Local structure evolution of FexNi77-xCu(1-)Nb2P14B6 soft magnetic materials by mechanical alloying

Mechanically alloyed Fe(x)Ni77-xCu1Nb2P14B6 soft magnetic materials have been prepared with different atomic compositions. The alloy structures are investigated by X-ray absorption fine structure (XAFS). The results show that mechanical alloying (MA) can drive the Fe(x)Ni77-xCu1Nb2P14B6 powder mixture to produce amorphous alloy while the atomic concentration of Fe element is about and over 40%. On the contrary, the MA Fe(x)Ni77 xCu1Nb2P14B6 is a solid solution with a fcc-like structure in the region of lower Fe atomic concentration (<22%), preserving a medium-range order around Ni and Fe atoms. Moreover, we have found that the local structure geometry of Fe atom is similar to that of Ni atom for all the MA Fe(x)Ni77-xCu1NbP14B6 samples. It indicates that the local structures of Fe and Ni atoms in a Fe(x)Ni77-xCu1Nb2P14B6 sample only depend on the x value of element Ni after ball milling.

Annealed crystallization of ultrafine amorphous NiB alloy studied by XAFS

XAFS has been used to investigate the local structure evolutions of ultrafine amorphous NiB alloy during the annealed crystallization process. A nanocrystalline Ni phase with the local structure of crystalline Ni-like and a crystalline Ni3B, have been produced for ultrafine amorphous NiB alloy under the annealed temperature of 573 K. The results rule out Rojo et al.'s devitrification mechanism of Ni80B20 amorphous alloy in which they considered that an amorphous pure Ni phase is formed in the first exothermic process. However, our results are almost identical with Riveiro et al.'s conclusion in which the intermediate state is interpreted as two metastable crystalline phases of Ni3B and Ni-rich NiB alloy. With the annealed temperature going onto 773 K, the ultrafine NiB sample is further decomposed and crystallized into crystalline Ni with long-range order.

Urinary benzene as a biomarker of exposure among occupationally exposed and unexposed subjects

Urinary benzene (UB) was investigated as a biomarker of exposure among benzene-exposed workers and unexposed subjects in Shanghai, China. Measurements were performed via headspace solid phase microextraction of 0.5 ml of urine specimens followed by gas chromatography-mass spectrometry. This assay is simple and more sensitive than other methods (detection limit 0.016 microg benzene/l urine). The median daily benzene exposure was 31 p.p.m. (range 1.65-329 p.p.m.). When subjects were divided into controls (n = 41), those exposed to < or =31 p.p.m. benzene (n = 22) and >31 p.p.m. benzene (n = 20), the median UB levels were 0.069, 4.95 and 46.1 microg/l, respectively (Spearman r = 0.879, P < 0.0001). A linear relationship was observed between the logarithm of UB and the logarithm of benzene exposure in exposed subjects according to the following equation: ln(UB, microg/l) = 0.196 + 0.709 ln (exposure, p.p.m.) (r = 0.717, P < 0.0001). Considering all subjects, linear relationships were also observed between the logarithm of UB and the corresponding logarithms of four urinary metabolites of benzene, namely t,t-muconic acid (r = 0.938, P < 0.0001), phenol (r = 0.826, P < 0.0001), catechol (r = 0.812, P < 0.0001) and hydroquinone (r = 0.898, P: < 0.0001). Ratios of individual metabolite levels to total metabolites versus UB provide evidence of competitive inhibition of CYP450 enzymes leading to increased production of phenol and catechol at the expense of hydroquinone and muconic acid. Among control subjects UB was readily detected with a mean level of 0.145 microg/l (range 0.027-2.06 microg/l), compared with 5.63 microg/l (range 0.837-26.38 microg/l) in workers exposed to benzene below 10 p.p.m. (P < 0.0001). This suggests that UB is a good biomarker for exposure to low levels of benzene.

Clinical application of botulinum toxin in otolaryngology, head and neck practice (brief review)

Botulinum toxin (Botox) is useful in controlling the symptoms of patients with movement disorders. Application of Botox serves to (1) inhibit hypertonicity, (2) enhance the action of the antagonistic muscles, and (3) avoid an impingement in order to reestablish "the balance of forces". In accordance with the principles mentioned above, Botox can be used to treat dystonias of the larynx (adductor laryngeal spasmodic dysphonia, abductor laryngeal spasmodic dysphonia), laryngeal granulomas, laryngeal joint dislocation, cricopharyngeal spasm, and posterior glottic synechiae. In addition, extra-laryngeal disorders such as blepharospasm, hemifacial spasm, oromandibular dystonia, and spasmodic torticollis respond well to Botox. The effects of Botox are reversible and have specific localized activity. Hence, Botox has served as a powerful diagnostic method in exploring the underlying mechanism of various types of dystonias and provides some therapeutic benefits before pursuing surgical options. Here we review the literature and describe our experiences with Botox, including such topics as preparing and storing Botox, identifying the target muscles under EMG-guidance, choosing an appropriate dose, and outlining the applications of Botox in Otolaryngology, Head and Neck Surgery practice.

Osteogenic protein-1 (bone morphogenetic protein-7) in the treatment of tibial nonunions

BACKGROUND

The role of bone morphogenetic proteins (BMPs) in osseous repair has been demonstrated in numerous animal models. Recombinant human osteogenic protein-1 (rhOP-1 or BMP-7) has now been produced and was evaluated in a clinical trial conducted under a Food and Drug Administration approved Investigational Device Exemption to establish both the safety and efficacy of this BMP in the treatment of tibial nonunions. The study also compared the clinical and radiographic results with this osteogenic molecule and those achieved with fresh autogenous bone.

MATERIALS AND METHODS

One hundred and twenty-two patients (with 124 tibial nonunions) were enrolled in a controlled, prospective, randomized, partially blinded, multi-center clinical trial between February, 1992, and August, 1996, and were followed at frequent intervals over 24 months. Each patient was treated by insertion of an intramedullary rod, accompanied by rhOP-1 in a type I collagen carrier or by fresh bone autograft. Assessment criteria included the severity of pain at the fracture site, the ability to walk with full weight-bearing, the need for surgical re-treatment of the nonunion during the course of this study, plain radiographic evaluation of healing, and physician satisfaction with the clinical course. In addition, adverse events were recorded, and sera were screened for antibodies to OP-1 and type-I collagen at each outpatient visit.

RESULTS

At 9 months following the operative procedures (the primary end-point of this study), 81% of the OP-1-treated nonunions (n = 63) and 85% of those receiving autogenous bone (n = 61) were judged by clinical criteria to have been treated successfully (p = 0.524). By radiographic criteria, at this same time point, 75% of those in the OP-1-treated group and 84% of the autograft-treated patients had healed fractures (p = 0.218). These clinical results continued at similar levels of success throughout 2 years of observation, and there was no statistically significant difference in outcome between the two groups of patients at this point (p = 0.939). All patients experienced adverse events. Forty-four percent of patients in each treatment group had serious events, none of which were related to their bone grafts. More than 20% of patients treated with autografts had chronic donor site pain following the procedure.

CONCLUSIONS

rhOP-1 (BMP-7), implanted with a type I collagen carrier, was a safe and effective treatment for tibial nonunions. This molecule provided clinical and radiographic results comparable with those achieved with bone autograft, without donor site morbidity.

[Posterior semicircular canal occlusion with microwave assisted technique in guinea pigs]

OBJECTIVE

To study the effectiveness of posterior semicircular canal occlusion with microwave assisted technique.

METHOD

Posterior semicircular canal occlusion with microwave assisted technique was performed in 20 guinea pigs. Electronystagmography (ENG) and auditory brainstem response (ABR) were recorded preoperatively and postoperatively. Morphological changes were observed under light microscopy.

RESULT

Left and right nystagmus returned symmetrical on the 3rd postoperative day. Two ears showed normal symmetrical nystagmus to icc-water stimulation on preoperation and the 30th postoperative day. There were no significant changes of the thresholds of ABR before and after surgery. Histopathological findings revealed that posterior semicircular canal was completely occluded, and that Organ of Corti and crista ampullaris were normal.

CONCLUSION

Posterior semicircular occlusion with microwave technique is suggested as an effective and safe treatment for the benign paroxysmal positional vertigo.

Regeneration of articular cartilage chondral defects by osteogenic protein-1 (bone morphogenetic protein-7) in sheep

The efficacy of osteogenic protein-1 (OP-1; BMP-7) in regeneration of articular cartilage was examined by creating knee chondral defects in sheep. With a specially designed instrument in both knees, two 10 mm (diameter) chondral defects were created: one in the trochlea and the other on the femoral condyle. The recombinant BMP was delivered via an extra-articulary positioned mini-osmotic pump, which was fixed to the femoral diaphysis above the knee joint, and connected by a polyethylene tubing to the articular space. Prior to use, the compatibility of OP-1 with mini-osmotic pumps was tested in vitro by measuring aggregation/precipitation and modification of the released protein by size exclusion and reversed phase HPLC. The average amount of aggregation was 15% and about 5% of OP-1 was modified. However, the biological activity of OP-1 released from pumps over a period of 2 weeks at 37 degrees C was equal to ROS cell assay OP-1 standard. Following surgery, a total of 55 microg (low dose) or 170 microg (high dose) OP-1 in acetate buffer (pH 4.5) was slowly released from the pump over a period of 2 weeks. The pumps connected to control knees were filled with acetate buffer as a vehicle. Twelve animals were operated, six of which were treated with the low OP-1 dose, and six with the high OP-1 dose. Three sheep of each group were killed either at 3 or 6 months following surgery, based on arthroscopical evaluation. The chondral defects in the control knees remained empty during the observation period. At 3 months following surgery, defects treated with both OP-1 doses were filled with connective tissue and cartilage. At 6 months following surgery, both doses of OP-1 stimulated regeneration in treated knees. The boundaries between new and old cartilage were well fused and mechanically resisted animals' weight bearing. The regenerated cartilage was rich in proteoglycans and type II collagen, as demonstrated by toluidine blue staining and immunohistochemistry. No signs of endochondral bone formation above the bony tidemark were observed. We suggest that a recombinant bone morphogenctic protein stimulates ingrowth of mesenchymal cells into the chondral defects which then transform into newly formed articular cartilage-like tissue.

Calorigenic actions of leptin are additive to, but not dependent on, those of thyroid hormones

We examined a possible mechanistic interaction between leptin and thyroid hormones in rats with hypothyroidism induced by thyroidectomy (TX) and propylthiouracil administration. In study 1, the TX rats were treated by vehicle (V, n = 9) or by recombinant murine leptin (L, 0.3 mg. kg(-1). day(-1), n = 9) or were pair-fed (PF, n = 9) against L. In study 2, the TX rats were all given 3, 3'5'-triiodo-L-thyronine (T(3)) replacement (T, 5 microg. kg(-1). day(-1)) to correct hypothyroidism. They were then subdivided into three groups, namely, vehicle (T+V, n = 9), leptin (T+L, n = 10), and pair-feeding (T+PF, n = 9), similar to study 1 except for T(3) (T). Reduced food consumption and weight gain in the TX rats were reversed by T(3) replacement. Leptin suppressed food intake in the TX rats regardless of T(3) replacement. O(2) consumption (VO(2)) and CO(2) production (VCO(2)) were reduced in TX rats (P < 0.05 vs. normal) but were normalized by either T(3) or leptin treatment. T+L additively increased VO(2) and VCO(2) (P < 0.05 vs. TX, T(3), and L). The respiratory exchange ratio was unaltered in TX rats, with and without T(3), but was significantly reduced by L or T+L treatments. These results indicate that the metabolic actions of leptin are not dependent on a normal thyroid status and that the effects of leptin and T(3) on oxidative metabolism are additive.

Benzene and lymphohematopoietic malignancies in China

While this study is larger than previous investigations and includes workers with a wide range of exposures to benzene, the estimates of risk, as measured by statistical confidence intervals, are still fairly broad, and would benefit from the larger numbers that could be provided by continued follow-up of this population. Nevertheless, the study confirms earlier findings of increased risk for ANLL and aplastic anemia among benzene-exposed workers, provides the first substantial evidence that MDS is linked to benzene exposure, and provides evidence that benzene increases risk for ANLL/MDS at lower levels of exposure than had previously been demonstrated. Currently we are evaluating the potential for extending the follow-up of workers included in this study. A new study would include expanded data collection for cases of hematopoietic malignancy and related disorders and for an appropriate control series.

Performance of a 2D image-based anthropometric measurement and clothing sizing system

Two-dimensional, image-based anthropometric measurement systems offer an interesting alternative to traditional and three-dimensional methods in applications such as clothing sizing. These automated systems are attractive because of their low cost and the speed with which they can measure size and determine the best-fitting garment. Although these systems have appeal in this type of application, not much is known about the accuracy and precision of the measurements they take. In this paper, the performance of one such system was assessed. The accuracy of the system was analyzed using a database of 349 subjects (male and female) who were also measured with traditional anthropometric tools and techniques, and the precision was estimated through repeated measurements of both a plastic mannequin and a human subject. The results of the system were compared with those of trained anthropometrists, and put in perspective relative to clothing sizing requirements and short-term body changes. It was concluded that image-based systems are capable of providing anthropometric measurements that are quite comparable to traditional measurement methods (performed by skilled measurers), both in terms of accuracy and repeatability.

[Establishment of the animal model of triple semicircular canal occlusion]

OBJECTIVE

To establish the animal model of triple semicircular canal occlusion(TCO) in guinea pigs.

METHODS

TCO was performed on 20 guinea pigs. Electronystagmography, auditory brainstem responses (ABR) and distortion product otoacoustic emissions(DPOAE) were recorded pre- and post-operatively. The non-operated ear was used as control.

RESULTS

There was spontaneous nystagmus towards non-operated side on the 1st postoperative day and no nystagmus to stimuli of sinusoidal angular acceleration in operated side. On the 30th postoperative day, left and right nystagmus returned symmetrical. Pre-operation, ice-water stimulation induced normal symmetric nystagmus in both sides. On the 30th postoperative day, ice-water stimulation only induced normal nystagmus in non-operated ear and failed in operated one. ABR thresholds increased approximately 10 dB post-operation. There were no significant changes of the amplitudes of DPOAE before and after surgery. Histologic examination revealed complete occlusion in the three semicircular canals with newly formed bone and connective tissue.

CONCLUSION

This study showed that the animal model of TCO was successfully established. These findings suggests that TCO might be a safe and simple procedure for the treatment of intractable peripheral vertigo.

Transcriptional regulation of human 11beta-hydroxylase (hCYP11B1)

Steroid 11beta-hydroxylase is a mitochondrial enzyme that catalyzes the conversion of deoxycortisol to cortisol. The gene encoding human 11beta-hydroxylase (hCYP11B1) is expressed in the adrenal cortex under the control of circulating levels of ACTH. The current study was undertaken to define the cis-regulatory elements and transacting factors that regulate hCYP11B1 transcription. The hCYP11B1 5'-flanking DNA was studied using transient transfection of luciferase reporter constructs in NCI-H295R human adrenocortical cells. A cAMP analogue ((Bu)2cAMP) increased expression of a construct containing -1102 bp of hCYP11B1 5'-flanking DNA (pB1-1102). An element at position -71/-64 (TGACGTGA, previously termed Ad1) resembling a consensus cAMP response element (CRE) was required for maximal induction by cAMP. The Ad1 element bound several transcriptional factors in electrophoretic mobility shift assays, including CRE-binding protein, activating transcription factor-1 (ATF-1), and ATF-2, but only the ATF-2 complex migrated similarly to a complex seen using H295R nuclear extract. In addition, Western analysis of H295R and adrenal lysates demonstrated expression of high levels of ATF-2 and ATF-1. CRE-binding protein levels varied among the strains of H295R cells tested. Transcription of CYP11B1 also appeared to be regulated by steroidogenic factor-1 (SF-1). Luciferase reporter gene activity was increased after cotransfection with expression vectors containing SF-1. An element in hCYP11B1 at positions 242/-234 (CCAAGGCTC), previously termed Ad4, was required for maximal induction by SF-1 and was found to bind SF-1 in electrophoretic mobility shift assays. The key role for SF-1 in hCYP11B1 transcription is in contrast to its lack of an effect on expression of the hCYP11B2 (aldosterone synthase) isozyme. The differential effects of SF-1 on transcription of hCYP11B1 and hCYP11B2 may be one of the mechanisms controlling differential expression of these isozymes within the zonae fasciculata and glomerulosa of the human adrenal cortex.

Minor groove interactions at the DNA polymerase beta active site modulate single-base deletion error rates

The structures of open and closed conformations of DNA polymerase beta (pol beta) suggests that the rate of single-nucleotide deletions during synthesis may be modulated by interactions in the DNA minor groove that align the templating base with the incoming dNTP. To test this hypothesis, we measured the single-base deletion error rates of wild-type pol beta and lysine and alanine mutants of Arg(283), whose side chain interacts with the minor groove edge of the templating nucleotide at the active site. The error rates of both mutant enzymes are increased >100-fold relative to wild-type pol beta. Template engineering experiments performed to distinguish among three possible models for deletion formation suggest that most deletions in repetitive sequences by pol beta initiate by strand slippage. However, pol beta also generates deletions by a different mechanism that is strongly enhanced by the substitutions at Arg(283). Analysis of error specificity suggests that this mechanism involves nucleotide misinsertion followed by primer relocation, creating a misaligned intermediate. The structure of pol beta bound to non-gapped DNA also indicates that the templating nucleotide and its downstream neighbor are out of register in the open conformation and this could facilitate misalignment (dNTP or primer terminus) with the next template base.

[Application of polyester fiber heart patches to secondary intraorbital implantation of hydroxyapatite spheres]

OBJECTIVE

To observe the effect of intraorbital implantation of hydroxyapatite spheres wrapped with polyester fiber heart patches.

METHOD

According to the rectus contraction points four rectus were found and the rectus valves were created in anophthalmos. Then the hydroxyapatite sphere wrapped by the polyester fiber heart patch was inserted in the orbit.

RESULT

There were 13 cases in this group. Of them 11 patients showed very good operative results, Local poor healing of bulbar conjunctiva and fascia occurred in 2 patients. The wound in one patient healed very well after a simple repairing operation and in the other the wound healed spontaneously without any special treatments.

CONCLUSION

The effect of secondary intraorbital implantation of hydroxyapatite spheres wrapped by polyester fiber heart patches is positive. The polyester fiber heart patch is safe, reliable, cheap, very convenient in use and easy to obtain. It is a better substitute for sclera which is used to wrap the HA sphere.

Critical evaluation of neurolaryngological disorders

Otolaryngological examinations, videostroboscopic image analysis, and laryngeal electromyography were used as a test battery for a critical evaluation in 80 patients. Vocal fold movements were categorized into mobility, restricted mobility, immobility with different positions, and overactive movement. Laryngeal electromyographic examinations were conducted in all patients, and the results were classified into normal, neuropathic, and myopathic patterns. The electromyographic data were integrated with videostroboscopic findings, interpreted with knowledge of biomechanical and electrophysiological mechanisms of the larynx, and correlated clinically with underlying diseases. It is suggested that neurolaryngological procedures are most clinically useful when dictated by a decision-making algorithm.

[Influence of pravastatin on expression of platelet CD(62P) and CD(41) in patients with hypercholesterolemia in vitro and in vivo]

OBJECTIVE

To study in vitro and in vivo effect of hypercholesterolemia (HC) on expression of platelet CD(62P) and CD(41) and their changes after treatment with pravastatin.

METHODS

Twenty patients with HC were given 10 - 20 mg/d pravastatin orally for 4 - 8 weeks. Changes of blood cholesterol and expression of platelet CD(62P) and CD(41) were detected by flow cytometry.

RESULTS

After 4 and 8 weeks' treatment, blood cholesterol level and platelet aggregation function decreased. The expression of CD(62P) average fluorescence intensity decreased from 31.8 +/- 7.8 to 27.2 +/- 6.9 and 26.8 +/- 4.9; CD(62P) (%) from (31.3 +/- 9.3)% to (26.4 +/- 7.4)% and (25.3 +/- 9.1)% (P < 0.05); CD(41) from 483.2 +/- 263.9 to 348.1 +/- 192.4 and 306.8 +/- 128.0 (P < 0.05), respectively. Similar results were obtained in vitro study.

CONCLUSION

Improvement of platelet function and expressions of CD(62P) and CD(41) in HC patients after prevastatin treatment may be resulted from enhancing arteriosclerosis regression. It suggested from the in vitro result that pravastatin might play a direct effect on platelet function.

Apoptosis induced by the nuclear death domain protein p84N5 is associated with caspase-6 and NF-kappa B activation

Although the mechanisms involved in responses to extracellular or mitochondrial apoptotic signals have received considerable attention, the mechanisms utilized within the nucleus to transduce apoptotic signals are not well understood. We have characterized apoptosis induced by the nuclear death domain-containing protein p84N5. Adenovirus-mediated N5 gene transfer or transfection of p84N5 expression vectors induces apoptosis in tumor cell lines with nearly 100% efficiency as indicated by cellular morphology, DNA fragmentation, and annexin V staining. Using peptide substrates and Western blotting, we have determined that N5-induced apoptosis is initially accompanied by activation of caspase-6. Activation of caspases-3 and -9 does not peak until 3 days after the peak of caspase-6 activity. Expression of p84N5 also leads to activation of NF-kappaB as indicated by nuclear translocation of p65RelA and transcriptional activation of a NF-kappaB-dependent reporter promoter. Changes in the relative expression level of Bcl-2 family proteins, including Bak and Bcl-Xs, are also observed during p84N5-induced apoptosis. Finally, we demonstrate that p84N5-induced apoptosis does not require p53 and is not inhibited by p53 coexpression. We propose that p84N5 is involved in an apoptotic pathway distinct from those triggered by death domain-containing receptors or by p53.

Adenovirus-mediated N5 gene transfer inhibits tumor cell proliferation by induction of apoptosis

Gene therapy designed to initiate apoptotic cell death provides a potentially effective method to treat cancer. A prerequisite for this approach is the identification of genes that function in distinct apoptotic pathways. Although apoptotic pathways initiated by receptors such as tumor necrosis factor receptor-1 are well characterized, little is known about apoptotic pathways initiated within the nucleus in response to genotoxic stress. We have demonstrated previously that the nuclear, death domain-containing protein p84N5 can induce apoptosis upon transfection into cells, suggesting that it may play a role in an apoptotic pathway initiated within the nucleus. To test the possibility that N5 could be used in the gene therapy of cancer, we have generated a recombinant adenovirus engineered to express N5 and tested the effects of viral infection on the growth and tumorigenicity of tumor cells. N5 adenovirus infection significantly reduced the proliferation and tumorigenicity of breast, ovarian, and osteosarcoma tumor cell lines. Reduced proliferation and tumorigenicity were mediated by an induction of apoptosis as indicated by DNA fragmentation in infected cells. The results suggest that the N5 cDNA is a candidate for the gene therapy of cancer.

[Effects of the expression of mouse metallothionein-I gene in human HeLa cell line on drug resistance]

Metallothionein-I (MT-I) gene was inserted into EcoRI site by using pSV2-neo plasmid vector. Recombiant plasmid was transfected into HeLa cells by DNA-calcium phosphate precipitation technique. MT-I expression colones were growing in medium including G418. The amount of MT-I expression in transfected cells was found 2.6 times higher than that of non-transfected ones. In order to observe the relationship between the expression of MT-I gene in cells and drug resistance, cells were treated with different concentrations of cisplatin and adriamycin respectively. The results indicated that cisplatin (0.1 mumol/ml) inhibited the growth of both transfected and non-transfected cells. The inhibitory rates were 34% and 82% respectively(P < 0.05). IC50(50% inhibitory concentration for cell growing) was 0.144 mumol/ml and 0.061 mumol/ml and the ratio of them was 2.36: 1 after the treatment of cisplatin 72 h later. The cells were treated with adriamycin 72 h later, the inhibitory rates of transfected and non-transfected cells were 18% and 25% separately. The rates showed no significant difference (P > 0.05). The results indicated that MT was related to drug resistance of tumor cells.

Laryngeal reflexomyographic responses in rabbits: a neurolaryngological study of glottal movement

The role of the laryngeal reflex in glottal movement has been reported, but its mechanism remains unclear. To further investigate the neurophysiological characteristics of glottal movement, we recorded the laryngeal reflexomyographic responses (LRMRs) to electrical stimulation of the superior laryngeal nerve (SLN) in rabbits. The procedure involved simultaneous recording of the LRMRs from the thyroarytenoid muscles by means of bipolar hooked wire electrodes after electrical stimulation to the SLN. The results demonstrated characteristic patterns of the responses, consisting of R1 and R2, similar to those found in humans. The R1 response was obtained with a latency of 10.7 +/- 0.78 ms. The ipsilateral R2 response was obtained with a latency of 43.76 +/- 4.67 ms in all rabbits, and the contralateral R2 response with a latency from 42.6 to 50.2 ms in 4 rabbits. It was concluded that LRMRs may serve as a potential central laryngeal function test in the investigation of glottal movement control.

Validation of biomarkers in humans exposed to benzene: urine metabolites

BACKGROUND

The present study was conducted among Chinese workers employed in glue- and shoe-making factories who had an average daily personal benzene exposure of 31+/-26 ppm (mean+/-SD). The metabolites monitored were S-phenylmercapturic acid (S-PMA), trans, trans-muconic acid (t,t-MA), hydroquinone (HQ), catechol (CAT), 1,2, 4-trihydroxybenzene (benzene triol, BT), and phenol.

METHODS

S-PMA, t,t-MA, HQ, CAT, and BT were quantified by HPLC-tandem mass spectrometry. Phenol was measured by GC-MS.

RESULTS

Levels of benzene metabolites (except BT) measured in urine samples collected from exposed workers at the end of workshift were significantly higher than those measured in unexposed subjects (P < 0.0001). The large increases in urinary metabolites from before to after work strongly correlated with benzene exposure. Concentrations of these metabolites in urine samples collected from exposed workers before work were also significantly higher than those from unexposed subjects. The half-lives of S-PMA, t,t-MA, HQ, CAT, and phenol were estimated from a time course study to be 12.8, 13.7, 12.7, 15.0, and 16.3 h, respectively.

CONCLUSIONS

All metabolites, except BT, are good markers for benzene exposure at the observed levels; however, due to their high background, HQ, CAT, and phenol may not distinguish unexposed subjects from workers exposed to benzene at low ambient levels. S-PMA and t,t-MA are the most sensitive markers for low level benzene exposure.

[Study on the absorption of environmental contaminants in low-level exposure by pharmacokinetic analysis]

A dynamic generating toxic gas system and a nose-only exposure system were used for the pharmacokinetic study of inhaled environmental contaminants for benzene, toluene, xylene, ethylbenzene, chlorobenzene, styrene, isopropyl benzene, tetrachloroethylene, nonane and methylcyclohexane in male guinea pig. The change of these substances in blood with time was determined simultaneously by solid phase micro-extraction(SPME) gas chromatography (GC). The results showed that the fraction of absorption of benzene at low (121 micrograms/m3) exposure was 4.8 times higher than that at high(12.1 mg/m3) exposure. The pharmacokinetics of these substances were evaluated by using linear compartment models. The data showed that more styrene was absorbed than tetrachloroethylene at low-exposure. The metabolic elimination of these compounds at various exposure concentrations was extrapolated by using estimated pharmacokinetic parameters. Moreover, not only should the differences in absorption quantities be considered in evaluation of potential risk assessment, the metabolic elimination rates should also be considered although the exposure concentrations in gas for all chemicals were equal. The data presented in this paper was fundamental data used for risk assessment.

Fiber bragg grating strain sensor demodulation with quadrature sampling of a mach-zehnder interferometer

A simple and highly sensitive phase-demodulation technique is proposed, and its use for a fiber Bragg grating strain sensor is experimentally demonstrated. Sampling a phase-modulated Mach-Zehnder output with controlled time delay produced two quadrature data streams that have relative quadrature phase difference (90 degrees ). The Bragg wavelength-dependent phase information is extracted by application of digital arctangent function and phase unwrapping to the quadrature signals. By use of this technique with a reference grating, strain sensing at as much as a 30-kHz sampling rate was obtained with strain resolution of 3.5 microstrains and 6 nanostrains/[square root]Hz in quasi-static and dynamic strain measurements, respectively.

[Effect of green and yellow vegetables on serum carotenoid in children]

OBJECTIVE

To assay the effect of green and yellow vegetables on serum carotenoid concentration and its relation to serum retinol level in children.

METHODS

A ten-week green and yellow vegetable intervention study was conducted in children aged 5.3 to 6.4 years of two classes in a kindergarten in Tai'an City of Shandong Province in early September 1996, one class of light-colored vegetable supplemented with daily 193 grams of light colored vegetables, such as cabbage, Chinese cabbage, potato, cucumber, cauliflower and turnip, and 56 grams of yellow-green vegetables, such as spinach, Chinese chive, carrots and red yams; and the other one of yellow-green vegetables with daily 238 grams of yellow-green vegetables and 34 grams of light colored vegetables, both without change in regular diet. Venous blood specimens were collected before and after the experiment from each of the subjects. Serum retinol and carotenoid were determined with high performance liquid chromatography.

RESULTS

Serum level of carotenoid, including all-trans-beta-carotene, cis-beta-carotene, cryptoxanthin and lutein were significantly higher after intervention in yellow-green vegetable group, as compared to their baseline levels. However, in the light-colored vegetable group, all those components, including all-trans-beta-carotene, 13-cis-beta-carotene and lutein, decreased significantly after intervention, as compared with those at their baseline levels. Serum carotene level correlated significantly with that of retinol, and their coefficient of correlation was greater in the winter than in the autumn.

CONCLUSION

Carotenoid nutrition status can be improved by supplementation of green and yellow vegetables.

Biological repair of thyroid cartilage defects by osteogenic protein-1 (bone morphogenetic protein-7) in dog

The efficacy of human recombinant osteogenic protein-1 (OP-1; bone morphogenetic protein-7) in regeneration of dog larynx was examined by treating thyroid cartilage defects (1.5 cm2) in dogs with thyroid allografts covered with host perichondrium or fascia. Prior to implantation allografts were frozen, thawed and demineralized. The treatment groups were as follows: I--Allograft control implant (n = 3); II--Implants coated with 500 micrograms OP-1 (n = 4); III--Implants coated with 100 micrograms OP-1 (n = 3); IV--Implants coated with 500 micrograms OP-1 and covered with neck fascia (n = 3); and V--Implants extracted with 1 M NaCl and guanidine hydrochloride, and coated with 500 micrograms OP-1 (n = 4). Dogs were sacrificed four months following surgery. Each larynx was removed, carefully dissected and a three-dimensional reconstruction of the defect area was performed on serial sections. The results revealed that the implants of control dogs remained intact with no apparent reduction in size and new tissue formation. OP-1 enriched thyroid allografts, dose dependently induced bone, cartilage and ligament-like structures comprising up to 80% of the total regenerated defect area. Boundaries of the defects healed by formation of new bone when bone resided within the old thyroid cartilage layers. Old cartilage not containing bone within its layers healed by complete integration with newly formed cartilage. Both new bone and cartilage were embedded into layers of new ligament-like tissue which expressed specific morphologic and molecular markers. The three newly formed tissues were tightly connected into a "bone-cartilage-ligament continuum" of tissues, suggesting that OP-1 served as a multiple tissue morphogen in this specific microenvironment.

Genotoxic markers among butadiene polymer workers in China

While 1,3-butadiene is carcinogenic in rodents, cancer causation in humans is less certain. We examined a spectrum of genotoxic outcomes in 41 butadiene polymer production workers and 38 non-exposed controls, in China, to explore the role of butadiene in human carcinogenesis. Because in vitro studies suggest that genetic polymorphisms in glutathione S-transferase enzymes influence genotoxic effects of butadiene, we also related genotoxicity to genetic polymorphisms in GSTT1 and GSTM1. Among butadiene-exposed workers, median air exposure was 2 p.p.m. (6 h time-weighted average), due largely to intermittent high level exposures. Compared with unexposed subjects, butadiene-exposed workers had greater levels of hemoglobin N-(2,3,4-trihydroxybutyl)valine (THBVal) adducts (P < 0.0001) and adduct levels tended to correlate, among butadiene-exposed workers, with air measures (P = 0.03). Butadiene-exposed workers did not differ, however, from unexposed workers with respect to frequency of uninduced or diepoxybutane-induced sister chromatid exchanges, aneuploidy as measured by fluorescence in situ hybridization of chromosomes 1, 7, 8 and 12, glycophorin A variants or lymphocyte hprt somatic mutation. Also among the exposed, greater THBVal levels were not associated with increases in uninduced sister chromatid exchanges, aneuploidy, glycophorin A or hprt mutations. Butadiene-exposed workers had greater lymphocyte (P = 0.002) and platelet counts (P = 0.07) and lymphocytes as a percentage of white blood cells were moderately correlated with greater THBVal levels (Spearman's phi = 0.32, P = 0.07). Among butadiene-exposed workers, neither GSTM1 nor GSTT1 genotype status predicted urinary mercapturic acid butanediol formation, THBVal adducts, uninduced sister chromatid exchanges, aneuploidy or mutations in the glycophorin A or hprt genes. Overall, the study demonstrated exposure to butadiene in these workers, by a variety of short-term and long-term measures, but did not show specific genotoxic effects, at the chromosomal or gene levels, related to that exposure.

Green and yellow vegetables can maintain body stores of vitamin A in Chinese children

BACKGROUND

Vitamin A activity of plant provitamin A carotenoids is uncertain.

OBJECTIVE

The objective was to determine whether plant carotenoids can sustain or improve vitamin A nutrition during the fall season in kindergarten children in the Shandong province of China.

DESIGN

The serum vitamin A concentration of 39% of the children was <1.05 micromol/L and of 61% of the children was > or = 1.05 micromol/L. For 5 d/wk for 10 wk, 22 children were provided approximately 238 g green-yellow vegetables/d and 34 g light-colored vegetables/d. Nineteen children maintained their customary dietary intake, which included 56 g green-yellow vegetables/d and 224 g light-colored vegetables/d. Octadeuterated and tetradeuterated vitamin A were given before and after the interventions, respectively, and their enrichments in the plasma were determined by gas chromatography-mass spectrometry. Serum retinol and carotenoid concentrations were measured by HPLC.

RESULTS

Carotenoid nutrition improved after consumption of green-yellow vegetables. Serum concentrations of retinol were sustained in the group fed green-yellow vegetables but decreased in the group fed light-colored vegetables (P < 0.01). The isotope-dilution tests confirmed that total-body vitamin A stores were sustained in the group fed green-yellow vegetables, but decreased 27 micromol (7700 microg retinol) per child, on average, in the group fed light-colored vegetables (P < 0.06).

CONCLUSION

Green-yellow vegetables can provide adequate vitamin A nutrition in the diet of kindergarten children and protect them from becoming vitamin A deficient during seasons when the provitamin A food source is limited.

[Transantral orbit decompression to malignant ophthalmopathy]

OBJECTIVE

To recognize the indication and the value of transantral orbit decompression to malignant ophthalmopathy.

METHOD

9 eyes of 5 cases undergone transantral orbital decompression from November 1986 to October 1998 were reviewed.

RESULT

After 3 months-2 years of follow-up. We found this approach successfully improved visual function of all 5 cases. Average proptosis reduction was 5 mm. The eye lids could be closed in 4 of the 5 cases and the palpebral fissures was decreased 1-2 mm in 1 of the 5 cases. Preoperative exposure keratitis resolved in both of the 2 cases. Diplopia was cured in both of the 2 cases. Secondary glucorna also recovered in both the 2 cases. Disturbance of ocular motility in both of the 2 cases improved postoperatively and preoperative visual acurity worsen also improved in both of the 2 cases.

CONCLUSION

It has been suggested that the transantral decompression of the orbit provided a safe, effective therapeutic modality for patients with vision-threatening or major cosmetic problem.

Apoptosis induced by the nuclear death domain protein p84N5 is inhibited by association with Rb protein

Rb protein inhibits both cell cycle progression and apoptosis. Interaction of specific cellular proteins, including E2F1, with Rb C-terminal domains mediates cell cycle regulation. In contrast, the nuclear N5 protein associates with an Rb N-terminal domain with unknown function. The N5 protein contains a region of sequence similarity to the death domain of proteins involved in apoptotic signaling. We demonstrate here that forced N5 expression potently induces apoptosis in several tumor cell lines. Mutation of conserved residues within the death domain homology compromise N5-induced apoptosis, suggesting that it is required for normal function. Endogenous N5 protein is specifically altered in apoptotic cells treated with ionizing radiation. Furthermore, dominant interfering death domain mutants compromise cellular responses to ionizing radiation. Finally, physical association with Rb protein inhibits N5-induced apoptosis. We propose that N5 protein plays a role in the regulation of apoptosis and that Rb directly coordinates cell proliferation and apoptosis by binding specific proteins involved in each process through distinct protein binding domains.

[Evaluation on the nutritional status of carotenoid in healthy elder people]

The possible relations between carotenoid status and their health indicators were investigated in an elderly group aged 60-75 years. Fasting serum samples were taken from 41 healthy subjects (20 men and 21 women). The concentrations of carotenoids and vitamin A of serum samples were assayed by HPLC. The results showed that vitamin A level of seven subjects was lower than 0.3 mg/L. Lutein and Zeaxanthin were the predominant carotenoids in serum. The concentration of total carotenoids had inverse correlations with blood glucose, serum cholesterol and triglyceride, and blood pressure. Carotenoids were inversely and significantly correlated with diastolic pressure and body mass index.

Critical evaluation of deafness

OBJECTIVE

The purpose of this study is to investigate the clinical aspects of profound hearing loss (PHL) and their significance for defining deafness.

METHODS

The audiological data were reviewed from 3660 patients who were evaluated in the Otolaryngology Clinic at Louisiana State University in Shreveport, LA, over a 5-year period. The medical charts from the patients were also reviewed for the information of medical diagnosis, surgical records and radiological findings.

RESULTS

There were 34 patients identified with bilateral PHL or deaf, 177 patients with unilateral PHL and 123 patients with borderline PHL. Congenital hearing loss and unknown-cause hearing loss in this series were predominant with 267 cases (79.9%). A surgical management was indicated in 39 cases (11.7%) including middle ear infection, ossicular chain abnormalities and auditory nerve/brainstem tumors.

CONCLUSION

This study suggests that audiometrically PHL should be thoroughly evaluated to detect reversible or remediable conditions by surgical and medical approaches. The diagnosis of deafness should be confirmed by an integration of the audiological data and medical documents including surgical and radiological findings. Aural rehabilitation program should be designed for deaf patients with varied etiology and degree of residual peripheral hearing sensitivity following medical clearance.

[Vegetables rich in carotenoids on the vitamin A status of children]

Vitamin A (VA) deficiency is still an important nutritional problem in our country. In order to determine whether plant carotenoids ingestion can improve VA nutrition, a study by using yellow and dark green vegetables was conducted in two classes of a kindergarten for ten weeks in September through December in 1996. The VA nutritional status was marginal to adequate among 41 children (5.3-6.6 year-old), and serum retinols in 39% of these children were below 0.30 mg/L. Each child in class A was provided with about 238 g/d of green and yellow vegetables (spinach, Chinese chive, carrots, and red yams) and 34 g/d of light colored vegetables (cabbage, Chinese cabbage, potato, cucumber, turnip and winter melon). Each child in class B consumed the usual diet with only 56 g/d of green and yellow vegetables and 193 g/d of light colored vegetables. Serum retinol concentration collected before and after the intervention were used to assess VA nutritional status. The results showed that vitamin A nutrition was improved by increasing the intake of green and yellow vegetables. Serum retinol was sustained in the group fed green and yellow vegetables and decreased in the group fed light colored vegetables. Thus, dietary green and yellow vegetables could provide adequate VA nutrition in these children.

[Long-term results of surgical treatment of intractable Menière's disease for control of vertigo]

OBJECTIVE

To acquire the long-term (an average of over 10 years follow-up) results of surgical treatment of patients with Meniere's disease for control of vertigo.

METHOD

Endolymphatic sac surgery was done in 6 cases (1 case of endolymphatic sac decompression and 5 cases of sac-mastoid shunting) and translabyrinth vestibular neurotomy was operated on 6 cases.

RESULT

Complete relief from symptoms of vertigo occurred in the 6 cases through vestibular neurotomy and there were no recurrence in 11-13 years follow-up. Three of 6 cases with endolymphatic sac surgery had complete control of vertigo and were cured clinically. Symptoms of vertigo of the rest 3 cases were effectively controlled.

CONCLUSION

Endolymphatic sac surgery and translabyrinth vestibular neurotomy are effective way for control of vertigo of patients with intractable Meniere's disease. Translabyrinth vestibular neurotomy are more effective for control of vertigo for appropriately selected patients.

Botulinum toxin: adjunctive treatment for posterior glottic synechiae

INTRODUCTION

Synechiae formation of the posterior glottis can result in tracheostomy dependence secondary to airway obstruction. Stenosis is caused by total or partial fixation of the vocal folds in adduction resulting from scar contracture. The treatment poses a management dilemma because of recurrent scar formation, made worse by mobility of the vocal folds. Although various treatment options from conservative endoscopic repair to open procedures have been proposed, the results are not satisfactory and patients often require multiple procedures.

METHODS

We present the trial of a conservative approach that includes microscopic CO2 laser resection of the scar with concomitant botulinum toxin injection of the interarytenoid and thyroarytenoid muscles of the more mobile cord. This results in a temporary paresis of the adductor muscles and hence prevents overadduction in the posterior commissure during the postoperative healing period.

STUDY DESIGN

We present the surgical technique and results in three patients who underwent the procedure.

RESULTS

Treatment in all three patients was successful.

CONCLUSIONS

The appropriate use of botulinum toxin may help improve the treatment outcome of posterior synechiae of the larynx without sacrificing any laryngeal components.

[Study on the risk factors influencing the epidemicity of epidemic cerebrospinal meningitis]

Based on a 8-year surveillance data, a factor analysis theory was used to analyze the 12 risk factors influencing the epidemicity of epidemic cerebrospinal meningitis. The results showed that the first sixth risk factors were the rate of carrying meningococci A and B in the population, relative air humidity in January, morbidity rate in January, vaccination rate before epidemic, and the titre of antibody. Although the incidences of epidemic cerebrospinal meningitis are scattered, the risk factors influencing the epidemicity did not disappear. It is important to use meningococci A vaccine continuously and widely to strengthen the surveillance among migrated population and population at high risk.

[Application of molecular epidemiology in the study of occupational chemical carcinogenesis]

This paper described the concept of moleculalr epidemiology, it's differences from traditional epidemiology and what the author learned from conducting molecular epidemiology recently. 1. Molecular epidemiology is the borderline subject in combination of molecular biology with epidemiology. 2. The level of chemical carcinogen formed in vivo and the amount of combination of chemical carcinogen either in the level from vivo or in biologic effective dose of combination of chemical carcinogen with macromolecular are all related to cancer development. 3. The syndrome of chromosome aberration is an early biologic effect in cancer process and oncogen activation or suppressing gene inactivation might be necessary for malignant transformation from initiated cell. 4. Individual susceptibility could be affected by host and acquired factors. 5. Biologic bank could provide continuous observation and comparision between before and after cancer formation.

Benzene increases aneuploidy in the lymphocytes of exposed workers: a comparison of data obtained by fluorescence in situ hybridization in interphase and metaphase cells

Benzene is an established human leukemogen that increases the level of chromosome aberrations in lymphocytes of exposed workers. Numerical aberrations (aneusomy) can be observed by fluorescence in situ hybridization (FISH) in both interphase and metaphase cells. Whereas interphase FISH allows nondividing cells to be analyzed, one advantage of metaphase FISH is that it can also detect structural changes. The present study compares the abilities of metaphase and interphase FISH to detect aneusomy of chromosomes 7 and 8 in healthy benzene-exposed human subjects. Metaphase and interphase cells from the peripheral blood of 43 workers exposed to benzene (median = 31 ppm, 8-hr TWA) and 44 frequency-matched controls were analyzed by FISH. Normal diploid cells contained two hybridization signals, whereas those that were potentially monosomic contained one, trisomic 3 and tetrasomic 4. The frequency of cells with one hybridization signal for chromosome 7 in metaphase spreads rose from 2.72 +/- 0.19 (%, mean +/- SE) in controls to 3.79 +/- 0.63 in workers exposed to 31 or fewer ppm benzene and 5.9 +/- 0.85 in those exposed to more than 31 ppm (P(trend) < 0.0001). No similar dose-dependent increase in the frequency of cells with one hybridization signal was observed by interphase FISH, probably because of probe overlap artifact. Although significant dose-dependent increases in the frequency of cells with three hybridization signals for chromosome 7 were detected by both methods in the higher-exposed group, a larger, more significant difference was detected by metaphase FISH between controls and workers exposed to 31 or fewer ppm. Similar data were obtained for chromosome 8. Interphase and metaphase FISH were moderately correlated for three hybridization signals but not for one hybridization signal in chromosome 7 or 8. In general, metaphase FISH was more sensitive in detecting both monosomy and trisomy in the lymphocytes of exposed workers.

The prolonged hematologic effects of a single injection of PEG-rHuMGDF in normal and thrombocytopenic mice

A single injection of > or =10 microg/kg PEG-rHuMGDF in mice causes a dose-dependent increase in circulating platelets beginning on day 3 and peaking on days 5-6. The mean platelet volume and platelet distribution width at doses > or =100 microg/kg initially increase in a dose-dependent fashion and later decrease. However, the mean platelet volume does not change when platelets are incubated with PEG-rHuMGDF in vitro. The number of marrow megakaryocytes increases in a dose-dependent fashion as early as day 1 and peaks on day 3. Marrow megakaryocyte colony-forming units (CFU-Meg) do not increase on days 1-3 at a dose of 100 microg/kg (a dose that increases platelet numbers two- to threefold and may be clinically relevant), but the relative frequency of high ploidy megakaryocytes and the proportion of large marrow megakaryocytes (29-50 microm in diameter) increases. After a dose of 1,000 microg/kg the percentage of megakaryocytes in mitosis peaks at 24-48 hours and the percentage of megakaryocytes incorporating BrdU is maximal at 48 hours, the relatively delayed peak of BrdU incorporation most likely representing endomitosis. The relative frequency of type II and III megakaryocytes peaks on days 3 and 4, respectively. Pharmacokinetic analysis of PEG-rHuMGDF shows peak serum concentrations at 2-4 hours and a terminal half-life of 11.4+/-2.5 hours. A single injection of PEG-rHuMGDF ameliorates carboplatin-induced megakaryocytopenia and thrombocytopenia in a dose-response dependent fashion. In conclusion, a single injection of PEG-rHuMGDF increases megakaryocyte and platelet production in normal and myelo-suppressed mice.

Design and fabrication of a 24-channel acousto-optic spatial light modulator

Acousto-optic (AO) devices are important spatial light modulators. They can be used as light-beam deflectors, rf true-time-delay lines, etc. To increase their spur-free dynamic range, we present what to our knowledge is a novel multichannel AO device structure, in which different channels have different carrier frequencies, so a wideband signal can automatically be decomposed into a set of narrow-band signals. Design, fabrication, and testing of this 24-channel, 10-mus AO spatial light modulator are addressed.

Increased aneusomy and long arm deletion of chromosomes 5 and 7 in the lymphocytes of Chinese workers exposed to benzene

Two of the most common cytogenetic changes in therapy- and chemical-related leukemia are the loss and long (q) arm deletion of chromosomes 5 and 7. The detection of these aberrations in lymphocytes of individuals exposed to potential leukemogens may serve as useful biomarkers of increased leukemia risk. We have used a novel fluorescence in situ hybridization (FISH) procedure to determine if specific aberrations in chromosomes 1, 5 and 7 occur at an elevated rate in the blood cells of workers exposed to benzene. Forty-three healthy workers exposed to a wide range of benzene concentrations (median 31 p.p.m., 8 h time-weighted average) and 44 unexposed controls from Shanghai were studied. Whole blood was cultured and metaphase spreads were harvested at 72 h. Benzene exposure was associated with increases in the rates of monosomy 5 and 7 but not monosomy 1 (P < 0.001, P < 0.0001 and P = 0.94, respectively) and with increases in trisomy and tetrasomy frequencies of all three chromosomes. Long arm deletion of chromosomes 5 and 7 was increased in a dose-dependent fashion (P = 0.014 and P < 0.0001) up to 3.5-fold in the exposed workers. These results demonstrate that leukemia-specific changes in chromosomes 5 and 7 can be detected by FISH in the peripheral blood of otherwise healthy benzene-exposed workers. We suggest that aberrations in chromosomes 5 and 7 may be useful biomarkers of early biological effect for benzene exposure.

Intravenous keratinocyte growth factor protects against experimental pulmonary injury

Keratinocyte growth factor (KGF) administered by intratracheal instillation is well documented to stimulate the proliferation of alveolar and bronchial cells. In the present study, intravenous KGF was also shown to stimulate the proliferation of alveolar and bronchial cells in mice and rats, although to a lesser degree than intratracheal KGF. Despite the decreased potency of intravenous KGF on pulmonary cell 5-bromo-2'-deoxyuridine incorporation compared with intratracheal KGF, intravenous KGF was very effective in preventing experimental bleomycin-induced pulmonary dysfunction, weight loss, and mortality in either mice or rats and experimental hyperoxia-induced mortality in mice. The effectiveness of intravenous administration of KGF in preventing lung injury suggests that the mechanisms of the protective effect of KGF may involve more than pulmonary cell proliferation and also suggests the potential use of systemic KGF for clinical trials in settings of pulmonary injury.

[Trans-ethmoidal optic nerve decompression in traumatic optic neuropathy]

To evaluate the outcome of trans-ethmoidal optic nerve decompression (TOND).

METHOD

Between November 1984 and May 1996, 35 patients with traumatic optic neuropathy (TON) underwent TOND. While 6 patients were treated with high dose corticosteroids (HDC).

RESULTS

13(37.14%) cases of 35 patients who underwent TOND showed improvement in vision. 1 (16.67%) of 6 patients who were treated with HDC showed improvement in vision. Of the 12 patients with some initial vision, 8 patients underwent TOND and 7(87.5%) patients showed improvement in vision. Another 4 patients treated with HDC, 1(25.0%) patient showed improvement in vision. Of the 29 patients who presented with no light perception, 27 patients underwent TOND and 6(22.22%) patients showed improvement in vision. 2 patients treated with HDC failed to get vision improvement.

CONCLUSION

TOND can improve vision in patients with TON. It is rational to perform surgical decompression early. Using of HDC before and after surgery may improve the outcome of TON. No light perception and absence of waveform on visual evoked response is not contradict, some patients may show improvement in vision.

Hemoglobin and albumin adducts of benzene oxide among workers exposed to high levels of benzene

Benzene oxide (BO) reacts with cysteinyl residues in hemoglobin (Hb) and albumin (Alb) to form protein adducts (BO-Hb and BO-Alb), which are presumed to be specific biomarkers of exposure to benzene. We analyzed BO-Hb in 43 exposed workers and 42 unexposed controls, and BO-Alb in a subsample consisting of 19 workers and 19 controls from Shanghai, China, as part of a larger cross-sectional study of benzene biomarkers. The adducts were analyzed by gas chromatography-mass spectrometry following reaction of the protein with trifluoroacetic anhydride and methanesulfonic acid. When subjects were divided into controls (n = 42) and workers exposed to < or =31 (n = 21) and >31 p.p.m. (n = 22) benzene, median BO-Hb levels were 32.0, 46.7 and 129 pmol/g globin, respectively (correlation with exposure: Spearman r = 0.67, P < 0.0001). To our knowledge, these results represent the first observation in humans that BO-Hb levels are significantly correlated with benzene exposure. Median BO-Alb levels in these 3 groups were 103 (n = 19), 351 (n = 7) and 2010 (n = 12) pmol/g Alb, respectively, also reflecting a significant correlation with exposure (Spearman r = 0.90, P < 0.0001). The blood dose of BO predicted from both Hb and Alb adducts was very similar. These results clearly affirm the use of both Hb and Alb adducts of BO as biomarkers of exposure to high levels of benzene. As part of our investigation of the background levels of BO-Hb and BO-Alb found in unexposed persons, we analyzed recombinant human Hb and Alb for BO adducts. Significant levels of both BO-Hb (19.7 pmol/g) and BO-Alb (41.9 pmol/g) were detected, suggesting that portions of the observed background adducts reflect an artifact of the assay, while other portions are indicative of either unknown exposures or endogenous production of adducts.

[Influence of pravastatin therapy on expression of P-selectin]

OBJECTIVE

To study the mechanism of pravastatin enhancing atherosclerosis regression.

METHODS

Patients with hypercholesterolemia were treated with pravastatin 10-20 mg/d for 4 and 8 weeks. The changes of blood cholesterol and platelet functions were examined.

RESULTS

After 4 weeks and 8 weeks treatment, the expression of platelet membrane P-selectin was decreased from 748 +/- 154 molecular number(MN)/platelet to 478 +/- 110 MN/platelet and 378 +/- 119 MN/platelet, respectively, plasma P-selectin was decreased from 24.3 +/- 9.9 micrograms/L to 16.8 +/- 4.5 and 16.1 +/- 4.0 micrograms/L, respectively, correlative with the lowering of blood cholesterol. Platelet P-selectin was positively correlated with plasma P-selectin(r = 0.8722).

CONCLUSION

The early benefit of pravastatin in enhancing atherosclerosis regression was partly due to the improvement of platelet function.

[Impulsive angular acceleration evoked middle and long latency potentials in guinea pigs]

Middle and long latency evoked potentials have been successfully recorded in guinea pigs with impulsive angular acceleration delivered by a specially developed motor. The middle latency responses elicited by impulsive angular acceleration had peaks at about 9 ms, 15 ms and 24 ms with a mean peak to peak amplitude of about 28muV and the long latency responses after the delivering of impulsive angular acceleration in guinea pigs composed of a triphasic wave with a mean peak to peak amplitude of about 50 muV occurring during 32 ms to 130 ms with respect to the start of head stimuli. A series of experiments lead to the conclusion that the middle latency responses to impulsive angular acceleration are middle latency vestibular evoked potentials. The long latency response elicited by impulsive angular acceleration is not a specific response of auditory or vestibular pathway.

[Study on expression of nm23-H1 protein/NDPK-A in laryngeal carcinoma]

To investigate the expression of nm23-H1 gene in laryngeal squamous cell carcinoma, immunohistochemistry was carried out with a monoclonal antibody against nm23-H1. Of 48 cancer tissues tested, 35(72.9%) showed a positive immuno-reaction for nm23-H1. The percentage of nm23-H1 positivity was significantly lower (P < 0.01) in the tumors with cervical lymph node metastasis than in those without metastasis. Moreover, the percentage of nm23-H1 positivity was significantly lower (P < 0.05) in tumors of stages III-IV than in those of stages I-II. No significant correlation was found between nm23-H1 expression and tumor sites or histopathological grades. Analyzed with following up date, we found that the overall survival was better (P < 0.01) in patients with nm23-H1 expression than in those without expression. These results suggest that nm23-H1 gene may play a role in the suppression of lymph node metastasis and tumor progression in laryngeal carcinoma, and the expression of nm23-H1 gene is a useful predictor of prognosis.