Portable Device for Quick Detection of Viable Bacteria in Water

(1) Background: Access to clean water is a very important factor for human life. However, pathogenic microorganisms in drinking water often cause diseases, and convenient/inexpensive testing methods are urgently needed. (2) Methods: The reagent contains 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and phenazine methosulfate (PMS) and can react with succinate dehydrogenase within bacterial cell membranes to produce visible purple crystals. The colorimetric change of the reagent after reaction can be measured by a sensor (AS7262). (3) Results: Compared with traditional methods, our device is simple to operate and can provide rapid (i.e., 5 min) semi-quantitative results regarding the concentration of bacteria within a test sample. (4) Conclusions: This easy-to-use device, which employs MTT-PMS reagents, can be regarded as a potential and portable tool for rapid water quality determination.

Long-term results of coronary artery bypass grafting in patients with dialysis-dependent renal failure

AIM

Coronary artery disease is the main cause of mortality and morbidity in dialysis-dependent renal failure patients. Both the prevalence and incidence of renal failure are high in Taiwan. However, there were few reports exploring the outcome of coronary aortic bypass grafting (CABG) in these patients. The aim of this study was to determine the survival outcome and risk factors for mortality from CABG in this population.

METHODS

The operative, early postoperative and late results of 170 dialysis patients undergoing isolated coronary artery bypass grafting from January, 2000 to January, 2012 were retrospectively reviewed. Operative mortality, long-term survival, and risk factors were analyzed.

RESULTS

One hundred and seventeen patients (68.8%) were male, and the mean age was 61.5±10.3 years (range, 34-86 years). Follow-up was 40.3±32.1 months. Operative mortality was 8.2%. Actuarial survival, including operative mortality, was 81±3% at 1 year, 68±4% at 3 years, 58±5% at 5 years and 49±6% at 10 years, better than the natural course of dialysis-dependent renal failure patients. Age, emergent operation, postoperative ventricular tachycardia or fibrillation, postoperative intra-aortic balloon pump insertion, gastrointestinal bleeding, and left internal mammary artery graft were significant predictors of operative or long term mortality. Most causes of late death were due to infection or cardiac events.

CONCLUSION

CABG in dialysis patients is associated with a higher incidence of complications, but has acceptable mortality. CABG is beneficial in this population. Internal mammary artery grafting may provide more favorable long term outcomes.

White thin-film flip-chip LEDs with uniform color temperature using laser lift-off and conformal phosphor coating technologies

We fabricated a phosphor-conversion white light emitting diode (PC-WLED) using a thin-film flip-chip GaN LED with a roughened u-GaN surface (TFFC-SR-LED) that emits blue light at 450 nm wavelength with a conformal phosphor coating that converts the blue light into yellow light. It was found that the TFFC-SR-LED with the thin-film substrate removal process and surface roughening exhibits a power enhancement of 16.1% when compared with the TFFC-LED without a sapphire substrate. When a TFFC-SR-LED with phosphors on a Cu-metal packaging-base (TFFC-SR-Cu-WLED) was operated at a forward-bias current of 350 mA, luminous flux and luminous efficacy were increased by 17.8 and 11.9%, compared to a TFFC-SR-LED on a Cup-shaped packaging-base (TFFC-SR-Cup-WLED). The angular correlated color temperature (CCT) deviation of a TFFC-SR-Cu-WLED reaches 77 K in the range of -70° to + 70° when the average CCT of white LEDs is around 4300 K. Consequently, the TFFC-SR-LED in a conformal coating phosphor structure on a Cu packaging-base could not only increase the luminous flux output, but also improve the angular-dependent CCT uniformity, thereby reducing the yellow ring effect.

Enhanced light output power of thin film GaN-based high voltage light-emitting diodes

The characteristics of high-voltage light-emitting diodes (HVLEDs) consisting of a 64-cell LED array were investigated by employing various LED structures. Two types of HVLED were examined: a standard HVLED with a single roughened indium tin oxide (ITO) surface grown on a sapphire substrate and a thin-film HVLED (TF-HVLED) with a roughened n-GaN and ITO double side transferred to a mirror/silicon substrate. At an injection current of 24 mA, the output powers of the HVLEDs fabricated using a sapphire substrate and those fabricated using a mirror/silicon substrate were 170 and 216 mW, respectively. Because the TF-HVLED exhibited improved thermal dissipation and light extraction, it produced a greater output power than the HVLED fabricated using the sapphire substrate did.

A novel integrated structure of thin film GaN LED with ultra-low thermal resistance

This study proposes a novel packaging structure for vertical thin-GaN LED applications by integration of LED chip and silicon-based packaging process. The vertical thin film LED is directly mounted on package submount. The shortest thermal path structure from junction to package submount achieves the lowest thermal resistance of 1.65 K/W for LED package. Experimental results indicate that low thermal resistance significant improved forward current up to 4.6A with 1.125 × 1.125 mm² LED chip size.

Clinical significance of tumor suppressor PTEN in colorectal carcinoma

BACKGROUND

It has been demonstrated that the deletion, mutation, hypermethylation and subcellular location of the tumor suppressor phosphatase and tensin homologue (PTEN) are closely correlated with carcinogenesis, progression and prognosis of malignancy. Both mutation and the microsatellite instability of the PTEN gene influence regulation of the PI3K/Akt signaling pathway. This study investigated whether loss of nuclear PTEN is correlated with chemosensitivity, clinicopathological parameters and survival.

METHODS

Intracellular levels of PTEN of multiple cell lines of colorectal carcinoma (CRC) were evaluated by Western blotting and immunocytochemistry. The chemosensitivity of cell lines with various expression levels of PTEN was evaluated using 5-flurouracil (5-FU), oxaliplatin and irinotecan (CPT), and clinical significance was evaluated by immunohistochemical analysis of 133 CRC specimens.

RESULTS

Colon cancer cell lines HT-29, LoVo and SW480 differed in expression of PTEN, with high, moderate and low levels, respectively. HT-29 and LoVo PTEN expression was suppressed by a low concentration of 5-FU and oxaliplatin; however, SW480 was insensitive to these chemotherapeutic agents. Nuclear PTEN was overexpressed in most (>80%) normal colon mucosa samples, but the incidence significantly decreased (89.2% → 53.4%) in the CRC group. PTEN in the nucleus was negatively correlated with tumor size and vascular invasion in CRC, and CRC patients with negative PTEN expression in the nucleus exhibited poor survival.

CONCLUSION

Cell lines with a high expression of PTEN are sensitive to chemotherapy with 5-FU and oxaliplatin. Nuclear PTEN expression gradually decreases after malignant transformation, and loss of PTEN expression in the nucleus is associated with tumor progression and poor clinical outcome in CRC.

Pre-tracheal lymph node metastasis in squamous cell carcinoma of the thoracic esophagus

AIMS

To clarify the incidence of pre-tracheal lymph node metastasis in squamous cell carcinoma of the esophagus, and their impact on survival.

METHODS

A cohort of 101 patients with squamous cell carcinoma of the thoracic esophagus who underwent esophagectomy together with 2-field lymphadenectomy including the pre-tracheal region was analysed, retrospectively. The p-TNM staging included stage I in 9, stage IIa in 33, stage IIb in 4, stage III in 43, and stage IV in 12 cases.

RESULTS

Nodal metastases were identified in 56 patients (55.4%). Subcarinal lymph node and pre-tracheal lymph-node metastases were found in 24 patients (23.8%) and 15 patients (14.9%), respectively. The 5-year cumulative survival rates were 26.5 and 2.5% in nodal negative and nodal positive patients, respectively. Patients with pre-tracheal nodal metastasis all died within 2 years. Cox proportional hazards model in patients with nodal involvement revealed T-factor (p=0.0017), pre-tracheal nodal involvement (p=0.0055) and distant metastasis (p=0.0024) as independent prognostic factors.

CONCLUSIONS

Our findings suggest that pre-tracheal lymph node metastasis indicates a dismal prognosis. Its occurrence is not unusual, especially in tumour of upper or middle thoracic esophagus. The subcarinal node cannot be regarded as a sentinel node of the pre-tracheal nodal station. Complete lymphadenectomy excluding the pre-tracheal lymph nodes in treating esophageal cancers is only a myth.

Expression of apoptosis-regulating proteins p53, Bcl-2, and Bax in primary resected esophageal squamous cell carcinoma

Apoptosis plays a key role in the pathogenesis, aggressiveness, and therapy responsiveness of cancer. Proteins of the Bcl-2 family as well as p53 are important regulators of apoptosis. The present study retrospectively examines the expression of apoptosis-regulating proteins in primary resected esophageal squamous cell carcinoma (ESCC) and the correlation between the outcome of patients' treatment and the expression of the proteins. We used antibodies specific for the human p53, Bcl-2 and Bax proteins to examine the expression of these apoptosis-regulating proteins in 40 archival specimens of patients with primary resected esophageal squamous cell carcinoma. The overall expression of p53, Bcl-2, and Bax was 73%, 18%, and 100%, respectively. No significant correlations were found between the expression of p53, Bcl-2, and Bax. The expression of Bcl-2 had a negative influence on survival in this population of primary resected ESCC patients (p=0.03). But no differences in survival were observed in relation to the expression of p53 or Bax. In conclusion, Bcl-2 expression may provide additional and prognostic information for the clinical course of the disease and therefore to be developed as a prognostic indicator for primary resected esophageal squamous cell carcinoma.

Effects of verapamil on coronary vascular resistance in rabbits: measurement with pulsed Doppler velocimetry

BACKGROUND

Verapamil is an effective vasodilator. The purpose of this study was to investigate the in vivo effect of verapamil on coronary blood flow velocity and vascular resistance in anesthetized, open-chest rabbits.

METHODS

Twenty-one male New Zealand white rabbits were anesthetized, and a 3-mm suction-type pulsed Doppler velocimeter probe was applied to the proximal part of the left anterior descending coronary artery after median sternotomy. The rabbits received intravenous bolus infusion of 4 different doses of verapamil (0.01 mg/kg, n = 5; 0.1 mg/kg, n = 5; 1 mg/kg, n = 5, and 10 mg/kg, n = 6). The percent changes in coronary blood flow velocity and coronary vascular resistance were examined.

RESULTS

There was 10.0+/-1.6% increase in coronary blood flow (CBF) and 12.5+/-1.9% reduction in coronary vascular resistance (CVR) after infusion of 0.01 mg/kg of verapamil. The CBF increased 23.0+/-9.5% and CVR decreased 24.2+/-5.2% after infusion of 0.1 mg/kg of verapamil. Infusion of 1 mg/kg of verapamil induced 34.8+/-10.5% increase in CBF and 32.6+/-2.5% reduction in CVR. The CBF increased 41.1+/-14.8% and CVR decreased 45.1+/-5.4% after infusion of 10 mg/kg of verapamil.

CONCLUSIONS

Compared with baseline condition, all doses of verapamil increased coronary blood flow velocity and decreased coronary vascular resistance significantly in anesthetized, open-chest rabbits.

Correlation between epithelial cell permeability of cephalexin and expression of intestinal oligopeptide transporter

The proton-coupled oligopeptide transporter (PEPT1) has been shown to mediate mucosal cell transport of di- and tripeptide, and some peptidomimetic drugs. In this study, we determined the correlation between PEPT1 protein expression and the permeability of cephalexin, a substrate of PEPT1, in human PEPT1 (hPEPT1)-overexpressed Caco-2 cells (Caco-2/hPEPT1 cells) and rat jejunum. Caco-2/hPEPT1 cells with various levels of hPEPT1 expression were established by an adenoviral transfection system. The effective intestinal permeability (P(eff)) in rat jejunum was evaluated using a single pass in situ perfusion method. The level of PEPT1 in Caco-2/hPEPT1 cells and rat intestinal mucosal samples was quantitated by densitometry after immunoblotting and enhanced chemiluminescence detection. In Caco-2/hPEPT1 cells, an excellent correlation was observed between cephalexin uptake and hPEPT1 expression (R2 = 0.96, P < 0.005). This demonstrates that cephalexin uptake is directly proportional to hPEPT1 expression. In the rat perfusion study, the mean P(eff) +/- S.D. (n = 15) of cephalexin was 3.89 +/- 1.63 x 10(-5) cm/s. A very significant correlation between PEPT1 expression and cephalexin permeability with an R2 = 0.63 (P < 0.001) was observed. This indicates that the variation in PEPT1 expression is one of the major factors accounting for variable intestinal cephalexin absorption. To our knowledge, this is the most direct evidence that variation of PEPT1 expression is correlated with absorption permeability variation of peptide-like compounds in vitro and in vivo.

Suppression of proline-directed protein kinase F(A) potentiates apoptotic induction and greatly enhances chemosensitivity in human acute lymphoblastic leukemia cells

BACKGROUND

Previously, the authors reported that specific antisense suppression of overexpressed proline-directed protein kinase (PDPK) F(A) enhances the chemosensitivity of various clinical anticancer drugs up to > 100-fold in human prostate carcinoma cells, suggesting an association of PDPK F(A) with drug resistance in human malignancies.

METHODS

In this report, by using a similar approach, the authors demonstrate further that the suppression of PDPK F(A) enhances even more dramatically the chemosensitivity of clinically used anticancer drugs in various types of human acute lymphoblastic leukemia (ALL) cells.

RESULTS

Compared with parental and control transfected cells, transduced ALL cells (both Jurkat and CCRF-CEM cells) with low levels of PDPK F(A) displayed an enhanced sensitivity to vincristine, vinblastine, paclitaxel, methotrexate, doxorubicin, and daunorubicin. Estimation of the 50% inhibitory concentration (IC(50)) index further revealed that the transduced cells displayed up to > 3000-fold drug sensitivity, and there was a correlation between suppressed levels of PDPK F(A) and drug sensitivity. A mechanistic study further revealed that the enhanced chemosensitivity in transduced ALL cells was due mainly to the potentiation of apoptotic induction.

CONCLUSIONS

Taken together, the results demonstrate that the suppression of overexpressed PDPK F(A) greatly enhances the chemosensitivity of various clinical anticancer drugs in both types of human ALL cells, providing initial evidence for an important role of this PDPK in controlling multidrug resistance of ALL.

Experiences in thoracoscopic sympathectomy for axillary hyperhidrosis and osmidrosis: focusing on the extent of sympathectomy

HYPOTHESIS

A more selective sympathectomy can improve the outcome of axillary hyperhidrosis and osmidrosis and minimize the potential sequelae.

DESIGN

Retrospective cohort.

SETTING

Tertiary care center.

PATIENTS

Between July 1, 1996, and May 30, 2000, 171 patients with axillary hyperhidrosis and osmidrosis were studied.

INTERVENTIONS

T3-4 sympathectomies were performed in 40 patients (group 1), T4 sympathectomies were performed in 56 patients (group 2), and T4-5 sympathectomies were performed in 75 patients (group 3).

MAIN OUTCOME MEASURES

The surgical outcomes were evaluated by direct patient interview in the outpatient clinic or by telephone or mail questionnaires. The results were categorized as excellent (significant or complete disappearance of symptoms), good (>/=50% improvement), or poor (<50% improvement).

RESULTS

There were no surgical mortalities in this study. Twenty-eight group 1 patients (70%), 16 group 2 patients (29%), and 22 group 3 patients (29%) developed compensatory perspiration (P<.001). Six group 1 patients (15%), 1 group 2 patient (2%), and 1 group 3 patient (1%) developed dry hands (P =.02). In the group 1 patients, the surgical outcomes were excellent in 21 (52%), good in 6 (15%), and poor in 13 (32%). In the group 2 patients, the surgical outcomes were excellent in 29 (52%), good in 10 (18%), and poor in 17 (30%). In the group 3 patients, the surgical outcomes were excellent in 53 (71%), good in 11 (15%), and poor in 11(15%) (P =.04). (Percentages may not sum to 100 because of rounding.)

CONCLUSION

T4-5 sympathectomies provide higher patient satisfaction rates in treating axillary hyperhidrosis and osmidrosis, with fewer sequelae.

Ascending aorta to lower limbs revascularization for reoperation via ministernotomy

The extra-anatomic bypasses, femorofemoral or axillofemoral, have been performed in selected patients for lower extremity revascularization of aortoiliac occlusion. However, significant graft occlusion rate does exist and reoperation constitutes an increasing proportion of vascular surgery practice. We presented our experience in a high-risk patient who received bypass surgery for the third time using the ascending aorta as the source of inflow with good result.

Optimizing Caco-2 cell monolayers to increase throughput in drug intestinal absorption analysis

INTRODUCTION

The aim of this investigation was to evaluate methods for increasing Caco-2 cell throughput for assessing drug intestinal absorption. The use of 6-, 12-, and 24-well membranes and the effect of membrane size on permeability and the integrity of the Caco-2 cell monolayer were assessed. In an effort to optimize the assessment of drug permeability, increased throughput was investigated by testing compounds singly or as mixtures of analytes.

METHOD

The transepithelial electrical resistance (TEER) of cell monolayers was measured on 0.33, 1.0, and 4.7 cm2 polycarbonate membranes using EVOM, over a 25-day period. Absorptive transport was determined on all compounds tested using LC-MS/MS assays, or liquid scintillation spectrometry.

RESULTS

The effect of multiple compounds in one well compared to single compounds was assessed with atenolol, nadolol, metoprolol, and propranolol for mixtures of four compounds and with RWJ-53308, atenolol, terbutaline, propranolol, naproxen, piroxicam, topiramate, and furosemide for mixtures of eight compounds. The apparent permeability (Papp) values correlated well between single analytes and mixtures of four and eight analytes in each well. Drug permeability decreased slightly with an increase in well size. The TEER value increased with the number of days in culture for each of the 6-, 12-, and 24-well sizes.

DISCUSSION

It was demonstrated that the 24-well format system is ideal for high-throughput assessment. Furthermore, the approach of mixing four or eight analytes in each well to further increase throughput was also demonstrated to be valid.

Study of anticipation in Chinese families with schizophrenia

The anticipation phenomenon is an important aspect in several genetic disorders in which the age at onset (AAO) decreases and the severity of illness increases in successive generations. This phenomenon has been reported in several schizophrenic family studies, and expanded repeat mutations are implicated. In the present study, we investigate the anticipation phenomenon in Chinese schizophrenic families. We compare the AAO between two generations of 38 unilinear schizophrenic families. Intergenerational comparisons show that the AAO was significantly earlier in the offspring generation (mean AAO, 22.2 years) than that in the parental generation (mean AAO, 31.0 years) (P < 0.001). When only including the offspring generation who married, the AAO difference between the two generations was not significant (28.4 years vs 31.0 years, P = 0.151). Our findings suggest that a selection bias in the parental group might greatly impact the study of anticipation in schizophrenia. Other unavoidable biases associated with these analyses are discussed in the text.

Suppression of proline-directed protein kinase F(A) systemically inhibits the growth of human acute leukemia cells

Initial studies revealed that proline-directed protein kinase F(A) (PDPK F(A)) was overexpressed in various cancerous tissues relative to normal controls. However, the functional role of overexpressed PDPK F(A) in cancer remains to be established. In this report, we explore the potential role of PDPK F(A) in leukemia cell growth by investigating the effects of partial inhibition of this kinase on human acute promyelocytic leukemia (HL-60) and acute lymphoblastic leukemia (Jurkat) cells. Cloning of PDPK F(A) cDNA and its recombinant antisense expression vector and antibody were successfully developed. Several stable antisense clones of HL-60 and Jurkat cells were subcloned, which expressed a low level of PDPK F(A) when compared with the control-transfected clone in immunoblot analysis. Moreover, these antisense clones potently inhibited cell growth, clonogenic growth in soft agar and serum-independent growth. The results taken together demonstrate that suppression of PDPK F(A) is able to interfere with the growth of HL-60 and Jurkat cells, suggesting an essential role of this PDPK in human acute leukemia cell growth.

Prediction of prognosis by the extent of lymph node involvement in squamous cell carcinoma of the thoracic esophagus

OBJECTIVES

Current criteria of the N-category in the TNM staging system for carcinoma of the esophagus needs further subgrouping due to its simplicity in mixing together patients with different prognosis.

METHOD

A retrospective cohort study of 186 patients (176 men and ten women; mean age, 59.9 years) with squamous cell carcinoma (SCC) of the thoracic esophagus who underwent esophagectomy followed by two-field lymphadenectomy and cervical lymph node sampling between 1992 and 1999 was conducted. A proposed N-category which involved dividing the nodal status into N0 (no nodal involvement), N1 (< or =4 nodes or < or =20% nodal involvement), and N2 (>4 nodes, or >20%, or non-regional nodal involvement) subgroups was used for survival analysis.

RESULTS

The overall 5-year cumulative survival rate was 27%. Lymph node metastases were identified in 101 (54.3%) patients. Cumulative survival rates were 46% at 4 years in the N0 group and 21% at 4 years in the N1 group, whereas no patients in N2 group survived longer than 3 years (P<0.01). A multivariable analysis revealed that independent prognostic factors included the depth of tumor invasion (P<0.01), nodal involvement (P<0.01), and organ metastasis (P<0.01).

CONCLUSION

In addition to the location of nodes, the extent of nodal involvement in SCC of the thoracic esophagus also plays an important role in prognosis prediction.

Surgical management of substernal goiter

PURPOSE

We describe the clinical results and complications associated with different surgical approaches to the treatment of substernal goiter.

METHODS

We retrospectively reviewed the medical records of 56 patients treated for substernal goiter from 1983 through 1999. Eight had undergone previous thyroidectomy. Posterior mediastinal goiter was diagnosed in eight patients, hyperthyroidism in seven, acute respiratory failure in three, and superior vena cava syndrome in two. All but one of the patients underwent thyroidectomy.

RESULTS

Thyroid scan revealed that 88% of patients had substernal goiter. A cervical incision alone was used in 46 of 55 patients. Nine patients underwent thyroidectomy via a thoracic approach. Both lobes were resected in 16 patients. Two deaths occurred: one patient suffered a stroke and another patient developed pneumonia after surgery. The most frequent complication was recurrent laryngeal nerve injury, followed by removal of a normal parathyroid gland and pneumonia. Multinodular goiter occurred in 52 patients. Resected goiter with occult malignancy was found in three patients, two of whom underwent lobectomy only. These three patients had survived at 5, 7, and 11 years postoperatively, respectively. All patients with tracheal lumen narrowing showed a normal sized tracheal lumen 2 to 3 months postoperatively.

CONCLUSION

Our data indicate that the presence of a substernal goiter should be considered an indication for resection based on risk of acute respiratory distress, risk of malignancy, and lower surgical morbidity. Most secondary substernal goiters can be simply resected through cervical incision and curation.

Femtosecond dynamics of the forbidden carotenoid S1 state in light-harvesting complexes of purple bacteria observed after two-photon excitation

Time-resolved excited-state absorption intensities after direct two-photon excitation of the carotenoid S(1) state are reported for light-harvesting complexes of purple bacteria. Direct excitation of the carotenoid S(1) state enables the measurement of subsequent dynamics on a fs time scale without interference from higher excited states, such as the optically allowed S(2) state or the recently discovered dark state situated between S(1) and S(2). The lifetimes of the carotenoid S(1) states in the B800-B850 complex and B800-B820 complex of Rhodopseudomonas acidophila are 7+/-0.5 ps and 6+/-0.5 ps, respectively, and in the light-harvesting complex 2 of Rhodobacter sphaeroides approximately 1.9+/-0.5 ps. These results explain the differences in the carotenoid to bacteriochlorophyll energy transfer efficiency after S(2) excitation. In Rps. acidophila the carotenoid S(1) to bacteriochlorophyll energy transfer is found to be quite inefficient (phi(ET1) <28%) whereas in Rb. sphaeroides this energy transfer is very efficient (phi(ET1) approximately 80%). The results are rationalized by calculations of the ensemble averaged time constants. We find that the Car S(1) --> B800 electronic energy transfer (EET) pathway ( approximately 85%) dominates over Car S(1) --> B850 EET ( approximately 15%) in Rb. sphaeroides, whereas in Rps. acidophila the Car S(1) --> B850 EET ( approximately 60%) is more efficient than the Car S(1) --> B800 EET ( approximately 40%). The individual electronic couplings for the Car S(1) --> BChl energy transfer are estimated to be approximately 5-26 cm(-1). A major contribution to the difference between the energy transfer efficiencies can be explained by different Car S(1) energy gaps in the two species.

Suppression of proline-directed protein kinase F(A) expression potentiates erythroid differentiation of human myeloid leukemia cells

BACKGROUND

Initial clinic studies revealed that the overexpression of proline-directed protein kinase F(A) (PDPK F(A)) is associated conversely with various stages of tumor tissue differentiation. However, the role of overexpressed PDPK F(A) in tumor cell differentiation remains unknown and needs to be established. In this report, the authors explore the potential role of PDPK F(A) in cellular differentiation by investigating the effects of partial inhibition of this kinase on erythroid differentiation of chronic myeloid leukemia cells (K562).

METHODS

PDPK F(A) antisense expression vector and its specific antibody were developed successfully. Two stable, transfected antisense clones of human myeloid leukemia cells were subcloned that expressed approximately 80% and approximately 50% of the total PDPK F(A) existing in control-transfected clones, as determined by both immunoprecipitate activity assay and immunoblot analysis. In sharp contrast, the PDPK F(A) antisense clones expressed no significant suppression of any other related PDPK members' expression, demonstrating the specificity of these two antisense clones.

RESULTS

The antisense clones proportionally induced spontaneous erythroid differentiation up to approximately 30% of the total K562 cells. Moreover, antisense suppression of PDPK F(A) expression appeared to potentiate sodium butyrate/hemin-induced erythroid differentiation of K562 cells to a more complete stage compared with the control.

CONCLUSIONS

The results demonstrate that specific antisense suppression of overexpressed PDPK F(A) in human myeloid leukemia cells is sufficient to potentiate both spontaneous and drug-induced erythroid differentiation, indicating that PDPK F(A) is an important negative regulator in controlling the erythroid differentiation of human myeloid leukemia cells.

Suppression of proline-directed protein kinase F(A) expression inhibits the growth of human chronic myeloid leukaemia cells

Initial studies revealed that proline-directed protein kinase F(A) (PDPK F(A)) was overexpressed in various cancerous tissues relative to normal controls. However, the functional role of overexpressed PDPK F(A) in cancer remains to be established. In this report, we explore the potential role of PDPK F(A) in leukaemia cell growth by investigating the effects of partial inhibition of this kinase on the malignant phenotype of human chronic myeloid leukaemia cells (K562). Cloning of PDPK F(A) cDNA and its recombinant antisense expression vector and PDPK F(A)-specific antibody were successfully developed. Two stable antisense clones of K562 cells were subcloned which expressed 70% and 45% of PDPK F(A) respectively, compared with control-transfected clone in both immunoprecipitate activity assay and immunoblot analysis. In sharp contrast, these two antisense clones expressed no significant suppression of any other related PDPK family members, indicating the specificity of these two antisense clones. Moreover, these antisense clones proportionally and potentially exhibited cell growth retardation, poor clonogenic growth in soft agar and loss of serum independence. The results demonstrate that specific antisense suppression of PDPK F(A) is sufficient to interfere with the growth of K562 cells, indicating that PDPK F(A) is essential for human chronic myeloid leukaemia cell growth.

Surgical repair of postinfarction ventricular septal defect

BACKGROUND

Rupture of the interventricular septum complicates 1% to 2% of all acute myocardial infarction patients and its natural course is ominous. The purpose of this study is to present our experience with surgical ventricular septal defect (VSD) repair and examine the possible risk factors and explanations for surgical mortality.

METHODS

Fourteen patients underwent repair of postinfarction VSD from 1996 to 1998 at the Taipei Veterans General Hospital. Thirteen patients were in New York Heart Association (NYHA) Functional Class IV and one was in Functional Class III. Eleven patients were in cardiogenic shock with intra-aortic balloon pumps (IABPs) prior to surgery. The operative techniques for VSD repair range from extensive infarctectomy with reconstruction of the septum and the right and left ventricular free walls using single or double patches, to minimal or no infarctectomy with closure of the VSD by excluding the infarcted muscle from the left ventricular cavity and leaving the right ventricle intact.

RESULTS

Overall surgical mortality occurred in four patients. All deaths occurred in patients with cardiogenic shock, two with anterior VSD and two with posterior VSD. Three late survivors had limited exercise tolerance with NYHA Functional Class II to III. Left ventricular function was moderately impaired in most patients with a mean nuclear scan ejection fraction of 0.32. However, all patients were elderly and adapted to their residual symptoms without significant life-style changes.

CONCLUSIONS

The surgical mortality for treating patients with postinfarction VSD has decreased with improvements in surgical technique. Rapid diagnosis, appropriate preoperative management and delicate surgical repair improve the overall results and help to attain long-term survival.

Antisense suppression of proline-directed protein kinase FA enhances chemosensitivity in human prostate cancer cells

Initial clinic studies revealed that proline-directed protein kinase FA (PDPK FA) is overexpressed manyfold in various human cancerous tissues relative to the normal control. However, the role of overexpressed PDPK FA in cancers remains unknown and needs to be established. To determine whether PDPK FA is associated with drug sensitivity, we investigated the effects of partial inhibition of this kinase on the human prostate carcinoma cell line (PC-3). PDPK FA antisense expression vector and its specific antibody were successfully developed. Two stable transfected antisense clones (PA7 and PA3) of human prostate carcinoma cell were subcloned, and they expressed approximately 75% and approximately 35% of the total PDPK FA existing in the control-transfected clone as determined by both immunoprecipitate activity assay and immunoblot analysis. In sharp contrast, the PDPK FA antisense clones expressed no significant suppression of any other related proline-directed protein kinase member expression, demonstrating the specificity of these two antisense clones. When compared with parental or control-transfected cells, the low-PDPK FA-expressing antisense clones displayed an enhanced sensitivity to carboplatin, 5-fluorouracil, paclitaxel, and hydroxyurea. Estimation of the IC50 index further revealed that the antisense clones displayed up to > 100-fold drug sensitivity, and there was a correlation between suppressed levels of PDPK FA and drug sensitivity. Taken together, the results demonstrate that specific antisense suppression of overexpressed PDPK FA in human prostate cancer cells is sufficient to enhance various drug sensitivity, indicating that PDPK FA is an important regulator in controlling multiple drug resistance of human prostate cancer cells.

Transthoracic oesophagomyotomy in the treatment of achalasia--a 15-year experience

Oesophageal achalasia was treated with modified Heller's oesophagomyotomy in 51 patients (19 males, 32 females) via thoracotomy in 47 cases and thoracoscopy in 4 cases. A Belsey Mark IV antireflux procedure was added to transthoracic oesophagomyotomy in two cases, because of extended cardiomyotomy. There were no hospital deaths. The overall improvement rate was 93.5%, with excellent results in 80.6%. Postoperative follow-up averaged 7.4 years. In all four cases of thoracoscopic oesophagomyotomy, simultaneous oesophagoscopy was performed to facilitate the procedure. One patient required repeat surgery 2 months later because of inadequate myotomy. Thirty-one patients, including three with severe gastro-oesophageal reflux, received long-term medication. Barrett's oesophagus developed in two of the 31 patients (6.5%) 4.7 and 7.6 years, respectively, after myotomy and squamous cell carcinoma was diagnosed in a 44-year-old woman 2.2 years postoperatively. The study suggests that transthoracic oesophagomyotomy without antireflux procedure can provide excellent long-term relief of dysphagia in oesophageal achalasia and carries a low risk of serious postoperative complications.

Function and immunolocalization of overexpressed human intestinal H+/peptide cotransporter in adenovirus-transduced Caco-2 cells

PURPOSE

To determine the localization of the human intestinal H+/peptide cotransporter (hPepT1) and its function in intestinal epithelial cells after adenoviral transduction.

METHODS

Caco-2 cells grown on Transwell membrane filters were transduced with a recombinant replication-deficient adenovirus carrying the hPepT1 gene. The transport of Gly-Sar across both apical and basolateral membranes was measured after adenoviral transduction as a function of pH, temperature, inhibitors, and substrate concentration. The localization of hPepT1 was examined by immunocytochemistry using confocal laser scanning microscopy.

RESULTS

The apical-to-basolateral and basolateral-to-apical transport of Gly-Sar in Caco-2 cells after viral transduction was increased 3.3 and 3.5-fold, respectively. The similar magnitude of Gly-Sar permeability from either direction indicates involvement of identical transport pathways in both membranes. This was further confirmed by immunocytochemistry showing that hPepT1 was localized in the apical and basolateral membrane of Caco-2 cells after adenoviral transduction. In both directions, Gly-Sar transport was enhanced in the presence of a pH gradient. In addition, the basolateral-to-apical Gly-Sar transport was dependent on temperature, multiplicity of infection (MOI), and Gly-Sar concentration. It was inhibited in the presence of excess Gly-Pro and cephalexin.

CONCLUSIONS

Caco-2 cell monolayers represent an appropriate model to study gene expression in intestinal epithelial cells. Transport characteristics of Gly-Sar from the basolateral to the apical side in adenovirus-transduced Caco-2 cells are in agreement with those from the apical to the basolateral side, indicating that hPepT1 is also expressed in the basolateral membrane and displays a similar level of transport enhancement after adenovirus mediated hPepT1 gene expression.

Serotonin-6 receptor variant (C267T) and clinical response to clozapine

Clozapine is an effective atypical antipsychotic that has high affinity for serotonin type 6 receptors (5HT6). We tested the hypothesis that clinical response to clozapine in patients refractory to typical antipsychotic treatment is related to the genetic variant (C267T) of the 5HT6 receptors. Ninety-nine schizophrenic patients with a history of non-response to typical antipsychotics were included in the study. The results demonstrated a modest but significant relationship between presence of the variant of the 5HT6 receptors and the response to clozapine in these patients. Patients with homogenous 267T/T genotype had a better response than other patients. Although replication is required, these results suggest that the 5HT6 receptor C267T polymorphism may be involved in clozapine response, especially in patients with anxious or depressed symptoms.

Adenosquamous carcinoma of the lung. Surgical results compared with squamous cell and adenocarcinoma

The outcome of surgery for adenosquamous carcinoma of the lung in 39 patients treated in 1982-1996 was compared with results in squamous cell carcinoma and adenocarcinoma. Adenosquamous carcinoma comprised only 4.2% of all 914 resected primary lung cancers. The cumulative 5-year postoperative survival rate was 22.6% for the adenosquamous tumours. Comparison of survival curves with those for squamous cell carcinoma and adenocarcinoma indicated non-significant differences. The incidence of lymph-node metastasis was significantly higher in the patients with adenosquamous carcinoma than in the other patient groups.

CHO/hPEPT1 cells overexpressing the human peptide transporter (hPEPT1) as an alternative in vitro model for peptidomimetic drugs

The present study characterized Chinese hamster ovary cells overexpressing a human intestinal peptide transporter, CHO/hPEPT1 cells, as an in vitro model for peptidomimetic drugs. The kinetic parameters of Gly-Sar uptake were determined in three different cell culture systems such as untransfected CHO cells (CHO-K1), transfected CHO cells (CHO/hPEPT1) and Caco-2 cells. Vmax in CHO/hPEPT1 cells was approximately 3-fold higher than those in Caco-2 cells and CHO-K1 cells, while Km values were similar in all cases. The uptake of beta-lactam antibiotics in CHO/hPEPT1 cells was three to twelve fold higher than that in CHO-K1 cells, indicating that CHO/hPEPT1 cells significantly enhanced the peptide transport activity. However, amino acid drugs also exhibited high cellular uptake in both CHO-K1 and CHO/hPEPT1 cells due to the high background level of amino acid transporters. Thus, cellular uptake study in CHO/hPEPT1 cells is not sensitive enough to distinguish the peptidyl drugs from amino acid drugs. The potential of CHO/hPEPT1 cells as an in vitro model for peptidomimetic drugs was also examined through the inhibition study on Gly-Sar uptake. Peptidomimetic drugs such as beta-lactam antibiotics and enalapril significantly inhibited Gly-Sar uptake whereas the nonpeptidyl compounds, L-dopa and alpha-methyldopa, did not compete with Gly-Sar for cellular uptake within the therapeutic concentrations. In conclusion, the present study demonstrates the further characterization of CHO/hPEPT1 cells as an uptake model as well as inhibition study and suggests their utility as an alternative in vitro model for drug candidates targeting the hPEPT1 transporter.

No evidence for association of serotonin-2A receptor variant (102T/C) with schizophrenia or clozapine response in a Chinese population

The serotonin hypothesis in schizophrenia had regained interest with the superior efficacy of clozapine in the refractory schizophrenic patients. Among the serotonin receptors, the serotonin 2A (5HT2A) receptor subtype is the most widely studied. Previous studies on the association between a silent mutation polymorphism of the 5HT2A gene (102T/C) and schizophrenia or clozapine response have yielded conflicting findings. Therefore, we investigated whether these genetic variants of the 5HT2A receptor are associated with schizophrenia or with response to clozapine treatment in a Chinese population. Ninety-seven schizophrenic patients and 101 control subjects were included in the study. The receptor variants were found at similar frequencies in schizophrenic patients and healthy control subjects. Also, we did not find the variants to influence the response to clozapine in schizophrenic patients. We suggest that the assessment method of clozapine response and the ethnicity may influence the result.

Outpatient thoracoscopic limited sympathectomy for hyperhidrosis palmaris

Thoracoscopic sympathectomy is considered the most effective treatment for hyperhidrosis palmaris. We have treated 1,043 cases of this disease by this method. We have developed an outpatient technique of thoracoscopic sympathectomy using electrocautery. This procedure has been used in 47 patients with hyperhidrosis palmaris. The early results have been favorable. We describe this fast, safe, economic, and effective method for the treatment of hyperhidrosis palmaris.

Resympathectomy for palmar and axillary hyperhidrosis

BACKGROUND

The aim was to analyse patterns of failure or symptom recurrence after primary sympathectomy for palmar or axillary hyperhidrosis, and to carry out tactical problem-solving for resympathectomy and review the operative findings.

METHODS

Over a 2-year period, 20 patients (six men and 14 women) underwent resympathectomy for palmar hyperhidrosis (13 patients, 20 sides) or axillary hyperhidrosis (seven patients, ten sides). T2-3 sympathectomy for palmar hyperhidrosis or T4-5 sympathectomy for axillary hyperhidrosis was performed during the repeat procedure. Criteria for evaluation by means of patient questionnaire included good (more than 80 per cent), fair (50-80 per cent) and poor (less than 50 per cent) improvement.

RESULTS

Operative findings included inadequate sympathectomy on 19 sides, nerve regeneration on eight sides and no evidence of previous sympathectomy on three sides. One patient had Kuntz fibre in addition to inadequate sympathectomy. In the palmar hyperhidrosis group, good results were obtained in all 13 patients on all 20 sides after resympathectomy. In the axillary hyperhidrosis group, six of seven patients, or eight of ten sides, showed good results after resympathectomy.

CONCLUSION

The main cause of primary sympathectomy failure was inadequate surgery, and recurrence of palmar or axillary hyperhidrosis was seldom caused by nerve regeneration. The key factor for preventing failed sympathectomy or recurrent palmar or axillary hyperhidrosis is a first-time sympathectomy that is both accurate and adequate. Most patients with recurrent symptoms can be cured by resympathectomy.

Color Doppler ultrasound pulsatile flow signals of thoracic lesions: comparison of lung cancers and benign lesions

Color Doppler ultrasound (US) was performed in 153 patients (including 102 with lung cancer and 51 with benign lesions) to assess pulsatile flow signals in thoracic lesions. The values of resistive index (RI) and pulsatility index (PI) of color Doppler US pulsatile flow signals in lung cancers and benign lesions were measured, analyzed, and compared. In the enrolled 153 patients with thoracic lesions, 61 lung cancers and 34 benign lesions had detectable color Doppler US pulsatile flow signals, and lung cancers had lower RI and PI values than benign lesions (RI: 0.70+/-0.03 vs. 0.79+/-0.04, p < 0.05; PI: 1.61+/-0.15 vs. 2.44+/-0.25, p < 0.005). However, overlapping RI and PI values in lung cancers and benign lesions somewhat limited color Doppler US pulsatile flow signals to differentiate lung cancers from benign lesions. Further analysis of RI and PI values in subgroups of lung cancers [squamous cell carcinoma (SCC, n = 34), adenocarcinoma (AC, n = 18), and small-cell lung cancer (SCLC, n = 6)] and benign lesions [cavitary benign lesions (CBL, n = 8), and noncavitary benign lesions (NCBL, n = 26)] revealed that all different cell types of lung cancers (SCC, AC, and SCLC), indeed, had lower RI and PI values than NCBL (for RI, all p < 0.01; for PI, all p< or =0.001). Moreover, the mean RI and PI values showed a significant incremental decrease from NCBL (mean RI, PI = 0.88, 2.94) toward SCC and AC (for SCC, mean RI, PI = 0.71, 1.68; for AC, mean RI, PI = 0.68, 1.67) and, finally, to SCLC (mean RI, PI = 0.62, 1.05). In contrast, CBL had relatively lower RI and PI values than AC and SCLC (for CBL, mean RI, PI = 0.53, 0.80; both p > 0.05 for RI and PI), and even a significant difference from SCC (p < 0.05 for RI and PI). We conclude that color Doppler US pulsatile flow signal is somewhat limited to differentiate lung cancers from benign lesions, but provides a noninvasive in vivo model to assess the neovascularity intensity of lung cancers.

Beta cyclodextrins enhance adenoviral-mediated gene delivery to the intestine

PURPOSE

In general, the intestinal epithelium is quite refractory to viral and non-viral methods of gene transfer. In this report, various cyclodextrin formulations were tested for their ability to enhance adenoviral transduction efficiency in two models of the intestinal epithelium: differentiated Caco-2 cells and rat jejunum.

METHODS

Transduction efficiency of replication-deficient adenovirus type 5 vectors encoded with either the E. coli beta-galactosidase or the jellyfish green fluorescent protein gene was assessed by X-gal staining or visualization of fluorescence 48 hours after infection. In vivo experiments were performed using an intestinal loop ligation technique.

RESULTS

Several formulations of neutral and positively charged beta cyclodextrins significantly enhanced adenoviral-mediated gene transfer in the selected models. The cyclodextrin formulations studied increased adenoviral transduction in the intestine by enhancing both viral binding and internalization. Viral binding was significantly increased on cell membranes treated with positively charged cyclodextrins, as seen with confocal microscopy and rhodamine-labeled virus. Permeability studies and TEER readings revealed that the most successful formulations gently disrupt cell membranes. This enhances internalization of viral particles and results in increased levels of gene expression.

CONCLUSIONS

These formulations can be of value in gene transfer to cells and tissues in which adenoviral infection is limited due to a lack of fiber and alpha(v) integrin receptors. They are simple to prepare and do not affect the ability of the virus to transduce target cells.

Overexpression of human intestinal oligopeptide transporter in mammalian cells via adenoviral transduction

PURPOSE

Our goals are to establish an in vitro screening system and to evaluate a new approach in improving oral absorption of peptides and peptide-like drugs by overexpression of the human intestinal oligopeptide transporter (hPepT1). This study characterizes the expression of hPepT1 in human intestinal Caco-2 cells, rat intestinal epithelial cells (IEC-18), and human cervix epithelial cells (Hela) after adenoviral transduction.

METHODS

A recombinant replication-deficient adenovirus carrying the hPepT1 gene was made and used as a vector for the expression of hPepT1. The increase in the uptake permeability of cephalexin and Gly-Sar was determined. The effects of time, dose, apical pH, and substrate specificity were evaluated.

RESULTS

A significant increase in the uptake permeability of Gly-Sar and cephalexin was found in all three cell lines after viral transduction. The increase of Gly-Sar permeability in Hela. IEC-18, and Caco-2 cells was 85-, 46-, and 15-fold respectively. Immunoblotting using an antibody against hPepT1 detected high levels of a 85-98-kDa protein in all three infected cell lines. Substrate permeability was dependent on time of infection, inward pH gradients, and multiplicity of infection (MOI). Decreased infectivity and lower hPepT1 expression were observed in differentiated Caco-2 cells. The uptake was inhibited by dipeptides and beta-lactam antibiotics but not amino acids.

CONCLUSIONS

Adenoviral infected Hela cells displayed a pronounced level of hPepT1 expression with a low background and high specificity to dipeptides. These features make this system a useful tool for screening of potential substrates. The success of overexpression of hPepT1 in Caco-2 and IEC-18 cells may lead to a novel approach in improving oral absorption of peptides and peptidornimetic drugs.

Intracerebral hemorrhage in a young woman with arteriovenous malformation after taking diet control pills containing phenylpropanolamine: a case report

Administration of phenylpropanolamine (PPA) is a rare cause of intracerebral hemorrhage. We present the case of a young female patient with arteriovenous malformation who suffered an intracerebral hemorrhage after ingestion of diet pills containing PPA. The literature on PPA-related intracerebral hemorrhage is also reviewed. This is the first report of PPA-associated intracerebral hemorrhage in a patient with pathology-proven arteriovenous malformation of the brain. Because intracerebral hemorrhage may develop as a side effect of PPA when patients take the manufacturer's recommended dose, especially in patients with vascular abnormalities, we conclude that this medicine should be prescribed carefully and patients should be closely monitored by experienced physicians. Furthermore, its use should be contraindicated in patients who have, or possibly have, a family history of vascular abnormalities.

Differential tyrosine phosphorylation/activation of oncogenic proline-directed protein kinase F(A)/GSK-3alpha in well and poorly differentiated human prostate carcinoma cells

Computer analysis of protein phosphorylation site sequences revealed that transcriptional factors and viral oncoproteins are prime targets for regulation of proline-directed protein phosphorylation, suggesting an association of the proline-directed protein kinase (PDPK) family with neoplastic transformation and tumorigenesis. In this report, an immunoprecipitate activity assay of proline-directed protein kinase F(A)/glycogen synthase kinase-3alpha (PDPK F(A)/GSK-3alpha) has been optimized to demonstrate significantly increased (p < 0.01) activity in poorly differentiated human prostate carcinoma PC-3 cells (55.5+/-3.8 units/mg) when compared to well-differentiated LNCaP cells (28.1+/-2.3 units/mg). Immunoblotting analysis revealed that increased activity of this PDPK in PC-3 cells is due not to overexpression of the protein, but to enhanced tyrosine phosphorylation of the kinase. When treated with genistein (a protein tyrosine kinase PTK inhibitor), the enhanced tyrosine phosphorylation/activation of the kinase in PC-3 cells can be blocked. Conversely, when treated with vanadate (a protein tyrosine phosphatase PTP inhibitor), the phosphotyrosine content of PDPK F(A)/GSK-3alpha in LNCaP cells can be promoted to the level of PC-3 cells. In sharp contrast, the PTK inhibitor has little effect on the tyrosine phosphorylation level of the kinase in LNCaP cells, whereas the PTP inhibitor has little effect on the tyrosine phosphorylation level of the kinase in PC-3 cells. Taken together, the results provide initial evidence that the tyrosine phosphorylation/activation levels of this oncogenic PDPK can be differentially regulated in well- and poorly differentiated prostate carcinoma cells.

Acute inductive effects on oncogenic proline-directed protein kinase FA/GSK-3 alpha in NIH 3T3 cells by ethanol and cadmium

Exposure of NIH 3T3 cells to 375 mM ethanol at 37 degrees C for 20 min could induce a rapid increase in the protein level and cellular activity of oncogenic proline-directed protein kinase FA/glycogen synthase kinase-3 alpha (PDPK FA/GSK-3 alpha), up to approximately 300% of the control level, in a time- and concentration-dependent manner. The maximal inductive effect on PDPK FA/GSK-3 alpha also occurred within 40 min when cells were treated with only 100 mM ethanol. Similarly, exposure of NIH 3T3 cells to 100 microM cadmium for 2 h could induce a rapid increase in the protein level and cellular activity of PDPK FA/GSK-3 alpha, up to approximately 250% of the control level, in a time- and concentration-dependent manner. The maximal inductive effect on this kinase reached within 3 h when cells were treated with only 50 microM cadmium. The results demonstrate that PDPK FA/GSK-3 alpha may not represent a constitutively active/mitogen-inactivated protein kinase as previously conceived. Taken together with the previous report that PDPK FA/GSK-3 alpha is a heat-inducible protein kinase, the results further demonstrate that PDPK FA/GSK-3 alpha may represent a typical cellular stresses-inducible protein kinase subject to early induction by heat, ethanol and cadmium.

Clinical experience in radical lymphadenectomy for adenocarcinoma of the gastric cardia

OBJECTIVES

We evaluated the pattern of nodal metastasis and its prognosis after radical lymphadenectomy in adenocarcinoma of the gastric cardia.

METHODS

We conducted a retrospective cohort study of 70 patients (52 men and 18 women; mean age 63.6 years) with adenocarcinomas of the gastric cardia who underwent extended gastrectomy (65 total gastrectomies and 5 proximal gastrectomies) and radical lymphadenectomy (D2 to D4) at Taichung Veterans General Hospital between 1989 and 1995.

RESULTS

Twenty-four complications developed in 22 (31.4%) patients, and seven (10.0%) hospital deaths occurred. An overall 5-year cumulative survival of 37.6% was obtained. Lymph node metastases were identified in 53 (75.7%) patients. Nodal involvement was closely related to the depth of tumor invasion (p = 0.005). When the gastric wall invasion was limited to the subserosal layer (T1 and T2, n = 15), no patient had N4 group nodal metastasis. Once the serosal layer had been involved (beyond T3), N4 group nodal metastasis was frequently seen (30.9%, 17 of 55 patients). A multivariable analysis revealed that the level of nodal involvement, the depth of tumor invasion, and the presence of complications were independent prognostic factors. Cumulative 5-year survivals of curability A (n = 12), B (n = 19), and C (n = 32) resections were 100%, 21.2%, and 27.5%, respectively (p = 0.0001). The long-term survival of the patients after resection was also closely related to their pTNM stages (p = 0.0004).

CONCLUSIONS

We conclude that gastrectomy accompanied by radical lymphadenectomy provides a reasonable long-term survival expectancy that is closely related to the stage of the disease and the curability of resection.

High rate of hepatitis C virus infection in an isolated community: persistent hyperendemicity or period-related phenomena?

We investigated underlying risks for hyperendemic hepatitis C virus (HCV) infection among the 1853 inhabitants of a mountainous village in Eastern Taiwan with high prevalence of HCV and hepatitis B virus (HBV). Among the 80 selected adults, we found that having resided away from the village before 1985 was protective against HCV infection, while residing in the village after 1985 posed little risk for HCV infection to children and young adults < 30 years of age. Among the 559 school children 7 through 14 years of age, anti-HCV prevalence was 1.9%, and the HBV carrier rate was 29%. Following up 270 children 1 year later, we found that new HCV infection occurred in 0.74% and new or repeated HBV infection occurred in 6.5% of the children, indicating distinct transmission patterns between HBV and HCV. Children of anti-HCV-positive mothers were either anti-HCV-negative or were infected by distinct genotypes of HCV from those infecting their mothers; most married couples in whom both were infected, were infected by HCV of discordant genotypes, indicating negligible importance of sexual or vertical HCV transmission. A case-control study comparing 13 anti-HCV-positive and 53 anti-HCV-negative children showed that having received parenteral medication in local clinics was a significant risk for HCV infection. Our data indicate that, unlike the case of HBV, HCV transmission by vertical or sexual route, or through casual contact are extremely inefficient, and our data further suggest that HCV hyperendemicity is unlikely to persist as a result of the more stringent practice of parenteral precautions in nearly all aspects of daily life.

Esophageal reflux after total or proximal gastrectomy in patients with adenocarcinoma of the gastric cardia

OBJECTIVES

To demonstrate gastroesophageal reflux induced by proximal gastrectomy and to report preventive measures, such as total gastrectomy followed by Roux-en-Y esophagojejunostomy.

METHODS

Thirteen patients underwent proximal gastrectomy (PG), and six patients underwent total gastrectomy (TG). Two of the 13 patients who received PG later underwent completion total gastrectomy. All patients were followed with endoscopy, radionuclide scintigraphy, and 24-h pH monitoring.

RESULTS

Endoscopic examination revealed evidence of esophagitis in all PG group patients; however, none of the TG group had esophagitis. Prolonged esophageal transit was observed in 11 patients (10 in the PG group, one in the TG group). Increased residual fraction was found in 10 patients (nine in the PG group, one in the TG group). An increase in the retrograde index was found in 14 cases (11 in the PG group, three in the TG group). Positive enterogastroesophageal reflux was identified in 11 patients (eight in the PG group, three in the TG group). Twenty-four hour pH monitoring resulted in 10 positives (10 in the PG group, none in the TG group).

CONCLUSIONS

Frequently, proximal gastrectomy will lead to significant gastroesophageal reflux and, subsequently, to varying degrees of esophagitis. The clinical symptoms are usually characteristic. However, the severity of esophagitis and the mechanism of reflux can be determined only by integrated interpretation of a reflux study. The study should include endoscopy, radionuclide scintigraphy, and 24-h pH monitoring. Although a total gastrectomy with Roux-en-Y diversion can reduce the incidence of acid reflux, neutral enteroesophageal reflux may be observed during a radioactive isotope study. Fortunately, neutral refluxes rarely cause esophagitis. A proximal gastrectomy should be avoided in adenocarcinoma of the gastric cardia, except in early cancer. Symptomatic palliation can be relieved by medication. However, completion total gastrectomy is the only effective method for eradicating unrelenting symptoms.

Surgical treatment and its long-term result for caustic-induced prepyloric obstruction

OBJECTIVE

To present our long-term results of the treatment of caustic-induced prepyloric obstruction, and to set out guidelines for the management of such patients.

DESIGN

Retrospective study.

SETTING

General hospital (medical centre), Taiwan.

SUBJECTS

30 patients (8 male and 22 female, mean age 34 years, range 13-62) who developed prepyloric obstruction out of 271 treated for caustic injuries of the upper gastrointestinal tract.

INTERVENTIONS

Gastrojejunostomy (n = 24), antrectomy and Billroth I reconstruction (n = 4), and antrectomy and Billroth II reconstruction (n = 2). Four patients required second operations: oesophageal reconstruction for stricture (n = 3), and gastrojejunostomy for restenosis of Billroth I anastomosis (n = 1).

MAIN OUTCOME MEASURES

Morbidity and mortality.

RESULTS

No patient died postoperatively, and there were three complications--wound infection, internal bleeding, and stenosis of the Billroth I anastomosis. 21 patients were able to enjoy their normal diet postoperatively, 5 required periodic dilatation of oesophageal strictures, and 4 required further operations.

CONCLUSIONS

Gastrojejunostomy gives good long term results as long as there is no oesophageal stricturing, and morbidity and mortality are low. The long term outcome is dependent on the degree of oesophageal involvement.

Detection of k-ras point mutations in codons 12 and 13 in non-small cell lung cancers

Point mutations of the K-ras gene have been reported in a wide variety of human tumors. By using polymerase chain reaction followed by direct DNA sequencing, we screened for point mutations at codons 12 and 13 of the K-ras gene in specimens obtained from fresh frozen tumors in 38 patients with non-small cell lung cancers. Point mutations were detected in two of 38 (5.3%) resected non-small cell lung cancers. Both of them were G to T transversions. One patient was found to have a K-ras codon 13 point mutation (GGC to TGC, gly to cys), while the other had a codon 12 point mutation (GGT to GTT, gly to val). Based on the limited numbers in this study, we found that the frequency of K-ras point mutations in codons 12 and 13 among Asian patients with lung adenocarcinomas was lower than that detected among Caucasian patients.

Change of lower esophageal sphincter pressure in rabbits by Teflon injection

BACKGROUND

The mechanically incompetent lower esophageal sphincter (LES) plays a key role in patients with gastroesophageal reflux disease. The purpose of the study was to assess the pressure changes of LES in rabbits by intraabdominal injection of Teflon paste (Polytetrafluoroethylene) at the gastroesophageal junction.

METHODS

New Zealand white breed of rabbits were used in these studies. The anesthetized rabbit was injected with a 21-gauge needle and a syringe loaded with Teflon paste. The injection sites were around the gastroesophageal junction. LES pressure was measured by conventional methods using a water-filled infused system. The pressure gradient was measured immediately before and after the injection as well as by a weekly measurement over four weeks. The histologic characteristics of the injection sites were studied four weeks later.

RESULTS

The mean pressure gradient of LES of twelve rabbits of immediate preinjection and post-injection was 29.71 +/- 8.10 mmHg and 37.58 +/- 10.69 mmHg (mean +/- S.D.), respectively (p value, 0.0329) Animals were followed upifor from one to four weeks, and were then sacrificed. The mean pressure gradient of LES of the twelve rabbits in the first week, the second week, the third week and the fourth week was 37.80 +/- 11.36 mmHG, 35.77 +/- 3.54 mmHg, 33.42 +/- 4.95 mmHg and 32.68 +/- 4.62 mmHg (mean +/- S.D.), respectively. Compared to pre-injection data, a significant difference was found in the first week and the second week (p value, 0.0342 and 0.0281, respectively). Gross examination of the gastroesophageal regions showed a welldefined Teflon mass of firm consistency at the site of the injection. Histological examination showed encapsulation of the implant by a thin layer of fibrous tissue and a benign foreign body granulomatous reaction with round cells surrounding the implant.

CONCLUSIONS

It is technically feasible to produce experimentally pressure changes of LES in rabbits by intraabdominal injection of Teflon paste. Nevertheless, the clinical validity on patients with gastroesophageal reflux induced by the incompetence of LES remains to be verified.

Color Doppler ultrasound signals of thoracic lesions. Correlation with resected histologic specimens

Sixty-eight patients with thoracic lesions (48 with lung cancer and 20 with benign lesions) underwent color Doppler ultrasound (US) examinations. Of those, 21 patients (13 with lung cancer and eight with benign lesions) also received resections, and the correlation between color Doppler US signals and resected histologic specimens was evaluated. Our results showed that three patterns of color Doppler US signals could be detected and confirmed: pulsatile flow (artery), constant flow, and triphasic flow (pulmonary vein). Among the 48 patients with lung cancer, pulsatile flow, constant flow, and/or triphasic flow were detected in 34 (71%), 24 (50%), and 14 (29%), respectively. Among the 20 patients with benign lesions, only pulsatile flow and/or triphasic flow were detected in nine (45%) and eight (40%), respectively. From the correlation between color Doppler US signals and histologic specimens, constant flow was representative of the true neovascularity of lung cancers, and it was valuable for differentiating lung cancers from benign lesions (p = 0.00008, sensitivity = 0.50, and specificity = 1.0). Although color Doppler US still had some limitations in detecting blood vessels in thoracic lesions, the correlation between the vascularity represented by color Doppler US signals and histologic specimens was excellent. We conclude that color Doppler US is a valuable method for assessing blood flow in thoracic lesions and differentiating lung cancers from intrapulmonary benign lesions.

Surgical experience in treating T4 lung cancer: its resectability, morbidity, mortality and prognosis

Extensive experience in the treatment of locally advanced lung cancers is rare. The aim of this study is to show the rationality and effectiveness of an aggressive surgical approach in T4 lung cancers. Between 1984 and 1994, 111 consecutive cases of T4 lung cancers were operated on. The patients included 91 males and 20 females, with mean ages of 61.8 years and 55.3 years, respectively. The cell types included 57 squamous cell carcinomas, 42 adenocarcinomas, and 12 miscellaneous malignancies. Fifty-three (47.7%) procedures were non-resectional. The remaining 58 (52.3%) procedures had various extents of pulmonary resection. These surgical procedures included 24 (21.6%) pulmonary resections with gross residual tumour (R2), nine (8.1%) pulmonary resections with microscopic residual tumour (R1), and 25 (22.5%) curative pulmonary resections without residual tumour (R0). Post-operative adjuvant therapy included radiotherapy ( > or = 3000 rads) in 53 patients (47.7%), and cisplatin-based chemotherapy in 15 patients (13.5%). The overall median survival time of these 111 patients was 9.1 months. The overall cumulative survival rates at 1, 2, 3 and 5 years were 38.0%, 20.4%, 15.3%, and 5.5%, respectively. There were 24 (21.6%) complications and eight (7.2%) hospital mortalities. Most of the pleural seedings were caused by adenocarcinomas, while most of the curatively resected tumours were squamous cell carcinomas. Our data demonstrate that: (1) Almost a quarter (22.5%) of T4 lung cancers could be curatively resected, and the cumulative 5-year survival rate was 23.4%; (2) squamous cell carcinoma had a higher curative resection rate (P = 0.0381), while adenocarcinoma showed higher possibility of pleural seeding (P = 0.0000); (3) the prognosis of T4 lung cancers did not relate to their nodal status (P = 0.7978), and cell type (P = 0.4169); (4) complete surgical resection provided the best rates for long-term survival (P = 0.0263); (5) the complication rate was higher in the resectional group (P = 0.0221); (6) post-operative irradiation did not lengthen survival times (P = 0.1720); and (7) post-operative chemotherapy did not improve survival (P = 0.1577). We conclude that surgery to T4 lung cancers should only be performed in highly selected patients due to their poor prognosis, and the associated high complication and mortality rates.

Oesophageal squamous cell carcinoma after gastrectomy for benign ulcer disease

Of 684 patients treated for squamous cell carcinoma of the oesophagus in 1982-1993, 19 (2.8%) had previously undergone partial gastrectomy for benign ulcer disease. The average interval between gastrectomy and diagnosis of oesophageal carcinoma was 14 years. In six of the 19 (31.6%) cases the carcinoma was in the lower thoracic oesophagus, an incidence not significantly higher than the 25% in the total series. The oesophageal resectability rates were 52.6% in the gastrectomized patients and 44.4% in the total series (intergroup difference not significant). Of the ten gastrectomized patients who underwent oesophageal resection, only one had oesophagitis at the oesophagogastric junction, without significant histologic characteristics. The relationship between oesophageal squamous cell carcinoma and previous gastrectomy for benign ulcer disease may be incidental.

Pleural non-Hodgkin's lymphoma arising in a patient with a chronic pyothorax

A 69 year old man with a chronic left pyothorax was treated by decortication. Although the treatment rapidly improved respiratory function, histopathological examination revealed a diffuse large B cell non-Hodgkin's lymphoma. Subsequent bone marrow biopsy samples disclosed bone marrow involvement. It is possible that non-Hodgkin's lymphoma may develop from a chronic pyothorax.

Diagnostic video-assisted thoracoscopic procedures

OBJECTIVE

The authors evaluated the effectiveness and the limitations of video-assisted diagnostic thoracoscopy.

SUMMARY BACKGROUND DATA

The initial successes achieved with the use of video-assisted diagnostic thoracoscopic techniques has lead to an enthusiastic propagation of its use by thoracic surgeons as well as by some pulmonologists. However, detailed analyses of the diagnostic yield and potential limitations of this technique in relation to the roentgenographic and pathologic presentations of the patients are necessary to ensure its safe and effective application.

METHODS

From July 1991 to December 1993, 102 diagnostic video-assisted thoracoscopic procedures were performed. All patients received other preoperative diagnostic workups without a definitive diagnosis. The initial roentgenographic presentations of these patients included 42 pulmonary nodules, 23 interstitial processes, 11 parenchymal infiltrates, 6 pleural effusions, 10 mediastinal tumors, and 10 mediastinal lymphadenopathies. If the procedure was completed without minithoracotomy or extension of any port site, then it was defined as an exclusive thoracoscopic biopsy (ETB); if the procedure was completed with the assistance of minithoracotomy (4-6 cm), then it was defined as a supplementary thoracoscopic biopsy (STB).

RESULTS

Ninety-two of the pathology reports (90.2%) were interpreted as conclusive. Of these, 35 tumors were malignant and 67 benign. Ten pathology reports were inconclusive and on initial roentgenography had presented as pulmonary infiltrates (4 cases), pulmonary nodule (2), pleural effusion (2), interstitial process (1), and mediastinal lymphadenopathy (1). Seventy-six procedures (74.5%) were completed thoracoscopically and were classified as ETB. The remaining 26 procedures (25.5%) were completed with minithoracotomy and were classified as STB. The underlying diseases in the STB group were carcinoma (8 cases), Hodgkin's lymphoma (3), sarcoidosis (3), tuberculosis (2), interstitial pneumonitis (2), organizing pneumonia (2), mesothelioma (1), and miscellaneous disease (5). The reasons given for minithoracotomy were diffuse intrapleural adhesion (10 cases), technical inexperience (8), inability to localize the lesion (5), problems with anesthesia (1), poor patient tolerance (1), and unknown (1). Four patients (3.9%) experienced complications and three (2.9%) died while in the hospital.

CONCLUSIONS

Diagnostic thoracoscopy provides high diagnostic yield with very low risk. However, 25.5% of the procedures require minithoracotomy to obtain adequate tissue for definitive diagnosis. This finding supports the assertion that diagnostic thoracoscopy should be performed only by experienced thoracic surgeons who can extend the procedure when indicated.

Bronchioloalveolar carcinoma

Bronchioloalveolar carcinoma is a subtype of adenocarcinoma of the lung with a relatively better prognosis. We reviewed the cases of 50 consecutive patients with bronchioloalveolar carcinoma treated during a 10-year period and attempted to analyze factors related to prognosis. During the 10-year study period, the prevalence of bronchioloalveolar carcinoma relative to adenocarcinoma of the lung remained steady. The subjects included 32 male and 18 female patients with mean ages of 64.7 years and 55.1 years, respectively (p = 0.0030). The preoperative radiographic findings included 40 cases of localized and 10 cases of diffuse bronchioloalveolar carcinoma. The clinicopathologic TNM staging included 20 patients with stage I cancer, 4 with stage II cancer, 11 with stage IIIa cancer, 3 with stage IIIb cancer, and 12 with stage IV cancer. Forty patients with clinical stage I, II, or III disease underwent operation (operability 80%). The resectability rate was 90% (36 of 40). Thirty-four procedures were considered as curative. The overall cumulative survival at 5 years was 22.2% (46.4% for stage I). Different TNM stages showed significant differences in survival time (p = 0.0001). The median survival times were 64.6 months for stage I, 48.0 months for stage II, 24.7 months for stage IIIa, 9.0 months for stage IIIb, and 4.5 months for stage IV disease. The median survival time for localized bronchioloalveolar carcinoma was 27.5 months, and the median survival time for diffuse bronchioloalveolar carcinoma was 4.3 months (p = 0.0002). The median survival time for the curative resection group was 30.6 months, and the median survival time for the noncurative resection or nonresection group was 5.8 months (p = 0.0001). On the basis of this study we conclude that (1) the prevalence of bronchioloalveolar carcinoma is quite steady, (2) bronchioloalveolar carcinoma presents at an earlier age in women, (3) bronchioloalveolar carcinoma frequently presents with lymphatic spread or systemic metastasis at diagnosis, (4) most localized bronchioloalveolar carcinomas are resectable and the prognosis with this type is better than that of the diffuse type, and (5) long-term survival correlates closely with initial roentgenographic appearance, TNM stage, and completeness of surgical resection.

Prediction of probability of pneumonectomy for lung cancer using Tc-99m MAA perfusion lung imaging

Pulmonary perfusion scintigraphy with Tc-99m MAA was performed on 182 patients, on whom either pneumonectomy or lobectomy was performed, because of primary nonsmall-cell lung carcinoma. Among them, 76 underwent pneumonectomy, and 106 underwent lobectomy. The mean value of the perfusion fraction (PF) of the affected lung of the patients undergoing pneumonectomy was 32.3 +/- 13.6% (range, 4%-50%) and was less than that of the patients undergoing lobectomy, 43.5 +/- 4.5% (range, 27%-50%). The difference was statistically significant (t-test, t = 6.82; P < 0.001). Among the 28 patients whose PF of the affected lung was equal to or less than 30%, 26 underwent pneumonectomy and only 2 had a lobectomy. Among the 154 patients whose PF of the affected lung was more than 30%, 50 underwent pneumonectomy and 104 had a lobectomy. These result suggest that "30%" can be a cutoff value (Yates correction X(2) test, X2 = 33.09; P < 0.001).