[Microrough surface and its bio-effects of metallic biomaterials (II)--bio-effects of microrough surface of metallic biomaterials]

As for bio-effect of microrough surface of metallic biomaterials, seven aspects are reviewed in this article: i.e., the relationship between microrough surface (MRS) and corrosion resistance, ion release rate; the relationship between MRS and inflammation; the relationship between MRS and epithelium cells, fibroblast cells; the relationship between MRS and soft tissue; the relationship between MRS and bone; the relationship between MRS and blood tissue; the relationship between MRS and microorganism, contamination, decontamination. To sum up, MRS has its advantages in biocompatibility.

Effect of simulated weightlessness on TNF-alpha production and the response of bone marrow cells to GM-CSF in rats

The purpose of this experiment was to investigate the effect of 15 and 30 d simulated weightlessness (SWL) on tumor necrosis factor-alpha(TNF-alpha) production secreted by macrophage stimulated with lipopolysaccharide(LPS) and the ability of bone marrow cells to respond to granulocyte/monocyte colony-stimulating factor(GM-CSF) in tail-suspension rats. The TNF-alpha production was assessed by radioimmunoassay. The ability of bone marrow cells to respond to GM-CSF was measured by 3H-TdR incorporation method. The results showed that after 15 d SWL, TNF-alpha production showed a tendency to decrease; and that after 30 d SWL, the decrease became significant (P < 0.05). The results also demonstrated that the ability of bone marrow cells to respond to GM-CSF decreased significantly after 15 d SWL (P < 0.01); and there was no significant change after 30 d SWL. It suggested that SWL could depress immune function, and that reduction of TNF-alpha production might be related to bone marrow cell proliferation function.

Anatomical gradients in proliferation and differentiation of embryonic rat CNS accessed by buoyant density fractionation: alpha 3, beta 3 and gamma 2 GABAA receptor subunit co-expression by post-mitotic neocortical neurons correlates directly with cell buoyancy

Development of the CNS occurs as a complex cascade of pre-programmed events involving distinct phases of cell proliferation and differentiation. Here we show these phases correlate with cells of specific buoyant densities which can be readily accessed by density gradient fractionation. Sprague-Dawley dams were pulse-labelled with bromodeoxyuridine (BrdU) and selected regions of embryonic (E) CNS tissues at E11-22 dissociated with papain into single-cell suspensions. Proliferative cell populations were assessed by anti-BrdU and propidium iodide staining using flow cytometry. Cell differentiation was evaluated using molecular and immunocytochemical probes against mRNAs and antigens differentiating the neuroepithelial, neuronal and glial cell lineages. The results show the emergence of distinctive spatiotemporal changes in BrdU+ populations throughout the CNS during embryonic development, which were followed by corresponding changes in the cellular distributions of antigens distinguishing specific cell types. Fractionation of neocortical cells using discontinuous Percoll gradients revealed that an increasing number of cells increase their buoyancy during corticogenesis. Immunocytochemical and molecular characterization showed that the proliferative and progenitor cell populations are for the most part associated with lower buoyancy or higher specific buoyant densities (> 1.056 g/ml) whereas the post-mitotic, differentiated neurons generally separated into fractions of higher buoyancy or lower specific buoyant densities (< 1.043 g/ml). Immunostaining with antibodies against several GABAA receptor subunits (alpha 3, beta 3, gamma 2) revealed that the highest percent (70-90%) of immunopositive cells could be identified in the most buoyant, differentiating neurons found in the cortical plate/subplate regions, with the lowest percent of the immunopositive cells found in the least buoyant, proliferative and progenitor cell populations originating from the ventricular/subventricular zones. Taken together, these results indicate that buoyant density is a distinguishing characteristic of embryonic CNS cells transforming from primarily proliferative to mainly differentiating, and that fractionation of these cells according to their buoyant densities provides rapid access to the properties of specific cell lineages during the prenatal period of CNS development.

[Microrough surface and its bio-effects of metallic biomaterials (I)--microrough surface of metallic biomaterials]

In this paper, four aspects of microrough surface of metallic biomaterials are reviewed: the preparation of microrough surface, the technology of surface roughness measurement, the parameters of roughness and the microrough surface bio-effect.

The plasma concentrations of lidocaine after slow versus rapid administration of an initial dose of epidural anesthesia

We measured venous blood concentrations of lidocaine in 15 patients undergoing lower abdominal or extremity surgery after epidural injection of lidocaine. Patients were divided into either an infusion group (Group I, n = 6) or a bolus injection group (Group II, n = 9). We administered 15 ml of 2% lidocaine into the epidural space at 1 mL/min in Group I and at 1 mL/3 in Group II. Venous blood was drawn at 3, 6, 9, 12, 15, 18, 21, 30, 60, and 90 min after injection for measurement of plasma lidocaine concentrations. The peak plasma concentration (Cmax) of lidocaine in Group I was significantly less than that in Group II (P < 0.0005). We conclude that slow epidural infusion can produce a lower Cmax of lidocaine compared with that of a bolus administration and thereby decrease the potential for systemic toxicity of the local anesthetic.

Oct-1 and CCAAT/enhancer-binding protein (C/EBP) bind to overlapping elements within the interleukin-8 promoter. The role of Oct-1 as a transcriptional repressor

Interleukin-8 (IL-8), a potent neutrophil chemoattractant, can be expressed at high levels by many different cell types after immune stimulation. In contrast, expression of IL-8 in these same cells is virtually absent in the unstimulated state, demonstrating the tight regulation of the IL-8 gene. Although much is known about how this gene is transcriptionally activated after immune stimulation, little is known about the regulation of the IL-8 promoter in the absence of immune activation. In this study we examine how the IL-8 promoter is transcriptionally regulated in the uninduced state and how these mechanisms are altered in response to immune stimulation by IL-1beta. Electrophoretic mobility shift assay and transfection studies show that the IL-8 promoter is transcriptionally regulated by both positive and negative elements. Although the nuclear factor-kappaB (NFkappaB) element regulates only inducible activity of the IL-8 promoter in response to stimulation with IL-1beta, the AP-1 and CCAAT/Enhancer-binding Protein (C/EBP) elements influence both basal and inducible activities. In contrast to these three positive regulatory elements, the binding of the ubiquitously expressed POU-homeodomain transcription factor, Oct-1, strongly represses transcriptional activity of the IL-8 promoter by binding independently to an element overlapping that of C/EBP.

Electrochemical and histomorphometric evaluation of the TiNiCu shape memory alloy

By means of electrochemical and quantitative histomorphometric methods, the corrosion resistance and tissue biocompatibility of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) were investigated. It is discovered that the repassivation potential of Ti50Ni50-xCux (x = 2, 4, 6, 8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. Namely, the addition of Cu raises the repassivation potential of TiNi shape memory alloys and improves their corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys increase with solution pH value, but the repassivation potentials keep constant. The adding of Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys are irrelevant to its Cu content and the values are almost the same as those of TiNi alloys. The connective tissue layer covering the plates is statistically significantly thicker for Ti50Ni42Cu8 plates (p < 0.05) than that of Ti50Ni50, Ti50Ni48Cu2, Ti50Ni44Cu6 plates after one month. The numbers of connective tissue cells, polynucleated cells, macrophages and round cells are higher for Ti50Ni42Cu8 plates than those of the other three types of plates, but no statistically significant differences are detected. There are no significant differences on tissue reaction parameters after two and three months among four alloys. After one, two and three months implantation, no corrosion is observed on the plates surfaces. A preliminary conclusion can be drawn that Ti50Ni50-xCux (x = 2, 6, 8) shape memory alloys have good biocompatibility.

Repression of the alpha0 gene by ICP4 during a productive herpes simplex virus infection

During a productive infection by herpes simplex virus type 1 (HSV-1), ICP4, the major regulatory protein encoded by the alpha4 gene, binds to its transcription initiation site and represses the accumulation of alpha4 RNA. Evidence suggests that the degree of repression by ICP4 is a function of the absolute distance of an ICP4 binding site 3' from a TATA box. However, repression of HSV-1 gene expression by ICP4 through binding sites located 5' of TATA boxes, as in the case of the alpha0 gene, has not been adequately addressed. To this end, recombinant alpha0 promoters with various arrays of ICP4 binding sites flanking the alpha0 TATA box were constructed and recombined into the HSV-1 genome. Our results demonstrate the following. (i) Destruction of the endogenous alphaO ICP4 binding site, located 5' of the TATA box, results in derepression of alpha0 protein and RNA accumulation in infected Vero cells. (ii) The degree of alpha0 derepression is equivalent to that reported for the alpha4 gene following destruction of the ICP4 binding site at the alpha4 mRNA cap site in HSV-1. (iii) Introduction of an ICP4 binding site at the alpha0 mRNA cap site represses the accumulation of alpha0 RNA greater than threefold relative to the wild type. (iv) Changes in the abundance of alpha0 protein and RNA in infected cells do not affect replication or growth of HSV-1 in tissue culture. Our findings are consistent with the conclusion that alpha0 transcription is repressed by ICP4. These results demonstrate that repression by ICP4 can occur through binding sites located 5' of virus gene TATA boxes in HSV-1. Thus, models addressing repression of HSV-1 gene expression by ICP4 should incorporate the role of binding sites located 5', as well as 3', of virus gene TATA boxes.

Noninvasive indexes of cardiac systolic and diastolic function in hyperthyroid and senescent mouse

The mouse is a common model for transgenic manipulation, however, their small size has made hemodynamic study difficult. A noninvasive 10-MHz pulsed Doppler probe was used to measure aortic and mitral flow velocities in anesthetized, intact mice to study the effects of aging and hypethyroidism (induced by thyroxine) one systolic and diastolic cardiac function. In 10 hyperthyroid mice peak aortic velocity (PAV, an index of systolic function) was 34% higher than in 10 control mice (108 +/- 2 vs. 80 +/- 3 cm/s, P < 0.05). The ratio of early to late mitral filling velocity (E/A ratio, an index of diastolic function) was 47% higher (5.6 +/- 0.8 vs. 3.8 +/- 0.2, P < 0.05) in the hyperthyroid mice. In six old (30 mo) mice PAV was similar to eight young (4 mo) mice (73 +/- 3 vs. 75 +/- 3 cm/s), but the E/A ratio was 59% lower (1.8 +/- 0.3 vs. 4.4 +/- 0.4, P < 0.05). Despite a wide range of observed heart rates, the systolic and diastolic parameters of the groups were clearly separated. We conclude that cardiac systolic and diastolic function in mice, measured by pulsed Doppler ultrasound, are similar to larger species both in magnitude and in their response to hyperthyroidism and aging.

Developmental kinetics of GAD family mRNAs parallel neurogenesis in the rat spinal cord

GABA (gamma-amino butyric acid), a fast-acting synaptic transmitter in the mature CNS, is synthesized from glutamate by GAD (glutamic acid decarboxylase). We have developed an ultrasensitive PCR technique to quantify the expression of GAD-related mRNAs during the development of the rat cervical spinal cord and have localized them using in situ hybridization. GAD65, GAD67, and an alternatively spliced variant of GAD67, EP10, were quantified each day from embryonic (E) day 11 through E21, and at postnatal days 0, 7, 14, and adult. GAD65 and GAD67 mRNAs were detected at E11 and increased exponentially over three orders of magnitude during embryonic development, then declined approximately threefold in the first-2 postnatal weeks. While the exponential growth phase coincided with the progressive appearance of GAD67 in situ signals in both the ventral and dorsal cord, the postnatal decline coincided with the virtual disappearance of expression in the ventral region. EP10 expression was prominent in the embryo, then declined markedly together with the mRNA encoding the neuroepithelial stem cell marker, nestin. The concerted appearance of GAD-related mRNAs paralleled transcripts encoding neuronal markers (light and heavy neurofilaments) and also closely correlated with the expression of GABA, mRNAs encoding GABAA receptor subunits, and depolarizing responses to GABA. We have used the results on GAD-related mRNA expressions to formulate a simple, minimal mathematical model that accounts for their kinetics in terms of positive and negative feedback loops.

[Combined operation for the foreign body in the eye complicated with traumatic cataract: an analysis of 88 cases]

The foreign body in the eye complicated with traumatic cataract is one of the common causes of blindness. The rate of blindness ranges from 20% to 48.9%. This paper analyses combined operation for 88 cases of foreign body in the eye with traumatic cataract. The visual acuity below 0.05 accounted for 85.2% of the cases before operation and reduced to 27.3% after operation. Postoperatively, the corrected visual acuities were from 0.06 to 1.5 in 73.3% of the cases and 0.6 to 1.5 in 22.7% respectively. The patients should be treated with combined operation earlier. The way of operation depends on the property and the location of foreign body and the situation of lens. Chinese-Western medicine treatment should be used postoperatively to control the tissue response. Combined operation can improve the effect, reduce the complication, the number of operation and decrease medical expenses.

Effect of son preference and population policy on sex ratios at birth in two provinces of China

Two samples of births were used to examine the effect of son preference and population policy on sex ratios in Hebei and Shaanxi provinces of China. The results from all births to women aged 15-49 in the 1985 In-Depth Fertility Survey indicated a strong son preference but no clear policy impact on sex ratios at different birth orders. In a sample of selected births during 1975-84 to women aged 40 or under, the mixed influences of son preference and population policy were clearly reflected in the high and rising overall ratios at birth, and the increasing sex ratios with parity. Possible explanations for these findings are discussed.

[Vitrectomy combined with intravitreal injection of drugs for the management of advanced suppurative endophthalmitis]

Sixty cases (60 eyes) of advanced suppurative endophthalmitis treated by a combination of vitrectomy and intravitreal injection of drugs (antibiotics or/and corticosteroids) were investigated perspectively. Of the 60 cases, 43 were infected after trauma, 12 were infected after surgical procedures, while the others were of unknown causes. During the follow-up period of 1/2-5 years, 57 cases (95%) retained functioning eyes, the postoperative visual acuity of 34 eyes (57%) being 0.05 or better and the postoperative visual acuity of 17 eyes (28%) 0.4 to 1.0. The advantages of the therapeutic regimen are analyzed. We believe that it is the most effective therapy for suppurative endophthalmitis. The timing of the operation and the factors influencing the results are discussed. This report also presents our clinical experiences in the management of advanced suppurative endophthalmitis.

Regulation of fat body mitochondrial respiration in Periplaneta americana by a novel factor from the corpus cardiacum

Respiration of fat body (Periplaneta americana) mitochondria is increased by pretreatment of the tissue with corpus cardiacum (CC) extract. The magnitude of the increase depends on the type of substrate supplied for oxidation. With 5 mM pyruvate the respiration increased 22%, decreasing to 0 with 1 mM pyruvate. In contrast, 50 microM and 0.2 mM palmitic acid supported an increase in CC-stimulated respiration of 14 and 44%, respectively. Unlike crude CC extract, the synthetic hyperglycemic peptides CCI and CCII failed to alter the respiratory activity of fat body mitochondria. In common with the action of CC extract pretreatment of the fat body in vitro with 10(-5) M cyclic AMP, 10(-5) M 8-bromo-cyclic AMP, or 10(-5) M forskolin increased mitochondrial respiration approximately 30%. Octopamine (10(-4) M) elicited a response similar to that obtained with CC extract. Neither 10(-5) M cyclic AMP nor 10(-5) M 8-bromo-cyclic AMP stimulated respiration when applied directly to the mitochondria. These results suggest that the factor in CC extract manifests its effect intracellularly through the activation of a cyclic AMP-dependent protein kinase. This interpretation is also based on the finding that diamide, an inhibitor of protein kinase, inhibits CC-dependent and cyclic AMP-dependent mitochondrial respiration. The physiological role of the CC factor responsible is not known.

[Steroid alkaloids from stems and leaves of Fritillaria ussuriensis Maxim]

Three crystalline chemical components were isolated from the stems and leaves of Fritillaria ussuriensis by column chromatographic technique. On the basis of the IR, MS and 1HNMR spectra, the structure has been identified as pingbeimine B, pingbeimine C and pingbeininoside.

[Bacteriologic studies of the occurrence of Chlamydia psittaci in organs of swine and in aborted swine fetuses]

By inoculation of embryonating chicken eggs via the yolk sac route Chlamydia psittaci was grown from 11 lungs of 45 pigs with pneumonia (24.4%). From the lungs of 55 pigs with other diseases the organism was isolated in five cases (9.1%). Chlamydiae were not detectable by cultural methods in the uterine mucosa of 87 sows, arthritic joints of 30 store pigs and in aborted fetuses. A commercial available enzyme amplified immunoassay indicated the presence of chlamydial antigen in mucosal scrapings from the uterus of two sows and in the fetal membranes as well as fetal organs in one case of porcine abortion.

[Management of foreign bodies in transparent lens and a long-term follow-up--the analysis of 25 cases]

25 cases of foreign bodies in transparent lens are reported in this paper. The foreign bodies retained in transparent lens are rare intraocular foreign bodies. In all cases, the foreign bodies were magnetic and the injured lens had local opacity. In 20 cases of them, the foreign bodies were removed by different magnets according to the different sites of the foreign bodies retained in transparent lens. In most cases the effect was sufficient. The patients were followed-up postoperatively during different period. The visual acuity was quite good. Effect of the foreign bodies on the transparent lens, and the management of the foreign bodies in transparent lens and the operative methods for removal of the foreign bodies in the transparent lens are discussed.