSF1PO,TPOX, TH01,F13A01, FESFPS and vWA were carried out. Using denaturing polyacrylamide gel electrophoresis and silver stain, the authors investigated the distribution of allele frequencies of CSF1PO, TPOX,TH01,F13A01,FESFPS and vWA loci in Bai ethnic group living in Yunnan province.

RESULTS

7 alleles and 19 genotypes of CSF1PO locus, 5 alleles and 11 genotypes of TPOX locus, 6 alleles and 16 genotypes of TH01 locus 6 alleles and 16 genotypes of F13A01 locus, 7 alleles and 15 genotypes of FESFPS locus,and 7 alleles and 21 genotypes of vWA locus were observed.

CONCLUSION

The allele distribution of the loci was in good agreement with the Hardy-Weinberg equilibrium.

Neuroprotection by pramipexole against dopamine- and levodopa-induced cytotoxicity

Pramipexole, a novel non-ergoline dopamine (DA) agonist, has been applied successfully for treatment of Parkinson's disease (PD). We report here that pramipexole can protect dopaminergic cell line Mes23.5 against dopamine- and levodopa-induced cytotoxicity possibly through a mechanism related to antioxidant activity. In the MES 23.5 cultures, DA and L-DOPA induce a dose- and time-dependent cytotoxicity, as determined by tetrazolium salt and trypan blue assays. Furthermore, an in situ terminal deoxynucleotidyl transferase assay demonstrates that DA-induced cell death is apoptotic. Pretreatment with pramipexole in a concentration range (4-100 microM) significantly attenuates DA- or L-DOPA-induced cytotoxicity and apoptosis, an action which is not blocked by D3 antagonist U-99194 A or D2 antagonist raclopride. Pramipexole also protects MES 23.5 cells from hydrogen peroxide-induced cytotoxicity in a dose-dependent manner. In cell-free system, pramipexole can effectively inhibit the formation of melanin, an end product resulting from DA or L-DOPA oxidation. These results indicate that pramipexole exerts its neuroprotective effect possibly through a mechanism, which is independent of DA receptors but related to antioxidation or scavenging of free radicals (e.g. hydrogen peroxide). As a direct DA agonist and potentially neuroprotective agent, pramipexole remains attractive in the treatment of PD.

Suppression of chronic experimental autoimmune neuritis by nasally administered recombinant rat interleukin-6

Experimental autoimmune neuritis (EAN) is a CD4+ T-cell-mediated demyelinating disease of the peripheral nervous system (PNS) and serves as experimental model for human immune-demyelinating neurophathies, especially the Guillain-Barré syndrome. In this study, we examined the effect of recombinant rat interleukin-6 (rrIL-6) on chronic EAN in Lewis rats induced by immunization with P2 peptide 57-81 and Freund's complete adjuvant (FCA). Nasal administration of rat rIL-6 (1 microg/rat/day) beginning in the initial phase of EAN as a therapeutic agent, decreased the severity and the duration of clinical EAN. Low-grade inflammation and suppression of regional demyelination within the sciatic nerves were seen in rrIL-6-treated rats. Hyporesponsiveness of lymph node T cells, down-regulation of serum tumour necrosis factor-alpha (TNF-alpha) and increased levels of P2-specific immunoglobulin G1 (IgG1) antibodies document that nasal administration of rrIL-6 was effective systemically. However, because of the non-specific nature of the treatment and multiple effects of IL-6, more experience and great caution are needed, before nasal administration of IL-6 can be considered as a treatment of human autoimmune demyelinating neurophathies.

[The experience of treatment of 7 cases of olfactory neuroblastoma]

OBJECTIVE

To improve the treatment result of olfactory neuroblastoma.

METHOD

Introduce the experience of treatment of 7 patients with this disease. Among these 7 cases, 2 of them were stage B while the others were stage C according to the system proposed by Kadish. 3 cases received radiotherapy alone, and 4 others received radiotherapy pre-operation. The radiation dose was 5000-7000 cGy. All the patients were followed-up until December 1997.

RESULT

5 cases are still alive, survival time are 20, 22, 23, 29 and 76 months respectively. The other 2 patients died with the survival time of 6 and 48 months respectively.

CONCLUSION

Radiotherapy seems effective in the treatment of olfactory neuroblastoma; the combination of chemo-radio-therapy is preferable for advanced or metastasis olfactory neuroblastoma. We extrapolate there are different subtypes on pathology in this tumor.

[Distribution of three STR loci in Dai ethnic group in China]

OBJECTIVE

This study was conducted to investigate the distribution of three STR loci in Dai ethnic group.

METHODS

Multiplex amplifications of CSF1PO, TPOX and TH01 were carried out. Using denaturing polyacrylamide gel electrophoresis and silver staining the authors investigated the distribution of allele frequencies of CSF1PO, TPOX and TH01 loci in Dai ethnic group living in Yunnan province.

RESULTS

7 alleles and 15 genotype of CSF1PO locus, 7 alleles and 18 genotypes of TPOX locus, 6 alleles and 17 genotypes of TH01 locus were observed.

CONCLUSION

The allele distribution of the loci is in good agreement with the Hardy-Weinberg equilibrium.

[Study on the volatile oils of Murraya microphylla]

The essential oils from the leaves of Murraya microphylla (Merr. et Chun) Swing. growing in Sangya city, Hainan province have been studied by GC-MS and 22 compounds have been isolated and identified. Major compounds are identified as beta-terpinene (27.86%), decahdro-1, 1,7-trimethylene-1H-cyclopop[e] azulene (24.572%), 1,2,3,4,4 alpha, 5,6,8 alpha-octahydro-7-methyl-1-(1-methyl) naphthalene (11.426%), 3-carene (10.125%), 1, 1-dimethy1-2-(3-methyl-1, 3-butadienyl) cyclopropane (5.581%). According to Mr. Bipeixi's opinion, it exists two distinct sections within Murraya microphylla (Merr. et Chun) Swing. belongs to Murraya section Bergera. Monoterpene must be the dominated volatile fractions according Li Qian's opinion, but it is a exception. Maybe it has special taxonomic significance.

[Detecting expression of the multidrug resistance gene product (P170) in human tumor tissues and cells by flow cytometry]

We have detected the human multidrug resistance gene (MDR1) product P170 in 29 solid tumor samples and K562 cell line through indirectimmunoflourence staining by flow cytometry using mouse monoclonal antibody (McAb). The results showed that the expression of P170 was detected in 18 samples, the positive ratio being 62.1%; the expression was not detected in 11 samples, the negative ratio being 37.9%; and 99.9% of K562 cells expressed P170. In 16 of the 18 positive samples, the percent ratio of tumor cells for expression of P170 was less than 30%; in the other 2, more than 30%. This indicated that the positive ratio of P170 of most tumor samples was high, but their percent ratio of P170 was low. Thus it provided a parameter for reference in evaluating the efficacy of clinical antitumor treatments.

Up-regulation of type 2 iodothyronine deiodinase mRNA in reactive astrocytes following traumatic brain injury in the rat

Type 2 5'-deiodinase (5'-D2), which converts thyroxine to the more active thyroid hormone 3,5,3'-triiodothyronine (T3), is believed to be an important source of intracellular T3 in the brain. The activity of this enzyme is increased in hypothyroidism and decreased in hyperthyroidism, and as such, it serves an important role to protect the brain from wide fluctuations in T3 during changes in thyroidal state. Although it has been hypothesized that T3 may facilitate neuronal regeneration after CNS injury, the 5'-D2 response to brain injury is unknown. To assess the 5'-D2 mRNA response to injury, we performed in situ hybridization following traumatic brain injury. In unlesioned animals, 5'-D2 mRNA was undetectable. At 3 days posttrauma, 5'-D2 mRNA was detected in ipsilateral cortex near the contusion. A significant further increase of 5'-D2 mRNA was noted 7 days posttrauma in both hippocampus and cortex. Similar response was also observed on the contralateral side. Colocalization of 5'-D2 mRNA with glial fibrillary acidic protein indicates that reactive astrocytes were the major cellular source for the trauma-induced 5'-D2 expression. These data demonstrate, for the first time, a trauma-induced, astrocytic up-regulation of 5'-D2 mRNA, suggesting a potential role for T3 action in adult brain's response to injury and recovery.

[The role of fetus decalcified bone matrix (FDBM) in inducing pure titanium-bone implant integration]

Because of its high biological compatibility, titanium has been a good biomaterial. The implanted artificial bone made from titanium can contact with the vital and mature osseous tissue directly within 3-6 months, the so-called osteointergration. In order to promote the process of osteointergration, FDBM of rabbit was prepared and was combined with pure titanium so as to speed up osteointergration. The study focused on bone density, bone intergration rate, new bone growth rate around the pure titanium, and the Ca2+ and PO(4)3- density of titanium-bone interface. A control group of pure titanium inplant without FDBM was set up. The results showed FDBM had no antigenicity. It could induce and speed up the new bone formation at titanium-bone interface. The titanium-bone intergration time was within 2 months. It was suggested that there were more bone morphogenesis protein (BMP) or other bone induction and bone formation factors in brephobone than that in child and adult bone. As a kind of bone induction material, FDBM was easy prepared, cheap in price, easy to storage, no antigenicity and obvious bone-inductive function.

[Analysis of the density of insulin-like growth factor-1 receptor on tendon cell]

For the purpose of understanding the distribution of insulin-like growth factor-1 (IGF-1) receptor on the tendon cell, the continuous cultured tendon cell line was studied by following experiments. With the methods of immunohistochemical study and flow cytometric study, the density of IGF-1 receptor of the primary, 6th and 13th generation of tendon cell was analyzed. The results showed that there was no difference of the receptor density among those generations. However, in the cell cycle, the numbers of IGF-1 receptor in G2M phase tendon cells were more than that in G1 phase cells (P < 0.01). These works provided sufficient evident which suggested there were stable density of IGF-1 receptor on the tendon cell though out the life span of tendon cell. This may build some foundation in growth control of tendon cell by growth factor in the research of tendon tissue engineering.

Formation of a preinitiation complex by S-phase cyclin CDK-dependent loading of Cdc45p onto chromatin

Cdc45p, a protein essential for initiation of DNA replication, associates with chromatin after "start" in late G1 and during the S phase of the cell cycle. Binding of Cdc45p to chromatin depends on Clb-Cdc28 kinase activity as well as functional Cdc6p and Mcm2p, which suggests that Cdc45p associates with the prereplication complex after activation of S-phase cyclin-dependent kinases (CDKs). As indicated by the timing and the CDK dependence, binding of Cdc45p to chromatin is crucial for commitment to initiation of DNA replication. During S phase, Cdc45p physically interacts with minichromosome maintenance (MCM) proteins on chromatin; however, dissociation of Cdc45p from chromatin is slower than that of MCMs, which indicates that the proteins are released by different mechanisms.

[Distribution of three STR loci in Jingpo ethnic group in Yunnan province]

OBJECTIVE

This study was aimed at the use of old blood stains for investigating the distribution of three STR loci in Jingpo ethnic group.

METHODS

DNA extraction from old blood stains (106 in number) and multiplex amplification of CSF1PO, TPOX and TH 01 were carried out. Using denaturing polyacrylamide gel electrophoresis and silver stain, the authors investigated the distribution of allele frequencies of CSF1PO, TPOX and TH01 loci in a Jingpo ethnic group in the southwestern part of Yunnan province.

RESULTS

7 alleles and 26 genotypes of CSF1PO locus,7 alleles and 19 genotypes of TPOX locus, and 6 alleles and 18 genotypes of TH01 locus were observed.

CONCLUSION

The satisfactory results demonstrate that multiplex amplification of CSF1PO, TPOX and TH01 is sensitive and the old stain of a drop of blood is sufficient for such amplification.

Tensile strength of lens capsules in eye-bank eyes

PURPOSE

To measure the tensile strength of the anterior and posterior lens capsules in eye-bank eyes and study the tensile strength of capsules dehydrated with hypertonic glucose solution.

SETTING

Tongren Hospital, Beijing, China.

METHODS

The in situ anterior and posterior capsules of 35 eye-bank eyes (Group 1) donated by healthy men aged 20 to 40 years (mean 27.1 years) were measured with a biomembrane strength device. Sixteen eyes (Group 2), from donors aged 20 to 37 years (mean 27.0 years) and similar to those in Group 1, were measured in the same way after the anterior and posterior capsules were exposed to glucose 50% solution for 15 minutes.

RESULTS

In Group 1, anterior and posterior capsule strength was 6.269 +/- 1.118 and 3.755 +/- 0.835 g, respectively (P < .01), and the correlation between the tensile strength of the anterior and posterior capsules was statistically significant (r = .94; P < .001). In Group 2, the strength of the capsules increased to 9.024 +/- 0.586 and 4.424 +/- 0.761 g, respectively, a finding that was statistically significantly different from that in Group 1 (P < .01 and .05, respectively.

CONCLUSION

The tensile strength of the anterior capsule was stronger than that of the posterior capsule under the experimental conditions. Glucose 50% solution has the potential to increase the tensile strength of anterior and posterior capsules.