The accuracy of endoscopic ultrasound, endoscopic retrograde cholangiopancreatography, computed tomography, and transabdominal ultrasound in the detection and staging of primary ampullary tumors

BACKGROUND/AIMS

To compare the accuracy between EUS (endoscopic ultrasound), ERCP (endoscopic retrograde cholangiopancreatography), CT (computed tomography), and transabdominal US (ultrasound) in the detection and staging of primary ampullary tumors. We will also try to discuss the influence of endobiliary stent on EUS in staging ampullary tumors.

METHODOLOGY

Twenty-one patients with ampullary tumors were evaluated by EUS, ERCP, CT, and US before operation. The accuracy was assessed with TNM staging and compared with the surgical-pathological findings.

RESULTS

EUS was superior to CT and US in detecting ampullary tumors, but EUS and ERCP are of similar sensitivity (EUS 95%, ERCP 95%, CT 19%, US 5%). EUS was superior to CT and US in T staging (EUS 75%, CT 5%, US 0%) and detecting lymph node metastasis (EUS 50%, CT 33%, US 0%) of ampullary tumors. The accuracy of EUS in T and N staging of ampullary tumors tended to be decreased in the presence of endobiliary stent (stenting: T 71%, N 75%; nonstenting T 83%, N 100%), but there was no statistical significance.

CONCLUSIONS

EUS was superior to CT and US in assessing primary ampullary tumors, but it was not significantly superior to ERCP in detecting ampullary tumors. The presence of endobiliary stent may decrease the accuracy of EUS in staging ampullary tumors.

Arthroscopic evaluation and treatment of scaphoid nonunion

Scaphoid fractures are one of the most common carpal fractures and heal without complication in a majority of cases. Nonunion of the scaphoid, unfortunately, can occur secondarily to several reasons; namely, delay in treatment, delay in diagnosis, the intra-articular nature of the fracture, the precarious vascular supply of the scaphoid, and significant biomechanical stresses across the fractured scaphoid.

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.

The correlation between alteration of p16 gene and clinical status in oral squamous cell carcinoma

The purpose of the study was to evaluate the presence of alteration of the tumor suppressor gene p16 and to correlate these changes with the clinical status of the patients in oral squamous cell carcinoma. Forty-eight oral squamous cell carcinomas were included in the analyses. Deletion analysis was performed by the polymerase chain reaction (PCR). Mutation analysis was restricted to exon 1 and exon 2 of the p16 gene, previously shown to have a high incidence of mutations. The sequences containing exon 1 and exon 2 were amplified by PCR and screened with a single-strand conformation polymorphism (SSCP) technique. Samples showing band shifts in SSCP were sequenced by PCR direct sequencing. Western blots were used to detect the protein expression of the p16 gene, and the results were evaluated with regard to their biological relevance in correlation with clinicopathological factors. Seven (14.6%) deletions were found; 5 (10.4%) mutations were discovered and located in different codons; 26 (54%) specimens had no p16 protein expression; in 11 specimens with p16 deletion or mutation, p16 protein could not be detected. One mutation was non-sense. The p16 gene alterations showed no relationship with location and clinical stage of cancer; however, a close relationship between p16 alterations and cancer metastasis to neck lymph node was found. The alteration rate gradually elevated from well to poorly differentiated grades. We perceive two results. First, the alterations of the p16 gene are common in oral squamous cell carcinoma. Second, the alterations of the p16 gene may attribute to the metastatic behavior or histological grade of cancer cells.

Turing model for the patterns of lady beetles

We simulate the patterns on the hard wings of lady beetles using a reaction-diffusion equation based on the Turing model. A part of a spherical surface is used to approximate the geometry of the hard wings. Various patterns common to lady beetles in Taiwan can be produced on this curved surface by adjusting the parameters of the model.

The role of a beta-bulge in the folding of the beta-hairpin structure in ubiquitin

It is known that the peptide corresponding to the N-terminal beta-hairpin of ubiquitin, U(1-17), can populate the monomeric beta-hairpin conformation in aqueous solution. In this study, we show that the Gly-10 that forms the bulge of the beta-turn in this hairpin is very important to the stability of the hairpin. The deletion of this residue to desG10(1-16) unfolds the structure of the peptide in water. Even under denaturing conditions, this bulge appears to be important in maintaining the residual structure of ubiquitin, which involves tertiary interactions within the sequence 1 to 34 in the denatured state. We surmise that this residual structure functions as one of the nucleation centers in the folding process and is important in stabilizing the transition state. In accordance with this idea, deleting Gly-10 slows down the refolding and unfolding rate by about one half.

Broadband infrared generation with noncollinear optical parametric processes on periodically poled LiNbO(3)

Broadband signal and idler generation based on the spectral retracing behavior in noncollinear phase matching of optical parametric generation in periodically poled LiNbO(3) (PPLN) is reported. Using PPLN of 29.5-mum quasi-phase-matching period and a Q-switched Nd:YAG laser as a pump, we obtained a broad signal spectrum from 1.66 to 1.96 mum and corresponding idler wavelengths from 2.328 to 2.963 mum. The experimental results were consistent with theoretical predictions. Circular and elliptical pump beams were also compared.

Acute toxicities of betel nut: rare but probably overlooked events

BACKGROUND

Betel nut chewing has long been a social habit in Taiwan and other Asian and tropical countries. It produces various autonomic and psychoneurologic effects including tachycardia, flushing, warmth, cholinergic activation, alertness, and euphoria. Although the oral carcinogenic effects are well known, data concerning its acute toxicity are few. To better understand the toxicity of betel nut, cases reported to the Taiwan Poison Control Center as probable or possible betel nut-related toxicity (January 1988-June 1998) were reviewed. In the 17 cases suitable for review (14 males, 3 females, age 21 to 60 years), the most common manifestations were tachycardia/palpitations (7); tachypnea/dyspnea (6); hypotension and sweating (5); vomiting, dizziness, and chest discomfort (4); abdominal colic, nausea, numbness, and coma (3); and acute myocardial infarction and related manifestations (2). The reported quantity of betel nut used was low (1 to 6 nuts), except an extract of 100 betel nuts was used in 1 case and 66 chewed in another. Most cases recovered within 24 hours after the exposure. One patient developed probable acute myocardial infarction and ventricular fibrillation and died despite repeated cardiac defibrillation. Although betel nut chewing is widespread, significant toxicity as reported to a poison center is rare. Because most betel nut-related effects are transient and mild in nature, the incidence of such events is likely to be underreported. Nevertheless, betel nut chewing can produce significant cholinergic, neurological, cardiovascular, and gastrointestinal manifestations. It is possible that it may aggravate cardiac diseases in susceptible patients but this hypothesis must be further investigated. Treatment is symptomatic. With timely support, rapid and complete recovery is anticipated but a small risk of major complications cannot yet be discounted.

Perinephric abscesses in the neurologically impaired

STUDY DESIGN

Retrospective chart review.

OBJECTIVES

To document the occurrence and management of large perinephric abscesses in neurologically impaired patients at high risk for this infectious complication.

SETTING

US Veterans Affairs hospital.

METHODS

The records, radiographs, operative findings and outcomes of all patients who presented with perinephric abscesses evident on physical exam within the last 5 years were reviewed.

RESULTS

Four patients presented with large perinephric abscesses evident on physical examination. All had severe neurologic impairment with high sensory levels; three had spinal cord injuries, one had advanced multiple sclerosis. All had neurogenic bladders and recurrent urinary tract infections. The diagnosis was made through a combination of history, physical examination and computed tomography (CT) examination. All were found to have upper tract obstruction. All were managed with immediate abscess drainage and three had elective nephrectomy once the infection had resolved. No patients died of their perinephric abscess.

CONCLUSIONS

These four cases illustrate that although advances in antibiotics, imaging and percutaneous management have improved the speed of diagnosis and reduced the mortality in patients with perinephric abscesses, the neurologically impaired population continues to remain at significant risk for the development and the delayed diagnosis of these morbid renal infections.

Comparison of technetium-99m tetrofosmin and gallium-67 citrate scintigraphy for detecting malignant lymphoma

The aim of this study was to compare the value of technetium-99m tetrofosmin (Tc-TF) scintigraphy with that of gallium-67 citrate (Ga-67) scintigraphy for detecting malignant lymphoma. In this study, 50 patients with malignant lymphoma underwent Tc-TF and Ga-67 scintigraphy before receiving any therapy. Tc-TF scintigraphy detected malignant lymphoma in 44 (88%) patients, but was false-negative in 4 cases of infradiaphragmatic malignant lymphoma and in 2 cases of malignant lymphoma with chemotherapy resistance. Ga-67 scintigraphy detected malignant lymphoma in 45 (90%) patients, but was false-negative in 3 cases of low-grade non-Hodgkin's lymphoma and in 2 cases of malignant lymphoma with bone marrow involvement. There was no significant difference in sensitivity between Tc-TF and Ga scintigraphy. However, a combination of Tc-TF and Ga-67 scintigraphy detected malignant lymphoma in all 50 patients (100%). We conclude that it is necessary to combine Tc-TF and Ga-67 scintigraphy to accurately detect malignant lymphoma.

The features of perforated peptic ulcers in conventional computed tomography

BACKGROUND/AIMS

CT is not usually of priority to evaluate the pathology of the gastrointestinal tract, especially perforated peptic ulcer. However CT might be employed when the presentation is atypical. The study was to summarize the imaging features of perforated peptic ulcer in conventional CT and assess its ability of detecting perforated peptic ulcer.

METHODOLOGY

The CTs of 14 consecutive patients with perforated peptic ulcer confirmed by operation were retrospectively reviewed. The CTs were obtained after intravenous contrast medium, but oral contrast medium was administered only in 5 patients. The CT findings were correlated with surgical findings.

RESULTS

Among these 14 patients, all the 14 patients (100%) had extraluminal air accumulation, 10 patients (71%) had abnormal fluid accumulation, and 5 (36%) patients had inflammatory changes in surrounding soft tissues. In addition, conventional CT could only demonstrate the site of perforation in 5 patients (36%) of them.

CONCLUSIONS

Conventional CT was valuable in the diagnosis of perforated peptic ulcer, and pneumoperitoneum was the most common feature. However the ability of conventional CT in localizing the site of perforation was poor.

Neurophysiologic testing in chronic pelvic pain syndrome: a pilot study

OBJECTIVES

Studies of male chronic pelvic pain syndrome (CPPS) have generally centered on the pathologic features of the prostate rather than on the neurology of pain. Electrodiagnostic studies examine the integrity of somatosensory nerve pathways consisting of large, group A fibers. Heat sensation and visceral (autonomic) pain is mediated through small, unmyelinated C fibers, which can be tested cutaneously by thermal sensory analysis. We hypothesized that CPPS pain is mediated by these small C fibers.

METHODS

All subjects and controls had no history of neurologic disease and had normal neurologic examinations. Phase I: 14 patients with CPPS underwent electrodiagnostic testing using pudendal somatosensory evoked potentials and bulbocavernosus reflex latency measurements. Phase II: 31 patients with CPPS and 14 controls underwent thermal sensory analysis testing on the perineum and anterior thigh using noxious heat stimuli. Subjects used a computer-generated visual analog scale to dynamically report their discomfort. The peak and slope of the computer-generated visual analog scale were analyzed.

RESULTS

Phase I: two patients had delayed latency of the somatosensory evoked potentials, but additional evaluation with magnetic resonance imaging revealed no definable lesion. Phase II: with thermal sensory analysis, men with CPPS reported higher intensity pain at lower temperatures (P = 0.03). Men with CPPS also had higher peak computer-generated visual analog scale scores on perineal testing. No difference in thermal testing on the anterior thigh was found between the two groups.

CONCLUSIONS

Large, myelinated somatic fibers do not play a significant role in the pathophysiology of CPPS. Patients with CPPS have an altered sensation of perineal pain elicited by heat, which may represent a C-fiber-mediated effect.

Physiologic studies of male sexual dysfunction in multiple sclerosis

OBJECTIVE

We conducted this investigation to better define the neural disruptions that result in sexual dysfunction in men with multiple sclerosis (MS), using genital electrodiagnostic testing and nocturnal penile tumescence and rigidity monitoring.

METHODS

Thirteen men with MS and sexual dysfunction were recruited for the study. Twelve healthy, sexually potent men were enrolled as controls. All underwent pudendal somatosensory evoked potential (SEP) testing using standard methods, and a new modification to isolate the right and left dorsal nerves of the penis. RigiScan testing was performed on the MS subjects to assess nocturnal erectile function.

RESULTS

Unilateral and bilateral DNP SEPs were able to be performed on the control subjects. In all but one MS subjects, DNP SEP abnormalities were found. Three men had normal latency bilateral DNP SEP latencies, but on unilateral DNP testing, abnormalities were identified. Seven men, including those with abnormal or absent SEP latencies, had normal nocturnal erectile activity. There was no correlation between overall functional status, presence of abnormal or absent SEP, and quality of nocturnal erectile activity.

CONCLUSIONS

Genital SEP abnormalties are common in men with MS and sexual dysfunction. Unilateral DNP SEP testing was more sensitive in identifying abnormalities than the standard method of pudendal SEP testing. One of the causes of sexual dysfunction in men with MS may be due to genital somatosensory pathway disruption, with sparing of the efferent tracts in some men.

Glutaraldehyde cross-linking alters the environment around Trp(29) of cobrotoxin and the pathway for regaining its fine structure during refolding

Cobrotoxin, purified from the venom of Naja naja atra (Taiwan cobra), was subjected to modification with glutaraldehyde in order to prepare intra- and intermolecule cross-linked derivatives. Monomeric and dimeric derivatives were separated from polymeric derivatives by gel filtration. The results of amino acid analysis and sequence determination revealed that only Lys residues were selectively modified by glutaraldehyde. Glutaraldehyde cross-linking was accompanied by a change in the gross conformation of cobrotoxin as revealed by circular dichroism spectra of the modified derivatives. Compared with cobrotoxin, Trp(29) of monomeric and dimeric derivatives was in an apolar microenvironment. This was in agreement with acrylamide quenching studies showing that the spatial position of the Trp indole ring became buried in the interior of the molecule after glutaraldehyde cross-linking. Moreover, the Trp of modified derivatives was less accessible for iodide than that observed with cobrotoxin. Notably, disulfide reduction could not completely unfold the structure of glutaraldehyde-modified derivatives as evidenced by the results of acrylamide quenching studies and enzyme-linked immunoassay. Study of the characteristic changes in Trp fluorescence after the initiation of refolding suggested that the fine structure around Trp(29) of cobrotoxin and glutaraldehyde-modified derivatives was formed differently. These results suggest that glutaraldehyde cross-linking leads to a change in the microenvironment of cobrotoxin Trp(29) and alters the pathway of its fine structure formation during the refolding of cobrotoxin.

Preoperative evaluation of periampullary tumors by endoscopic sonography, transabdominal sonography, and computed tomography

PURPOSE

The purpose of this retrospective study was to compare the sensitivity of endoscopic sonography (EUS), transabdominal sonography (US), and CT in the detection of, local staging of, and prediction of vascular involvement by or distant metastasis from periampullary tumors.

METHODS

Seventy-four consecutive patients with presumed periampullary tumors were evaluated by EUS, US, and CT during a 3.25-year period. The local staging accuracy of the modalities was assessed in the 36 patients with solid tumors who underwent surgery. The sensitivity of the modalities in predicting vascular involvement and distant metastasis was assessed in the 56 patients with carcinomas.

RESULTS

EUS was the most sensitive modality in the detection (EUS, 97%; US, 24%; and CT, 39%; p < 0.001 for EUS versus US or CT) and T classification (EUS, 72%; US, 11%; CT, 22%; p < 0.001 for EUS versus US or CT) of periampullary tumors. EUS also had better sensitivity than US in detecting lymph node metastasis from periampullary cancers (EUS, 47%; US, 7%; and CT, 33%; p = 0.02 for EUS versus US; p = 0.7 for EUS versus CT). The accuracy of EUS in determining the T classification (without stent, 81%; with stent, 65%) and N classification (without stent, 80%; with stent, 70%) tended to decrease in the presence of an endobiliary stent, but the differences were not significant. EUS was the most sensitive modality in demonstrating vascular involvement (EUS, 100%; US, 0%; and CT, 33%; p = 0.002 for EUS versus US; p = 0.03 for EUS versus CT) but was not significantly different in detecting distant metastasis (EUS, 11%; US, 44%; and CT, 44%).

CONCLUSIONS

EUS is superior to US and CT in the local assessment of periampullary tumors. The staging accuracy of EUS is minimally but not significantly affected by the presence of an endobiliary stent.

Role of upright chest radiography and ultrasonography in demonstrating free air of perforated peptic ulcers

BACKGROUND/AIMS

The purpose of this study was to determine the value of upright chest radiography and ultrasonography in demonstrating free air of perforated peptic ulcers. METHOLOGY: Eighty-four patients with perforated peptic ulcers receiving both upright chest radiography and ultrasonography before laparotomy. The sensitivity of each modality in demonstrating free air was correlated.

RESULTS

Among the 84 patients receiving both examinations, free air was demonstrated in only 39 (46%) upright chest radiographs and 46 (55%) ultrasonographs, the direct sign could be demonstrated in 57 (68%) patients by combined radiography and ultrasonography. Besides, the indirect sign of ascites could be demonstrated in 26 (31%) ultrasonographs.

CONCLUSIONS

Ultrasonography is more sensitive than upright chest radiography to demonstrate free air of perforated peptic ulcers, and it should be considered in those patients of suspected perforated peptic ulcers with negative upright chest radiography. Combined methods of upright chest radiography and ultrasonography can increase the overall sensitivity in demonstrating free air.

Refolding of Taiwan cobra neurotoxin: intramolecular cross-link affects its refolding reaction

In order to explore the effect of intramolecular cross-linking in the folding reaction of cobrotoxin from Naja naja atra (Taiwan cobra) venom, the toxin molecule was modified with glutaraldehyde (GA). The monomeric GA-modified cobrotoxin (mGA-cobrotoxin) was separated from the dimeric and trimeric derivatives using gel filtration. The results of electrophoretic and chromatographic analyses revealed that mGA-cobrotoxin comprised two modified derivatives, which contained modified Lys residues at positions 26 and 27 and at positions 26, 27, and 47, respectively. Moreover, an intramolecular cross-linking of loops II and III by Lys residues was noted with the monomeric derivative containing three modified Lys residues. In sharp contrast to cobrotoxin observations, the folding rate of mGA-cobrotoxin decreased in the presence of GSH/ GSSG, but notably increased in the absence of thiol compounds. Particularly, the accelerated effect of GSH/GSSG on the refolding reaction was affected by the presence of the intramolecular cross-link. Comparative analyses on cobrotoxin and mGA-cobrotoxin CD spectra revealed that modification with the GA reagent caused a change in the gross conformation of cobrotoxin. Fluorescence measurement revealed that the stability of the microenvironment around the single Trp-29 in mGA-cobrotoxin and unfolded mGA-cobrotoxin was appreciably higher than in cobrotoxin and unfolded toxin. Moreover, the ordered structure formation around Trp-29 in refolded mGA-cobrotoxin was faster than in refolded cobrotoxin as evidenced by fluorescence quenching studies. Taken together, these results suggest that the structural flexibility of unfolded cobrotoxin should be favorable for the thiol catalyst to exert its action in the refolding reaction after modification with GA.

Evidence for alterations in circulating low-molecular-weight antioxidants and increased lipid peroxidation in smokers on hemodialysis

BACKGROUND/AIM

Cardiovascular disease is the major cause of mortality in dialysis patients, accounting for about 40% of deaths in most large registries. Oxidative stress has been strongly implicated in the pathogenesis of these events. As end-stage renal disease is a state of elevated free radical activity, the aim of the present study was to investigate the negative impact of smoking in 57 male hemodialysis patients.

METHODS

The patients, who were 20-85 years of age (mean age 51.0 +/- 14 years), had been on hemodialysis for at least 6 months before participating in this study. Fasting blood sampling for serum lipid, albumin, urate and lipophilic antioxidants such as tocopherols, carotenes, ascorbate and lipid peroxides was performed.

RESULTS

The plasma malondialdehyde (MDA) concentration was significantly higher in hemodialysis patients who smoked compared to hemodialysis patients who were nonsmokers (1.92 +/- 0.52 vs. 1.59 +/- 0.42 nmol/ml, p = 0.006). No association was found between levels of MDA in smokers and parameters such as body mass index, serum cholesterol, serum triglycerides and smoking index. There were no significant differences in the plasma levels of uric acid, alpha-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-carotene, beta-carotene and retinol between the two groups. A significantly lower level of plasma ascorbate was observed in hemodialysis patients who smoked compared to the nonsmoking hemodialysis patients or healthy controls (4.59 +/- 4.0 vs. 9.57 +/- 4.0 and 10.16 +/- 4.6 microg/ml, p < 0.05). Moreover, in smokers, the plasma levels of ascorbate were negatively correlated with the levels of plasma MDA (r = -0.43, p < 0.001) of each patient. Partial correlation analysis of the plasma levels of the measured antioxidants and the smoking index revealed a negative correlation between the plasma levels of lipid-normalized lycopene and the smoking index (r = -0.53, p < 0.05).

CONCLUSION

Our data suggest that cigarette smoking further increases plasma-circulating products of lipid peroxidation, which are already increased in nonsmoking hemodialysis patients as compared to matched healthy controls. The lower plasma levels of ascorbate in hemodialysis patients who smoke suggest that these patients may be more susceptible to oxidative tissue damage caused by smoking.

Bethlem myopathy in a Taiwanese family

We report three cases of Bethlem myopathy from three consecutive generations of a Taiwanese family, including one woman aged 70, one man aged 40, and a boy aged 8. The clinical features of the patients included autosomal dominant inheritance, childhood or adolescent onset, mainly proximal and extensor involvement, early diffuse joint contractures, and absence of cardiac involvement. These features fulfilled the diagnostic criteria for Bethlem myopathy. Though the clinical course of the disease was once thought to be benign, our female patient became wheelchair-bound at the age of 53. This suggests that the disease process in Bethlem myopathy is slow but ongoing.

In vitro cellular response of retinoic acid treated human oral cancer cell lines

BACKGROUND

The purpose of this study is to identify the cellular response ofretinoic acid-treated human oral cancer cell lines.

METHODS

Seven human oral cancer cell lines KB, SCC4, SCC9, SCC15, SCC25, OEC-M1, OC1 and OC2 were used for cell culture experiments. Direct cell number counting method was utilized to evaluate cellular response of these human oral cancer cells at the presence or absence of all-trans RA at 1 mM.

RESULTS

Through 7-day observation, the cell population of SCC9, SCC15 and SCC25 of RA-treated groups decreased when compared with the non RA-treated groups. These three cell lines were further verified using [3H] thymidine incorporation DNA synthesis assay. KB, SCC4, OC1, OC2 and OEC-M1 cell lines did not show growth inhibition at the presence of RA at 1 mM.

CONCLUSIONS

The molecular event of how SCC9, SCC15 and SCC25 are inhibited by RA and how KB, OC1, OC2 and OECM1 are resistant to RA can be further explored on the basis of this study.

On-line concentration of s-triazine herbicides in micellar electrokinetic chromatography using a cationic surfactant

On-line concentration of neutral species of s-triazine herbicides in micellar electrokinetic chromatography using tetradecylammonium bromide (TTAB) as a cationic surfactant was investigated. Factors affecting the stacking of analytes were examined. The results indicate that the stacking efficiency is markedly improved with addition of phosphate buffer in the sample matrix. It was found that, depending on the nature of the analytes, the most effective stacking of these analytes occurs when the ratio of the conductivity of buffer electrolyte to that of sample matrix is in the range 1.4-1.2, with sample matrix containing phosphate buffer. Micelle concentration in the separation buffer is also a crucial factor to enhance the stacking efficiency and detection sensitivity of analytes. Moreover, the stacking efficiency of each individual analyte depends on its binding constant to TTAB micelles. The concentration effect is primarily based on sweeping mechanism which is operated in a normal stacking mode with reversed electrode polarity in the presence of reversed electroosmotic flow. As a result of concentration enhancement, the detection limits of these herbicides can reach about 9-15 ng/ml with UV detection.

IS1550 from Mycoplasma fermentans is transposable in Escherichia coli

An insertion sequence (IS)-like element (ISMil) was previously isolated from the incognitus strain of Mycoplasma fermentans. With polymerase chain reaction primers corresponding to the left and right terminal inverted repeats of ISMil, a 1.4-kb DNA fragment was amplified from the genome of the M64 strain of M. fermentans. This DNA fragment has structural characteristics similar to those of ISMil and is designated IS1550. One copy of IS1550 encoded two considerable overlapping open reading frames (ORFs), ORF1 and ORF2. A putative translation frame-shift signal AAAAAAG (A6G) was located near the 3'-end of ORF1. This signal might cause a -1 frame-shift to form a fused product of ORF1 and ORF2 with 444 amino acids, which has a significant similarity to the putative transposase of the IS3 family. This copy of IS1550 was shown to be transposable in Escherichia coli ISM612. Its transposition caused a 1465-bp deletion immediately adjacent to the 3'-end of the element and the creation of a pair of 3-bp direct repeats flanking the element at the new insertion site. On the basis of these results, IS1550 was considered a typical transposable element.

Polarization gating in ultrafast-optics imaging of skeletal muscle tissues

By comparing the results of polarization-dependent, time-resolved intensity profiles of photons transmitted through diluted milk, chicken breast tissue, and chopped chicken breast tissue, we found that the inherent anisotropic optical property of skeletal muscle tissue resulted in coherent coupling between two mutually perpendicular polarization directions. This coupling process led to difficulty in using the conventional polarization gating method for imaging unless the anisotropy characteristics were well understood. However, imaging based on polarization gating in diluted milk and chopped chicken breast tissue, which had an isotropic random-scattering nature, was quite effective.

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.

Tracheal length of infants under three months old

The measurement of tracheal length in infants is difficult to perform in vivo. In adults, tracheal length may be consistent with age, but in infants, tracheal length may vary much more with age and other factors. This study used video rigid ventilation bronchoscopy to evaluate the length of the airway, concentrating on the population younger than 3 months old. There were 34 infants in this study: 14 boys and 20 girls. The mean length from the superior border of the vocal fold to the carina was 5.04 cm, and the mean tracheal length (from the ridge of the first tracheal ring to the carina) was 4.12 cm. There was no significant difference between boys and girls in the length from the vocal fold to the carina or in the tracheal length. The length from the vocal fold to the carina is best correlated to body weight, followed by body height and age.

Bladder management in women with neurologic disabilities

Women with neurologic disabilities can experience an array of bladder disorders. There are many aspects of lower urinary tract management that are specific to women. Treatments should be based on urodynamic findings, and individualized for each woman's physical and cognitive abilities.

Smad proteins function as co-modulators for MEF2 transcriptional regulatory proteins

An emerging theme in transforming growth factor-ss (TGF-ss) signalling is the association of the Smad proteins with diverse groups of transcriptional regulatory proteins. Several Smad cofactors have been identified to date but the diversity of TGF-ss effects on gene transcription suggests that interactions with other co-regulators must occur. In these studies we addressed the possible interaction of Smad proteins with the myocyte enhancer-binding factor 2 (MEF2) transcriptional regulators. Our studies indicate that Smad2 and 4 (Smad2/4) complexes cooperate with MEF2 regulatory proteins in a GAL4-based one-hybrid reporter gene assay. We have also observed in vivo interactions between Smad2 and MEF2A using co-immunoprecipitation assays. This interaction is confirmed by glutathione S:-transferase pull-down analysis. Immunofluorescence studies in C2C12 myotubes show that Smad2 and MEF2A co-localise in the nucleus of multinuclear myotubes during differentiation. Interestingly, phospho-acceptor site mutations of MEF2 that render it unresponsive to p38 MAP kinase signalling abrogate the cooperativity with the Smads suggesting that p38 MAP Kinase-catalysed phosphorylation of MEF2 is a prerequisite for the Smad-MEF2 interaction. Thus, the association between Smad2 and MEF2A may subserve a physical link between TGF-ss signalling and a diverse array of genes controlled by the MEF2 cis element.

Migration of endoclip into duodenum. A rare complication after laparoscopic cholecystectomy

The long-term effect of spilled clips within the abdominal cavity after laparoscopic cholecystectomy is unknown. However, most surgeons agree that the migration of clips has limited clinical consequences. A few cases have been reported of clips that have migrated into the common bile duct, causing stone formation and/or obstructions. We present a case of gallstone pancreatitis treated with laparoscopic cholecystectomy that was complicated by bile leakage from the cystic duct stump 1 day after the procedure. Although the leaking stump sealed itself spontaneously after the placement of a biliary stent, a clip had migrated directly to the superior wall of the first portion of the duodenum. Herein the details of the patient's history are presented. We also discuss the possible mechanisms of clip migration and describe some preventive measures.

Abdominal wall abscess secondary to spilled gallstones: late complication of laparoscopic cholecystectomy and preventive measures

Spilled gallstones left in the abdominal cavity or trapped at trocar sites may cause considerable morbidity. We saw a patient with an abdominal wall abscess 2 years after laparoscopic cholecystectomy secondary to spilled stones. After we reviewed the operative procedure in addition to the accumulated experience in laparoscopic surgery, we believe that retrieval of specimens and their contents is of paramount importance, especially when the gallbladder is infected, contains several stones, or may harbor malignancy. Therefore, we made use of a simple surgical glove with a long pursestring suture surrounding the opening to collect the specimen. This method proved to be simple and quite convenient, with the needed materials readily available. It can collect the spilled stones within the abdominal cavity as well as the gallbladder and can transport these stones out of the abdominal cavity with ease and safety. It also protects the specimen in contact with the wound and cuts short the operating time. The technique and advantages are described.

Cortical evoked potentials of the dorsal nerve of the clitoris and female sexual dysfunction in multiple sclerosis

PURPOSE

We evaluated whether disrupting genital central nervous system pathways is associated with subjective reports of sexual dysfunction in women with multiple sclerosis.

MATERIALS AND METHODS

We performed pudendal somatosensory evoked potential testing in and had sexual questionnaires completed by 14 women with a mean age of 47 years who had multiple sclerosis.

RESULTS

The mean expanded disability status score was 5. All but 1 woman reported the desire for sexual intercourse. There was a high rate of dissatisfaction with their sex life and all study participants had concomitant bladder and bowel function problems. The most common sexual complaint was difficult or no orgasm, which was statistically associated with abnormalities or absence of 1 or both pudendal cortical evoked potentials. Fatigue and arousal disorders were also common.

CONCLUSIONS

Women with multiple sclerosis have a high self-reported rate of sexual dysfunction, which decreases quality of life. Electrodiagnostic data imply that pudendal somatosensory innervation is necessary for normal female orgasmic function. More study is needed to confirm these findings.

Intracranial fibrosarcoma arising 5 years after chemotherapy alone for glioblastoma multiforme in a child

We present a child diagnosed with glioblastoma multiforme during infancy and successfully treated with the 'eight-in-one' chemotherapy regimen, who developed an intracranial fibrosarcoma 5 years later. After resection of the fibrosarcoma, she received cranial radiation therapy and high dose chemotherapy with bone marrow transplant. She remains alive and recurrence-free 7 years following the diagnosis of her second intracranial malignancy.

Repair of CFTR mRNA by spliceosome-mediated RNA trans-splicing

Most messenger RNA precursors (pre-mRNA) undergo cis-splicing in which introns are excised and the adjoining exons from a single pre-mRNA are ligated together to form mature messenger RNA. This reaction is driven by a complex known as the spliceosome. Spliceosomes can also combine sequences from two independently transcribed pre-mRNAs in a process known as trans-splicing. Spliceosome-mediated RNA trans-splicing (SMaRT) is an emerging technology in which RNA pre-therapeutic molecules (PTMs) are designed to recode a specific pre-mRNA by suppressing cis-splicing while enhancing trans-splicing between the PTM and its pre-mRNA target. This study examined the feasibility of SMaRT as a potential therapy for genetic diseases to correct mutations using cystic fibrosis (CF) as an example. We used several versions of a cystic fibrosis transmembrane conductance regulator (CFTR) mini-gene expressing mutant (deltaF508) pre-mRNA targets and tested this against a number of PTMs capable of binding to the CFTR target intron 9 and trans-splicing in the normal coding sequences for exons 10-24 (containing F508). When 293T cells were cotransfected with both constructs, they produced a trans-spliced mRNA in which normal exon 10-24 replaced mutant exon 10. To test whether SMaRT produced mature CFTR protein, proteins were immunoprecipitated from lysates of cotransfected cells and detected by Western blotting and PKA-phosphorylation. Tryptic phosphopeptide mapping confirmed the identity of CFTR. This proof-of-concept study demonstrates that exon replacement by SMaRT can repair an abnormal pre-mRNA associated with a genetic disease.

Acoustic-induced switching of the reflection wavelength in a fiber Bragg grating

Coupling between copropagating core and cladding modes was implemented by acoustic generation of lateral vibration of an etched fiber. When these coupling processes were combined with counterpropagating coupling of a core mode and a cladding mode and the Bragg reflection of a fiber grating, switching of reflection wavelength between the Bragg wavelength and cladding-mode coupling wavelengths was achieved. We report the implementation of such acoustically induced switching behaviors and explain their operation principles. The implemented results can be used for wavelength-division multiplexed add-drop filtering.

Prosthesis folding as a cause of the saline breast implant partial deflation 12 years after augmentation mammaplasty: a case report

In this paper, I report a case of delayed slow leakage (partial deflation) from an inflatable saline breast implant, 12 years after augmentation mammaplasty. The patient had a history of breast foreign body injection and developed a complication with multiple painful indurated mass. She received a subcutaneous mastectomy to remove all the injected breast foreign body in November 1986 and an inflatable breast implant was given for augmentation simultaneously. Owing to the accidental deflation of the left implant, the breast implant was removed and replaced in January 1999. Examination of the removed breast implant revealed a linear fold (13 cm in length) on the lower pole of the prosthesis and a small leaking hole (microscopic tear) in the middle of that fold. The possible mechanisms of implant deflation may include faulty manufacturing process, fold flaw leak (crease fold failure) and capsular contracture. In this case report the capsular contracture had caused prosthesis folding and the prosthesis had become partial deflation finally. Besides the better surgical intervention to prevent capsular contracture, I believe that choosing a correct implant size preoperatively and filling that implant to its optimal level will best minimize the possibility of breast silicone shell folding.

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.

Different forms of HSV-1 VP22a within purified virion and infected cells

Utilizing the monoclonal antibody MCA406, our experimental data suggest that the herpes simplex virus type 1 (HSV-1) protein, VP22a, is present in the purified virus in a different form from that present within infected cells, namely the virion and infected-cell form, respectively. It seems reasonable to suggest that two different forms of VP22a are synthesized during the HSV-1 productive cycle. Using varying quantities of reducing agents, both inter- and intramolecular disulfide linkages were demonstrated in this protein family. Moreover, the VP22a-virion form could not be detected under nonreducing conditions by monoclonal antibody, even in the presence of proteolysis inhibitors, i.e. aprotinin, phenyl-methane-sulfonyl fluoride (PMSF) and soybean trypsin inhibitor. Varying temperature had little effect on the breakdown of VP22a disulfide bonds. A higher molecular-weight band, present in the nonreduced gel tracks, clearly indicates the presence of intermolecular disulfide bonds. Similarly, the appearance of bands of lower apparent molecular weight in the nonreduced tracks suggests the presence of intramolecular disulfide bonding. The VP22a infected-cell form may be modified to the virion form during the capsid-assembly process, prior to full capsid formation.

Association between seropositivity of antibodies against hepatitis a virus and Helicobacter pylori

Helicobacter pylori and hepatitis A virus (HAV) are documented to share common transmission routes including fecal-oral. This study examined the association between seropositivity of antibodies against H. pylori (anti-HP) and HAV (anti-HAV) via a community-based survey of 40 randomly selected kindergartens in 10 urban and 10 rural areas. Serum samples from 2,047 healthy preschool children and 104 teachers were screened for anti-HP by enzyme-linked immunosorbent assay, and for anti-HAV by microparticle enzyme immunoassay. In children, a low prevalence of anti-HAV (0.44%) was found, in contrast to a high prevalence in their teachers (78.8%); anti-HP seroprevalence was 6.4% for children and 30.8% for teachers. Anti-HAV and anti-HP seropositivities were significantly associated in teachers after adjustment for age, sex, and residential area through multiple logistic regression analysis (multivariate-adjusted odds ratio = 7.3; 95% confidence interval [CI] = 1.4-36.8, P < 0.001). Our findings suggest that HAV and H. pylori may have shared transmission routes in central Taiwan 15 years or more ago, but not any recently.

Laparosopic removal of large gastric phytobezoars

Large gastric bezoars are difficult to remove endoscopically. A 78-year-old man presenting with abdominal pain and loss of appetite for 4 months was admitted and evaluated. Gastroscopy disclosed two large phytobezoars within the stomach. Laparoscopic removal was undertaken. The bezoars were removed via a gastrotomy using the three-trocar technique. They were successfully retrieved from the abdominal cavity using an improvised "endobag" made from a simple surgical glove. Such an endobag presents several advantages; they are easy to make, sterile, economical, readily available, disposable, there is ample space to manipulate the specimen within, and there is minimal risk of contamination throughout the procedure. The authors recommend this approach for the treatment of patients with large gastric bezoars in whom laparotomy is indicated.

Liberal use of a bag made from a surgical glove during laparoscopic surgery for specimens retrieval

Laparoscopic surgery has been gaining wide acceptance in recent years. Tissue removal from the abdominal cavity becomes a paramount issue, especially when the specimen is infected, contains several fragments, or potentially contains a malignancy. Several sophisticated instruments and devices have been designed for this purpose. However, most of these are expensive, difficult to handle, and come in a fixed size. Condoms, glove fingers, and zipper-type plastic bags have been tried also, but with limited success. The authors report use of a simple bag made from a surgical glove to collect specimens; a long purse-string suture surrounds the opening or the base of the glove finger to secure material during retrieval. This method has been found to be simple and convenient, and necessary construction material is readily available. The bag not only protects the specimen from contact with the wound but also cuts short the operating time. The technique and advantages are described.

Resectional treatment for thyroid cancer with tracheal invasion: a long-term follow-up study

HYPOTHESIS

Transmural invasion of the trachea by well-differentiated thyroid carcinomas is a locally advanced disease condition. It frequently causes deaths owing to airway obstruction. We hypothesized that resection of the invaded trachea followed by primary anastomosis provides the opportunity for cure.

DESIGN

A retrospective review study of medical records.

SETTING

The surgical department of a tertiary referral center.

PATIENTS

Eight patients with well-differentiated thyroid carcinomas, complicated with tracheal invasion resulting in bleeding and airway obstruction, operated on by tracheal resection and immediate anastomosis, were included.

INTERVENTIONS

All patients received total thyroidectomy and neck lymph node dissection as well as segmental tracheal resection followed by primary reconstruction. Postoperative radioactive sodium iodine I 131 treatment and suppression therapy with thyroxine were applied to all of them.

MAIN OUTCOME MEASURE

Postoperative follow-up of serum levels of human thyroglobulin and abnormal radioactive iodine 131I from whole body scan.

RESULTS

Seven patients are alive. Of these patients, 5 had no evidence of disease: (3 had no evidence of cancer for more than 10 years' follow-up), 2 had regional lymph node metastasis, and 1 had lung metastases. The remaining patient had anastomotic site recurrence with airway obstruction and needed tracheostomy to relieve stridor. She was lost to follow-up 39 months after undergoing the initial operation.

CONCLUSIONS

Patients with mucosal invasion of the trachea by well-differentiated thyroid carcinomas should be treated by surgical resection followed by primary reconstruction when technically feasible. This facilitates postoperative care, and it is possible to achieve long-term survival with improvement of the quality of life and possible cures.

Antegrade continence enema for the treatment of neurogenic constipation and fecal incontinence after spinal cord injury

OBJECTIVE

To describe the effects of an antegrade continence enema stoma formed in a paraplegic man with intractable constipation and fecal incontinence.

DESIGN

Case report.

SETTING

Spinal cord injury unit, Veterans Affairs hospital.

PARTICIPANTS

Spinal cord injury (SCI) patient with T12 paraplegia.

INTERVENTION

Surgical formation of antegrade continence enema stoma.

MAIN OUTCOME MEASURES

Time of bowel program care, ease of fecal elimination, safety of procedure.

RESULTS

Bowel care time was decreased from 2 hours to 50 minutes daily; 6 bowel medications were discontinued; fecal incontinence was eliminated; and no surgical or medical side effects noted after the procedure.

CONCLUSION

The antegrade continence enema procedure is a safe and effective means of treating intractable constipation and fecal incontinence in the adult SCI patient. This option should be considered for those persons in whom medical management of bowel care has been unsuccessful.

Reflex innervation of the bulbocavernosus muscle

OBJECTIVE

To determine the somatic reflex innervation of the bulbocavernosus muscle (BCM) and to illustrate the role of the perineal nerve in BCM contraction, using electrophysiological techniques. Subjects and methods Ten healthy, potent men underwent genital electrophysiological testing. Stimuli were applied to the dorsal nerve of the penis at the base of the penis, glans and anterior urethra, and the perineal nerve branch to the BCM. The electromyographic (EMG) responses of the BCM were recorded and onset latencies measured at baseline, both after anaesthetising the perineal nerve and after recovery from the anaesthetic.

RESULTS

A reflex BCM contraction was elicited from all stimulation sites. Anaesthetizing the perineal nerve resulted in alterations of the EMG response. After the anaesthetic effect wore off, the responses returned to baseline values.

CONCLUSIONS

Three distinct somatic bulbocavernosus reflexes were detected which are components of normal ejaculation. BCM contraction can be elicited after stimulating the dorsal penile nerve at the glans and the anterior urethra; these are the flexor responses of the bulbocavernosus reflex. BCM contraction can also be induced on stimulating the perineal nerve, which is the pathway through which the stretch and the tendon organ reflexes are carried to mediate muscle tone. The motor innervation of the BCM for all reflexes is carried through a branch of the perineal nerve. The findings may be relevant to the evaluation of ejaculatory disorders.

Preeclamptic pregnancy is associated with increased sympathetic and decreased parasympathetic control of HR

Previous work from our laboratory using heart rate variability (HRV) has demonstrated that women before menopause have a more dominant parasympathetic and less effective sympathetic regulations of heart rate compared with men. Because it is still not clear whether normal or preeclamptic pregnancy coincides with alternations in the autonomic functions, we evaluated the changes of HRV in 17 nonpregnant, 17 normotensive pregnant, and 11 preeclamptic women who were clinically diagnosed without history of diabetic neuropathy, cardiac arrhythmia, and other cardiovascular diseases. Frequency-domain analysis of short-term, stationary R-R intervals was performed to evaluate the total variance, low-frequency power (LF; 0.04-0.15 Hz), high-frequency power (HF; 0.15-0.40 Hz), ratio of LF to HF (LF/HF), and LF in normalized units (LF%). Natural logarithm transformation was applied to variance, LF, HF, and LF/HF for the adjustment of the skewness of distribution. We found that the normal pregnant group had a lower R-R value and HF but had a higher LF/HF and LF% compared with the nonpregnant group. The preeclamptic group had lower HF but higher LF/HF compared with either the normal pregnant or nonpregnant group. Our results suggest that normal pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of heart rate, and such alterations are enhanced in preeclamptic pregnancy.

Impact of pulse pressure on the respiratory-related arterial pressure variability and its autonomic control in the rat

The autonomic control of respiratory-related arterial pressure variability (RAPV) remains uncharacterised. We set out to test the hypothesis that the autonomic nervous system may participate in RAPV via its effect on pulse pressure (PP). Experiments were performed on adult male Sprague-Dawley rats anaesthetised with ketamine and paralysed with pancuronium under positive-pressure ventilation. Respiratory variability in each parameter was quantified by auto-spectral analysis and the relationship between variabilities in two signals assessed by cross-spectral analysis. PP and systolic pressure (SP) exhibited similar powers of respiratory variability that were far more pronounced than for diastolic pressure (DP) or mean pressure (MP). The variability in PP preceded that in SP, MP or DP. The largest phase lag occurred between PP and DP and was equivalent to the time delay of one pulse interval. Coherence between respiratory variabilities in PP and MP was nearly perfect. Propranolol dose dependently suppressed respiratory variability in each pressure parameter and eventually disrupted the PP-MP relationship in respiratory variability. However, the influence of lung volume on MP persisted with a near-zero phase lag. Combined administration of phentolamine and atropine facilitated respiratory variability in PP and SP and failed to block the effect of propranolol. However, the combined administration moved the dose/response curve of propranolol and respiratory variability in each pressure parameter to the right. We conclude that, in addition to non-autonomic mechanisms, RAPV may be facilitated by cardiac sympathetic function via the effect on PP variability. The autonomic mechanism can still be evoked during combined alpha-adrenoceptor and muscarinic blockade, possibly via baroreflex mechanisms.

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.

Opposition of rapid baroreceptor resetting by prostanoids in rabbits

Arterial baroreceptors reset rapidly within minutes during acute hypertension; baroreceptor pressure threshold (Pth) is increased and the pressure-baroreceptor activity relation is shifted to the right. The purpose of the present study was to determine if prostacyclin (PGI2) or other prostanoids, released during acute hypertension modulate the magnitude of baroreceptor resetting. Baroreceptor activity was recorded from the vascularly-isolated carotid sinus during distension of the sinus with slow pressure ramp in rabbits anesthetized with chloralose. Pressure-activity curves were generated after holding carotid sinus pressure for 10-15 min from 30 to 100 mmHg. In control, the elevation of holding pressure increased Pth from 44+/- to 65+/-5 mmHg (p < 0.05, n = 12). In the presence of PGI2 (20 microM), Pth averaged 43+/-4 and 45+/-3 mmHg (n = 12) after holding pressure at 30 and 100 mmHg, respectively. In the control group before exposing the carotid sinus to indomethacin, an elevation of holding pressure increased Pth from 49+/-2 to 71+/-3 mmHg (p < 0.05, n = 12). After inhibition of the endogenous formation of prostanoids with indomethacin (20 microM), Pth increased by a significantly greater extent from 61+/-2 to 90+/-3 mmHg (p < 0.05, n = 12) with the increase in holding pressure. The slope of the pressure-activity curve (baroreceptor gain) was not influenced by the change in holding pressure. It was increased significantly by PGI2, while decreased by indomethacin. Neither the change in holding pressure nor PGI2 affected the circumferential wall strain of carotid sinus over a wide range of pressure alteration. The results suggest that PGI2 or other prostanoids released during acute hypertension sensitizes baroreceptors and provides a negative feedback mechanism that opposes and limits the magnitude of rapid baroreceptor resetting.

Inadequate stocking of antidotes in Taiwan: is it a serious problem?

OBJECTIVE

Insufficient hospital stock of a variety of poisoning antidotes is a worldwide problem. In an attempt to establish an antidote storage and distribution system for the response of the various poisoning accidents, we conducted a nationwide survey to characterize the current availability of selected antidotes and their anticipated need in Taiwan.

MATERIALS AND METHODS

A questionnaire was mailed to 834 hospitals to gather information on the availability, anticipated need, and preferred purchase policy of 20 selected antidotes. A survey on the availability of cyanide antidote in 523 cyanide-handling facilities and their neighboring hospitals was also conducted.

RESULTS

Hospitals of different size and service levels had a statistically significant difference in response rates. Except for pyridoxine, the availability and anticipated need for antidotes also varied significantly among different hospital groups. We found that physostigmine, cyanide antidote kit, BAL, EDTA, methylene blue, Vipera Russell formosensis antivenin, and botulism antitoxin were not available in most (>90%) hospitals. Interestingly, these antidotes are also among the most needed antidotes. Most hospitals preferred a government-ordered purchase of antidotes. In the survey of cyanide-processing facilities, a response rate of 24.1% was obtained and only 9.3% of these 107 facilities that both replied to the questionnaire and continued handling cyanide products had stocked cyanide antidote. It is noteworthy that cyanide antidote was also frequently lacking in the neighboring hospitals.

CONCLUSIONS

The appropriate storage of antidotes in hospitals or workplaces in rural areas is instrumental in the timely treatment of certain poisonings, while nationwide unavailability is the critical problem. Raising awareness of the importance of antidotes by education, regular review of antidote storage, distribution plans, and appropriate legislation might provide solutions.

Current seroprevalence of hepatitis A virus infection among kindergarten children and teachers in Taiwan

Taiwan was a hyperendemic area for hepatitis A virus (HAV) infection before the late 1980s. The seroprevalence of HAV infection was higher than 90% with most HAV infection occurring during childhood. This study was to estimate the seroprevalence of HAV infection among preschool children in central Taiwan. A community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas and 2 aboriginal areas randomly selected through stratified sampling. Serum samples of 2,549 healthy preschool children and 104 teachers in study kindergartens were screened for the HAV antibodies (anti-HAV) by means of a commercially available microparticle enzyme immunoassay (AxSYM HAVAB). Among aboriginal kindergarten children, more than 96% of them were anti-HAV seropositive due to a mass HAV vaccination program. In urban and rural areas, kindergarten children had a very low prevalence of anti-HAV (0.4%) in contrast to a high seroprevalence in their teachers (78%). There was no gender difference in seroprevalence of anti-HAV, while the anti-HAV seroprevalence was significantly higher in urban areas than in rural areas. Crowdedness of living in urban areas might facilitate the person-to-person transmission of infectious agents.

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.