Early T-cell precursor lymphoblastic leukaemia with monocytic morphology negative for CD3 by flow cytometry: A diagnostic challenge solved by immunohistochemistry

No abstract available.

Effects of dietary supplementation with Taiwanese tea byproducts and probiotics on growth performance, lipid metabolism, and the immune response in red feather native chickens

Objective

This study compared the catechin composition of different tea byproducts and investigated the effects of dietary supplementation with green tea byproducts on the accumulation of abdominal fat, the modulation of lipid metabolism, and the inflammatory response in red feather native chickens.

Methods

Bioactive compounds were detected, and in vitro anti-obesity capacity analyzed via 3T3-L1 preadipocytes. In animal experiments, 320 one-day-old red feather native chickens were divided into 4 treatment groups: control, basal diet supplemented with 0.5% Jinxuan byproduct (JBP), basal diet supplemented with 1% JBP, or basal diet supplemented with 5×10⁶ colony-forming unit (CFU)/kg Bacillus amyloliquefaciens+5×10⁶ CFU/kg Saccharomyces cerevisiae (BA+SC). Growth performance, serum characteristics, carcass characteristics, and the mRNA expression of selected genes were measured.

Results

This study compared several cultivars of tea, but Jinxuan showed the highest levels of the anti-obesity compound epigallocatechin gallate. 3T3-L1 preadipocytes treated with Jinxuan extract significantly reduced lipid accumulation. There were no significant differences in growth performance, serum characteristics, or carcass characteristics among the groups. However, in the 0.5% JBP group, mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were significantly decreased. In the 1% JBP group, FAS, ACC and peroxisome proliferator-activated receptor γ levels were significantly decreased. Moreover, inflammation-related mRNA expression levels were decreased by the addition of JBP.

Conclusion

JBP contained abundant catechins and related bioactive compounds, which reduced lipid accumulation in 3T3-L1 preadipocytes, however there was no significant reduction in abdominal fat. This may be due to a lack of active anti-obesity compounds or because the major changes in fat metabolism were not in the abdomen. Nonetheless, lipogenesis-related and inflammation-related mRNA expression were reduced in the 1% JBP group. In addition, dietary supplementation with tea byproducts could reduce the massive amount of byproducts created during tea production and modulate lipid metabolism and the inflammatory response in chickens.

Frequent loss of CD10 expression in follicular lymphoma with leukaemic presentation

INTRODUCTION

Follicular lymphoma (FL) is usually a nodal lymphoma expressing CD10, rarely with leukaemic presentation (FL-LP).

MATERIALS AND METHODS

We searched for FL-LP in our institution from 2000 to 2018 and characterised the neoplastic cells by flow cytometry, immunohistochemistry and fluorescence in situ hybridization. Thirteen (6.1%) of 212 FL cases were FL-LP, all de novo neoplasms. The leukaemic cells were small in 12 cases and large in one. All had concurrent FL, mostly (92%; 12/13) low-grade. The single case with large leukaemic cells had a concurrent primary splenic low-grade FL and a double-hit large B-cell lymphoma in the marrow.

RESULTS

CD10 was expressed in the leukaemic cells in 38% (5/13) cases by flow cytometry and in 77% (10/13) cases in tumours (p= 0.0471). IGH/BCL2 reciprocal translocation was identified in 85% (11/13) cases. Most patients were treated with chemotherapy. In a median follow-up time of 36 months, nine patients were in complete remission. The 2- and 5-year survival rates were at 100% and 83%, respectively. In this study, we characterised a series of de novo FL-LP in Taiwan. All patients had concurrent nodal and/or tissue tumours, which might suggest that these patients seek medical help too late.

CONCLUSION

The lower CD10 expression rate by flow cytometry than by immunohistochemistry might be due to different epitopes for these assays. Alternatively, loss of CD10 expression might play a role in the pathogenesis of leukaemic change. The clinical course of FL-LP could be aggressive, but a significant proportion of the patients obtained complete remission with chemotherapy.

Effects of mushroom waster medium and stalk residues on the growth performance and oxidative status in broilers

OBJECTIVE

The study developed mushroom stalk residues as feed additives in the broiler diet for improving the growth performance and immunity of broilers as well as to increase the value of mushroom stalk residues.

METHODS

In total, 300 ROSS 308 broilers were randomly allocated into fifteen pens with five dietary treatments: i) control, basal diet; ii) CMWM, supplemented with 1% Cordyceps militaris waster medium (CM); iii) CMPE, supplemented with 0.5% CM+0.5% Pleurotus eryngii stalk residue (PE); iv) CMPS, supplemented with 0.5% CM+0.5% Pleurotus sajorcaju stalk residue (PS); v) CMFV, supplemented with 0.5% CM+0.5% Fammulina velutipes stalk residue (FV).

RESULTS

The chemical analysis results showed that CM extracts, PE extracts, PS extracts, and FV extracts contain functional components such as polysaccharides and phenols and have both 2, 2-diphenyl-1-picryl-hydrazyl-hydrate scavenging and Ferrous scavenging capacities. The group CMWM saw increased body weight gain and feed conversion rate and the promotion of jejunum villus growth, but there is no significant difference in the intestinal bacteria phase. Antioxidant genes in the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)- antioxidant responsive element pathway among the groups are significantly higher than that of the control group, especially in group CMWM.

CONCLUSION

The mushroom stalk residues have antioxidant functional components, can improve the intestinal health and body weight gain of chickens, and can activate the antioxidant pathway of Nrf2 to increase the heme oxygenase-1 expression. The treatment with 1% CM was the most promising as a feed additive.

P5644Hypoglycemic episodes increase the risk of ventricular arrhythmias and sudden cardiac arrest in patients with type 2 diabetes - a nationwide cohort study

Background

Hypoglycemic episode (HE) increases the risk of cardiovascular mortality. The impact of HE on the risk of sudden death remains unclear. We hypothesized that HE increases the risks of ventricular arrhythmia (VA) and sudden cardiac arrest (SCA), and that anti-diabetic agents (ADAs) causing hypoglycemia also increase the risks of VA and SCA.

Methods

Patients aged ≥20 years with newly diagnosed diabetes were identified from the Taiwan National Insurance Database. HE was defined as the presentation of hypoglycemic coma or specified/unspecified hypoglycemia. For control group, we included diabetic patients without HE, and they were frequency-matched to the HE group at a 4:1 ratio. The primary outcome was the occurrence of any event of VA (including ventricular tachycardia and fibrillation) and SCA during the defined follow-up periods. Multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for VA or SCA.

Results

A total of 54,303 diabetic patients were screened with 1,037 of them in the HE group, and 4,148 in the control group. During a mean follow-up period of 3.3±2.5 years, 29 VA/SCA events had occurred. Compared to the control group, the HE group had a higher incidence of VA/SCA (adjusted HR: 2.42, p=0.04). Diabetic patients medicated with insulin for glycemic control increased the risk of VA/SCA compared to those without insulin (adjusted HR: 3.05, p=0.01).

Kaplan-Meier survival curves

Conclusions

HEs in patients with diabetes increased the risks of VA and SCA compared to those without. Their use of insulin also independently increased the risk of VA/SCA.

P2564Levosimendan shortens action potential duration, decreases alternans threshold and prevents ventricular arrhythmia during therapeutic hypothermia in isolated rabbit hearts

Background

Therapeutic hypothermia (TH) increases the susceptibility to ventricular arrhythmias (VA) by prolonging action potential duration (APD) and facilitating arrhythmogenic spatially discordant alternans (SDA). The calcium sensitizer levosimendan has been reported to shorten APD by enhancing ATP-sensitive K current. We hypothesize that levosimendan might shorten the already prolonged APD during TH, decreasing SDA threshold, and prevent the occurrence of VA.

Methods

Langendorff-perfused isolated rabbit hearts were subjected to 15-min TH (30°C) followed by 30-min treatment with levosimendan (0.5 μM, n=9) or vehicle (n=8). Using an optical mapping system, epicardial APD was evaluated by S1 pacing. SDA threshold was defined as the longest pacing cycle length (PCL) that induced SDA phenomenon. Ventricular fibrillation (VF) inducibility was evaluated by burst pacing for 30 s using the shortest PCL that achieved 1:1 ventricular capture.

Results

Levosimendan shortened the ventricular APD (at PCL 300 ms, from 229±9 ms to 211±18 ms, p=0.02) and decrease the SDA threshold (from 327±88 ms to 311±68 ms, p=0.001) during TH. The VF inducibility was decreased by levosimendan from 39±30% at 30°C to 14±12% after levosimendan infusion. In control hearts, the APD (p=0.75), SDA threshold (p=ns) and VF inducibility (p=0.12) were not changed by vehicle during TH.

Conclusions

Levosimendan protects the hearts against VA during TH by shortening APD and decreasing SDA threshold. Enhancing ATP-sensitive K current with levosimendan might be a novel approach to prevent VA during TH.

An investigation of targeted inhibition of transcription factor activity with pyrrole imidazole polyamide (PA) in chronic myeloid leukemia (CML) blast crisis cells

Tyrosine kinase inhibitor (TKI) therapy is the standard treatment for chronic phase (CP)-chronic myeloid leukemia (CML), yet patients in blast crisis (BC) phase of CML are unlikely to respond to TKI therapy. The transcription factor E2F1 is a down-stream target of the tyrosine kinase BCR-ABL1 and is up-regulated in TKI-resistant leukemia stem cells (LSC). Pyrrole imidazole polyamides (PA) are minor groove binders which can be programmed to target DNA sequences in a gene-selective manner. This manuscript describes such an approach with a PA designed to down-regulate E2F1 controlled gene expression by targeting a DNA sequence within 100 base pairs (bp) upstream of the E2F1 consensus sequence. Human BC-CML KCL22 cells were assessed after treatment with PA, TKI or their combination. Our PA inhibited BC-CML cell expansion based on cell density analysis compared to an untreated control after a 48-hour time-course of PA treatment. However, no evidence of cell cycle arrest was observed among BC-CML cells treated with PA, with respect to their no drug control counterparts. Thus, this work demonstrates that PAs are effective in inhibiting E2F1 TF activity which results in a temporal reduction in BC-CML cell number. We envisage that PAs could be used in the future to map genes under E2F1 control in CML LSCs.

High performance and high power circularly polarized horn antenna for K-band microwave processing systems

A single-ridged K-band circularly polarized horn antenna offering excellent performance has been developed by improving the polarization conversion and manufacturing complexity. The numerical and experimental results are consistent showing the return loss of this antenna to be less than -20 dB and the axial ratio at the boresight direction to be less than 0.7 dB in the frequency range from 23.5 GHz to 24.5 GHz. In addition, the gain of this antenna is higher than 20 dB. The newly designed circularly polarized horn antenna has a simple structure and outperforms many existing circular polarization devices in high-power operations.

Unusual pox lesions found in Chinese jungle mynahs (Acridotheres cristatellus)

Pox lesions involving feathered and unfeathered skin, the oral cavity and the uropygial gland were found in Chinese jungle mynahs. Characteristic intracytoplasmic inclusions were detected in the proliferative cells of all lesions. Ultrastructurally, the virus particles consisted of a convoluted outer membrane enclosing lateral bodies and a biconcave central core, typical for poxvirus. The nucleotide sequences of the amplicon obtained with a set of primers for the 4b core protein of fowl poxvirus revealed that the mynah poxvirus was phylogenetically related to wood pigeon poxvirus. This is the first report of poxvirus infection affecting the uropygial gland.

Delayed therapy with curative intent in a contemporary prostate cancer watchful-waiting cohort

OBJECTIVE

To identify predictors of delayed therapy with curative intent, an increasingly common option in contemporary patients with prostate cancer who initially choose watchful waiting.

PATIENTS AND METHODS

The characteristics of all patients at one institution and diagnosed with T1-4NXM0 prostate cancer between 1993 and 2000 were prospectively recorded. Factors recorded included: age, tumour stage, histological type, Gleason score, serum prostate specific antigen (PSA) level, prostate volume, PSA density (PSAD), percentage of positive biopsy cores, and the initial treatment selection. Outcomes, including all cancer-directed interventions, all serum PSA values, and initial outcomes of all interventions with curative intent, were determined by review of all medical records and cancer registry data.

RESULTS

Of 187 patients on watchful waiting, 175 had stage T1 or T2 cancer and were analysed primarily. Thirty-eight (22%) of these patients received delayed intervention with curative intent (15 radical prostatectomy, 17 external beam radiotherapy, six brachytherapy). Age (P < 0.001) and percentage of positive biopsy cores (P = 0.042) were significant independent predictors of intervention with curative intent. When the PSA doubling time was added to the model it became a significant predictor (P = 0.018), with percentage positive biopsy cores (P = 0.022) and age (P < 0.001).

CONCLUSIONS

Therapy with curative intent is common in contemporary patients with prostate cancer who initially choose watchful waiting. Age and percentage positive biopsy cores are independent predictors of such intervention, with PSA doubling time also an independent predictor.

A New Design Method to Improve Flow Uniformity in a Reaction Injection Mold Entry

Reaction injection molding involves the injection of two or more kinds of liquid polymers into a mold at relative high speed. Such high inertia effect may result in air pocket inside the mold or non-uniform velocity distribution. How to design the mold entry geometry to provide uniform velocity distribution becomes one of the major topics in reaction injection molding process. Thus a new and simple method was developed in this work to optimize the reaction mold entry design. Several regulation islands were located in a fish tail entrance to help distribute the flow more even. Dimensions and locations of the islands will affect the flow uniformity and become the factors to be optimized. Taguchi's design of experiments coupled with computer flow simulation was used to achieve die geometry optimization. Effects of different dimensions of the islands on the flow uniformity can also be evaluated through statistical analyses in the flow simulation. Flow visualization technique was done by capturing flow images with high speed CCD. The experimental results showed very good agreements with the Fluent simulation results. The design methodology proposed here can help the molders in designing different reaction injection mold entries for better uniformity and performance.

Prediction of the distance from skin to epidural space for low-thoracic epidural catheter insertion by computed tomography

BACKGROUND

It may be clinically useful to predict the depth of the epidural space.

METHODS

To investigate the accuracy of preoperative abdominal computed tomography (CT) in prediction of the distance for low-thoracic epidural insertion, a single group observational study was conducted in 30 male patients undergoing elective major abdominal surgery requiring epidural analgesia for postoperative pain relief. Using the paramedian approach, low-thoracic epidural insertion at T10-11 interspace was performed with a standardized procedure to obtain an actual insertion length (AIL). According to the principles of trigonometry, an estimated insertion length (EIL) was calculated as 1.26 times the distance from skin to epidural space measured from the preoperative abdominal CT.

RESULTS

The mean (SD) EIL and AIL were 5.5 (0.7) and 5.1 (0.6) cm, respectively, with a significant correlation (r=0.899, P<0.01). The EIL tended to have a higher value than the AIL (0.4 (0.3) cm). There were significant correlations of both EIL and AIL with weight (P<0.01), BMI (P<0.01), and body fat percentage (P<0.01), but not with height (P>0.05).

CONCLUSIONS

We conclude that the preoperative abdominal CT is helpful in prediction of the distance for low-thoracic epidural insertion using the paramedian approach.

Clinical outcome in children with craniopharyngioma treated with primary surgery and radiotherapy deferred until relapse

BACKGROUND

To report the clinical outcome in children with craniopharyngioma following primary surgery and deferred radiotherapy at relapse.

PROCEDURE

Twenty-five children with craniopharyngioma were treated with primary surgery. Total resection was achieved in 19 children (76%), while in 24% total resection was not achieved due to tumor adhesion to adjacent critical structures. None of these children received radiation therapy immediately after total or sub-total resection. Radiotherapy was delivered at the time of relapse in 11 patients (44%).

RESULTS

The median follow-up from primary surgery was 10 years (3-16 years). The 14 year overall survival was 100%. Tumor recurrence was observed in (12/25) 48% at a median interval of 17 months. Tumor recurrence following total resection was 6/19 (32%) compared to 100% (6/6) following sub-total resection, and radiotherapy. The 2, 3, and 6 years relapse-free survival following initial surgery was 72, 55, and 50%, respectively. Univariate analysis revealed only extent of surgery to be significant for local recurrence (P < 0.0001). The sequelae observed in these patients included panhypopituitarism (100%), appetite disorders and hypothalamic obesity (32%), neuropsychological and behavioral disorders (20%), and sleep disorders (12%). Majority of children with non-endocrine complications had a local recurrence requiring further surgery and radiotherapy.

CONCLUSIONS

The two standard treatment options in children with craniopharyngioma are primary surgery and sub-total resection followed by radiotherapy. In certain subgroups of patients such as those with large tumors and hypothalamic extension, primary surgery is associated with a high incidence of complications and high failure rates. We recommend utilization of an individualized risk-based treatment approach, that attempts to maximize cure rates without compromising long-term functional outcome in children with craniopharyngiomas.

Clinical features of atypical Kawasaki disease

From 1989 through 1998, a total of 132 children admitted to the National Taiwan University Hospital were identified as having Kawasaki disease. Twenty (15%) of them did not meet the diagnostic criteria of Kawasaki disease, but were considered atypical Kawasaki based on the specific clinical signs and exclusion of other causes by serologic study and culture result. The patients' age ranged from 5 months to 11 years, with a mean of 22.2 months and a median of 15 months. The male to female ratio was 1.9:1. Twenty-five percent (5/20) of them had coronary arterial lesion. No difference was found in the age distribution, sex, and rate of coronary artery involvement between typical and atypical Kawasaki disease. All patients were treated with intravenous immunoglobulin and aspirin except for 2 patients. At follow-up, patients with coronary arterial lesions had a prognosis as good as those with typical Kawasaki disease. According to these observations, atypical Kawasaki disease may be part of Kawasaki disease occurring via the same pathogenesis, but has incomplete manifestation. Clinical practitioners should have a high index of suspicion to diagnose and initiate prompt treatment to reduce the comorbidity of coronary arterial disease in patients with atypical Kawasaki disease.

Results of the Lynn Sage Second-Opinion Program for local therapy in patients with breast carcinoma. Changes in management and determinants of where care is delivered

BACKGROUND

The treatment options of breast conservation therapy (BCT) and immediate reconstruction for patients with carcinoma of the breast have not been adopted widely. The objectives of this study were to determine how often a second opinion on the local therapy of breast carcinoma changed patient management and to identify factors predictive of remaining at the second-opinion site for therapy.

METHODS

Two hundred thirty-one patients with intraductal carcinoma or Stage I and II breast carcinoma were reviewed retrospectively. At the time of the second opinion, patients completed a questionnaire regarding their initial surgical opinion and the reason for seeking consultation.

RESULTS

Only 46% of patients had a complete discussion of treatment options prior to the second opinion. The second opinion changed management in 54 patients (20.3%). The most common finding was eligibility for BCT in patients who were offered only mastectomy. Definitive local therapy occurred at the second-opinion site in 65.8% of patients. The only predictors of remaining at the second-opinion site were insurance type (P = 0.008) and the patient's perception that options were not discussed at the initial opinion (P < 0.001).

CONCLUSIONS

Second opinions provide useful information to patients and may change the management of their disease. They result in significant patient capture for an institution.

Empirical monotherapy with meropenem in serious bacterial infections in children

The efficacy and safety profile of meropenem were analyzed according to data collected from hospitalized pediatric patients aged 4 days to 20 years who had serious bacterial infections and were treated in a major teaching hospital in Taipei. Of the 53 patients enrolled, 47 were analyzed for clinical efficacy and 53 for safety. The satisfactory clinical response rate was 57% in lower respiratory tract infection, 58% in septicemia, 100% in complicated urinary tract infection, osteomyelitis, and central nervous system infection, 83% in skin and soft tissue infection, and 93% in intra-abdominal infection. Eleven (21%) patients experienced adverse events related to meropenem. The most commonly observed adverse reactions were elevated hepatic enzymes (7.5%), increased alkaline phosphatase (3.8%), and thrombocytosis (3.8%). There was no meropenem-related seizure, withdrawal, or death. The results of this study suggested that meropenem is well tolerated even in young infants, and is effective in treating serious childhood bacterial infection. However, this study also identified a proportion of hospitalized pediatric patients with isolates that were resistant to meropenem. The trends in meropenem resistance among nosocomially acquired bacteria should be monitored closely.

A phase II study of irinotecan with 5-fluorouracil and leucovorin in patients with previously untreated gastric adenocarcinoma

BACKGROUND

A phase II study testing the safety and efficacy of irinotecan (CPT-11). 5-fluorouracil (5-FU), and leucovorin (LCV) was conducted in patients with advanced gastric adenocarcinomas.

PATIENTS AND METHODS

Patients with metastatic or recurrent adenocarcinoma of the gastroesophageal junction (GEJ) or stomach were entered onto this study. Previous chemotherapy for metastatic disease was not allowed. Treatment consisted of repeated 6-week cycles comprising CPT-11 125 mg/m2 intravenously (i.v.) followed immediately by LCV 20 mg/m2 i.v. and 5-FU 500 mg/m2 i.v., all given weekly for four weeks followed by a two-week rest.

RESULTS

Thirty-eight patients were enrolled and 36 eligible patients received protocol therapy. Grade 3-5 toxicities consisted primarily of neutropenia (36%) and diarrhea (28%). Neutropenic infection was observed in 14% of patients, with 3 (8%) dying of neutropenic sepsis. The overall response rate was 22% (95% confidence interval [CI] 8.5% to 35.5%). Median survival was 7.6 months, and median time to progression was 4.4 months.

CONCLUSION

This weekly regimen of CPT-11 with bolus 5-FU/LCV is active in patients with advanced adenocarcinomas of the stomach or gastroesophageal junction. While rates of grade 3-4 neutropenia and diarrhea were similar to those observed historically in patients receiving this regimen for colorectal cancer, neutropenic fever/sepsis appeared to be more frequent, and dose modifications were substantial. Future trials of this combination in patients with gastric cancer should decrease the absolute starting drug doses and/ or employ altered scheduling that better accommodates the pattern of toxicity.

Effects of calcium channel antagonists on the corpora allata of adult male loreyi leafworm Mythimna loreyi: juvenile hormone acids release and intracellular calcium level

The effects of voltage-dependent calcium channel (VDCC) antagonists and the non-specific calcium channel antagonists on both juvenile hormone acids (JHA) release and cytosolic free calcium concentration ([Ca2+]i) are investigated in the corpora allata (CA) of the adult males loreyi leafworm Mythimna loreyi. The VDCC antagonists used in this study are: the L-type antagonists diltiazem, nifedipine, and verapamil, the N-type antagonist omega-Conotoxin (CgTx) GVIA, the N- and P/Q-type antagonist omega-CgTx MVIIC, and the T-type antagonist amiloride. The non-specific calcium channel antagonists used in this study were cadmium (Cd2+), cobalt (Co2+), nickle (Ni2+), and lanthanum (La3+). The results show that both the DHPs-sensitive L-type antagonist nifedipine and the N-type antagonist omega-CgTx GVIA were able to inhibit JHA release, but only omega-CgTx GVIA was able to reduce the [Ca2+]i. Among the non-specific calcium channel antagonists, Cd2+ is the most potent in reducing JHA release but without obvious effect on the [Ca2+]i, La3+ significantly increases the [Ca2+]i but without effect on JHA release.

Baicalein induces a dual growth arrest by modulating multiple cell cycle regulatory molecules

Baicalein, a flavonoid present in the root of Scutellaria baicalensis Georgi, has been reported to inhibit cell proliferation in several types of cells. In this study, the effect of baicalein on cell growth and the mechanism of growth modulation were examined in primary cultured rat heart endothelial cells. Here, we report that treatment with 100-microM baicalein caused an almost complete inhibition of cell proliferation after 5 days of incubation. Baicalein mediated G1 and G2 growth arrest accompanied by the down-regulation of cyclin D2, cyclin A, cyclin-dependent kinase 1 (Cdk1) and cyclin-dependent kinase 2 (Cdk2), and up-regulation of p15(Ink4B), p21(CIP1/Waf1), p53 and cyclin E. Evaluation of the kinase activity of cyclin-Cdk complexes showed that baicalein decreased Cdk1, Cdk2, cyclin D2 and cyclin A expression in endothelial cells, leading to markedly reduced Cdk/cyclin-associated kinase activities. These results suggest that baicalein inhibits the proliferation of rat heart endothelial cells via G1 and G2 arrest in association with the down-regulation of the expression and function of Cdk1, Cdk2, cyclin D2 and cyclin A proteins, and up-regulation of cyclin E, p15(Ink4B), p53 and p21(CIP1/Waf1).

Protamine sulfate enhances the transduction efficiency of recombinant adeno-associated virus-mediated gene delivery

PURPOSE

The purpose of this study was to evaluate glucose responsiveness in HepG2 human hepatoma cells transduced by a recombinant adeno-associated virus (rAAV) vector containing the insulin gene promoter. and to investigate the effect of protamine sulfate on rAAV-mediated gene delivery.

METHODS

Recombinant AAV vector, AAV.Ins.Luc.delta EGFP, was employed to transduce HepG2 hepatoma cells. Virus infection was carried out either in the absence or presence of protamine sulfate, followed by fluorescence microscopic examination, luciferase activity assay, and flow cytometric analysis. Electrokinetic measurements were carried out to determine the effect of protamine sulfate on zeta potential of the cells and the virus.

RESULTS

Glucose-responsive luciferase gene expression was obtained in rAAV-transduced HepG2 cells. Addition of 5 microg/ml protamine reversed the zeta potential of the cells and the virus particles, leading to enhanced transgene expression in rAAV-transduced HepG2 cells. Enhancement of protamine sulfate on rAAV-mediated gene transfer was dose-dependent. Addition of more than 5 microg/ml protamine resulted in a reduction of infectability of the virus.

CONCLUSIONS

Glucose responsiveness in the millimolar concentration range can be obtained in rAAV-transduced HepG2 cells. Protamine sulfate, up to 5 microg/ml, enhanced the rAAV transduction efficiency in HepG2 cells. The enhancement was correlated with zeta potential of the cells and the virus.

Statistical measures of DNA sequence dissimilarity under Markov chain models of base composition

In molecular biology, the issue of quantifying the similarity between two biological sequences is very important. Past research has shown that word-based search tools are computationally efficient and can find some new functional similarities or dissimilarities invisible to other algorithms like FASTA. Recently, under the independent model of base composition, Wu, Burke, and Davison (1997, Biometrics 53, 1431 1439) characterized a family of word-based dissimilarity measures that defined distance between two sequences by simultaneously comparing the frequencies of all subsequences of n adjacent letters (i.e., n-words) in the two sequences. Specifically, they introduced the use of Mahalanobis distance and standardized Euclidean distance into the study of DNA sequence dissimilarity. They showed that both distances had better sensitivity and selectivity than the commonly used Euclidean distance. The purpose of this article is to extend Mahalanobis and standardized Euclidean distances to Markov chain models of base composition. In addition, a new dissimilarity measure based on Kullback-Leibler discrepancy between frequencies of all n-words in the two sequences is introduced. Applications to real data demonstrate that Kullback-Leibler discrepancy gives a better performance than Euclidean distance. Moreover, under a Markov chain model of order kQ for base composition, where kQ is the estimated order based on the query sequence, standardized Euclidean distance performs very well. Under such a model, it performs as well as Mahalanobis distance and better than Kullback-Leibler discrepancy and Euclidean distance. Since standardized Euclidean distance is drastically faster to compute than Mahalanobis distance, in a usual workstation/PC computing environment, the use of standardized Euclidean distance under the Markov chain model of order kQ of base composition is generally recommended. However, if the user is very concerned with computational efficiency, then the use of Kullback-Leibler discrepancy, which can be computed as fast as Euclidean distance, is recommended. This can significantly enhance the current technology in comparing large datasets of DNA sequences.

Regulated secretion of proinsulin/insulin from human hepatoma cells transduced by recombinant adeno-associated virus

To employ hepatocytes as surrogate beta-cells for gene therapy of diabetes, a regulatory system was devised in this study by placing the human insulin cDNA under the control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter, followed by the cytomegalovirus immediate early promoter-driven enhanced-green-fluorescent-protein open reading frame. The expression cassette was inserted into the adeno-associated virus vector between two inverted terminal repeats, and used to produce recombinant adeno-associated virus (rAAV). HepG2 human hepatoma cells were transduced by rAAV at the desired multiplicity of infection, followed by treatment with various concentrations of retinoic acid, dexamethasone, dibutyryl cAMP (dbcAMP) and 3-isobutyl-1-methylxanthine (IBMX). The cell-culture media were collected at 8, 16 and 24 h later. Proinsulin/insulin levels were determined with human proinsulin/insulin radioimmunoassay kits. Transduction of HepG2 cells by rAAV showed that green fluorescence was produced as early as 12 h after rAAV infection. Flow-cytometrical analysis demonstrated that transduction efficiency increased with the numbers of transducing rAAV particles used. The transduced hepatocytes were shown to secrete immunoreactive proinsulin/insulin, which were stimulated by the concentrations of retinoic acid, dexamethasone and dbcAMP in the culture medium. High conversion from proinsulin into insulin occurred when these cells were treated with dexamethasone and dbcAMP. The presence of IBMX enhanced the secretion of proinsulin/insulin from the dbcAMP-treated cells. We conclude that rAAV is a promising vector for gene therapy of diabetes. Regulated secretion of proinsulin/insulin can be obtained in the rAAV-transduced HepG2 cells conferred with the PEPCK promoter via rAAV-mediated gene transfer.

Clinical outcome in children with recurrent craniopharyngioma after primary surgery

PURPOSE

The purpose of this article is to report the clinical outcome in children with recurrent craniopharyngioma after primary surgery. PATIENT AND MATERIALS: Fourteen children with craniopharyngioma treated with primary surgery developed local recurrence. The median time to recurrence from primary surgery was 19 months (range, 2-156 months). At first recurrence (n = 14), seven children (50%) underwent reoperation. Five children (36%) received radiotherapy, and two children did not undergo any treatment. At second recurrence (n = 7), six children underwent radiotherapy (86%), and one had surgery. External-beam radiation was delivered with 6-MV or 10-MV x-rays by use of three-dimensional conformal technique (n = 4) or fractionated stereotactic radiotherapy (n = 7) using the Laitinen stereoadapter. Total dose ranged from 54 to 55.8 Gy at 1.8 Gy/fraction.

RESULTS

The median follow-up from primary surgery is 8.5 years (range, 3-15.8 years). The 5-, 10-, and 15-year overall survival was 100%, 86%, and 86%, respectively, and the disease-free survival was 92%, 60%, and 60%, respectively. The median follow-up from date of first relapse was 6 years (range, 2.5-10 years). After treatment for first recurrence, the 2- and 5-year second-recurrence-free survival was 71% and 29%, respectively. After radiotherapy, the 2- and 5-year second-recurrence-free survival was 100% and 100%, respectively, compared with 43% and 0%, respectively, for surgery alone. Univariate analysis revealed significantly superior local control with radiotherapy compared with surgery. The local control rate at last follow-up, after stratifying for treatment at first and second recurrence, were analyzed at first and second relapse was 90% and 0% after radiotherapy and surgery, respectively. If radiotherapy was used for first or second recurrence, the 5-, 10-, and 15-year relapse-free survival was 100%, 83%, and 83%, respectively, compared with 67%, 0%, and 0%, respectively, for surgery alone. The median time to second relapse after surgery for first relapse was 12 months (range, 2-36 months). After primary surgery, all 14 children developed panhypopituitarism, requiring lifelong hormone supplementation. After surgery at recurrence, three children (3/7, 43%) experienced intraoperative bleeding, resulting in permanent neurologic deficits in two. No child has shown any signs of radiation-induced optic neuropathy.

DISCUSSION

In children with recurrent craniopharyngioma after radical resection, the use of three-dimensional conformal radiotherapy or fractioned stereotactic radiotherapy results in very good local control with a low incidence of complications. In young children with stable tiny recurrences, a policy of close surveillance could be adopted for the brain to mature before beginning radiotherapy. The use of secondary surgery for recurrent tumors is associated with a low cure rate and a high risk of complications.

Concomitant chemoradiotherapy as primary therapy for locoregionally advanced head and neck cancer

PURPOSE

To achieve locoregional control of head and neck cancer, survival, and organ preservation using intensive concomitant chemoradiotherapy.

PATIENTS AND METHODS

This study was a phase II trial of chemoradiotherapy with cisplatin 100 mg/m(2) every 28 days, infusional fluorouracil 800 mg/m(2)/d for 5 days, hydroxyurea 1 g orally every 12 hours for 11 doses, and radiotherapy twice daily at 1.5 Gy/fraction on days 1 through 5 (total dose, 15 Gy). Five days of treatment were followed by 9 days of rest, during which time patients received granulocyte colony-stimulating factor. Five cycles (three with cisplatin) were administered over 10 weeks (total radiotherapy dose, </= 75 Gy). Adjuvant chemoprevention with retinoic acid and interferon alfa-2A was offered.

RESULTS

Seventy-six patients were treated (stage IV, 93%; N2, 54%; N3, 21%). At a median follow-up of 38 months, the 3-year progression-free survival is 72%, locoregional control 92%, systemic control 83%, and overall survival 55%. Toxicities included mucositis (grade 3, 45%; grade 4, 12%), neutropenia (grade 4, 39%), and thrombocytopenia (grade 4, 53%). Surgery at the primary site was performed in 13 patients, and 39 had neck dissection. A majority of patients declined adjuvant chemoprevention. Pharmacokinetic parameters were not prognostic of tumor control. Quality of life declined during treatment but returned from good to excellent by 12 months after treatment.

CONCLUSION

Intensive concomitant chemoradiotherapy leads to high locoregional control and survival rates with organ preservation and a reversal of the historical pattern of failure (distant > locoregional). Surgery after concomitant chemoradiotherapy is feasible. Compliance with adjuvant chemoprevention is poor. Identification of less toxic regimens and improved distant disease control emerge as important future research goals.

Racial differences in prostate cancer related to loss of heterozygosity on chromosome 8p12-23

PURPOSE

To determine if there is a racial difference in prostate cancer related to loss of heterozygosity (LOH) on chromosome 8p12-23, the region most frequently altered in prostate cancer.

METHODS AND MATERIALS

A total of 51 prostate cancer patients, consisting of 23 African Americans and 28 Caucasians, were included in this study. All patients underwent radical prostatectomy, and patients in the two racial subgroups were matched for median serum PSA, Gleason score, and pathological stage of cancer. Paired normal prostate and cancer tissue DNA was isolated and amplified with 13 polymorphic markers mapped to 8p12-23 by radiolabeled polymerase chain reaction. The amplified products were resolved by polyacrylamide gel electrophoresis, autoradiographed, and analyzed for allelic losses.

RESULTS

The overall incidence of LOH at 8p12-23 was 53%, and 16% showed homozygous deletions. The incidence of LOH in Caucasians was 68% compared to 35% in African Americans. On univariate (p = 0.02) and multivariate logistic regression analysis (p = 0.02), only Caucasian race was a significant predictor for LOH. The other clinicopathologic parameters did not have any significant effect on incidence of LOH.

CONCLUSION

These results highlight the independent influence of Caucasian race on incidence of LOH at 8p12-23, and suggest that genetic differences at specific tumor suppressor loci may be a factor responsible for racial variations observed in prostate cancer.

Comparison of recovery characteristics of sevoflurane and halothane for outpatient surgery in infants

BACKGROUND

Sevoflurane, a newly approved potent inhaled anesthetic in Taiwan, provides rapid emergence from anesthesia in adults and children. Clinically, it is difficult to accurately assess the rate of recovery from anesthesia in infants. This study was designed to compare the emergence characteristics of halothane with those of sevoflurane having recourse to a respiratory agent monitor in infants undergoing outpatient surgery.

METHODS

Forty infants of ASA class I, scheduled for day-case urologic surgery were studied. Patients were randomly allocated to two groups of 20. Sevoflurane or halothane was used as the inhaled anesthetic. Toward the end of surgery, sevoflurane or halothane was turned off. The concentrations of exhaled sevoflurane or halothane were read every minute after its discontinuation until extubation. The decay curve of the exhaled concentration of either agent was recorded minute by minute for 10 minutes. The time intervals from discontinuation of the inhalation agent to spontaneous movement and tracheal extubation were recorded. Untoward side-effects during emergence were also compared.

RESULTS

Sevoflurane was eliminated faster than halothane. Based on the decay curves of the exhaled concentrations of the two agents, the time constant for halothane was 2.59 minutes and that for sevoflurane was only 1.43 minutes. The time from discontinuation of agent to extubation was also shorter for sevoflurane. Postoperative restlessness or agitation occurred more frequently in infants who received sevoflurane, although the difference was of no statistical significance.

CONCLUSIONS

Sevoflurane is superior to halothane for rapid elimination in infant outpatient surgery as gauged by observation of end-tidal concentration elimination curves recorded with a respiratory agent monitor. No other postoperative side-effect was evident in sevoflurane anesthesia.

Oral-facial-digital syndrome with Y-shaped fourth metacarpals and endocardial cushion defect

We report on a boy with pseudo-cleft of the upper lip, cleft palate, bifid uvula, lobulated tongue, hypoplasia of the epiglottis, both preaxial and central polydactyly of the hands (Y-shaped fourth metacarpals), bilateral preaxial polydactyly of the feet, postaxial polydactyly of the left foot, hearing impairment, and congenital heart disease with endocardial cushion defect. These clinical manifestations resembled oral-facial-digital syndrome type II (OFDS II, Mohr syndrome) or type VI (Váradi syndrome), associated with an atrioventricular canal. Clinical variability of OFDS II has been observed repeatedly. To the best of our knowledge, this is the first reported case of OFDS II with Y-shaped fourth metacarpals. In addition to Y-shaped fourth metacarpals, Mohr syndrome plus atrioventricular canal and hypoplasia of the epiglottis may represent an additional subgroup of OFDS.

Nonfunctioning pancreatic tumor manifestated as abdominal mass in a child

This report concerns a 9-year-old girl with a nonfunctioning pancreatic tumor presented as an abdominal mass. An encapsulated tumor, measuring approximately 8 x 7 cm, was found during operation, and debulking surgery was done. Histopathologic studies proved that it was a pancreatic tumor, compatible with non-functioning islet cell tumors. She displayed neither clinical picture of jaundice, nor excessive hormonal manifestations such as diarrhea or flushing. No evidence would suggest its association with multiple endocrine neoplasia type I. To our knowledge, it has never been reported in children in Taiwan.

Optimal proliferation of a hematopoietic progenitor cell line requires either costimulation with stem cell factor or increase of receptor expression that can be replaced by overexpression of Bcl-2

In vitro proliferation of hematopoietic stem cells requires costimulation by multiple regulatory factors whereas expansion of lineage-committed progenitor cells generated by stem cells usually requires only a single factor. The distinct requirement of factors for proliferation coincides with the differential temporal expression of the subunits of cytokine receptors during early stem cell differentiation. In this study, we explored the underlying mechanism of the requirement of costimulation in a hematopoietic progenitor cell line TF-1. We found that granulocyte-macrophage colony-stimulating factor (GM-CSF) optimally activated proliferation of TF-1 cells regardless of the presence or absence of stem cell factor (SCF). However, interleukin-5 (IL-5) alone sustained survival of TF-1 cells and required costimulation of SCF for optimal proliferation. The synergistic effect of SCF was partly due to its anti-apoptosis activity. Overexpression of the IL-5 receptor alpha subunit (IL5Ralpha) in TF-1 cells by genetic selection or retroviral infection also resumed optimal proliferation due to correction of the defect in apoptosis suppression. Exogenous expression of an oncogenic anti-apoptosis protein, Bcl-2, conferred on TF-1 cells an IL-5-dependent phenotype. In summary, our data suggested SCF costimulation is only necessary when the expression level of IL5Ralpha is low and apoptosis suppression is defective in the signal transduction of IL-5. Expression of Bcl-2 proteins released the growth restriction of the progenitor cells and may be implicated in leukemia formation.

Urinary bladder outlet obstruction in children

Bladder outlet obstruction, either functionally or structurally, could lead to bladder trabeculation, vesicoureteric reflux, hydronephrosis and, eventually, to renal parenchymal damage. If no treatment is given, end-stage renal failure will ensue. The cases of 17 patients of bladder outlet obstruction at National Taiwan University Hospital from 1984 to 1997 were reviewed. Initial presentation, etiology and treatment were discussed. Nine patients were victims of neurogenic bladder and two patients were victims of nonneurogenic neurogenic bladder. Four patients suffered from posterior urethral valve. Ureterocele and urethral rhabdomyosarcoma were noted in one case each. The most common clinical manifestation was urinary tract infection. Ultrasonography, urodynamic study and voiding cystourethrogram were used to delineate the cause and help to decide the appropriate treatment. In conclusion, early detection and prevention of deteriorated renal function are important for children with urinary bladder outlet obstruction.

Effect of BL-10 (tianzhu), BL-11 (dazhu) and GB-34 (yanglinquan) acuplaster for prevention of vomiting after strabismus surgery in children

BACKGROUND

Stimulation of P6 (Neiguan) acupoint can prevent nausea and vomiting in adults. However, there is no antiemetic effect in children undergoing strabismus surgery. The effect of P6 may act only on hollow organs; in contrast, BL-10 (Tianzhu), BL-11 (Dazhu) and GB-34 (Yanglinquan) are more related to the meridians of the eye. Therefore these three more relevant acupoints, BL-10, BL-11 and GB-34 were stimulated to evaluate the antiemetic effect in children undergoing strabismus surgery.

METHODS

Sixty-five children, ASA physical status I, between 3 and 14 years of age, were randomly divided into two groups as follows: placebo group (n = 31) and acuplaster group (n = 34). Bilateral acupressure using the Vital Point Needleless Acuplaster (Koa, Japan) was applied to BL-10, BL-11 and GB-34 points the night before surgery. Anesthesia was induced and maintained with halothane and nitrous oxide in oxygen. Postoperative emesis was assessed at early (at PACU) and late (at ward) phases, and was recorded by an investigator blind to the treatment characteristics.

RESULTS

In the early emesis phase, the incidence of vomiting was 35.5% for placebo group, compared with 14.7% for acuplaster group. In the late emesis phase, acuplaster patients had a significantly lower incidence of vomiting (23.5% vs. 58.1% in placebo patients, p < 0.05). The overall postoperative vomiting incidence in the acuplaster patients in a 24 h period which was significantly decreased was 29.4% as opposed 64.5% in the placebo group (p < 0.05).

CONCLUSIONS

The results demonstrated that prophylactic use of bilateral noninvasive acuplaster on the BL-10, BL-11, and GB-34 acupoints significantly reduces vomiting after strabismus correction. The mechanism may be dispersal of these three acupoints, thus diminishing the parasympathetic stimulation resulting from surgical traction of eye muscles.

Image contrast in polarization microscopy of magneto-optical disk data-storage media through birefringent plastic substrates

Using polarized-light microscopy, we have investigated the magnetic domains of perpendicularly magnetized media under several different conditions, including direct observation of the thin-film magnetic layer and observations through the glass or plastic substrates on which the magnetic film was deposited. The results show that the image contrast is reduced with an increasing numerical aperture of the objective lens. They also indicate that the polarization rotation caused by differences between the reflectivity-transmissivity of the p and s components of polarization deteriorate the magnetic image contrast. Furthermore, by comparing the image quality using the same objective lens on samples having different substrates, we found that the images obtained through plastic substrates are worse than those obtained through glass substrates. Birefringence of the plastic substrate is shown to be responsible for the additional degradation of the image contrast.

EMLA cream and lidocaine local injection in the treatment of extravenous thiopental injection--a case report

Thiopental extravasation which would cause tissue edema and necrosis in rapid progression by chemical reaction and vascular spasm is a potentially serious complication in anesthesia. Early diagnosis and treatment may bear a favorable outcome. A patient who sustained thiopental extravasation and received local injection of lidocaine and local application of EMLA (Eutectic Mixture of Local Anesthetics) for treatment with excellent results is presented hereunder.

Measurement of the thermal coefficients of nonreversible phase-change optical recording films

We have developed a procedure to obtain the critical temperature for the amorphous-to-crystalline phase transition as well as the thermal conductivity and the specific heat of the phase-change media of optical recording. The procedure involves estimating the thermal conductivity from the data obtained by measuring the threshold cw laser power required for inducing phase transition. Then, from the data obtained in short-pulse measurements, we estimate the specific heat. In principle this method can yield the thermal parameters of any number of layers, so long as one of the layers is made of a phase-change material having a well-defined transition temperature.

Acquired long QT syndrome in a child undergoing craniotomy: a case report

The long QT syndrome (LQTS) is a rare disorder of cardiac conduction in children. It may lead to severe arrhythmia, syncope or sudden death. Electrolyte disturbance and the use of procainamide are closely related to the acquired LQTS. This report concerns a fatality of acquired LQTS in a boy undergoing craniotomy. After induction of anesthesia, his electrocardiogram displayed a frequent torsade de pointes type of ventricular tachycardia with prolonged QT interval. Therefore, congenital LQTS was impressed. However, the arrhythmia was aggravated by intravenous propranolol. Isoproterenol infusion was given under the diagnosis of acquired LQTS. The arrhythmia was successfully abolished and a stable hemodynamic status was maintained. However, the child could not tolerate the anesthesia which lasted for 30 hours, and eventually succumbed, despite aggressive treatment and resuscitation attempts. Differential diagnosis between the types of LQTS should be made promptly. This may be of paramount importance in the outcome since prognosis depends upon proper treatment. This case report discusses the etiology and management of this rare abnormality.

Cognitive capacity in female adolescent substance abusers

Female adolescents who qualified for a DSM-III-R diagnosis of psychoactive substance use disorder (n = 106) were compared to normal controls (n = 74) on a battery of cognitive, intellectual and achievement tests. It was found that the substance abuse group performed deficiently on tests requiring language skills, sustained attention and perceptual efficiency and scored lower than controls on standardized tests of intelligence and academic achievement. No relationship between magnitude of cognitive deficit and severity of substance abuse was observed. The implications of these findings are discussed with respect to the etiology and maintenance of drug use.

Restoring the apoptosis suppression response to IL-5 confers on erythroleukemic cells a phenotype of IL-5-dependent growth

We have established a human IL-5 (hIL-5) dependent cell line, JYTF-1, derived from TF-1 parental human erythroleukemic cells by long-term cultivation in the presence of hIL-5. The ED50 values of hIL-5 for both TF-1 and JYTF-1 cell lines remained similar. However, when cells were grown in an optimal concentration of IL-5, some TF-1 cells but not JYTF-1 cells died via apoptosis. Although the rates of DNA synthesis were similar for TF-1 and JYTF-1 cells grown in IL-5, [3-H]thymidine releasing of pulse-labeled DNA analysis indicated that the viable TF-1 cells in IL-5 were more apoptosis-prone than were JYTF-1 cells. Therefore, in the JYTF-1 variant, the ability to suppress apoptosis has apparently been restored. The following findings suggest that overexpression of the hIL-5 receptor alpha-chain may be responsible for restoring the apoptosis suppression ability of IL-5: 1) the growth of JYTF-1 cells remained cytokine-dependent; 2) the proliferation of JYTF-1 cells in IL-5 was not mediated by autocrine secretion; 3) JYTF-1 and TF-1 cells responded similarly to other cytokines such as human erythropoietin; 4) Northern blot analysis revealed that JYTF-1 cells expressed approximately eightfold more IL-5 receptor alpha-chain mRNA than did TF-1. To our knowledge, JYTF-1 represents the first example in which coupling of mitogenesis stimulation and apoptosis suppression from otherwise uncoupled parental cells confers a phenotype of IL-5-dependent growth.

Restoring the apoptosis suppression response to IL-5 confers on erythroleukemic cells a phenotype of IL-5-dependent growth

We have established a human IL-5 (hIL-5) dependent cell line, JYTF-1, derived from TF-1 parental human erythroleukemic cells by long-term cultivation in the presence of hIL-5. The ED50 values of hIL-5 for both TF-1 and JYTF-1 cell lines remained similar. However, when cells were grown in an optimal concentration of IL-5, some TF-1 cells but not JYTF-1 cells died via apoptosis. Although the rates of DNA synthesis were similar for TF-1 and JYTF-1 cells grown in IL-5, [3-H]thymidine releasing of pulse-labeled DNA analysis indicated that the viable TF-1 cells in IL-5 were more apoptosis-prone than were JYTF-1 cells. Therefore, in the JYTF-1 variant, the ability to suppress apoptosis has apparently been restored. The following findings suggest that overexpression of the hIL-5 receptor alpha-chain may be responsible for restoring the apoptosis suppression ability of IL-5: 1) the growth of JYTF-1 cells remained cytokine-dependent; 2) the proliferation of JYTF-1 cells in IL-5 was not mediated by autocrine secretion; 3) JYTF-1 and TF-1 cells responded similarly to other cytokines such as human erythropoietin; 4) Northern blot analysis revealed that JYTF-1 cells expressed approximately eightfold more IL-5 receptor alpha-chain mRNA than did TF-1. To our knowledge, JYTF-1 represents the first example in which coupling of mitogenesis stimulation and apoptosis suppression from otherwise uncoupled parental cells confers a phenotype of IL-5-dependent growth.

Coping capacity in female adolescent substance abusers

Female adolescents who qualified for a DSM-III-R diagnosis of Psychoactive Substance Use Disorder were not distinguishable from depressed and conduct disorder subjects on measures of coping but were differentiable from normal controls. Age of onset of substance use, interval between age of first use and age of diagnosis of abuse, and severity of substance use involvement did not correlate with coping capacity. These findings indicate that deficient coping is not specifically related to drug abuse but rather, where present, is concomitant to comorbid psychopathology among females who have a substance abuse disorder.

A novel method for measuring the vertical birefringence of optical disk substrates

We describe a simple method of measuring vertical birefringence over the entire surface of an optical disk substrate.Our design consists of a linearly polarized He-Ne laser (1-2 mW) and a CCD camera interfaced to a computer. The measurement is non-intrusive, easy to set up, and needs only a few seconds to collect the data and plot a map of vertical birefringence over the surface area of the disk. The system described here is potentially useful as a qualitycontrol tool in substrate manufacturing environments.

Functional analysis of the 14 kDa protein of insertion sequence 2

The IS2 sequence encodes five open reading frames (ORF1 to ORF5) that are greater than 150 nucleotides each. Only one protein of 14 kDa was detected when the expression of IS2 genes was examined in minicells. This 14 kDa protein was referred to as InsA in this study and was determined to be encoded by ORF1. A sixfold decrease in IS2 transposition frequency was observed when insA was overexpressed. DNA footprinting results indicated that InsA binds to the sequence 5'-TAAATAA-3' located at IS2 nucleotide numbers 1286 to 1292. (The IS2 right terminal repeat spans nucleotides 1290 to 1331.) This InsA binding sequence is situated 4 bp upstream from the putative "-10" sequence of the insA promoter that overlaps the right terminal repeat of IS2. The presence of a promoter located in this region was demonstrated by the ability of a DNA fragment containing the right terminal repeat to drive the expression of a promoterless lacZ gene. The transcription of insA was determined to start at the A residue located at nucleotide number 1268. With the same insA promoter-lacZ fusion construct, overexpression of insA in the same cell was found to decrease the beta-galactosidase activity. The results of this study suggest that InsA affects IS2 transposition by regulating the transcription of IS2 genes.

Mutational specificity of chromium(VI) compounds in the hprt locus of Chinese hamster ovary-K1 cells

Chromium(VI) compounds exert their genotoxicity and mutagenicity by complex metabolic reducing pathways that generate a variety of reactive forms of chromium and free radicals. To investigate the molecular nature of chromium-induced mutations, we characterized the entire coding region of the hypoxanthine (guanine) phosphoribosyltransferase (hprt) gene of 27 independent mutants derived from chromium(VI) oxide (CrO3)-treated Chinese hamster ovary-K1 cells, by direct sequencing of PCR-amplified cDNA. Among these mutants, 10 consisted of single base substitutions, five contained two base substitutions, one had four base substitutions, six were splicing mutations, and five exhibited single base pair insertions or deletions. All of the base substitutions and most of the frameshift mutations observed were located at A/T-rich sequences. More than 90% of the base substitutions (22/24) occurred in A.T base pairs. Among them, T-->A and T-->G transversions (18/22) predominated. The mutational hotspots for single and double base substitutions were the 3' thymidine of 5'PuT and thymidines of 5'ATTT sequences respectively. This mutational specificity was also observed in CHO-K1 cells treated with two other chromium(VI) compounds, namely K2Cr2O7 and PbCrO4. Strand bias was noticed in chromium mutagenicity, since 77% of T base substitutions occurred on the non-transcribed strand. This highly sequence-specific mutation spectrum suggests that a particular form of chromium may directly interact with DNA at these hotspot sequences.

A new method for measurement of respiratory resistance

A new method for measuring the resistance of the total respiratory system is presented. The method uses a device comprising a solenoid valve, a multiperforated plate, and a pneumotachograph. The multiperforated plate serves as a constant resistor (Rk) that is used to partially occlude the airway opening, thus rapidly and briefly reducing airflow during natural expiration. If it is assumed that the driving pressure remains constant during the very short period the airway is partially occluded, the respiratory flow immediately preceding the addition of Rk (V) and the flow reduction during partial occlusion (delta V) allow calculation of the resistance of the total respiratory system. The resistance of 14 normal subjects and 18 patients with chronic obstructive pulmonary disease (COPD) was measured with this new method as well as with the body plethysmographic method: 90% of the interrupter values fell within +/- 0.6 cmH2O . l-1.s of the plethysmographic values, and all fell within +/- 0.8 cmH2O . l-1.s.