Use of urinary steroid profiling for diagnosing and monitoring adrenocortical tumours

It has been suggested that urinary steroid profiling may be used to provide information aiding the diagnosis and monitoring of adrenocortical carcinoma. Nonetheless, the abnormal patterns suggestive of adrenal malignancy are not well defined. We retrospectively studied the urinary steroid profiles of five patients with adrenocortical carcinoma at presentation and at follow-up, and compared these results with those from 76 patients with benign adrenocortical adenoma and 172 healthy controls. Three abnormal patterns of urinary steroid excretion were identified in patients with adrenocortical carcinoma at presentation and/or follow-up of residual disease: (1) hypersecretion in multiple steroid axes; (2) excretion of unusual metabolites, notably 5-pregnene-3alpha,16alpha,20alpha-triol, 5-pregnene-3beta,16alpha,20alpha-triol, and neonatal steroid metabolites in the post-neonatal period; (3) increase of tetrahydro-11-deoxycortisol relative to total cortisol metabolites. These preliminary findings offer ways in which urinary steroid profiling performed using gas chromatography-mass spectrometry can be helpful in the diagnosis and monitoring of adrenocortical carcinoma.

White-light electroluminescence from ZnO nanorods/polyfluorene by solution-based growth

We report bright white-light electroluminescence (EL) from a diode structure consisting of a ZnO nanorod (NR) and a p-type conducting polymer of poly(fluorine) (PF) fabricated using a hydrothermal method. ZnO NRs are successfully grown on an organic layer of PF using a modified seeding layer. The EL spectrum shows a broad emission band covering the entire visible range from 400 to 800 nm. White-light emission is possible because the ZnO-defect-related emission from the ZnO NR/PF heterostructure is enhanced to become over thousand times stronger than that from the usual ZnO NR structure. This strong green-yellow emission associated with the ZnO defects, combined with the blue PF-related emission, results in the white-light emission. Enhancement of the ZnO-defect emission is caused by the presence of Zn(OH)(2) at the interface between the ZnO NRs and PF. Fourier transform infrared spectroscopy reveals that the absorption peaks at 3441, 3502, and 3574 cm(-1) corresponding to the OH group are formed at the ZnO NR/PF heterostructure, which confirms the enhancement of defect emission from the ZnO NR/PF heterostructure. The processing procedure revealed in this work is a convenient and low-cost way to fabricate ZnO-based white-light-emitting devices.

Survey of commercially available chocolate- and cocoa-containing products in the United States. 2. Comparison of flavan-3-ol content with nonfat cocoa solids, total polyphenols, and percent cacao

A survey of a broad range of chocolate- and cocoa-containing products marketed in the United States was conducted to provide a more detailed analysis of flavan-3-ol monomers, oligomers, and polymers, which can be grouped into a class of compounds called procyanidins. Samples consisted of the three or four top-selling products within the following six categories: natural cocoa powder, unsweetened baking chocolate, dark chocolate, semisweet baking chips, milk chocolate, and chocolate syrup. Composite samples were characterized for percent fat (% fat), percent nonfat cocoa solids (% NFCS), antioxidant level by ORAC, total polyphenols, epicatechin, catechin, total monomers, and flavan-3-ol oligomers and polymers (procyanidins). On a gram weight basis epicatechin and catechin content of the products follow in decreasing order: cocoa powder > baking chocolate > dark chocolate = baking chips > milk chocolate > chocolate syrup. Analysis of the monomer and oligomer profiles within product categories shows there are two types of profiles: (1) products that have high monomers with decreasing levels of oligomers and (2) products in which the level of dimers is equal to or greater than the monomers. Results show a strong correlation (R(2) = 0.834) of epicatechin to the level of % NFCS and also very good correlations for N = 2-5 oligomers to % NFCS. A weaker correlation was observed for catechin to % NFCS (R(2) = 0.680). Other analyses show a similar high degree of correlation with epicatechin and N = 2-5 oligomers to total polyphenols, with catechin being less well correlated to total polyphenols. A lesser but still good correlation exists between the calculated percent cacao (calcd % cacao) content, a proxy for percent cacao, and these same flavanol measures, with catechin again showing a lesser degree of correlation to calcd % cacao. Principal component analysis (PCA) shows that the products group discretely into five classes: (1) cocoa powder, (2) baking chocolate, (3) dark chocolate and semisweet chips, (4) milk chocolates, and (5) syrup. PCA also shows that most factors group closely together including the antioxidant activity, total polyphenols, and the flavan-3-ol measures with the exception of catechin and % fat in the product, which group separately. Because catechin distribution appears to be different from the other flavan-3-ol measures, an analysis of the epicatechin to catechin ratio was done, indicating there is a >5-fold variation in this measure across the products studied. The cocoa-containing products tested range from cocoa powder with 227.34 +/- 17.23 mg of procyanidins per serving to 25.75 +/- 9.91 mg of procyanidins per serving for chocolate syrup. These results are discussed with respect to other studies on commercial products, the bioavailability of the flavanols, and the possible role of processing on the amount of catechin in products.

Percutaneous transcatheter aortic valve replacement: first transfemoral implant in Asia

Surgical aortic valve replacement (AVR) is the standard of care for patients with symptomatic severe aortic stenosis (AS), providing relief of symptoms and prolonging survival. However, many patients are either denied or not offered surgery due to high surgical risk or non-operability for open AVR. The technology of percutaneous aortic valve implantation emerged in 2002, and has since evolved rapidly with satisfactory results. Currently, almost all the procedures are performed predominantly in Europe and North America. The first-in-Asia percutaneous transcatheter aortic valve implantation via the transfemoral route is described. A 77-year-old man with symptomatic severe AS and at high surgical risk was successfully treated, with sustained clinical improvement and satisfactory haemodynamic results at 30-day follow-up.

Diagnosis of 5alpha-reductase 2 deficiency: a local experience

5Alpha-reductase 2 deficiency is an autosomal recessive disorder characterised by lack of masculinisation in XY individuals due to failure to convert testosterone to dihydrotestosterone, the bioactive androgen. Traditionally, the testosterone-to-dihydrotestosterone ratio is used to diagnose this condition but interpreting these results is not always straightforward, thus they may be inconclusive. On the contrary, urinary steroid profiling unambiguously demonstrates a significantly reduced excretion of 5alpha-reduced steroid metabolites compared to their 5beta counterparts. This analytical technique can also simultaneously confirm or rule out other causes of ambiguous genitalia due to steroidogenic defects. Making a DNA-based diagnosis by studying the SRD5A2 gene has become increasingly popular. Here, we report six Chinese patients from different families who were all diagnosed with 5alpha-reductase 2 deficiency based on urinary steroid profile findings and mutational analysis of the SRD5A2 gene. R227Q was the most commonly identified mutation in these patients. Management of sexual development disorders is also discussed.

Diagnosis of bovine freemartinism by fluorescence in situ hybridization on interphase nuclei using a bovine Y chromosome-specific DNA probe

A heifer co-twin to a bull, in most cases, is a sterile freemartin which needs to be identified and culled from replacement stock. Various methods are available for the diagnosis of freemartinism, but none is ideal in terms of speed, sensitivity, or specificity. The present study was thus conducted to develop and validate a satisfactory fluorescence in situ hybridization procedure on interphase nuclei (I-FISH) for identifying the bovine XX/XY-karyotypic chimerism, the hallmark of freemartinism. A 190-bp DNA FISH probe containing the bovine male-specific BC1.2 DNA sequence was synthesized and labeled with digoxigenin by PCR. The FISH was performed on metaphase spreads and interphase nuclei of blood lymphocytes. Upon FISH, the probe expectedly bound to the nucleus of the male cell or to a region of the p12 locus of the Y chromosome. Twenty-four young heterosexual twins (Holstein-Friesian and Korean Cattle breeds; 10 pairs and 4 singletons) were analyzed in the present study; all but three exhibited the XX/XY-karyotypic chimerism to varying extents in both I-FISH and karyotyping. One heifer was identified to have 100% XX cells by both analyses, whereas two bulls were judged as 100% XY- and XX/XY-chimeric karyotypes by karyotyping and I-FISH, respectively. Nevertheless, the ratios of the XY to XX cells in these animals were very similar between the two analyses. In conclusion, the present I-FISH was a rapid and reliable procedure that can be used for early-life diagnosis of bovine freemartinism.

Statistical comparison of residential soil concentrations of PCDDs, PCDFs, and PCBs from two communities in Michigan

The University of Michigan dioxin exposure study was undertaken to address concerns that the industrial discharge of dioxin-like compounds in the Midland, MI area had resulted in contamination of soils in the Tittabawassee River floodplain and downwind of the incinerator. The study was designed in a rigorously statistical manner comprising soil measurements of 29 polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) from 766 residential properties, selected probabilistically, in the Midland area and in Jackson and Calhoun Counties (Michigan) as a background comparison. A statistical comparison determined that the geometric mean toxic equivalent (TEQ) levels in samples from the target populations were statistically significantly above background. In addition, the probabilities of being above the 75th and 95th percentiles of background were also greater. Congener contributions to the TEQ were dominated by 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF in the floodplain and by 2,3,7,8-TCDD in the incinerator plume. However, PCB 126 was the top congener contributing to the background TEQ. On the basis of statistical inference to the total population, it was estimated that about 36% of the properties in the floodplain and incinerator plume have at least one soil sample over the Michigan Department of Environmental Quality's soil direct contact criterion of 90 pg/g TEQ.

Effects of banana, orange, and apple on oxidative stress-induced neurotoxicity in PC12 cells

Banana, orange, and apple are the major fruits in Western and Asian diets. In order to find the effects of these fruits, neuron like PC12 cells were exposed to the extracts of these fruits before H(2)O(2) treatment. We found a significant viability of PC12 cells by the MTT reduction test, which indicated that the phenolics of banana, orange, and apple fruits prevented oxidative stress-induced neurotoxicity. Additional tests by lactate dehydrogenase and trypan blue exclusion assays showed that the extracts reduced oxidative stress-induced neuronal cell membrane damage. These results suggest that fresh apples, banana, and orange in our daily diet along with other fruits may protect neuron cells against oxidative stress-induced neurotoxicity and may play an important role in reducing the risk of neurodegenerative disorders such as Alzheimer's disease.

The activity of 2'-benzoyloxycinnamaldehyde against drug-resistant cancer cell lines

This study investigated the inhibitory effects of 2'-benzoyloxycinnamaldehyde (BCA) on cancer cells, including various drug-resistant cancer cell lines. To observe this activity, the anticancer drug-resistant cell lines were established by continuously exposing the parental cells to 5-fluorouracil (5-FU) and cyclophosphamide (CDDP), and examining the cells with the MTT assay and flow cytometric analysis. The BCA treatment produced similar growth inhibitory effects and apoptotic cell death on the drug-resistant cancer cells as their parental cells. The activation of the p38-mitogen activated protein kinase, an increased level of reactive oxygen species (ROS) generation and downregulation of Bcl-2 were observed in both the drug resistant and non-drug resistant cell lines. The GSH treatment effectively inhibited BCA-induced apoptosis by blocking ROS generation, suggesting that ROS is a major regulator in BCA-induced apoptotic cell death. These results suggest that BCA can be a useful drug candidate for treating drug-resistant cells.

Lateral self-aligned p-type In2O3 nanowire arrays epitaxially grown on Si substrates

Lateral orientated growth of In2O3 nanowire (NW) and nanorod (NR) arrays has been achieved by a vapor transport and condensation method on (001) and (111) surfaces of Si substrates. The single crystalline In2O3 NWs and NRs were grown along [211] in parallel to the Si +/-[110] and lying in the substrate plane. The electrical measurements show that the In2O3 NWs are p-type semiconductor. By N+ doping, the resistivity of the In2O3 NWs has been tuned. The lateral self-aligned In2O3 NW and NR arrays on Si can offer some unique advantages for fabricating parallel nanodevices that can be integrated directly with silicon technology.

Nasopharyngeal pleomorphic adenoma in the adult

INTRODUCTION

Salivary gland tumors account for less than 5% of all neoplasms in the head and neck, with pleomorphic adenoma being the most common type. These typically arise in the palate, but we report a rare case of nasopharyngeal pleomorphic adenoma in an adult.

MATERIALS AND METHODS

The authors conducted a case report and literature review.

RESULTS

The patient presented with unilateral otalgia, tinnitus, and aural fullness. Nasal endoscopy revealed a pedunculated mass adjacent to the left torus tubarius and he was treated with an excisional biopsy. Histologic evaluation demonstrated pleomorphic adenoma.

DISCUSSION

Pleomorphic adenomas seldom present as nasopharyngeal masses and have a nonspecific appearance on endoscopy. Microscopic examination has characteristic features to aid in an accurate diagnosis. Treatment is surgical and recurrence is unlikely.

Serological survey of racing pigeons for selected pathogens in Taiwan

To investigate the pathogens that racing pigeons in Taiwan are exposed to, a total of 3764 pigeons from 90 lofts were analysed by collection of blood samples in the period between October 2000 and September 2001. The haemagglutination inhibition (HI) test was performed to detect antibodies against Newcastle disease virus (NDV), type 2 avian paramyxovirus (APMV-2), and egg drop syndrome '76 virus (EDS-76V). The agar-gel precipitin (AGP) test was used to detect antibodies against fowl adenovirus (FAV), goose parvovirus (GPV), and avian reovirus (REO). The virus neutralisation (VN) test was applied to detect antibodies against the serotypes FAV-1 and FAV-8. A rapid serum agglutination test was applied for the detection of antibodies against Mycoplasma spp. Antibodies to several infectious agents were found, including NDV (43.3%), EDS-76V (19.2%), FAV (0.8%), REO (0.5%), APMV-2 (0.2%), Mycoplasma columbinum (10.3%), M. columborale (7.1%), M. synoviae (1.8%) and M. gallisepticum (1.3%). Antibodies against GPV, FAV-1, and FAV-8 were not detected in any serum sample. NDV seroprevalence was significantly higher in pigeons of more than one year of age than in pigeons younger than one year. ND or EDS-76 seroprevalence of pigeons vaccinated with ND vaccine or EDS-76 vaccine was significantly higher than that of pigeons that did not receive any vaccination.

Effects of Oral Administration of Insulin-Like Growth Factor-I on Circulating Concentration of Insulin-Like Growth Factor-I and Growth of Internal Organs in Weanling Mice

Insulin-like growth factor (IGF)-I is a polypeptide that mediates the growth-promoting action of growth hormone in postnatal animals. The present study was conducted to examine whether orally administered IGF-I would be absorbed into the general circulation and also whether ingested IGF-I would enhance the growth of whole body as well as internal organs, and tissues in 3-week-old ICR-strain female weanling mice. In experiment (Exp) 1, a total of 70 mice received IGF-I orally at 1 microg.g-1 in 0.2-ml PBS or the vehicle alone. Concentrations of IGF-I and glucose in heart blood were measured after killing 5 animals in each group every fourth hour during a 24-hour period. In Exp 2, a total of 40 mice received oral IGF-I administration at 1 microg.g-1 or vehicle every third day beginning from day 0 for a 13-day period. Half the animals were killed at day 7 and the other half at day 13. Weights of whole body and organs/tissues (small intestine, liver, thigh muscle, and brain) were measured every day and at slaughter, respectively. In Exp 1, following the oral IGF-I administration, serum IGF-I concentration increased at hour 4 (p<0.01) and returned to the hour 0 level by hour 8, whereas glucose concentration was lowest at hour 4 and returned to the hour 0 level by hour 16. In the PBS-fed group, neither IGF-I nor glucose concentration changed during the 24-hour period. In Exp 2, weight of small intestine increased (p<0.05) in response to the oral IGF-I, whereas weights of liver and thigh muscle of the IGF-I-fed group were greater (p<0.01) and tended to be greater (p=0.06), respectively, than those of the PBS-fed only at day 13. However, brain weight and serum concentrations of IGF-I and IGF-II were not affected by oral IGF-I administration. Results suggest that although orally administered IGF-I mainly acts at the intestine, a portion of ingested IGF-I is absorbed into the general circulation to enhance the growth of selective organs/tissues in weanling mice.

Seizure control of Gamma Knife radiosurgery for non-hemorrhagic arteriovenous malformations

OBJECTIVES

Although radiosurgery has been found to be a safe and effective alternative treatment, seizure outcome of arteriovenous malformation (AVM) radiosurgery has not been documented in detail. We report the effect of Gamma Knife radiosurgery (GKRS) on seizures associated with AVMs and discuss the various factors that influence the prognosis.

MATERIAL AND METHODS

Between 1992 and 2004, 246 patients were treated with GKRS for AVMs at Kyung-Hee medical center. Forty five (17.0%) patients have non-hemorrhagic AVMs and presenting symptom was seizure. Two patients of all were excluded from this study due to loss of follow-up after radiosurgery. In this study, retrospective analysis of clinical characteristics, radiologic findings, radiosurgical seizure outcome were performed.

RESULTS

There were 32 male and 11 female with age ranging from 10 to 74 years (mean 35 years). Type of seizure included: general tonic clonic (n = 28); focal motor or sensory (n = 7); partial complex (n = 8). The location of AVM was temporal (n = 18); frontal (n = 9); deep seated (n = 7): parietal (n = 5); occipital (n = 4). Follow-up period was from 8 months to 12 years (mean 46 months). Mean volume was 6.2 cc (2.7-20), mean marginal and maximal dosage was 19.5 (17-26) and 36.6 Gy (13-50). During follow-up after radiosurgical treatment, 23 (53.5%) of 43 patients were seizure-free, 10 (23.3%) had significant improvement, were unchanged in 8 (18.6%) and aggravated in 2 (4.6%) patients. In 33 patients, follow-up angiography or MRI was performed. Complete obliteration was achieved in 16 (49.0%) patients, partial obliteration in 13 (39.0%). Four were unchanged (12.0%). Of 33 patients with follow-up performed, 26 were followed for over 2 years. Eleven (84.6%) of 13 patients with complete obliteration were seizure-free (p < 0.005). Four (36.3%) of 13 with partial obliteration and unchanged remained seizure-free. Fifteen patients had experienced intractable seizure before radiosurgery. After radiosurgery, seizures disappeared in 8 (53%) patients. Seizure frequently decreased in 5 (33%) and 2 patients (14%) were unchanged but none was aggravated. Five (71%) of 7 patients with complete obliteration were seizure-free and 2 (40%) of 5 patients with partial obliteration were seizure-free.

CONCLUSION

Up to now, controversy about resective surgery or radiosurgery as treatment of seizure related to AVMs still remains. In this study, we experienced that Gamma Knife radiosurgery is commonly performed to treat AVMs and can improve symptomatic seizure associated with AVMs. To clarify the mechanism of seizure control in AVMs radiosurgery is difficult, but it seems to be closely related to hemodynamic effects after radiosurgery.

Effects of juvenile hormone analogs on new reproductives and colony growth of Pharaoh ant (Hymenoptera: Formicidae)

Two juvenile hormone analogs (JHAs), pyriproxyfen and S-methoprene, were impregnated into dried tuna fish and fed to colonies of Monomorium pharaonis (L.) at very low concentrations (1.0, 2.0, 3.0, 4.0, and 5.0 microg/ml). Its effects on the production of sexuals and colonial growth were observed. Colonies treated with pyriproxyfen yielded sexuals with physical abnormalities. Both female and male sexuals developed bulbous wings, decreased melanization, and died shortly after emergence. Sexuals emerged from colonies treated with S-methoprene did not possess anomalous characteristics. Both pyriproxyfen and S-methoprene did not have significant effects on colonial growth because of the low concentrations of the baits. A commercial bait containing 0.3% S-methoprene (Bioprene-BM) also was evaluated for its efficacy on Pharaoh's ant colonies. Results showed that Pharaoh's ant colonies succumbed to the lethal effects of S-methoprene. Colony members were reduced significantly. Production of queens also decreased significantly in treated colonies and treated queens were unable to lay eggs. JHAs are slow acting and eliminate ant colonies at a relatively slow rate. At low concentrations, pyriproxyfen recorded baffling results, i.e., bulbous wings and demelanized exoskeleton, and it is vital that further studies are initiated to solidify these findings.

Hepatic function in hypothermically stored porcine livers: Comparison of hypothermic machine perfusion vs cold storage

Hypothermic machine perfusion (HMP) has a potential to relieve the current donor liver crisis by providing an improved and extended preservation method. This study examined the effect of HMP on hepatocellular functions, using a prototype liver transporter capable of preserving livers for 24 hours. Livers obtained from adult farm pigs (28 to 32 kg body weight) were divided into three groups: fresh control, HMP, and simple cold storage (n = 4 each). A 4-hour normothermic reperfusion of livers was conducted to assess hepato-metabolic and cellular functions. The hepatic transport function, as indicated by canalicular excretion of indocyanine green, was improved in the HMP group than in the SCS group. The overall tissue viability, as indicated by oxygen consumption levels, was notably improved in HMP and control livers as compared to the SCS group. Higher bile production in both the preserved groups as compared to the fresh control livers could be a result of biliary edema and leakage of plasma into the canaliculus. The hepato-cellular injury, measured by ALT, release was significantly greater in the SCS group as compared to the HMP and control groups. These findings suggest that HMP could be a better method to preserve hepatic function and overall tissue viability as compared to SCS. Improved hepatic functions are indirect indicators of superior microcirculation and sinusoidal endothelial cell functions. Further studies in progress will evaluate these functions to confirm the significance of these observations.

Hypothermic machine perfusion of rat livers preserves endothelial cell function

This study was conducted to investigate the effect of starch in the preservation solution during hypothermic machine perfusion (HMP) on endothelial cell and hepatocyte functions in an isolated perfused rat liver model. Livers isolated from male Sprague-Dawley rats were perfused with the University of Wisconsin (UW) solution (HMP + starch group); modified UW solution (starch omitted) (HMP - starch group) at 0.4 mL/min per g liver; or simply stored in the UW solution (SCS group) at 4 degrees C for 24 hours. Following preservation, livers from HMP + starch, HMP - starch, SCS, and control group (without preservation) were perfused with Krebs-Henseleit Buffer solution at 37 degrees C for 30 minutes. Samples were taken every 10 minutes during 30-minute warm perfusion to assess hepatocyte and endothelial cell function and damage. After 24 hours of hypothermic preservation and 30 minutes rewarming, livers in the HMP + starch group displayed significantly lower lactate dehydrogenase levels and higher bile production. Endothelial cell function was also improved as indicated by hyaluronic acid uptake and shorter transient time for albumin observed in a multiple indicator dilution study. Liver wet and dry ratio and histological findings confirmed reduced edema formation in the tissue of the HMP + starch group livers compared with that of the HMP - starch and SCS group livers. These results suggest that HMP with the UW solution containing starch improve endothelial cell function and induce less hepatocellular damage following 24-hour preservation compared to SCS and HMP with the starch-free UW solution. These results also suggest that oncotic support may be an important component in preserving hepatic microcirculation in HMP.

Congenital absence of portal vein presenting as hepatopulmonary syndrome

A 9-year-old girl presented with cyanosis and decreased exercise tolerance. Chest X-ray, lung function and echocardiogram were normal. Contrasted echocardiogram showed intrapulmonary right to left shunt and computerized tomography of the thorax showed dilated pulmonary vasculature. There was no arteriovenous malformation. Computerized tomography of the abdomen revealed absence of the intrahepatic portion of the portal vein. The superior mesenteric and splenic veins joined as a common trunk, bypassed the liver and drained into the right atrium. We concluded that the patient had hepatopulmonary syndrome secondary to absence of the portal vein. This is the first report of hepatopulmonary syndrome in a female paediatric patient with a congenital absence of the portal vein. As all portal blood entered directly into systemic circulation, the condition was equivalent to congenital portosystemic shunt. Cases of congenital portosystemic shunt complicated by hepatopulmonary syndrome were also reviewed.

Hypercalcaemia and hypertransaminasaemia in a child with hyperthyroidism

Hypercalcaemia and hypertransaminasaemia are well recognized and not infrequent findings in hyperthyroidism in adults. Both conditions are seldom reported in children. Here we report the case of a 4-year-old girl with hyperthyroidism associated with hypercalcaemia and hypertransaminasaemia which were reversed after euthyroid state was achieved. We recommend that serum calcium and liver function should always be monitored in children with hyperthyroidism.

Mitochondria-Targeting Drug Oligomycin Blocked P-Glycoprotein Activity and Triggered Apoptosis in Doxorubicin-Resistant HepG2 Cells

BACKGROUND

Mitochondria are key regulators in apoptosis. This suggests that a mitochondrion can be a target for cancer treatment. To examine the feasibility of this approach, we investigated the effect of oligomycin on the induction of apoptosis in drug-resistant cells. As a mitochondrion-targeting agent, oligomycin inhibits mitochondrial F0F1-ATPase. Of 37,000 molecules tested against the 60 human cancer cell lines of the National Cancer Institute, oligomycin is among the top 0.1% most cell line selective agents.

METHODS

Changes in the doxorubicin (Dox) accumulation and mitochondrial potential (Deltapsim) in human hepatocarcinoma HepG2 and its derivative R-HepG2 with Dox resistance were determined by flow cytometry. P-glycoprotein (Pgp) expression and release of cytochrome c from mitochondria were analyzed by Western blot. Cytotoxicity was examined by DNA fragmentation and the alamar blue assay.

RESULTS

R-HepG2 cells produced Pgp, showed drug resistance and accumulated less Dox when compared to their parent. In both cell lines, oligomycin depolarized Deltapsim, released cytochrome c and elicited DNA fragmentation. Moreover, oligomycin blocked Pgp activity and accumulated more Dox in R-HepG2. Combined treatment with Dox and oligomycin elicited more cell death.

CONCLUSION

Our results suggest that oligomycin could bypass Dox resistance and trigger apoptosis in R-HepG2 cells.

Methicillin-resistant Staphylococcus aureus bacteraemia in neonatal intensive care units: an analysis of 90 episodes

AIM

To delineate the clinical features of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia in infants hospitalized at the neonatal intensive care unit.

METHODS

Episodes of MRSA bacteraemia in Chang Gung Children's Hospital neonatal intensive care unit from 1997 to 1999 were reviewed for incidence, predisposing factors, clinical presentations, treatment and outcome.

RESULTS

Ninety episodes of MRSA bacteraemia were identified. The overall rate of MRSA bacteraemia was 1.05 per 1000 patient days during the 3-y period. Most of the patients were premature infants (76%), with prior operation or invasive procedures (39%), had an indwelling intravascular catheter (79%) and exposure to antibiotic therapy (96%). A localized cutaneous infection was found in 53.3% of the episodes. The most common clinical diagnoses were catheter-related infections (54.4%), skin and soft tissue infections (21.1%), bacteraemia without a focus (20%) and pneumonia (16.7%). Metastatic infection occurred in 18% of these infants. Among the patients treated with vancomycin for < or = 14 d, 88.7% did not develop any complications, and 11.3% developed a recurrence.

CONCLUSIONS

MRSA is an established pathogen in our NICU. MRSA bacteraemia in the neonates predominantly presented as catheter-related infections, and metastatic infections were not infrequently seen. In uncomplicated MRSA bacteraemia, treatment with vancomycin for < or = 14 d seems to be adequate.

Intraocular large B-cell lymphoma. A case report

BACKGROUND

Large cell lymphoma involving the vitreous humor is uncommon, and its diagnosis in the absence of central nervous system disease can be difficult. The major diagnostic difficulties with vitreous washings in the absence of ancillary studies are in the distinction of inflammatory lymphoid infiltrate from intraocular lymphoma or diagnosing lymphoma when only very few neoplastic cells are present.

CASE

A 75-year-old, white male sought medical attention for bilateral blurred vision and decreased visual acuity of recent onset. A clinical diagnosis of bilateral uveitis to rule out primary intraocular lymphoma or an infectious process was made, and a right vitrectomy was performed. An unequivocal diagnosis of lymphoma could not be made due to the paucity of neoplastic cells on that specimen. Two months later smears from the Cytospin (Thermo Shandon, Pittsburgh, Pennsylvania, U.S.A.) prepared on the specimen from a left vitrectomy showed a greater number of large, pleomorphic cells. In addition, immunocytochemical staining confirmed the B-cell lineage of the neoplastic cells. Immunoglobulin gene rearrangement analysis performed by the polymerase chain reaction method on the frozen cell pellet from the left vitrectomy demonstrated the presence of a monoclonal B-cell population, confirming the diagnosis of large B-cell lymphoma.

CONCLUSION

Vitreous cytology in conjunction with ancillary studies is a sensitive procedure in the diagnosis of intraocular lymphoma.

Characteristics of granular sludge in a single upflow sludge blanket reactor treating high levels of nitrate and simple organic compounds

Simultaneous denitrification and methanogenesis were accomplished in a single upflow sludge blanket (USB) reactor. More than 99% and 95% of nitrate and chemical oxygen demand (COD) removal rates were obtained at a loading of 600 mg NO3-N/L x d and 3,300 mg COD/L x d, respectively. The specific denitrification rate (SDR) increased as COD/NO3-N ratios decreased. Maximum SDR with acetate could reach 1.05 g NO3-N/gVSS x d. Significant sludge flotation was observed at the top of the reactor due to the change of microbial composition and the formation of hollow granules. Granules became fluffy and buoyant due to the growth of denitrifiers. Microscopic examination showed that granules exhibited layered structure and they were mainly composed of Methanosarcina sp., Pseudomonas sp., and rod-shaped bacteria.