Multioctave midinfrared supercontinuum generation in suspended-core chalcogenide fibers

An As2S3 fiber-based supercontinuum source that covers 3500 nm, extending from near visible to the midinfrared, is successfully reported by using a 200-fs-pulsed pump with nJ-level energy at 2.5 μm. The main features of our fiber-based source are two-fold. On the one hand, a low-loss As2S3 microstructured optical fiber has been fabricated, with typical attenuation below 2 dB/m in the 1-4 μm wavelength range. On the other hand, a 20-mm-long microstructured fiber sample is sufficient to enable a spectral broadening, spreading from 0.6 to 4.1 μm in a 40 dB dynamic range.

Detection of submicroscopic chromosomal aberrations by array-based comparative genomic hybridization in fetuses with congenital heart disease

OBJECTIVES

To evaluate the usefulness of array-based comparative genomic hybridization (aCGH) for prenatal genetic diagnosis of congenital heart disease (CHD), with and without associated anomalies, and to explore the relationship between submicroscopic chromosomal aberrations and CHD.

METHODS

In this prospective study we investigated 76 consecutive singleton fetuses with abnormal cardiac ultrasound findings, normal karyotype and negative or no fluorescence in-situ hybridization results for 22q11.2 deletion syndrome. All pregnancies underwent aCGH in a comprehensive search for chromosomal aberrations. The relationship between copy number variations (CNVs) and CHD was determined by comparing clinical findings to chromosomal databases.

RESULTS

CNVs that were benign or had no clinical significance were detected in 18/76 (23.7%) cases. CNVs of unknown clinical significance (i.e. VOUS) were detected in 4/76 (5.3%) cases. Pathogenic CNVs were detected in 5/76 (6.6%) cases. Fetuses with CHD and additional structural abnormalities demonstrated no difference in number of pathogenic CNVs when compared with fetuses with isolated CHD (7.4% (n = 2/27) vs 6.1% (n = 3/49), P > 0.05).

CONCLUSION

In this study cohort, aCGH analysis significantly improved the detection of submicroscopic chromosomal aberrations in pregnancies with CHD, as compared with conventional cytogenetics. Our results suggest that aCGH can provide additional genetic information in fetuses with abnormal heart findings.

Fenofibrate increases serum vaspin by upregulating its expression in adipose tissue

Fenofibrate is a peroxisome proliferator-activated receptor-α that has been clinically used to treat dyslipidemia and insulin resistance. To better understand the molecular mechanisms underlying fenofibrate action, we investigated whether fenofibrate affects serum levels of vaspin, an adipocytokine that has recently been shown to link obesity and insulin resistance. Fenofibrate treatment significantly increased serum vaspin levels of dyslipidemic patients, which correlated with reduced body weight and increased insulin sensitivity. To elucidate the biochemical mechanisms of fenofibrate action, we investigated the effect of fenofibrate on vaspin mRNA and protein expressions in obese rats. Fenofibrate greatly increased vaspin mRNA and protein levels in visceral adipose tissue consisting of retroperitoneal, mesenteric, and periepididymal adipose tissue but not in the subcutaneous adipose tissue, which correlated with increased serum vaspin levels and increased insulin sensitivity in obese rats. Consistent with a direct effect on vaspin expression, fenofibrate treatment significantly increased the mRNA and protein expression levels of vaspin in 3T3-L1 adipocytes. Together, our results demonstrate for the first time that fenofibrate upregulates vaspin expression in dyslipidemic human subjects and suggest that upregulation of vaspin expression in adipocytes may provide a mechanism by which fenofibrate improves insulin sensitivity in dyslipidemic patients.

Acromegaly and diabetes mellitus associated with hyperthyroidism

A 66-year-old woman with acromegaly and diabetes mellitus as well as primary hyperthyroidism is described. Serum GH Levels were inappprpriately high.MRI revealed an enlarged sella turcica with intrasellar mass. Her HbAlc was 12.2% and fasting blood glucose 8.89 mmol/l. Thyroid hormone levels in serum and thyroidal radioiodine uptake values were elevated, while TSH measurements in serum were low. Anti TPO antibodies were negative, TSH receptor antibodies were normal. Thyrotoxicosis as the first presenting illness in acromegaly was particulary uncommon. An ultrasound thyroid scan showed a multinodular goiter. Histology of the pituitary lesion showed a typical eosinophilic adenoma which only secreted GH when tested with specific immunostain. Post-operatively, the patient's clinical conditions improved, however, secondary hypoadrenalism appeared.

Cell cytoskeletal changes effected by static compressive stress lead to changes in the contractile properties of tissue regenerative collagen membranes

Static compressive stress can influence the matrix, which subsequently affects cell behaviour and the cell's ability to further transform the matrix. This study aimed to assess response to static compressive stress at different stages of osteoblast differentiation and assess the cell cytoskeleton's role as a conduit of matrix-derived stimuli. Mouse bone marrow mesenchymal stem cells (MSCs) (D1 ORL UVA), osteoblastic cells (MC3T3-E1) and post-osteoblast/pre-osteocyte-like cells (MLO-A5) were seeded in hydrated and compressed collagen gels. Contraction was quantified macroscopically, and cell morphology, survival, differentiation and mineralisation assessed using confocal microscopy, alamarBlue® assay, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and histological stains, respectively. Confocal microscopy demonstrated cell shape changes and favourable microfilament organisation with static compressive stress of the collagen matrix; furthermore, cell survival was greater compared to the hydrated gels. The stage of osteoblast differentiation determined the degree of matrix contraction, with MSCs demonstrating the greatest amount. Introduction of microfilament disrupting inhibitors confirmed that pre-stress and tensegrity forces were under the influence of gel density, and there was increased survival and differentiation of the cells within the compressed collagen compared to the hydrated collagen. There was also relative stiffening and differentiation with time of the compressed cell-seeded collagen, allowing for greater manipulation. In conclusion, the combined collagen chemistry and increased density of the microenvironment can promote upregulation of osteogenic genes and mineralisation; MSCs can facilitate matrix contraction to form an engineered membrane with the potential to serve as a 'pseudo-periosteum' in the regeneration of bone defects.

QTL involved in the modification of cyanidin compounds in black and red raspberry fruit

Fruit from Rubus species are highly valued for their flavor and nutritive qualities. Anthocyanin content contributes to these qualities, and although many studies have been conducted to identify and quantify the major anthocyanin compounds from various Rubus species, the genetic control of the accumulation of these complex traits in Rubus is not yet well understood. The identification of the regions of the genome involved in the production of anthocyanins is an important first step in identifying the genes underlying their expression. In this study, ultra and high-performance liquid chromatography (UHPLC and HPLC) and two newly developed Rubus linkage maps were used to conduct QTL analyses to explore the presence of associations between concentrations of five anthocyanins in fruit and genotype. In total, 27 QTL were identified on the Rubus linkage maps, four of which are associated with molecular markers designed from transcription factors and three of which are associated with molecular markers designed from anthocyanin biosynthetic pathway candidate genes. The results of this study suggest that, while QTL for anthocyanin accumulation have been identified on six of seven Rubus linkage groups (RLG), the QTL on RLG2 and RLG7 may be very important for genetic control of cyanidin modification in Rubus.

Promoter methylation of BRCA1 in triple-negative breast cancer predicts sensitivity to adjuvant chemotherapy

BACKGROUND

BRCA1 function is inactivated through BRCA1 promoter methylation in a substantial number of triple-negative breast cancers. We investigated the impact of BRCA1-methylation status on the efficacy of adjuvant chemotherapy in patients with triple-negative breast cancer or with non-triple-negative breast cancer.

METHODS

BRCA1 promoter methylation was assessed in 1163 unselected breast cancer patients. Methylation was evaluated using a methylation-specific PCR (MSP) assay.

RESULTS

In the subgroup of 167 triple-negative breast cancer patients who received adjuvant chemotherapy, patients with BRCA1-methylated tumors had a superior 10-year disease-free survival (DFS)(78% versus 55%, P = 0.009) and 10-year disease-specific survival (DSS) (85% versus 69%, P = 0.024) than those with BRCA1-unmethylated tumors, and BRCA1 methylation was an independent favorable predictor of DFS and DSS in a multivariate analysis in this subgroup [DFS: hazard ratio (HR) = 0.45; 95% confidence interval (CI) 0.24-0.84; P = 0.019; DSS: HR = 0.43; 95% CI = 0.19-0.95; P = 0.044]. In contrast, in 675 non-triple-negative breast cancer patients who received adjuvant chemotherapy, BRCA1 methylation was an unfavorable predictor of DFS and DSS in univariate analysis (DFS: HR = 1.56; 95% CI 1.16-2.12; P = 0.003; DSS: HR = 1.53; 95% CI = 1.05-2.21; P = 0.026).

CONCLUSIONS

Triple-negative breast cancer patients with BRCA1-methylated tumors are sensitive to adjuvant chemotherapy and have a favorable survival compared with patients with BRCA1-unmethylated triple-negative tumors.

Botulinum toxin injections combined with or without sodium hyaluronate in the absence of electromyography for the treatment of infantile esotropia: a pilot study

OBJECTIVE

To evaluate the feasibility and safety of a revised technique of botulinum toxin type A (BTA) injections for the treatment of infantile esotropia.

METHODS

Forty-seven patients with infantile esotropia were randomly divided into two groups. In group A, 23 cases were treated with a bilateral injection of 2.5-3.75 U BTA combined with sodium hyaluronate (SH) to the medial rectus muscle. In group B, 24 cases were treated with a bilateral injection of 2.5-3.75 U BTA solution alone to the medial rectus muscle. Electromyography was not used in the study. All patients received one injection and were evaluated 2 weeks, 3 months, and 6 months following injection.

RESULTS

The measured changes between groups A and B included the frequencies of good alignment 6 months after injections (30.4% vs 37.5%), complicated ptosis (2.2% vs 20.8%), and vertical deviation (2.2% vs 2.1%).

CONCLUSION

BTA injections combined with or without SH in the absence of electromyography demonstrated effectiveness and feasibility in the treatment of infantile esotropia. A relative decrease in the frequency of complicated ptosis resulted from injections of BTA+SH.

Antibody targeting of anaplastic lymphoma kinase induces cytotoxicity of human neuroblastoma

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in neuroblastoma, a devastating pediatric cancer of the sympathetic nervous system. Germline and somatically acquired ALK aberrations induce increased autophosphorylation, constitutive ALK activation and increased downstream signaling. Thus, ALK is a tractable therapeutic target in neuroblastoma, likely to be susceptible to both small-molecule tyrosine kinase inhibitors and therapeutic antibodies-as has been shown for other receptor tyrosine kinases in malignancies such as breast and lung cancer. Small-molecule inhibitors of ALK are currently being studied in the clinic, but common ALK mutations in neuroblastoma appear to show de novo insensitivity, arguing that complementary therapeutic approaches must be developed. We therefore hypothesized that antibody targeting of ALK may be a relevant strategy for the majority of neuroblastoma patients likely to have ALK-positive tumors. We show here that an antagonistic ALK antibody inhibits cell growth and induces in vitro antibody-dependent cellular cytotoxicity of human neuroblastoma-derived cell lines. Cytotoxicity was induced in cell lines harboring either wild type or mutated forms of ALK. Treatment of neuroblastoma cells with the dual Met/ALK inhibitor crizotinib sensitized cells to antibody-induced growth inhibition by promoting cell surface accumulation of ALK and thus increasing the accessibility of antigen for antibody binding. These data support the concept of ALK-targeted immunotherapy as a highly promising therapeutic strategy for neuroblastomas with mutated or wild-type ALK.

Controlling physiological angiogenesis by hypoxia-induced signaling

The full sequence of signals leading to new blood vessel formation is a physiological response to tissue hypoxia through upregulation of angiogenic factor cascades. Controlled initiation of this mechanism for therapeutic/engineered angiogenesis must rely on precisely localized hypoxia. Here we have designed a 3D in vitro model able to test the effect and predictability of spatially positioned local hypoxic stimuli using defined cell depots within a 3D collagen matrix. Cell-mediated hypoxia was engineered using human dermal fibroblasts (HDFs), to generate a local population of Hypoxia-Induced Signaling (HIS) cells. HIS cell depots released angiogenic factors which induced directional endothelial cell (EC) migration and tubule formation in a spatially defined assay system. Non-hypoxic baseline control cultures induced minimal EC migration with little tubule formation. Furthermore, depots of HIS cells, positioned in the core of 3D collagen constructs directed host vessel in-growth deep into the implant by 1 week, which was at least 7 days earlier than in non-hypoxia pre-conditioned constructs. The functionality of in vivo vascularisation was verified by real-time monitoring of O2 levels in the core of implanted constructs. These findings establish the angiogenic potential of HIS cells applicable to in vitro tissue modeling, implant vascularization and engineering predictable angiogenic therapies.

Trichosanthin, an extract of Trichosanthes kirilowii, effectively prevents acute rejection of major histocompatibility complex-mismatched mouse skin allograft

Trichosanthin is an active component extracted from the root tuber of the Chinese medicinal herb Trichosanthes kirilowii. Trichosanthin has abortifacient, anti-tumor, anti-HIV, and immunoregulatory functions. In the current study, we explored its potential effect on allograft rejection in a murine skin transplantation model across a fully mismatched major histocompatibility complex. It was found that treatment of recipient mice with trichosanthin (0.25 or 1 mg/kg, IP) significantly delayed allograft rejection. T cells that originated from recipients treated with trichosanthin were restimulated with donor-specific splenocytes showed a significantly reduced response compared with that of control recipients. In line with these results, the mRNA levels for interleukin (IL)-2 and interferon-gamma were decreased and the levels of IL-4 and IL-10 were increased in splenic T cells originating from trichosanthin-treated recipients. These results indicated that trichosanthin may have potential therapeutic value for transplantation rejection and other inflammatory diseases.

Combination of CsA, MTX and low-dose, short-course mycophenolate mofetil for GVHD prophylaxis

In an effort to reduce the incidence and severity of acute GVHD (aGVHD), we have developed a new prophylaxis regimen combining cyclosporine and MTX with a short 30-day course of low-dose (500 mg per day) mycophenolate mofetil. This regimen was studied prospectively 100 patients undergoing HLA-matched and 1-antigen-mismatched allogeneic peripheral blood SCT from related donors. The cumulative incidence of aGVHD was 16% (grades II-IV (9.5%) and grades III-IV (1%)). The cumulative incidence of chronic GVHD (cGVHD) was 53% with 28% extensive cGVHD. The cumulative incidence of transplant-related mortality at 100 days and 3 years were 6 and 13%. The estimated probabilities of disease-free survival at 3 years in standard- and high-risk patients were 77 and 30%, respectively (P<0.0001). The estimated probabilities of overall survival at 3 years in standard- and high-risk patients were 77 and 37%, respectively (P<0.0001). These data show a substantial decrease in the risk of developing aGVHD without an increase in relapse or any adverse impact on survival in standard-risk patients.

Hyperhexosemia induced functional and structural changes in the kidneys: role of endothelins

BACKGROUND/AIMS

Glomerular basement membrane (GBM) thickening and mesangial matrix expansion are characteristic features of diabetic nephropathy. The present study investigates the role of endothelins (ETs) in the pathogenesis of such changes in diabetic nephropathy.

METHODS

Diabetic (streptozotocin-induced, 65 mg/kg), galactose-fed (30%) and control animals were followed up for 1 and 6 months. Animal groups also included diabetic and galactose fed animals on dual ET(A)/ET(B) receptor antagonist bosentan (100 mg/kg). A semi-quantitative reverse transcription polymerase chain reaction method was used to quantify mRNA expression of ET-1, ET-3, ET(A), ET(B), fibronectin and collagen alpha2(IV). Histological analyses of the kidneys and ET-1, ET-3 and fibronectin immunohistochemistry were performed. Morphometric assessment of the GBM after 6 months was performed.

RESULTS

Diabetes increased mRNA expression of ET-1, ET-3, ET(A), ET(B), fibronectin and collagen alpha2(IV) after one and six months. In contrast, although increased ET(A) and ET(B) mRNAs were present following galactose feeding both at 1 and 6 months, ET-1, ET-3, fibronectin and collagen alpha2(IV)mRNAs were increased after 6 months. Both diabetes and galactose feeding caused increased GBM thickening. Furthermore, diabetes caused an increase in mesangial matrix production. Bosentan prevented increased fibronectin and collagen alpha2(IV) mRNA expression, increased mesangial matrix deposition and GBM thickening.

CONCLUSION

This study has demonstrated that diabetes and galactose feeding induced functional and structural changes in the kidney are mediated via ETs.

[Inhibitive effects of lip repair on maxillary growth in patients with complete unilateral cleft lip and palate]

OBJECTIVE

The aim of this study was to assess the isolated effects of lip repair on inhibition of maxillary growth in patients with complete unilateral cleft lip and palate.

METHODS

The lateral cephalometric analysis were applied to 20 patients with unilateral cleft lip and palate who only had lip repaired in childhood, 32 patients with unilateral cleft lip and palate who had both lip and palate repaired in childhood, as well as 37 normal Chinese of the same age as controls.

RESULTS

Both complete unilateral cleft lip and palate groups had almost the same significant degree of maxillary retrusion compared with the normal control group.

CONCLUSION

Lip repair is one of important factors that could inhibit maxillary growth in patients with complete unilateral cleft lip and palate.

[The effect of lip repair on maxillary growth in patients with complete unilateral cleft lip and(or) palate]

OBJECTIVE

To investigate the different effects of lip repair on maxillary growth among patients with cleft lip and(or) palate, and also the possible mechanisms accounting for that differences.

METHODS

The lateral cephalometric analysis was applied to 84 Chinese patients with unilateral cleft lip and(or) palate at the early stage of permanent dentition, which included 32 UCLA, 20 UCLP (CP unrepaired), and 32 UCLP, and 37 normal Chinese of the same age as controls.

RESULTS

The patients with unilateral cleft lip and palate who had lip repaired while the palate was left unrepaired exhibited the similar inhibition on maxillary growth to those who had both lip and palate repaired but the patients with unilateral cleft lip and alveolus had much less inhibition on their maxilla.

CONCLUSIONS

The cleft and tissue defect of patients with cleft lip and palate might be the main cause that induced the inhibitive effects of lip repair on maxillary growth.

Helicobacter spp. infection in cats: evaluation of the humoral immune response and prevalence of gastric Helicobacter spp

The principal aims of this study were to evaluate the humoral immune response (IgG) of cats with gastric Helicobacter spp. infection, and to determine the prevalence of different types of Helicobacter spp. in the stomachs of cats. The Helicobacter infection status of 45 cats (12 healthy spay/neuter cats, 9 sick cats, 24 colony cats) was determined by evaluating endoscopic gastric biopsies for urease activity, presence of Helicobacter-like organisms (HLO) on histopathology, and genus and species-specific PCR. Serum samples were evaluated with a kinetic enzyme linked immunosorbent assay (ELISA) utilizing the high molecular cell-associated protein (HM-CAP) fraction of H. felis ATCC 49179.Seventeen of 45 cats were infected with Helicobacter spp.: "H. heilmannii" 9/17, H. felis 4/17, mixed "H. heilmannii" and H. felis 3/17, unclassified-Helicobacter spp. 7/17. H. pylori was not detected in any cat. Kinetic ELISA results were significantly higher for infected cats, than for uninfected cats. Cats infected with different Helicobacter spp. showed similar distribution of OD/min values. There were no effects of age or clinical signs on the results of kinetic ELISA. No correlation between colonization density and seroconversion was observed. There were statistically significant, but weak correlations between the degree of seroconversion and the degree of inflammation, and the number of lymphoid follicles. Infected cats had more severe inflammation in the pylorus and fundus than uninfected cats. Infected sick cats had a higher degree of pyloric, but not fundic inflammation, than healthy infected cats and uninfected sick cats. The results indicate that naturally acquired infection with gastric Helicobacter spp. is associated with seroconversion (IgG) in cats. The similar ELISA values in cats infected with a variety of Helicobacter spp. suggests substantial antigenic homology between different Helicobacter spp. The higher degree of inflammation in infected than uninfected cats, supports a role for Helicobacter as a cause of gastritis in cats.

Ovine metabolism of saponins: evaluation of a method for estimating the ovine uptake of steroidal saponins from Narthecium ossifragum

A sheep was dosed three times per day over six consecutive days with 70 g Narthecium ossifragum, and once on the seventh day with 70 g N. ossifragum. Additionally, it was dosed once on days 1-7 with 20 mg of [20,23,23-2H3]sarsasapogenin. After 7 days, the sheep was killed and GC-MS analysis of the free and conjugated sapogenin content in bile, urine, rumen, duodenum, jejunum, colon and rectum samples collected from the sheep, faecal samples collected on days 4-7, and dosed plant material was performed. The N. ossifragum contained mainly sarsasapogenin and smilagenin. Only neglible levels of deuterium-labelled sarsasapogenins were detected in the samples from the animal. Ingested saponins were quickly hydrolysed in the rumen to free sapogenins and, in part, epimerized at C-3 to afford episapogenins. The absorption of free sapogenins appeared to occur in the jejunum. The concentration of sapogenins in faeces reached a plateau 108 h after dosing started.

[Analysis of the methylation in CpG island by denaturing high-performance liquid chromatography]

OBJECTIVE

To establish a new approach for analyzing methylation circumventing the limitations of the existing methods.

METHODS

A region containing CpG sites in mismatch repair gene hMLH1 promoter was amplified by strand-specific polymerase chain reaction (PCR) after sodium bisulfite treatment. The retention time of the PCR product at partially denaturing temperature was determined by denaturing high-performance liquid chromatography (DHPLC). The methylation status obtained by DHPLC was proved by comparing it with that from sodium bisulfite-restriction enzyme digestion.

RESULTS

Methylation of hMLH1 promoter from a colorectal cancer cell line RKO and a gastric cancer cell line PACM82 was analyzed by DHPLC. The retention time of the PCR product from RKO was obviously longer than that from PACM82 (6.7 min vs. 6.2 min). Thus, it was concluded that the hMLH1 promoter from RKO was methylated, while that from PACM82 was not, since the longer retaining time of RKO was due to the higher C/G content after sodium bisulfite treatment. The results from DHPLC were consistent with those from sodium bisulfite-restriction enzyme digestion.

CONCLUSION

DHPLC method is a rapid and reliable approach for analyzing methylation in CpG island of the sequence of interest.

[Diagnosing complicated congenital heart disease with two-dimensional echocardiography and three-segment concept]

OBJECTIVE

To apply three-segment heart anatomy concept to two-dimensional echocardiography (2DE) in the diagnosis of complicated congenital heart disease (CHD).

METHODS

920 cases of CHD were diagnosed with 2DE and three-segment heart anatomy concept. 822 out of the 920 cases underwent angiocardiography, and 584 cases were confirmed by operation.

RESULTS

According to three-segment heart anatomy concept of atrial position, 855 cases were situs solitus (including 89 cases of left superior vena cava and 31 cases of complete anomalous pulmonary venous drainage), 53 cases were situs inversus, and 12 cases were situs ambigus. As to atrial-ventricular valve, 747 cases were both opening, 112 cases had one-side atresia, and 61 cases had one together valve; As to ventricle position, 606 cases were dextro-loop, 111 cases had levo-loop, and 203 cases had single ventricle (including 24 cases), As to cor biloculare of great artery relation, 304 cases had normal relation of great arteries, including 35 cases of pulmonary atresia, 219 cases had right-transposition of great arteries, 240 cases had left-transposition of great arteries, 32 cases were mirror to normal, and 25 cases had persistent truncus arteriosus. 823 cases were diagnosed with 2DE, with a total accurate rate of 89.5%.

CONCLUSION

Applying three-segment heart anatomy concept to 2DE to diagnose complicated CHD and analyzing the heart segment by segment will make the diagnosis simple and systematic, providing a concise basis for heart surgeries.

Formation of N-(Nitrosomethyl)urea in stomachs of experimental pigs and human volunteers given fish sauce in vivo

N-(Nitrosomethyl)urea (NMU) was characterized in carcinogenic nitrosated fish sauce recently (Deng et al. J. Agric. Food Chem. 1998, 46, 202-205; Biomed. Environ. Sci. 1999, 12, 54-61). To study the possibility of intragastric synthesis of NMU, experimental mini-pigs surgically fitted with a flexible stomach cannula and human volunteers were used. Fish sauce samples (20-30 mL) and nitrite were injected into the gastric lumen through the cannula for pigs or taken orally for human volunteers. Gastric juice samples were taken out 30 min later. Concentration of NMU in condensed extracts of these samples was analyzed with HPLC-photohydrolysis-pyrolysis-thermal energy analyzer. Results showed that there was formation of NMU in the gastric lumen of both models in vivo and that the formation of NMU was nitrite- and pH-dependent. NMU was also detectable in the condensed extract of 100 mL of a mixture of pooled fasting human gastric juice samples and fish sauce sample (9:1, v/v) after treatment with 500 micromol/L of nitrite in vitro. In conclusion, there is intragastric formation of NMU, even at natural amounts of nitrite.

[Study on composition of plaque fluid in individuals with no oral hygiene]

OBJECTIVE

To study the change of composition in long-term plaque fluid after sucrose rinse and the cariogenicity of plaque.

METHODS

43 subjects, who had no regular oral hygiene and no tooth brushing at least for one year, were selected. According to their caries status, 27 as caries-free group and 16 as caries-positive group. Plaque were obtained before and at 7 minutes after a 10% sucrose rinse. Additionally, plaque samples of 15 and 30 minutes after sucrose rinse from 11 subjects were collected. The pH value and the concentrations of organic acids and inorganic ions in plaque fluid were measured.

RESULTS

At 7 minutes after sucrose rinse, pH and the concentration of ammonium were significantly decreased, and the concentrations of lactic acid and formic acid were significantly increased. All these changes were similar to those of short-term plaque. No significant difference with any single component of plaque fluid was found between caries-free group and caries-positive group, neither before sucrose rinse nor after sucrose rinse.

CONCLUSIONS

Changes of the composition in the plaque fluid were basically similar between long-term and short-term plaque, but single component in plaque fluid could not reflect the cariogenicity of plaque.

[A study on formation of N-(nitrosomethyl) urea in experimental pig stomach gavaged with fish sauce]

OBJECTIVE

To study formation of N-(nitrosomethyl) urea (NMU), which is categorized as N-nitrosamides -- a sort of strong chemical carcinogen, by perfusion with fish sauce via pig stomach fistula, which is used daily as cooking flavor by local residents in Changle County, Fujian Province, a highly-prevalent area for gastric cancer.

METHODS

Fistulization was performed in fasting experimental pigs' stomach, and their gastric juice was suctioned 30 minutes after perfusion with fish sauce and sodium nitrite via fistula. Gastric juice specimen was purified and concentrated and determined for NMU with high performance liquid chromatography-photolysis pyrolysis-thermal energy analyzer.

RESULTS

NMU was detected in the pig stomach at pH 1 - 2, where NMU formed. Formation of NMU depended on the amount of nitrite added in a dose-dependent relationship. Level of NMU in gastric juice reached 25.4 and 7.97 micromol/L, respectively, when 3.48 and 0.87 mmol of sodium nitrite were fed into the stomach. No NMU could be detected, as 0.22 mmol of sodium nitrite fed.

CONCLUSION

Under the condition of pH 1 - 2 and presence of sodium nitrite, NMU was synthesized in the stomachs of experimental pigs fed with fish sauce via gastric fistula. It is postulated that N-nitrosamides, such as NMU could be formed endogenously in the stomachs of local residents who consume fish sauce often and have a higher exposure to nitrite in their stomachs.

Diabetes-induced vascular dysfunction in the retina: role of endothelins

AIMS/HYPOTHESIS

Vasoactive factors like endothelins, by virtue of the microvascular regulation as well as by other effects, possibly play important parts in the pathogenesis of diabetic retinal microangiopathy. We investigated retinal vascular dysfunction in streptozotocin-induced diabetes and its relation with endothelins in short- and long-term diabetes.

METHODS

Diabetic rats with or without an endothelin receptor antagonist (bosentan) treatment were investigated after 1 month and 6 months of follow-up. Retinal blood flow was measured and compared with age- and sex-matched non-diabetic control animals. Retinal tissues were analysed for endothelin-1, endothelin-3, endothelin A and endothelin B mRNA. Distribution of endothelin-1 and endothelin-3 was investigated by immunocytochemistry and that for endothelin receptors by ligand binding and autoradiography.

RESULTS

Diabetic animals showed hyperglycaemia, glycosuria, elevated glycated haemoglobin values and reduced body weight gain. Retinal blood flow showed an increased resistivity index, an indicator of vasoconstriction, after 1 month of diabetes which was prevented by treatment with bosentan. This functional change in diabetes was eliminated after 6 months of follow-up. The retina from the diabetic animals showed increased mRNA expression for endothelin-1, endothelin-3 and endothelin A after one month. In addition, endothelin B mRNA expression was increased after 6 months. Furthermore, endothelin-1 and endothelin-3 immunoreactivity and endothelin receptor concentrations were increased in the retina of diabetic rats.

CONCLUSION/INTERPRETATION

The results from this study indicate that the endothelin system is of importance in mediating retinal changes in diabetes although mechanisms of the endothelin system alteration as well as their effects might vary depending on the duration of diabetes. [Diabetologia (1999) 42: 1228-1234]

Corneal topographical changes following strabismus surgery

PURPOSE

To study corneal topographical changes after strabismus surgery.

METHODS

Computer-aided corneal topography was used in 43 strabismus patients (45 eyes) one or two days prior to and six or seven days after strabismus surgery. The spherical and cylindrical equivalents were calculated based on the simulated keratometry.

RESULTS

After the surgery, only the changes at 3 mm in the inferior quadrant were statistically significant. The changes at 3 mm in the rest quadrants and the changes at 7 mm were not significant. Significant changes in spherical equivalent were found post-operatively. Neither the horizontal nor the vertical meridional equivalent showed significant changes after surgery.

CONCLUSIONS

The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

Chromogranin A in the central nervous system of the rat: pan-neuronal expression of its mRNA and selective expression of the protein

Chromogranin A, a glycoprotein stored in secretory granules of neuroendocrine cells, displays a widespread distribution throughout the central nervous system of a variety of species. In situ hybridization histochemistry was employed to investigate the localization of chromogranin A mRNA in the central nervous system of the rat. The previously characterized monoclonal antibody, LK2H-10, was employed in an immunohistochemical study to compare the topographic localization of the chromogranin A protein with that of its mRNA. Although the latter, as revealed by in situ hybridization, displayed a ubiquitous, pan-neuronal localization throughout the rat brain, LK2H-10 immunoreactive cell bodies and axon terminals were disposed in a widespread, but highly regionally differential, distribution. This discrepancy suggests that chromogranin A is processed in a regionally differential fashion in the rat brain to yield one or multiple variant forms, one of which is specifically recognized by LK2H-10. Catecholaminergic cell groups consistently displayed LK2H-10 immunoreactivity. LK2H-10 immunopositive axon terminals were prominent in the circumventricular organs. In addition, LK2H-10 immunoreactivity was also detected in a subset of astrocytes which demonstrated a widespread, but anatomically restricted, pattern of distribution. Consequently, the variant of chromogranin A labelled by LK2H-10 represents a novel neurochemical marker for regionally differential astrocytic diversity.

Parathyroid hormone-related proteins is abundant in osteoarthritic cartilage, and the parathyroid hormone-related protein 1-173 isoform is selectively induced by transforming growth factor beta in articular chondrocytes and suppresses generation of extracellular inorganic pyrophosphate

OBJECTIVE

Parathyroid hormone-related protein (PTHrP) is a major, locally expressed regulator of growth cartilage chondrocyte proliferation, differentiation, synthetic function, and mineralization. Because mechanisms that limit cartilage chondrocytes from maturing and mineralizing are diminished in osteoarthritis (OA), we studied PTHrP expression by articular chondrocytes.

METHODS

PTHrP was studied in normal knee cartilage samples and cultured articular chondrocytes, and in cartilage specimens from knees with advanced OA, obtained at the time of joint replacement.

RESULTS

PTHrP was more abundant in OA than in normal human knee articular cartilage. Both demonstrated PTH/PTHrP receptor expression. PTHrP 1-173, one of three alternatively spliced PTHrP isoforms, was exclusively expressed and induced by transforming growth factor beta in cultured chondrocytes. Chondrocytes mainly used the GC-rich P2 alternative promoter to express PTHrP messenger RNA. Inhibition by PTHrP 1-173, but not by PTHrP 1-146 or PTHrP 1-87, of inorganic pyrophosphate (PPi) elaboration suggested selective functional properties of the 1-173 isoform. Exposure to a neutralizing antibody to PTHrP increased PPi elaboration by articular chondrocytes.

CONCLUSION

Increased expression of PTHrP, including the 1-173 isoform, has the potential to contribute to the pathologic differentiated functions of chondrocytes, including mineralization, in OA.

[The influence of implantal autograft bone in total cleft palate on maxillary growth an experiment study in dogs]

OBJECTIVE

To test the hypothesis that implant autograft bone in total cleft palate at primary cleft palate repair which may resists the disturbance of maxillary growth by cleft and denud bony wound.

METHODS

40 dogs were randomly divided into four groups: three control groups and one experimental group. The first control group was unoperated, the second group had a surgically created cleft plate, the third group also had a surgically created cleft palate. Using a two-flap procedure immidiately, the experiment group had a surgically created cleft palate, but the palate was recontracted by implanting a piece of autograft rib bone with two-flap repair. All animals were sacrificed on the 34th week after operation (43 weeks postnatal). Thirty-four metricranial variables were measured directy from the cleaned skulls.

RESULTS

The method is useful for maxillary growth and development by bone implant in total cleft palate, but it can cause maxillary deformity.

CONCLUSION

Clinical doctors should be cautious in using the method of primary-delay bone grafting in reparing total cleft of cleft palate.

Characterization of N-(Nitrosomethyl)urea in Nitrosated Fermented Fish Products

To characterize chemical carcinogens in acidic-nitrosated fish sauce sample, N-nitrosamides in the sample were separated by two kinds of reversed-phase HPLC columns, and with detection by photolysis-pyrolysis-thermal energy analyzer. A strong chromatographic peak at t(R) 12 or 4.5 min, same as that for N-(nitrosomethyl)urea (NMU), was obtained on PRP-1 or C(18) HPLC column from fish sauce sample with 10 mM trifluoroacetic acid as the basic mobile; acetonitrile, as organic modifier after the sample was nitrosated by 5 mmol/L of sodium nitrite (final concentration) at 37 degrees C and pH 2.0 for 1 h. No response above t(R) could be observed from the nitrosated sample in the detection system without photolysis. Such a peak could not be obtained from the unnitrosated fish sauce either. These results indicated that the component was NMU. Furthermore, this component, NMU, could also be detected in the nitrosated human gastric juice sample spiked with fish sauce. The formation of NMU in the sample was pH- and nitrite-dependent. This paper provides direct evidence that NMU formation could occur in fish sauce from the high-risk area for stomach cancer and in the fish sauce spiked human gastric juice during nitrosation under simulated gastric conditions.

[A study of human papillomavirus infection during pregnancy and transmission of virus to fetus]

To study the human papillomavirus (HPV) infection during pregnancy and transmission of virus to fetus, samples such as, cervical secretion, peripheral blood, amniotic fluid, neonatal umbilical blood from 96 women with normal pregnancy were screened for HPV DNA by polymerase chain reaction (PCR), and HPV DNA in condyloma acuminata tissues, amniotic fluid of 31 pregnant women were detected by PCR as well. The results showed HPV DNA positive rate of condyloma acuminata tissues was 92.32%, of cervical secretion in normal pregnant group, was 35.71%, of peripheral blood was 57.69%. The HPV DNA maternal-fetus transmission rate was 44.44%, the transmission rate via placenta was 60%. It is concluded that HPV DNA can be found not only in condyloma acuminata tissues, but also in genital tract, peripheral blood of pregnant women, Besides the transmission route of genital tract, there is also the blood-placenta route.