Perceptual changes in the anterior maxilla after placement of endosseous implants

BACKGROUND

The innervation of skin and oral mucosa plays a major physiologic role in exteroception. It is also of interest clinically, as illustrated by sensory changes after neurosurgical procedures.

PURPOSE

The goal of this study was to assess the perception of mechanical stimuli applied to the anterior maxilla in denture wearers and subjects rehabilitated with osseointegrated implants compared with that in subjects with a natural dentition.

MATERIALS AND METHODS

Five groups of subjects were selected and tested in the maxillary region only. Test groups included patients with a complete denture, an implant-supported fixed prosthesis (full or partial), or a single-tooth replacement. Light-touch sensation and two-point discrimination were performed on the buccal side of the alveolar mucosa and vibrotactile function was determined for natural teeth, full dentures, or implant-supported prostheses.

RESULTS

For light-touch sensation, no significant differences could be found between the groups. For two-point discrimination, full-denture patients showed higher threshold levels than the other groups. The threshold levels for vibrotactile function were higher in both full dentures and implant-supported prostheses compared with natural dentitions.

CONCLUSION

Natural dentitions offer superior vibrotactile function compared to any other dental status. Full dentures often show a stronger deterioration of the (vibro)tactile function compared with implant-supported prostheses.

The preventive effects of G115 on balloon injury-induced neointima formation in rats

After percutaneous transluminal coronary angioplasty (PTCA), 30-50% of the patients may present with restenosis within 6 months. The aim of this study was to search for a preventive remedy against the balloon injury-induced neointima formation. Ginseng, with its wide indications on immune and cardiovascular functions, has prompted us to explore its role in neointima formation. In the present study, we aimed to explore if a standardized Panax Ginseng extract G115 was able to inhibit neointimal formation. With BrdU luminencence assay, maximal proliferation of rat smooth muscle cells was reduced to 24% of control values by G115. Norepinephrine-induced vasocontraction was antagonized in 21% and 44% by 1.44mg/ml and 2.88mg/ml of G115, respectively. Neointima-to-lumen area ratio of balloon-injured rat carotid arteries was reduced 77.3% by G115 as compared to the sham control. These results demonstrate the preventive effects of ginsenosides on angioplasty-mediated neointima formation.

Association of globular beta-actin with intracellular lipid droplets in rat adrenocortical cells and adipocytes

Proteins located on the surface of lipid droplets may mediate intracellular lipid metabolism. In the present study, immunofluorescent staining and polyacrylamide gel electrophoresis demonstrated that actin (43 kD) is associated with isolated intracellular lipid droplets of rat adrenocortical cells and adipocytes. Two-dimensional gel electrophoresis and immunoblot analysis further confirmed that the lipid droplet-associated actin is the beta isoform. In cultured adrenocortical cells, stress fibers and the surface of intracellular lipid droplets were labeled with anti-beta-actin monoclonal antibody, whereas FITC-phalloidin staining did not mark the rim of lipid droplets. The present results provide the first morphological evidence that globular beta-actin is associated with intracellular lipid droplets. This significant association of actin with the surface of lipid droplets suggests that beta-actin might be involved in the regulation of intracellular lipid metabolism, particularly providing insight into the important transport of lipid constituents.

Mitochondrial cytochrome b gene sequence diversity in the Korean hare, Lepus coreanus Thomas (Mammalia, Lagomorpha)

Partial sequences of the mitochondrial cytochrome b gene of the Korean hare (Lepus coreanus) were analyzed to determine the degree of genetic diversity. Nine haplotypes were observed, and the maximum Tamura-Nei nucleotide distance among them was 2.8%, indicating that genetic diversity of L. coreanus is moderate. In order to clarify the Korean hare's taxonomic status and relationship with the Manchurian hare (L. mandshuricus) and the Chinese hare (L. sinensis), these nine haplotypes of the Korean hare were compared with 13 haplotypes from five other species of eastern Asian Lepus including L. mandshuricus and L. sinensis. The Korean hare was distinct in its cytochrome b gene, and it is confirmed that L. coreanus is a valid species, as noted by Jones and Johnson (1965, Univ. Kansas Publ. (Mus. Nat. Hist.) 16:357). Further analyses of mtDNA cytochrome b gene with additional specimens of L. coreanus from North Korea and other species of Lepus from eastern Asia are needed to clarify the taxonomic status of the divergent mtDNA clades of L. mandshuricus and L. sinensis.

Effects and mechanisms of aloe-emodin on cell death in human lung squamous cell carcinoma

Aloe-emodin (1,8-dihydroxy-3-(hydroxymethyl)-anthraquinone) is an active component from the root and rhizome of Rheum palmatum. The study investigated the effects and mechanisms of aloe-emodin-induced cell death in human lung squamous cell carcinoma cell line CH27. Aloe-emodin (40 microM)-induced CH27 cell apoptosis was confirmed by DNA fragmentation (DNA ladders and sub-G(1) formation). Aloe-emodin-induced apoptosis of CH27 cells involved modulation of the expression of Bcl-2 family proteins, such as BclX(L), Bag-1, and Bak, and was associated with the translocation of Bak and Bax from cytosolic to particulate fractions. Aloe-emodin-treated CH27 cells had an increased relative abundance of cytochrome c in the cytosolic fraction. Results demonstrated that the activation of caspase-3, caspase-8, and caspase-9 is an important determinant of apoptotic death induced by aloe-emodin. These results suggest that aloe-emodin induces CH27 cell death by the Bax and Fas death pathway.

The effect of an iron supplement on serum aluminum level and desferrioxamine mobilization test in hemodialysis patients

BACKGROUND

The serum aluminum (Al) measurement with desferrioxamine (DFO) mobilization is a screening test for uremic patients with an Al overload. In these patients, body iron status is one of the factors affecting the serum Al level. This study is designed to elucidate the effects of iron supplements on the serum Al and the DFO mobilization test.

METHODS

Our study featured ten hemodialysis patients with iron deficiency anemia. The iron supplement was given intravenously with saccharated ferric oxide, 40 mg three times weekly, at the end of each hemodialysis. The total amount of iron supplement was 1,000 mg. All the patients underwent a DFO test at a dose of 5 mg/kg. The same test was repeated two weeks after completion of the iron supplement.

RESULTS

After the iron supplement, patients' iron deficiency anemia improved with a serum ferritin elevation from 312.4 +/- 589.5 to 748.2 +/- 566.2 microg/L (p < 0.01), and iron saturation from 21.6 +/- 20.3 to 41.1 +/- 21.7% (p = 0.06). The basal serum Al level decreased from 34.3 +/- 13.8 to 21.8 +/- 8.5 microg/L (p = 0.01). In the DFO mobilization test, the peak serum Al level decreased from 63.4 +/- 19.3 to 50.7 +/- 20.5 microg/L (p < 0.01). The amount of Al increment (deltaAl) in DFO test was not changed (29.1 +/- 12.0 vs. 28.9 +/- 15.9 microg/L, p = 0.86). The change in basal Al level tended to negatively correlate with the percentage of increment in iron saturation (r = -0.628, p = 0.05).

CONCLUSION

Results in this study suggest that iron supplements may significantly reduce the basal serum Al and peak Al in DFO mobilization test, without significant change of the mean deltaAl. The data presented indicate that in the interpretation of serum aluminum levels the iron status should be taken into account.

Micro sequential injection: environmental monitoring of nitrogen and phosphate in water using a "Lab-on-Valve" system furnished with a microcolumn

A "Lab-on-Valve" manifold operated in the micro sequential injection (microSI) mode was adopted to accommodate EPA-approved methods for spectrophotometric determinations of nitrate, nitrite and orthophosphate in the ppb (N or P) concentration range. A computer programmable microSI protocol, utilizing stopped-flow within a copperized Cd-foil filled microcolumn was developed for nitrate reduction to nitrite with subsequent colorimetric measurement, yielding concentration ranges for nitrate of 100.0-4000.0 ppb (N) and for nitrite of 30.0-4000.0 ppb (N) and linear calibration responses of r2 = 0.9999 for nitrate and 0.9995 for nitrite. Using a stopped-flow reaction rate measurement, phosphate was determined in the range 1.0-30.0 ppb (P) with a calibration response of r2 = 0.9997. The technical improvement of this methodology, apart from micro miniaturization, is the use of the stopped-flow technique, that resulted in improved detection limits and allowed reagent consumption to be reduced 1500-fold compared with conventional procedure while the amount of metallic cadmium was reduced 20-fold compared with the EPA-approved continuous-flow assay.

Endoscopic ultrasonography to study the causes of extragastric compression mimicking gastric submucosal tumor

BACKGROUND AND PURPOSE

Many reports have confirmed that endoscopic ultrasonography (EUS) can differentiate gastric submucosal tumor from extragastric compression, but only a few specifically concentrated on EUS in identifying the causes of external compression.

MATERIALS AND METHODS

From May 1993 to May 2001, we used EUS in 238 patients to diagnose gastric submucosal tumor or external compression. We excluded 183 patients who had submucosal tumors and analyzed the remaining 55 patients with extragastric compression. Malignant causes of external compression were proved by surgery or biopsy. Benign causes of external compression were proved by other imaging examinations (abdominal ultrasound, computerized tomography, angiography) or surgery. Patients with external compression caused by normal organs were followed up with repeated upper gastrointestinal endoscopy or EUS.

RESULTS

The stomach was compressed by normal extragastric organs in 32 patients (spleen 10, splenic vessel 6, gall bladder 9, liver 3, pancreas 3, and intestine 1), by benign pathologic lesions in 12 patients (liver cyst 7, liver hemagioma 2, splenic cyst 1, pancreatic cyst 1, pancreatic cystadenoma 1) and by malignant tumors in 5 patients (hepatoma 1, liver metastasis from colon cancer 2, pancreatic cystadenocarcinoma 1 and lymphoma of spleen 1). In the remaining six patients, neither submucosal tumor nor external compression was found during EUS examination and the external compression was considered transient.

CONCLUSION

When an extragastric compression mimicking submucosal tumor is detected by upper gastrointestinal endoscopy, EUS is indicated to identify the cause of extragastric compression.

beta(2)-microglobulin induces apoptosis in HL-60 human leukemia cell line and its multidrug resistant variants overexpressing MRP1 but lacking Bax or overexpressing P-glycoprotein

In this study, we examined whether exogenous beta(2)-microglobulin (beta(2)m) can induce apoptosis in the drug sensitive HL-60 leukemia cell line and its drug resistant variants and investigated the molecular mechanism of beta(2)m-induced apoptosis. Our data revealed that beta(2)m is very significantly down-regulated in two multidrug resistant variants of the HL-60 cells: (a) the MRP1-bearing, Bax-deficient HL-60/ADR cell line, and (b) the P-glycoprotein (P-gp) overexpressing HL-60/VCR cell line. However, exogenous beta(2)m induced similar levels of apoptosis in HL-60 cells and these drug resistant variants. beta(2)m-induced apoptosis in HL-60 and HL-60/VCR cells was associated with decreased mitochondrial membrane potential (Deltapsim) but did not affect Deltapsim in HL-60/ADR cells. Surprisingly, cyclosporin A (CsA), a known inhibitor of the mitochondrial permeability transition (MPT) pore, inhibited beta(2)m-induced apoptosis in HL-60/ADR cells but not in HL-60 and HL-60/VCR cells, suggesting that the pro-apoptotic effect of beta(2)m in these cells is not through MPT pore formation. Furthermore, beta(2)m induced the release of cytochrome c and the apoptosis-inducing factor (AIF) from mitochondria in HL-60 and HL-60/VCR cells, but not in HL-60/ADR cells. Additionally, Z-VAD-fmk, a general inhibitor of caspases which inhibited cytochrome c release in HL-60 and HL-60/VCR cells, had no effect on AIF release in any of these cell lines, but inhibited beta(2)m-induced apoptosis in all three cell lines. However, Western blot analysis revealed that caspases-1, -3, -6, -8, and -9 are not activated during beta(2)m-induced apoptosis in these cells. Therefore, beta(2)m-induces apoptosis through an unknown caspase-dependent mitochondrial pathway in HL-60 and HL-60/VCR cells and by a Bax-independent, non-mitochondrial, caspase-dependent pathway in HL-60/ADR cells.

Long-lived immune response to early secretory antigenic target 6 in individuals who had recovered from tuberculosis

We sought to understand the persistence and relevance of the long-lived immune response to early secretory antigenic target (ESAT-6) of Mycobacterium tuberculosis in humans. ESAT-6 is recognized by memory cells involved in protection of animals against tuberculosis (TB). Recent reports also showed that ESAT-6 response can be recovered in patients with TB and in those soon after anti-TB therapy. We chose 18 individuals who had recovered from pulmonary TB (some in remission for >5 years), and 14 bacille Calmette-Guérin-vaccinated healthy individuals for this study. The results showed that peripheral blood mononuclear cells of 10 (55.6%) of 18 patients with TB remission responded to ESAT-6 with stimulation indices >3.0, whereas none of the healthy controls responded. Functional analysis showed that 13 (72.2%) of 18 patients with TB remission produced significant amounts of IFN-gamma in response to ESAT-6, whereas only 1 (7.1%) of the 14 healthy control subjects did so. It appears that responses to ESAT-6 can persist in individuals who had recovered from pulmonary TB.

Advanced glycosylation end products induce nitric oxide synthase expression in C6 glioma cells: involvement of a p38 MAP kinase-dependent mechanism

The mitogen-activated protein kinase (MAPK) pathway is believed to function as an important mediator of inducible nitric oxide synthase (iNOS) expression. In the present study, we investigated the role of the p38 MAPK signaling pathway in advanced glycosylation end products (AGEs)-induced iNOS expression in C6 glioma cells. AGEs caused a dose-dependent increase of nitrite accumulation in C6 glioma cells. The AGEs-stimulated nitrite production from C6 glioma cells was inhibited by actinomycin D, cyclohexamide, and the NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME), suggesting that the increase of AGEs-induced nitrite release is due to iNOS up-regulation. Consistently, treatment of C6 glioma cells with AGEs induced iNOS protein expression. AGEs-stimulated nitrite production was inhibited by pretreatment of C6 glioma cells with anti-AGEs antibodies (1:100 or 1:50). The tyrosine kinase inhibitor (genistein and tyrphostin), the Ras-farnesyl transferase inhibitor (FPT inhibitor-II), or the p38 MAPK inhibitor (SB203580) suppressed AGEs-induced iNOS expression and nitrite release from C6 glioma cells. AGEs activated p38 MAPK in C6 glioma cells, and this effect was blocked by genistein (20 microM), tyrphostin (30 microM), FPT inhibitor-II (20 microM), and SB203580 (10 microM). Taken together, our data suggest that AGEs may activate the pathways of tyrosine kinase and Ras to induce p38 MAPK activation, which in turn induces iNOS expression and NO production in C6 glioma cells.

Identification of a mouse thiamine transporter gene as a direct transcriptional target for p53

p53 tumor suppressor is a transcription factor that functions, in part, through many of its downstream target genes. We have identified a p53-inducible gene by performing mRNA differential display on IW32 murine erythroleukemia cells containing a temperature-sensitive p53 mutant allele, tsp53(Val-135). Sequence analysis of the full-length cDNA revealed its identity as the mouse homologue of the human thiamine transporter 1 (THTR-1). Induction of the mouse THTR-1 (mTHTR-1) mRNA was detectable as early as 1 h at 32.5 degrees C; upon shifting back to 38.5 degrees C, mTHTR-1 transcript was rapidly degraded with a half-life of less than 2 h. Elevation of mTHTR-1 expression was found in DNA damage-induced normal mouse embryonic fibroblast cells, but not in p53(-/-) mouse embryonic fibroblast cells, suggesting that mTHTR-1 induction was p53-dependent. A region within the first intron of the mTHTR-1 gene bound to p53 and conferred the p53-mediated transactivation. Furthermore, increased thiamine transporter activities were found in cells overexpressing mTHTR-1 and under conditions of DNA damage or p53 activation. Our findings indicate that p53 may be involved in maintaining thiamine homeostasis through transactivation of THTR-1.

Temporally patterned sound pulse trains affect intensity and frequency sensitivity of inferior collicular neurons of the big brown bat, Eptesicus fuscus

This study examined the effect of temporally patterned pulse trains on intensity and frequency sensitivity of inferior collicular neurons of the big brown bat, Eptesicus fuscus. Intensity sensitivity of inferior collicular neurons was expressed by the dynamic range and slope of rate-intensity functions. Inferior collicular neurons with non-monotonic rate-intensity functions have smaller dynamic ranges and larger slopes than neurons with monotonic or saturated rate-intensity functions. Intensity sensitivity of all inferior collicular neurons improved by increasing the number of non-monotonic rate-intensity functions when the pulse repetition rate of pulse trains increased from 10 to 30 pulses per second. Intensity sensitivity of 43% inferior collicular neurons further improved when the pulse repetition rate of pulse trains increased still from 30 to 90 pulses per second. Frequency sensitivity of inferior collicular neurons was expressed by the Q10, Q20, and Q30 values of threshold frequency tuning curves and bandwidths of isointensity frequency tuning curves. Threshold frequency tuning curves of all inferior collicular neurons were V-shape and mirror-images of their counterpart isointensity frequency tuning curves. The Q10, Q20, and Q30 values of threshold frequency tuning curves of all inferior collicular neurons progressively increased and bandwidths of isointensity frequency tuning curves decreased with increasing pulse repetition rate in temporally patterned pulse trains. Biological relevance of these findings to bat echolocation is discussed.

Variant palmaris profundus enclosed byan unusual loop of the median nerve

According to the usual description in most anatomy texts, the median nerve in the forearm passes between the 2 heads of pronator teres. It continues distally between flexor digitorum superficialis and profundus almost to the retinaculum. Muscular branches leave the nerve near the elbow and supply all superficial muscles of the anterior part of the forearm except flexor carpi ulnaris. Many variations of the median nerve in the forearm have been reported (Urban & Krosman, 1992). The palmaris profundus is also a rare anomaly of the forearm (Dyreby & Engber, 1982). It originates from the radial side of the common flexor tendon in the proximal forearm and inserts into the undersurface of the palmar aponeurosis. The origin of palmaris profundus may be close to the median nerve and its branches, and may be involved in compressive neuropathy of the anterior interosseous nerve. Its tendon crossing through the carpal canal has been implicated in the carpal tunnel syndrome (reviewed by Lahey & Aulicino, 1986). In some cases, palmaris profundus was found enclosed in a common fascial sheath with the median nerve (Stark, 1992; Sahinoglu et al. 1994). To indicate its close association with the median nerve, the palmaris profundus was also named ‘musculus comitans nervi mediani’ (Sahinoglu et al. 1994). This article reports an unusual loop of the median nerve encircling an anomalous palmaris profundus in the forearm, which, to the best of our knowledge, has not been previously described.

Snakebite complicated with Vibrio vulnificus infection

Snakebite may be complicated with bacteria infections, most of which are Gram-negative bacillus. Snakebite complicated with Vibrio vulnificus infection has not been reported previously. Vibrio vulnificus infection is characterized by a necrotizing wound infection similar to the local lesion of severe snakebite. In Vibrio infections, aggressive debridement with the administration of strong antibiotics as early as possible is the only effective treatment. We report a 79-y-o man who suffered from snakebite on the right palm with rapid progression of hemorrhagic bulla, necrotizing fasciitis, compartment syndrome, and septic shock. Vibrio vulnificuswas cultured from necrotic tissue after aggressive debridement and fasciotomy. The patient recovered from antibiotic treatment and several courses of reconstruction surgery. Severe bacteria infection, such as caused by Vibrio vulnificus, should be considered in snakebite cases refractory to antivenin dosage.

A ribonuclease H-oligo DNA conjugate that specifically cleaves hepatitis B viral messenger RNA

Ribonuclease H (RNaseH) recognizes and efficiently cleaves the RNA strand of DNA-RNA hybrids, but has no inherent sequence selectivity. However, the formation of DNA-RNA hybrids does require specific sequence recognition. On the basis of this concept, we wondered whether antisense oligonucleotides complementary to target RNA covalently linked to RNase H could be used to direct specific cleavage events mediated by RNase H. The aim of this research was to couple a DNA oligonucleotide to RNase H to confer specificity of ribonuclease activity toward hepatitis B viral (HBV) mRNA. A modified 13-base oligonucleotide that is specific for the DR1 region of HBV mRNA was conjugated to modified E. coli RNase H using a water soluble cross-linker. A 1200 base fragment of HBV RNA including the DR1 region was synthesized as a substrate using T7 RNA polymerase. Incubation of the RNase H-oligonucleotide conjugate with the RNA transcript resulted in cleavage of the HBV mRNA transcript in a concentration dependent manner. Eighty-five percent of substrate was cleaved under optimal conditions. Controls consisting of RNase H alone, oligonucleotide alone, and incubation of the conjugate with an unrelated mRNA substrate resulted in no cleavage activity. RNase H coupled to an HBV antisense oligonucleotide can specifically cleave target HBV transcripts.

Targeted polynucleotides for inhibition of hepatitis B and C viruses

AIM

To determine whether a combination of cell targeting and sequence recognition of nucleic acids can provide specificity for the inhibition of viral gene expression.

METHODS

Antisense oligonucleotides complexed to a protein-based DNA carrier system were used to target hepatocytes for the inhibition of human hepatitis viral gene expression. The DNA carrier system contained an asialoglycoprotein as a cell-targeting component, which could direct the uptake of complexed DNA specifically to asialoglycoprotein receptors present selectively on the surface of mammalian hepatocytes.

RESULTS

HBV and HCV viral gene expression were substantially and specifically inhibited by use of antisense oligonucleotides complexed to a protein-based DNA carrier system.

CONCLUSION

Targeted delivery of nucleic acids by use of receptor-mediated endocytosis can result in inhibition of viral gene expression without host toxicity.

Liver cell transplantation -- novel animal model for human hepatic viral infections

AIM

To generate a model of human hepatitis B infection (HBV) in immunocompetent rats with chimeric human liver.

METHODS AND RESULTS

Normal rats were tolerized to human hepatocytes by exposure to human hepatocytes at day 17 of gestation. We transplanted human hepatocytes and inoculated HBV into the rats after birth. Mixed lymphocytes assay, a measure for tolerance, indicated that animals fetally exposed to human hepatocytes developed tolerance to human hepatocytes. Spleen lymphocytes from tolerized animals did not proliferate when challenged with donor human hepatocytes. In contrast, control animals given saline fetally developed no tolerance to human hepatocytes. Tolerant animals with transplanted human hepatocytes were susceptible to HBV infection. Western blot analysis and immuno-histochemistry of liver sections from tolerized, HBV infected animals with transplanted human hepatocytes showed the presence of functioning human hepatocytes that synthesized human albumin, of which 30% were also positive for HB surface antigen and HBV DNA. The presence of covalent closed circular HBV DNA in the liver indicated active HBV viral replication.

CONCLUSION

Tolerized rats with chimeric human livers can be infected with HBV and used as an animal model for HBV infection. Tolerized rats with chimeric human livers can also be used for generating models of other human hepatic viral diseases.

Inhibition of neointimal formation in porcine coronary artery by a Ras mutant

BACKGROUND

Therapeutic approaches to reduce the neointimal formation caused by balloon injury have been focused mainly on experimental models of restenosis in the rat carotid artery. However, restenosis in rat carotid artery may not replicate the coronary arterial responses to injury in larger animals and humans.

METHODS

In this study, we used pig coronary arteries as an animal model to evaluate the preventive effects of a virus-mediated dominant negative mutant RasN17 on balloon injury-induced restenosis. The viral particles were delivered to the balloon-injured coronary arteries via a dispatch catheter to keep the virus in a confined arterial segment for 10 min to reach optimal transfection. Six weeks after balloon injury, the pigs were sacrificed and the left anterior descending arteries were isolated for histological analysis.

RESULTS

Neointima formation was prominent in the group receiving balloon injury as compared with the uninjured controls. A remodeling process with migration of collagen was also found in the injured coronary arteries. The application of AdRasN17 led to a 56% decrease in neointima formation and a 75% increase in lumen size, as compared with the balloon-injured vessels treated with AdLacZ control.

CONCLUSIONS

These results suggest that AdRasN17 is an effective therapeutic gene in preventing balloon injury-induced neointimal formation in pig coronary arteries.

Weekly and monthly regimens of paclitaxel and carboplatin in the management of advanced ovarian cancer. A preliminary report on side effects

This preliminary study was carried out over 18 months to evaluate whether the side effects in patients with advanced ovarian cancer receiving chemotherapy using paclitaxel-carboplatin differed between weekly (98 cycles in 14 patients) and monthly (102 cycles in 15 patients) administrations. We used paclitaxel (60 mg/m2) and carboplatin (AUC of 2) in the weekly regimen and 175 mg/m2 of paclitaxel and carboplatin (AUC of 6) in the monthly regimen. All eligible patients received at least four cycles of treatment in both regimens. The results revealed significantly decreased hematological toxicity in weekly regimens relative to monthly ones, ie, 7.1% vs. 18.6% of anemia (> or = grade 2), 7.1% vs. 32.3% of grade 3/4 granulocytopenia, and 0% vs. 15.7% of >grade 2 thrombocytopenia. There was no significant difference in nonhematological toxicities between the two regimens. The incidence of unscheduled events was much less in the weekly regimen than in the monthly one; ie, delayed treatment (3 vs. 18 events), unanticipated hospitalizations (3 vs. 15 times), and supplemental support with G-CSF (7 vs. 33 times). Complete responses were observed in 6 of 14 patients in the weekly regimen and in five of 15 patients in the monthly regimen, while partial responses were seen in four and five patients in the weekly and monthly regimens, respectively. The present results demonstrate that the weekly regimen can achieve the benefits of tolerable toxicity with significantly reduced myelosuppression and improved cost-effectiveness in terms of unscheduled events.

Characterization of self-T-cell response and antigenic determinants of U1A protein with bone marrow-derived dendritic cells in NZB x NZW F1 mice

Systemic lupus erythematosus (SLE) is characterized by the existence of a heterogeneous group of autoantibodies directed against nuclear intact structures, such as nucleosomes and small nuclear ribonucleoproteins (snRNPs). Autoantibodies against snRNPs are of special interest because they are detectable in the majority of SLE patients. Although the B-cell antigenic determinants have been well characterized, very limited data have been reported in regard to the T-cell epitopes of snRNPs. Furthermore, several studies have demonstrated that determination of the auto-T-cell epitopes recognized by freshly isolated T cells is difficult from unprimed lupus mice when self-antigen-pulsed B cells or macrophages are used as antigen-presenting cells (APCs) in vitro. In the present study, we showed a novel approach for determining the auto-T-cell epitopes, using bone marrow-derived dendritic cells (BMDCs) pulsed with the murine U1A protein - an immunodominant antigen of the U1 snRNPs - which is capable of activating freshly isolated T cells from unprimed (NZB x NZW) F1 (BWF1) mice in vitro. The T-cell epitope area was found to be located at the C-terminus of U1A, overlapping the T-cell epitope of human U1A that has been reported in human SLE. Identification of the autoreactive T-cell epitope(s) in snRNPs will help to elucidate how reciprocal T-B determinant spreading of snRNPs emerges in lupus. The results presented here also indicate that it is feasible to use this approach to further explore strategies to design immunotherapy for patients with lupus.

Sex differences of body fat distribution and cardiovascular dysmetabolic factors in old age

BACKGROUND

The relationship between sexual differences of body fat distribution and cardiovascular dysmetabolic factors in old people is controversial.

OBJECTIVES

To use centrality index-derived body fat distribution to clarify its relationship with glucose tolerance status, blood pressure and lipid profile.

DESIGN

Cross-sectional survey in a tertiary-care medical centre in Tainan, Taiwan.

SUBJECTS

114 men and 101 women, aged > or = 60 years.

METHODS

We measured total % body fat and body fat distribution (reflected as centrality index) by dual energy x-ray absorptiometry, and plasma glucose, glycosylated haemoglobin, blood pressure, total cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol and atherogenic index (total cholesterol/HDL cholesterol).

RESULTS

Centrality index showed better linear correlation with cardiovascular dysmetabolic factors than body mass index, total % body fat and waist-to-hip ratio, except in systolic blood pressure. Women had higher total % body fat, but the % abdominal fat and centrality index were both higher in men. Subjects with diabetes mellitus had the highest centrality index compared with those with impaired or normal glucose tolerance. After adjustment for age and total % body fat, men still had higher diastolic blood pressure, triglyceride levels and atherogenic indices, but lower HDL cholesterol levels than women. However, when further adjusted for centrality index, the sex differences in cardiovascular dysmetabolic factors were statistically insignificant.

CONCLUSIONS

Centrality index is a useful method for assessing body fat distribution in older people. Body fat distribution is an important factor in sex differences of cardiovascular dysmetabolic factors in old people.

[Bepridil inhibition on the delayed rectifier K+ currents in thyroxine induced hypertrophied guinea pig ventricular myocytes]

AIM

To study the effects of bepridil on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current and the inward rectifier potassium current (IK1) in hypertrophied guinea pig ventricular myocytes.

METHODS

The whole cell patch clamp techniques were used.

RESULTS

In hypertrophied guinea pig ventricular myocytes, bepridil 30 mumol.L-1 markedly inhibited IKr and IKs (by 20.9% and 27.2% at 0 mV and mV, respectively). The effect of bepridil on IKs was larger than on IKr. Bepridil 30 mumol.L-1 also significantly inhibited the inward component of IK1 (by 15.1% at +100 mV), but the reverse potential of IK1 was unaffected. Bepridil (1-100 mumol.L-1) was shown to inhibit IKr and IKs in a concentration-dependent manner. Their IC50 were 46.7 mumol.L-1 and 23.8 mumol.L-1, respectively.

CONCLUSION

Bepridil inhibit IKr, IKs and IK1 in hypertrophied guinea pig ventricular myocytes, which may be important in understanding the antiarrhythmic effects of this drug.

Origin of microglia

This paper reviews the various proposed hypotheses on the origin of microglia. The seminal study of del Rio-Hortega first stated that the cells were derived from the mesodermal pial cells that invaded the brain during embryonic development. Along with this was the description of precursor cells in the yolk sac in early development. Our results in the embryonic mouse brain have shown the occurrence of lectin-labelled precursor cells at the yolk sac that later appeared in the mesenchymal tissue associated with the neuroepithelium where they penetrated the nervous tissue to become the microglia. A second major view has held that microglia are of neuroectodermal origin; the cells either originate from glioblasts or the germinal matrix. Another school of thought is that microglia are derived from blood monocytes. In this connection, circulating monocytes enter the developing brain to assume the form as amoeboid microglia that subsequently evolve to become the ramified microglia. In traumatic brain lesions following an intravenous injection of colloidal carbon as a cytoplasmic marker for monocytes, it was found that carbon-labelled monocytes were the main source of brain macrophages, some of which transformed into microglia during the healing process. In conclusion, our results derived from the normal and altered brain development as well as from experimental lesions tend to favour the view of the monocytic nature of microglia. Recent studies by us also point to the possibility that some microglial cells may arise from the pial mesenchymal macrophages that appear to originate from the yolk sac precursors.

Long-term follow-up of interferon alfa treatment in Chinese patients with chronic hepatitis B infection: The effect on hepatitis B e antigen seroconversion and the development of cirrhosis-related complications

The long-term effect of interferon alfa (IFN-alpha) in Chinese patients with chronic hepatitis B infection is unknown. A total of 411 chronic hepatitis B patients (208 treated with IFN-alpha and 203 as control) were followed up for hepatitis B serology and the development of hepatoma and other cirrhosis-related complications. The hepatitis B e antigen (HBeAg) seroconversion rate in the IFN-alpha-treated group, though significantly greater at 6 and 24 months, was comparable with the control group on subsequent follow-up, irrespective of pretreatment alanine transaminase (ALT) levels. HBeAg seroreversion rate was higher in the IFN-alpha group compared with the control group (21.1% vs. 2.2%; P =.001). Loss of hepatitis B surface antigen (HBsAg) occurred in 2.4% of the IFN-alpha-treated patients and 0.49% of the control patients (P = NS). Around 90% of the anti-HBe-positive patients in both groups were still hepatitis B virus (HBV)-DNA-positive by polymerase chain reaction (PCR) assay. Two patients suffered from hepatic reactivation during the course of treatment. Nine (4.3%) patients in the IFN-alpha group and 2 (1.0%) in the control group developed complications of cirrhosis and hepatoma (P =.062). In Chinese HBsAg carriers, IFN-alpha was of no long-term benefit in inducing HBeAg seroconversion or in the prevention of hepatoma and other cirrhosis-related complications.

Response of amoeboid and differentiating ramified microglia to glucocorticoids in postnatal rats: a lectin histochemical and ultrastructural study

After glucocorticoid injection(s), the number of amoeboid microglial cells (AMC) in the corpus callosum labelled by lectin was markedly reduced when compared with the corresponding control rats. In rats killed at the age of 7 days, all the labeled cells differentiated to become ramified microglia. Ultrastructurally, the AMC in glucocorticoid-injected rats were extremely vacuolated and showed increased lipid droplets. Furthermore, the cells displayed varied lectin labelling patterns especially at both the trans saccules of the Golgi apparatus and lysosomes. In differentiating ramified microglia, massive cellular debris and lectin-stained vesicles or vacuoles were observed; some of the latter appeared to fuse with the plasma membrane. The most striking feature after glucocorticoid (GCC) treatment was the complete diminution of lectin labelling at the Golgi saccules in some differentiating ramified microglia. The present results have demonstrated different effects of glucocorticoids on AMC and differentiating ramified microglia. The differential response of AMC and differentiating ramified microglia to the immunosuppressive drugs may be attributed to the fact that these cells in the postnatal brains subserve different functions or that they are at different differentiation stages. In other words, the sensitivity of microglial cells to the immunosuppressive drugs is dependent upon the stage of cell maturation/differentiation.

Uterine leiomyoma with massive lymphocytic infiltration simulating malignant lymphoma. A case report with immunohistochemical study showing that the infiltrating lymphocytes are cytotoxic T cells

Uterine leiomyoma with massive lymphoid infiltration is very rare and may simulate malignant lymphoma. To the best of our knowledge, this is the first description of such a lesion occurring in an Oriental, and the ninth case in the English literature. A 50-year-old Taiwanese woman had urinary frequency and nocturia because of a uterine myoma. The myomectomy specimen was identified as a well-defined tumor, 6.5-cm in diameter, the cut surface of which was pale, white and whorled. A massive lymphocytic infiltration accompanied by plasma cells and histiocytes was noted in the leiomyoma but not in the surrounding non-neoplastic myometrial fibers. Most infiltrating lymphocytes were positive for CD3 and T cell intracellular antigen-1, a cytotoxic marker. The postoperative course was uneventful, and the urinary symptoms improved within a 6-month follow-up period.

Transplantation of human hepatocytes into tolerized genetically immunocompetent rats

AIM: To determine whether normal genetically immunocompetent rodent hosts could be manipulated to accept human hepatocyte transplants with long term survival without immunosuppression.

METHODS: Tolerance towards human hepatocytes was established by injection of primary human hepatocytes or Huh7 human hepatoma cells into the peritoneal cavities of fetal rats. Corresponding cells were subsequently transplanted into newborn rats via intrasplenic injection within 24 h after birth.

RESULTS: Mixed lymphocyte assays showed that spleen cells from non-tolerized rats were stimulated to proliferate when exposed to human hepatocytes, while cells from tolerized rats were not. Injections made between 15 d and 17 d of gestation produced optimal tolerizaton. Transplanted human hepatocytes in rat livers were visualized by immunohistochemical staining of human albumin. By dot blotting of genomic DNA in livers of tolerized rats 16 weeks after hepatocyte transplantation, it was found that approximately 2.5 × 10⁵ human hepatocytes survived per rat liver. Human albumin mRNA was detected in rat livers by RT-PCR for 15 wk, and human albumin protein was also detectable in rat serum.

CONCLUSION: Tolerization of an immunocompetent rat can permit transplantation, and survival of functional human hepatocytes.

Differential changes in regional bone mineral density in healthy Chinese: age-related and sex-dependent

To investigate the pattern of age-related and sex-dependent bone mineral density (BMD) changes in the six skeletal regions in healthy Chinese, total-body and regional BMD were measured by dual-energy X-ray absorptiometry (DXA) in 310 women and 387 men aged 20-80 years. In women, a five-phase change was discernible in the axial bones: (1) gradual bone increase from 20-29 years old to maximal BMD at 35-39 years old; (2) maintenance of this level from 35-39 to 40-44; (3) a mild bone decrease from 40-44 to 45-49; (4) a rapid bone decrease from 45-49 to 55-59; and (5) a decelerated bone decrease after 55-59 years old. After validation of menopause status, the decrease of BMD in the late 40s became insignificant in premenopausal women. In appendicular bones, no obvious peak was observed, and significant bone decrease started at 50-54 years old. The overall bone decrease from 35-39 to 70-80 years old was 19.3% for the total body, 16.4% for the head, 29% for the spine, 23% for the pelvis, 18.2% for the ribs, 23.9% for the arms, and 20.4% for the legs. In men, the maximal bone mass was attained at 30-34 and 35-39 years old for axial and appendicular bones, respectively. The age-related bone decrease in the skeletal regions was small, except from 60-64 to 65-69 years old. The overall bone decrease in each region from maximal bone mass to 70-80 years old was 6.7% for the total body, 1.7% for the head, 7.6% for the spine, 11.3% for the pelvis, 9.5% for the ribs, 7.8% for the arms, and 10.4% for the legs. The overall magnitude of reduction in total-body BMD in women was about three times greater than that in men. The pattern of BMD changes differs in each region and is age-related as well as sex-dependent. There appeared to be no significant premenopausal bone decrease.

Combustion modeling and performance evaluation in a full-scale rotary kiln incinerator

This work summarizes the results of numerical investigations and in situ measurements for turbulent combustion in a full-scale rotary kiln incinerator (RKI). The three-dimensional (3D) governing equations for mass, momentum, energy, and species, together with the kappa - epsilon turbulence model, are formulated and solved using a finite volume method. Volatile gases from solid waste were simulated by gaseous CH4 distributed nonuniformly along the kiln bed. The combustion process was considered to be a two-step stoichiometric reaction for primary air mixed with CH4 gas in the combustion chamber. The mixing-controlled eddy-dissipation model (EDM) was employed to predict the conversion rates of CH4, O2, CO2, and CO. The results of the prediction show that reverse flows occur near the entrance of the first combustion chamber (FCC) and the turning point at the entrance to the second combustion chamber (SCC). Temperature and species are nonuniform and are vertically stratified. Meanwhile, additional mixing in the SCC enhances postflame oxidation. A combustion efficiency of up to 99.96% can be achieved at approximately 150% excess air and 20-30% secondary air. Reasonable agreement is achieved between numerical predictions and in situ measurements.

Inhibitory effects of Cassia tora L. on benzo[a]pyrene-mediated DNA damage toward HepG2 cells

The effects of water extracts from Cassia tora L. (WECT) treated with different degrees of roasting on benzo[a]pyrene (B[a]P)-induced DNA damage in human hepatoma cell line HepG2 were investigated via the comet assay without exogenous activation mixtures, such as S9 mix. WECT alone, at concentrations of 0.1-2 mg/mL, showed neither cytotoxic nor genotoxic effect toward HepG2 cells. B[a]P-induced DNA damage in HepG2 cells could be reduced by WECT in a dose-dependent manner (P < 0.05). At a concentration of 1 mg/mL, the inhibitory effects of WECT on DNA damage were in the order unroasted (72%) > roasted at 150 degrees C (60%) > roasted at 250 degrees C (23%). Ethoxyresorufin-O-dealkylase activity of HepG2 cells was effectively inhibited by WECT, and a similar trend of inhibition was observed in the order unroasted (64%) > roasted at 150 degrees C (42%) > roasted at 250 degrees C (18%). The activity of NADPH cytochrome P-450 reductase was also decreased by unroasted and 150 degrees C-roasted samples (50% and 38%, respectively). Furthermore, glutathione S-transferase activity was increased by treatment with unroasted (1.26-fold) and 150 degrees C-roasted (1.35-fold) samples at 1 mg/mL. In addition, the contents of anthraquinones (AQs) in WECT, including chrysophanol, emodin, and rhein, were decreased with increasing roasting temperature. Each of these AQs also demonstrated significant antigenotoxic activity in the comet assay. The inhibitory effects of chrysophanol, emodin, and rhein on B[a]P-mediated DNA damage in HepG2 cells were 78, 86, and 71%, respectively, at 100 microM. These findings suggested that the decreased antigenotoxicity of the roasted samples might be due to a reduction in their AQs content.

The emission characteristics of a small D.I. diesel engine using biodiesel blended fuels

Biodiesel and biodiesel blends provide low emissions without modification on the fuel system of conventional diesel engines. This study aims to develop a new domestic biodiesel production procedure which makes use of waste fryer vegetable oil by transesterification method, and further investigates the emission characteristics of a small D.I. diesel engine using biodiesel blends and diesel fuels, respectively. The 20/80 and 30/70 blends of biodiesel to diesel fuel are used in this study. The emission characteristics include smoke emissions, gaseous emissions (CO, HC, NOx and SO2), particle size distributions and number concentrations at a variety of steady state engine speed points. We have found that diesel engine fueled with biodiesel blends emits more PM2 particle number concentrations than those with diesel fuel, and PM2 number concentration increases as biodiesel concentration increases. As for the smoke and gaseous emissions, such as CO, HC, NOx and SO2, the results favored biodiesel blends.

Blockade of U50488H on potassium currents of acutely isolated mouse hippocampal CA3 pyramidal neurons

The actions of the opioid agonist U50488H on IA and IK were examined in acutely isolated mouse hippocampal CA3 pyramidal neurons using the whole-cell patch clamp technique. U50488H caused a concentration dependent, rapidly developing and reversible inhibition of voltage-activated IA and IK. The inhibitory actions were still observed in the presence of 30 microM naloxone or 5 microM nor-binaltorphimine dihydrochloride. The IC50 values for the blockade of IA and IK were calculated as 20.1.9 and 3.7 microM, respectively. In the presence of 3.3 microM U50488H, repetitive stimulation induced use-dependent inhibition of IA and IK. A 10 microM concentration of U50488H positively shifted the half-activation membrane potential of IA by +11 mV, but negatively shifted IK by -14 mV. These results demonstrate that U50488H can directly inhibit neuronal IA and IK without involvement of the activation of kappa-opioid receptors.

Mechanisms in the inhibition of neointimal hyperplasia with triflavin in a rat model of balloon angioplasty

RGD-containing peptides are able to inhibit the binding of ligands to certain beta3 integrins, such as alpha(IIb)beta3 and alpha(v)beta3, both of which are involved in neointimal hyperplasia. The present study was designed to elucidate the detailed mechanisms involved in the inhibition of neointimal hyperplasia with triflavin in a rat model of balloon angioplasty. Triflavin (0.25 mg x kg(-1) x d(-1)), an RGD-containing disintegrin, time dependently inhibited both neointimal hyperplasia and lumen occlusion after angioplasty in carotid arteries of rats. Furthermore, electron micrographs highlighted that SMCs were phenotypically different from the typical contractile, spindle-shaped SMCs normally seen in uninjured vessel walls. PDGF-BB was strongly produced in thrombus formation and neointimal SMCs after angioplasty, and triflavin significantly reduced PDGF-BB expression in vessel lumens and neointimal SMCs after angioplasty. Balloon angioplasty caused a significant increase of nitrate and cyclic guanosine monophosphate levels compared with levels found in sham-operated rats, and these were not significantly changed with infusion of triflavin (0.25 mg x kg(-1) x d(-1)). Furthermore, the plasma level of TXB2 obviously increased after angioplasty, and triflavin markedly suppressed the elevation of plasma TXB2 concentration. The results indicate that triflavin effectively prevents neointimal hyperplasia, possibly through the following 2 mechanisms. First, triflavin binds to alpha(IIb)beta3 integrin on platelet membranes, resulting in inhibition of platelet adhesion, secretion, and aggregation in injured arteries, followed by inhibition of TXA2 formation and PDGF-BB release from platelets. Second, triflavin may also bind to alpha(v)beta3 integrin on SMCs, thus subsequently inhibiting cell migration and proliferation. These results provide new insights into the mechanisms of neointimal hyperplasia and have significant implications for disintegrin therapy for the treatment of restenosis and atherosclerosis.

Occlusal wear of a resin-modified glass ionomer cement following three surface treatments

Unacceptable occlusal wear has been reported for resin-modified glass ionomer cements (RMGICs) placed in permanent molar teeth. Three different surface treatments of a RMGIC were evaluated over periods of up to 2 years for their effects on restoration wear behaviour: (a) sealing with a thin layer of low viscosity unfilled resin (sealed restoration), (b) sealing with a thicker layer of a lightly-filled pit and fissure sealant (sealant restoration), and (c) co-curing the RMGIC with a posterior resin composite (co-cured restoration). After 2 years the cumulative median (quartiles) wear was for (a) 100 (50-150) microns, (b) 25 (0-50) microns, and (c) 25 (25-38) microns. Although method (b) effectively reduced the surface wear of the RMGIC, this treatment required frequent re-sealing, involving 52% of the restorations. Sealing the surface of a RMGIC placed in permanent molars was not a satisfactory method for reducing occlusal wear. However, co-curing the RMGIC with a posterior resin composite reduced occlusal wear significantly (P < 0.0001), without the need for frequent reapplications of a pit and fissure sealant to the RMGIC.

A novel chromosome region maintenance 1-independent nuclear export signal of the large form of hepatitis delta antigen that is required for the viral assembly

Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus, as it requires hepatitis B virus for virion production and transmission. We have previously demonstrated that sequences within the C-terminal 19-amino acid domain flanking the isoprenylation motif of the large hepatitis delta antigen (HDAg-L) are important for virion assembly. In this study, site-directed mutagenesis and immunofluorescence staining demonstrated that in the absence of hepatitis B virus surface antigen (HBsAg), the wild-type HDAg-L was localized in the nuclei of transfected COS7 cells. Nevertheless, in the presence of HBsAg, the HDAg-L became both nuclei- and cytoplasm-distributed in about half of the cells. An HDAg-L mutant with a substitution of Pro-205 to alanine could neither form HDV-like particles nor shift the subcellular localization in the presence of HBsAg. In addition, nuclear trafficking of HDAg-L in heterokaryons indicated that HDAg-L is a nucleocytoplasmic shuttling protein. A proline-rich HDAg peptide spanning amino acid residues 198 to 210, designated NES(HDAg-L), can function as a nuclear export signal (NES) in Xenopus oocytes. Pro-205 is critical for the NES function. Furthermore, assembly of HDV is insensitive to leptomycin B, indicating that the NES(HDAg-L) directs nuclear export of HDAg-L to the cytoplasm via a chromosome region maintenance 1-independent pathway.

Analysis of core promoter sequences located downstream from the TATA element in the hsp70 promoter from Drosophila melanogaster

TFIID recognizes multiple sequence elements in the hsp70 promoter of Drosophila. Here, we investigate the function of sequences downstream from the TATA element. A mutation in the initiator was identified that caused an eightfold reduction in binding of TFIID and a fourfold reduction in transcription in vitro. Another mutation in the +24 to +29 region was somewhat less inhibitory, but a mutation in the +14 to +19 region had essentially no effect. The normal promoter and the mutants in the initiator and the +24 to +29 region were transformed into flies by P element-mediated transformation. The initiator mutation reduced expression an average of twofold in adult flies, whereas the mutation in the +24 to +29 region had essentially no effect. In contrast, a promoter combining the two mutations was expressed an average of sixfold less than the wild type. The results suggest that the initiator and the +24 to +29 region could serve overlapping functions in vivo. Protein-DNA cross-linking was used to identify which subunits of TFIID contact the +24 to +29 region and the initiator. No specific subunits were found to cross-link to the +24 to +29 region. In contrast, the initiator cross-linked exclusively to dTAF230. Remarkably, dTAF230 cross-links approximately 10 times more efficiently to the nontranscribed strand than to the transcribed strand at the initiator.

Micro sequential injection: fermentation monitoring of ammonia, glycerol, glucose, and free iron using the novel lab-on-valve system

Using an integrated lab-on-valve manifold in a microfluidic sequential injection format (microSI), automated sample processing has been developed for off-line and on-line monitoring of small-scale fermentations. Spectrophotometric assays of ammonia, glucose, glycerol, and free iron were downscaled to use micro-quantities of commercial reagents. By monitoring the reaction rate, the response curves in a stopped-flow mode generate linear calibration curves for ammonia [r2 = 1.000 (0.9% SE)], glycerol [r2 = 0.999 (1.1% SE)], glucose [r2 = 0.999 (1.1% SE)], and free iron [r2 = 0.999 (1.5% SE)]. Since sample dilution and reagent quantities are easily adjusted within the programmable SI format, the lab-on-valve system can accommodate samples over a wide concentration range (ammonia: 3-1200 ppm; glycerol: 20-120 ppm; glucose: 35-1000 ppm; and free iron: 80-400 ppm). This work demonstrates the key advantages of miniaturization through the reduction of sample and reagent use, minimizing waste and providing a compact yet reliable instrument. The lab-on-valve manifold uses a universal hardware configuration for all analyses, only requiring changes in software protocol and choice of reagents. All of these features are of particular importance to small-scale experimental fermentation where multiple analyte analyses are needed in real-time using small sample volumes. It is hoped that this first real-life application of the lab-on-valve manifold will serve not only as a model system to downscale assays in a practical fashion, but will also inspire and promote the use of the integrated microSI manifold approach for a wider range of biotechnological applications.

Human hepatocytes transplanted into genetically immunocompetent rats are susceptible to infection by hepatitis B virus in situ

Immune tolerance of human cells without generalized immunosuppression was created in groups of normal fetal rats at 17 days of gestation by inoculation ip with primary human hepatocytes in utero. One day after birth, suspensions of human hepatocytes were transplanted via intrasplenic injection and one week later groups of rats were inoculated with hepatitis B virus (HBV). Tolerized rats that were transplanted with human hepatocytes and subsequently infected with HBV produced hepatitis B surface antigen (HBsAg) in serum beginning on day 3. Levels rose fivefold and remained stable at 0.75 pg/ml through at least 60 days. Of cells that stained positive for human serum albumin, approximately 30% were found to be also positive for HBsAg by immunohistochemistry. Serum HBV DNA was detectable from 1 to 15 weeks postinfection. Finally, covalently closed circular DNA, reflecting HBV replication, was found in liver and serum. Controls that were tolerized and not transplanted, but inoculated with HBV, as well as untreated controls, had no evidence of HBV gene expression or replication under identical conditions. The data support the conclusion that primary human hepatocytes transplanted into genetically immunocompetent rodent hosts, survive and maintain sufficient differentiation to produce human serum albumin and be infected by HBV.

Cadaveric study of blood supply to the lower intraorbital fat: etiologic relevance to the complication of anaerobic cellulitis in orbital floor fracture

BACKGROUND AND PURPOSE

Although orbital fractures are common, orbital cellulitis rarely develops following orbital fracture. We hypothesized that compromise of the blood supply to the intraorbital fat during orbital floor fracture is responsible for this condition. The purpose of this study was to determine whether or not the lower intraorbital fat is supplied by a branch of the infraorbital artery along the orbital groove or canal on the orbital floor.

MATERIALS AND METHODS

We dissected 14 orbits from seven fixed human cadavers and 12 orbits from six fresh cadaver heads following dye injection into the maxillary artery. The sites of dye-filled vessels branching from the infraorbital artery supplying the lower intraorbital fat were measured and plotted on a two-dimensional orbital floor graph.

RESULTS

A main branch of the infraorbital artery rose through the medial orbital floor to supply the lower intraorbital fat in all of the cadaver orbits. The sites of the branching point of the vessel ranged from 0 to 5 mm (mean, 2.2 mm; n = 14) medial to the line connecting the infraorbital foramen and the infraorbital groove. The shortest distance measured from the branching point to the orbital rim ranged from 3 to 20 mm (mean, 14.1 mm; n = 14). This suggests that if orbital fracture were to occur around the infraorbital groove or canal, this vascular pedicle would be in danger of being incarcerated by bone fragments.

CONCLUSION

Our cadaveric investigation revealed that the lower intraorbital fat is supplied by a branch of the infraorbital artery along the infraorbital groove or canal on the orbital floor. This finding suggests that compromised blood supply to the intraorbital fat may cause anaerobic cellulitis or enophthalmos.

Puerarin blocks transient outward K+ current and delayed rectifier K+ current in mice hippocampal CA1 neurons

AIM

To study the effects of puerarin (Pue) on IA and IK in mouse hippocampal neurons.

METHODS

The whole cell patch clamp techniques were used.

RESULTS

Pue reduced the amplitude of IA and IK, in a concentration-dependent, but not rate- or use-dependent manner (IC50 were 461 micromol/L and 215 micromol/L, respectively). Pue (0.5 mmol/L) shifted the steady state activation curves of IA and IK to positive and negative potentials (Vh about 20.6 mV and 28.6 mV) respectively, but inactivation curves of IA were not affected by Pue.

CONCLUSION

Pue inhibited IA and IK in mouse hippocampal CA1 neurons and its blocking effect on I(K) was much stronger than on IA.

Total creatinine appearance as indicator of risk of infectious complication in peritoneal dialysis

Peritonitis and exit-site infections are the main causes of complications in peritoneal dialysis. Death due to infectious complication is also one of the major causes of drop-out. The underlying cause of infection may include malnutrition. Total creatinine appearance (TCA) may reflect overall nutritional status. We determined TCA from the daily dialysate, urine, and estimated gut creatinine of patients and normalized it to actual body weight (nTCA). We examined the relationship between nTCA and the incidence of infection, and between nTCA and infection-related survival. The study included 323 adult patients in a single dialysis center. The mean nTCA of all patients was 19.73 +/- 4.75 mg/kg/day. The patients with an nTCA below 1 standard deviation from the mean (nTCA < 14.98 mg/kg/day) had a significantly higher peritonitis and exit-site infection rate (p < 0.01) and a higher chance of drop-out owing to infection-related complications (p < 0.0001). Our study concluded that the adult patient with malnutrition (nTCA < 14.98 mg/kg/day) has higher risk of infection.

Mechanisms involved in the inhibition of neointimal hyperplasia by abciximab in a rat model of balloon angioplasty

Monoclonal antibodies raised against beta(3) integrin are able to inhibit the binding of ligands to certain beta(3) integrins such as alpha(IIb)beta(3) (glycoprotein IIb/IIIa complex) and alpha(v)beta(3) (vitronectin receptor) and as such are inhibitors of platelet aggregation and smooth muscle cell (SMC) migration, both of which are involved in neointimal hyperplasia. The present study was designed to explore the detailed mechanisms of abciximab (Reopro), a monoclonal antibody (mAb) raised against alpha(IIb)beta(3) integrin in neointimal hyperplasia. In this study, carotid arteries of Wistar rats were damaged, and neointimal hyperplasia and lumen occlusion was determined at different time points. Abciximab was administered intravenously by an implanted osmotic pump. Abciximab (0.25 mg/kg/day) time-dependently inhibited both neointimal hyperplasia and lumen occlusion after angioplasty in carotid arteries of rats. Furthermore, the electromicrographs highlighted that SMCs were phenotypically different from the typical contractile, spindle-shaped SMCs normally seen in uninjured vessel walls. Platelet-derived growth factor (PDGF)-BB was strongly produced in thrombus formation and neointimal SMCs after angioplasty, while abciximab significantly reduced PDGF-BB expression in vessel lumens and neointimal SMCs after angioplasty. Balloon angioplasty caused a significant increase of nitrate and cyclic GMP as compared with sham-operated rats. Infusion of abciximab (0.25 mg/kg/day) did not significantly change. Furthermore, the plasma level of thromboxane B(2) (TxB(2)) obviously increased after angioplasty, while abciximab markedly suppressed the elevation of plasma TxB(2) concentration. The results indicate that abciximab effectively prevents neointimal hyperplasia, possibly through the following 2 mechanisms: (1) Abciximab binds to alpha(IIb)beta(3) integrin on platelet membranes resulting in inhibition of platelet adhesion, secretion, and aggregation in injured arteries, followed by inhibition of thromboxane A(2) formation and PDGF-BB release from platelets. (2) Abciximab may also bind to alpha(v)beta(3) integrin on SMCs, thus, subsequently inhibiting cell migration and proliferation.

Job stress and dissatisfaction in association with non-fatal injuries on the job in a cross-sectional sample of petrochemical workers

This cross-sectional study analysed the frequency and severity of work stressors and job satisfaction at workplaces in relation to work-related non-fatal injuries amongst a sample of petrochemical workers in Taiwan. The study participants consisted of 568 cases injured on the job between 1991 and 1997, and 954 injury-free controls matched to cases on frequencies of age, sex and work site. After adjusting for potential confounders, we found that cases were more likely than controls to report stressors with a higher frequency [odds ratio (OR) = 1.4, 95% confidence interval (CI) = 0.9-2.0] and a more severe reaction (OR = 1.3, 95% CI = 0.9-1.8). The dose-response analyses further indicated that the OR of injury was monotonically associated with stress reaction only (P for test for trend of ORs = 0.02). Job satisfaction, though, was unrelated to non-fatal injury. Although the cross-sectional nature of our study precludes a causal inference between stress reaction to stressors and risk of developing non-fatal injuries, our results tend to suggest that the severity of stress reaction is more associated with occupational non-fatal injury than is the frequency of stress or job dissatisfaction.

Modeling Competitive Adsorption of Molybdate, Sulfate, and Selenate on gamma-Al(2)O(3) by the Triple-Layer Model

Competitive adsorption of molybdate, sulfate, and selenate onto gamma-Al(2)O(3) was investigated in the present study. Binary solute systems of MoO(2-)(4)+SO(2-)(4), MoO(2-)(4)+SeO(2-)(4), and SO(2-)(4)+SeO(2-)(4) and a ternary solute system of MoO(2-)(4)+SO(2-)(4)+SeO(2-)(4) were evaluated to determine their relative effects on competitive adsorption on the gamma-Al(2)O(3) surface. Anionic competitive adsorption efficiency was pH dependent. The higher the pH, the lower the efficiency of MoO(2-)(4) in preventing SO(2-)(4) and SeO(2-)(4) adsorption; similar results were found in SeO(2-)(4) depressing SO(2-)(4) adsorption. This research found that more sites are occupied in mixed anionic adsorbate systems than when either ion is present alone. The results suggest that the gamma-Al(2)O(3) surface is composed of many groups of binding sites. Because of the heterogeneity of adsorption sites, the triple-layer model (TLM) predicted the competitive effects qualitatively but not quantitatively. TLM gave reasonable descriptions of molybdate adsorption in the presence of sulfate and selenate, indicating that the model may be useful in predicting molybdate adsorption on gamma-Al(2)O(3). Copyright 2001 Academic Press.

Liquid products from oxidative thermal treatment of oil sludge with different oxygen concentrations of air

Oxidative thermal treatment of oil sludge with different oxygen concentrations of air by using a dynamic thermogravimetric (TG) reaction system is investigated. The experimental conditions employed are: gas flow rate of 50 cm3/min (value at 298 K) for 300 mg dry waste, a constant heating rate of 5.2 K/min, the oxygen concentrations in air of 1.09, 8.62 and 20.95 vol. % O2, and the temperature (T) range of 378-873 K. From the experimental results, the residual mass fractions (M) are about 78.95, 28.49, 8.77 and 4.13 wt. % at the oxidative T of 563, 713, 763 and 873 K for the case with 20.95 vol. % O2, respectively. The values of M with 8.62 and 1.09 vol. % O2 at T of 873 K are 4.87 and 9.44 wt. %, respectively. The distillation characteristics of the oil portion of liquid products (condensates of gas at 298 K) from the oxidative thermal treatment of oil sludge with 20.95 vol. % O2 at T of 378-873 K is close to those of commercial gasoline. Nevertheless, the liquid product contains a large amount of water. The distillation characteristics of the oil portions of liquid products with 8.62 and 1.09 vol. % O2 at T of 378-873 K are close to those of diesel and fuel oils, respectively. The oil quality with 8.62 vol. % O2 is better than that with 1.09 vol. % O2. However, the liquid product with 8.62 vol. % O2 still contains a large amount of water; nonetheless, that with 1.09 vol. % O2 is with negligible water. Compared with the oil product of nitrogen pyrolysis, the oil quality with 1.09 vol. % O2 is better. Certainly, low oxygen conditions (i.e. 1.09 vol. % O2) not only accelerate the thermal reaction of oil sludge, but also at the same time avoid or reduce the production of water. Further, from the analysis of benzene (B), ethylbenzene (E), toluene (T) and iso-xylene (X) concentrations of the oil portion of liquid products, the BETX concentrations of oil with 20.95 vol. % O2 are higher than those with 8.62 and 1.09 vol. % O2. The yields of liquid products with 20.95, 8.62 and 1.09 vol. % O2 at T of 378-873 K are 31.96, 34.42 and 37.3 wt. %, respectively. From the experimental results, the improvement effects of oxygen on the qualities of the oil portion of liquid products are obvious. The above technique not only formats good quality gasoline and diesel oils but also reduces large amount of oil sludge. If the oil exists with water, it may be obtained by further separation or collected by fractional condensation.

iProClass: an integrated, comprehensive and annotated protein classification database

The iProClass database is an integrated resource that provides comprehensive family relationships and structural and functional features of proteins, with rich links to various databases. It is extended from ProClass, a protein family database that integrates PIR superfamilies and PROSITE motifs. The iProClass currently consists of more than 200,000 non-redundant PIR and SWISS-PROT proteins organized with more than 28,000 superfamilies, 2600 domains, 1300 motifs, 280 post-translational modification sites and links to more than 30 databases of protein families, structures, functions, genes, genomes, literature and taxonomy. Protein and family summary reports provide rich annotations, including membership information with length, taxonomy and keyword statistics, full family relationships, comprehensive enzyme and PDB cross-references and graphical feature display. The database facilitates classification-driven annotation for protein sequence databases and complete genomes, and supports structural and functional genomic research. The iProClass is implemented in Oracle 8i object-relational system and available for sequence search and report retrieval at http://pir.georgetown.edu/iproclass/.

Progress toward a synthetic virus : a multicomponent system for liver-directed DNA delivery

Vectors for gene transfer can be categorized as viral and nonviral. The advantages of nonviral carriers are their ease of preparation and scale-up, flexibility regarding the size of DNA to be transferred, and safety in vivo. Despite these advantages, nonviral vectors need to be further optimized for their efficiency is generally low. Thus, the future of non-viral vectors will be dependent on the possibility of creating synthetic efficient systems. A possible and reasonable approach is to develop artificial nucleic acid carriers that incorporate functional elements mimicking viruses.