Temperature variation of film tension above the bulk smectic-A-isotropic transition in freestanding liquid-crystal films

We have measured the temperature variation of film tension above the bulk smectic-A-isotropic transition in freestanding films of two liquid-crystal compounds. Above the transition, the tension increases sharply with temperature, and the slope is proportional to the film's thickness regardless of whether or not the compound exhibits regular layer-by-layer thinning. The data can be interpreted in the context of theoretical models for layer thinning.

Influences of pH and hydraulic retention time on anaerobes converting beer processing wastes into hydrogen

To convert high-solids organic wastes (3% w./w.) to high-value hydrogen, a full factorial experimental design was employed in planning the experiments for learning the effects of pH and hydraulic retention time (HRT) on the hydrogen production in a chemostat reactor using waste yeast obtained from beer processing wastes. For determining which experimental variable settings affect hydrogen production, predictive polynomial quadratic equation and response surface methodology were employed to determine and explain the conditions required for high-value hydrogen production. Experimental results indicate that a maximum hydrogen production rate of 460 mL/gVSS/d was obtained at pH = 5.8 and HRT = 32 hours. Moreover, hydrogenase targeted RT-PCR results indicate that Clostridium thermocellum and Klebsiella pneumoniae predominated.

Development of interesting step-climbing styles

OBJECTIVES

This study was to investigate the influence of stepping styles (forward, side, and cross steppings) and inclinations (25 and 45 degrees) on cardiorespiratory responses (C-R responses).

METHODS

Twenty volunteers were recruited and randomly arranged into two ten-people groups, exercising on step-climbing machines respectively of 25 and 45 degrees of inclination. C-R responses were recorded during each test which lasted for six minutes at 50 steps per minute on a step-climbing machine.

RESULTS

The group on 25-degree inclination had significantly lower C-R responses than the group on 45-degree inclination. Although only small differences, probably statistically insignificant, were found among the three step-climbing styles, these differences showed interesting trends independent of inclination.

CONCLUSIONS

Climbing stairs with the three interesting step-climbing styles in this study could be considered as an exercise of moderate intensity (60-80% HRmax ). Climbing on 25-degree inclination at 50 steps per minute is recommended for less fit individuals because of lower cardiovascular stress as compared with on 45-degree inclination.

Optical investigations on the biaxial smectic- A phase of a bent-core compound

Several unique optical properties have been obtained from freestanding films of a bent-core compound. Our experimental results indicate the existence of the antiferroelectric biaxial smectic-A (Sm A) phase. The critical exponent associated with the biaxiality through the uniaxial-antiferroelectric biaxial Sm A transition has been measured to be 0.82+/-0.04 , which is in good agreement with our theoretical calculation. Our theoretical advances further demonstrate that the critical behavior of the optical biaxiality with the order parameter being a vector is described by the secondary-order parameter of the three-dimensional XY model. We also observe a remarkable even-odd layering effect exhibited by the surface layers of freestanding films under an applied electric field (approximately 20 V/cm) in the film plane.

Mapping OI-4, a gene conferring resistance to Oidium neolycopersici and originating from Lycopersicon peruvianum LA2172, requires multi-allelic, single-locus markers

Lycopersicon peruvianum LA2172 is completely resistant to Oidium neolycopersici, the causal agent of tomato powdery mildew. Despite the large genetic distance between the cultivated tomato and L. peruvianum, fertile F1 hybrids of L. esculentum cv. Money maker x L.peruvianum LA2172 were produced, and a pseudo-F2 population was generated by mating F, half-sibs. The disease tests on the pseudo-F2 population and two BC,families showed that the resistance in LA2172 is governed by one dominant gene, designated as 01-4. In the pseudo-F2 population, distorted segregation was observed, and multi-allelic, single-locus markers were used to display different marker-allele configurations per locus. Para-meters for both distortion and linkage between genetic loci were determined by maximum likelihood estimation, and the necessity of using multi-allelic, single-locus markers was illustrated. Finally, a genetic linkage map of chromosome 6 around the 01-4 locus was constructed by using the pseudo-F2 population.

Hypercalcaemia and haemophagocytic syndrome: rare concurrent presentations of disseminated tuberculosis in a dialysis patient

Tuberculosis remains an important cause of infection in chronic haemodialysis patients. Frequent extrapulmonary involvement, non-specific presentation and limited diagnostic tools usually make early diagnosis difficult. Herein, we report on an 83-year-old female patient who had been on regular heamodialysis therapy for 15 years, who presented with asymptomatic hypercalcaemia and pancytopenia. Haemophagocytic syndrome was documented during the admission period. Mycobacterium tuberculosis was cultured from bone marrow 1 month after her demise. This case report highlights the non-specific manifestations of extrapulmonary tuberculosis in dialysis patients and the limited value of conventional diagnostic methods. We would like to recommend aggressive intervention and early tissue aspiration from possible infectious sites when tuberculosis cannot be completely ruled out. Disseminated tuberculosis should be considered as an indication of hypercalcaemia where haemophagocytic syndrome occurs simultaneously.

Symptomatic giant Müllerian duct cyst in an infant: radiographic and CT findings

We report an unusual case of Müllerian duct cyst in an 8-month-old infant who presented with frequent vomiting and recurrent urinary tract infections. Computed tomography showed a midline giant cyst in the pelvic floor. Delayed enhanced computed tomography demonstrated contrast filling of the cyst, indicating a communication with the urotract. Subsequent cystourethrogram and surgery confirmed a giant Müllerian duct cyst.

Deposition and characterization of germanium sulphide glass planar waveguides

Germanium sulphide glass thin films have been deposited on CaF2 and Schott N-PSK58 glass substrates directly by means of chemical vapor deposition (CVD). The deposition rate of germanium sulphide glass film by this CVD process is estimated about 12 microm/hr at 500oC. These films have been characterized by micro-Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Their transmission range extends from 0.5microm to 7microm measured by UV-VIS-NIR and FT-IR spectroscopy. The refractive index of germanium sulphide glass film measured by prism coupling technique was 2.093+/-0.008 and the waveguide loss measured at 632.8nm by He-Ne laser was 2.1+/-0.3 dB/cm.

New approaches to surgery of lentigo maligna

Lentigo maligna (LM) is a pigmented lesion that occurs most commonly on the sun-exposed skin of the head and neck of an older patient. LM can be difficult to completely remove due to its occasional extensive subclinical extension. Surgical treatments, including standard excision and margin-controlled excision (Mohs micrographic surgery or rush permanent sections), are reviewed. Immunostains that can increase sensitivity and specificity of margin-controlled excision are discussed, and other nonscalpel treatments including destruction, topical imiquimod, radiation therapy and cryotherapy are briefly discussed. The gold standard treatment for LM is margin-controlled excision.

Major brain lesions detected on sonographic screening of apparently normal term neonates

Major congenital or acquired structural abnormalities of the brain, with significant prognostic implications have rarely been emphasised in apparently normal infants. Our purpose was to investigate the prevalence and types of major brain lesions in clinically normal term neonates using sonography. From January 1999 to December 2001, we examined 2309 clinically normal term neonates within 3 days of birth. Of these, six (0.26%) had major brain lesions, including three cases of intracerebral haemorrhage (two grade II intraventricular and one temporal lobe haemorrhage), two of corpus callosum agenesis and one lacunar infarct in the territory of the left middle cerebral artery. One child was lost to follow-up, because of adoption, and four had borderline to significant developmental delay at a mean age of 24 months (range 12-36 months). Although the prevalence of major brain lesions was low, these infants have a higher risk of later neurodevelopmental disability, despite an early asymptomatic period. Universal neonatal brain ultrasound screening may help early diagnosis of rare major lesions, some of which have prognostic implications.

Experimental investigations of one liquid-crystal compound exhibiting the no-layer-shrinkage effect near the Sm-A-Sm- C(*) transition

Three experimental probes have been employed to investigate the nature of the smectic- A -smectic- C ( Sm-A-Sm- C(*) ) phase transition of one liquid-crystal compound showing almost no layer-shrinkage effect through the transition. Results from both x-ray diffraction and optical studies indicate that the compound exhibits a crossover behavior of different molecular packing arrangements within the bulk Sm-A phase window. The calorimetry results show a significant critical anomaly near the Sm-A-Sm- C(*) transition, although it was found to be weakly first order.

Infradiaphragmatic pulmonary sequestration combined with cystic adenomatoid malformation: unusual postnatal computed tomographic features

We present a surgically proven case of infradiaphragmatic pulmonary sequestration combined with cystic adenomatoid malformation. Prenatal magnetic resonance imaging revealed a well-defined hyperintense mass with a hypointense septum in the left infradiaphragmatic region. Postdelivery computed tomography (CT) and 3-month follow-up CT showed replacement of intralesional cystic areas by solid content. Such unusual postnatal CT changes, to our knowledge, have not been previously documented.

Prediction of disease persistence after conization for microinvasive cervical carcinoma and cervical intraepithelial neoplasia grade 3

We attempted to determine the significant variables and to predict the probability of disease persistence after conization for microinvasive cervical carcinoma and cervical intraepithelial neoplasia grade 3 (CIN3). We analyzed 133 patients from 2001 to 2002 who had a subsequent hysterectomy after conization. The histological findings of the cone specimens, together with the clinical parameters, were correlated with the presence of residual dysplasia in the hysterectomy specimen. The probability of having residual dysplasia was calculated based on the function of the significant variables obtained by logistic regression analysis. Of the 133 patients, 42 (31.6%) had residual disease in their hysterectomy specimens. Using multivariate analysis only for the postmenopausal state, positive endocervical curettage, positive margin, and microinvasive carcinoma were predictive of residual dysplasia. The probabilities of having residual dysplasia were about 0.99, 0.84, 0.4, 0.07, and 0.01 in patients with a presence of all four, any three, any two, any one, and no risk factors, respectively. The best cutoff probability determined by the receiver operating characteristic curve was 0.32, yielding a sensitivity of 81% and a specificity of 88%. Based on these results, patients with the presence of any two or more of the risk factors mentioned above should be considered as a high-risk group for having disease persistence after conization for the treatment of CIN3 and microinvasive carcinoma.

Unusual behavior of the surface-induced tilted layers in free-standing films of a non-layer-shrinkage liquid crystal compound

Null-transmission ellipsometry has been conducted to study the molecular arrangements in free-standing films of one chiral compound above the bulk smectic-A-smectic-C* transition temperature. Upon cooling under a proper electric field, a nonplanar-anticlinic-synclinic or a nonplanar-synclinic transition has been observed. The nonplanar structure continuously evolves into the anticlinic or synclinic structures. Increasing electric field can induce a rare transition from a synclinic to an anticlinic structure.

Optical studies on free-standing films of an achiral smectic liquid crystal

Employing null transmission ellipsometry and depolarized reflected light microscopy, we have studied two smectic phases, Sm-C1 and Sm-C2, of one achiral mesogen. Our results show that Sm-C1 and Sm-C2 are the synclinic Sm-C and anticlinic Sm-C(A) phases, respectively. We find no evidence to support recent claims that the Sm-C1 is chiral and ferroelectric [R. Stannarius et al., Phys. Rev. Lett. 90, 025502 (2003)].

Bacteria ascend to liver from the bilioenteric conduit after choledochojejunostomy in the cholestatic rat

The high incidence of postoperative cholangitis in children with clinical restoration of bile flow after Roux-Y choledochojejunostomy (RYCJ) assumed the concept of a direct ascending cholangitis caused by pathogens in the intestine, into the intrahepatic bile duct via the porta hepatis. It is also well known that jaundiced animals (patients) are more susceptible to infections of the bile ducts following the procedure of bilioenteric anastomosis. An animal experiment was conducted to compare quantitative bacterial cultures of the choledochojejunostomy area and the liver 24 hours after Escherichia coli (ATCC 25922) or sterile normal saline was injected into the bilioenteric conduit (BEC), following RYCJ in rats with or without the proceeding bile duct ligation. A significant increase of E. coli of the same strain (ATCC 25922), that we injected into the BEC, was proved with pulse-field gel electrophoresis (PFGE) and shown in the liver of the jaundiced rats receiving E. coli (ATCC 25922), compared to that in the nonjaundiced rats with normal saline treatment. It is concluded that bacteria often ascend early to the liver from the BEC following RYCJ. This ascending cholangitis model might be produced for further studies.

Critical behavior of thermal parameters at the smectic-A-hexatic-B and smectic-A-smectic-C phase transitions in liquid crystals

High temperature resolution measurements of thermal conductivity, thermal diffusivity, and specific heat, with simultaneous polarized light visual inspection of the sample, have been performed at two different liquid crystal phase transitions: the SmA-SmC (Smectic-A-Smectic-C) and the SmA-HexB (Smectic-A-hexatic-B) in racemic A7 [4-(3-methyl-2-chlorobutanoyloxy)-4(')-heptyloxybiphenyl] and 65OBC (n-hexyl-4(')-n-pentyloxybiphenyl-4-carboxylate) compounds, respectively. In the past, anomalies in the thermal conductivity at the transitions have been reported. Our results indicate a nonsingular behavior of the thermal conductivity at both transitions, similarly to what has been previously reported for the smectic-A-nematic phase transition. It is also shown how, in several cases, the nature of the transition can be affected by the sample thermal history due to the presence of strain annealing phenomena.

Optical characterization of a nanoscale incommensurate pitch in a new liquid-crystal phase

As a remarkable orientationally ordered soft-condensed matter system, the smectic-C*(alpha) phase exhibits an incommensurate nanoscale helical pitch of more than four smectic layers. Recent theoretical advances predict the existence of a new phase showing a helical pitch of less than four smectic layers (<16 nm). By applying a novel optical technique to the study of freestanding films with increments in thickness of one smectic layer, we have measured the size of this pitch using 633 nm HeNe laser light. Our results confirm the existence of the newly predicted phase in one unique compound.

Epidemiological and genetic studies of myotonic dystrophy type 1 in Taiwan

To investigate the prevalence and genetic characteristics of myotonic dystrophy type 1 (DM1) in Taiwan, DM-suspected patients and their families identified during the period of 1990-2001 had their clinical records reevaluated and the CTG repeat sizes at the DM1 locus examined. A total of 96 subjects belonging to 26 families were identified as DM1 patients, which gave a minimal disease prevalence of 0.46/100,000 inhabitants. Clinical anticipation was frequently observed in affected families, even in some parent-child pairs with transmission contraction of the CTG repeat size. The inverse correlation between age at onset and CTG repeat length was significant only in patients with small expansions. In addition, a DM1 carrier with a childhood-onset son was found to have CTG length heterogeneity in the range of 40-50, indicating that premutation alleles could be unstable during gametogenesis as well as in somatic tissues. Our data demonstrated that DM1 is a rare disease in Taiwan and showed that transmission contraction of repeat size is more likely to occur in alleles with large repeats.

Double reentrance of surface arrangements in freestanding liquid crystal films

The molecular arrangement of tilted surface layers on freestanding films above the bulk smectic-A-smectic-C(*) transition has been studied by null transmission ellipsometry. In the presence of an applied in-plane electric field, a synclinic-anticlinic-synclinic-anticlinic double reentrance has been observed. Furthermore, we have characterized a novel transition from the synclinic arrangement to a structure in which the interior layers tilt in the same orientation and the outermost surface layers tilt oppositely with the interior layers.

In-line liquid-crystal microcell polarimeter for high-speed polarization analysis

We report a type of high-speed microcell polarimeter that utilizes microelectrodes, liquid-crystal films, and ultrathin high-contrast polarizers, all integrated between the tips of two optical fibers. When combined with optimized nematic liquid-crystal materials, this compact (2.5 cm x 0.5 cm x 0.5 cm) device offers excellent optical properties and continuous, high-speed operation at > 2 kHz with moderately low operating voltages. It requires no bulk optical elements, and it shows excellent performance when implemented for the measurement of degree of polarization in 10-Gbit/s test systems. Polarimeters based on this design have promising potential applications in polarization analysis for high-speed optical communication systems.

Isocupressic acid blocks progesterone production from bovine luteal cells

The needles of ponderosa pine (Pinus ponderosa Laws.) were reported to induce abortions when fed to late-term pregnant beef cows in North America. An in vivo study of pregnant cows suggested that isocupressic acid (IA) was the main abortifacient isolated from needles and bark of the pine. However, the mechanism of abortifacient activity of IA is not clear yet. In a pregnant cow, the corpus luteum of the ovary helps the maintenance of pregnancy by its progesterone production. This study involved the IA extracted from the root of the Taiwan cypress (Juniperus formosana) and used a frozen-thawed bovine luteal cell culture system to investigate the action of IA on progesterone production. Thawed bovine luteal cells (1 x 10(5) cells/ml/well) in M199 medium were cultured in 24-well culture plates at 37 degrees C in a 5% CO2 incubator. Ten ml of tested drugs, IA at 1 to 1000 ng/ml and/or ovine luteinizing hormone (oLH) at 1 to 100 ng/microl or 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) with 0.1-10 mM, were added into each well. After 4 hours of incubation, the media were harvested and assayed for progesterone by an enzyme immunoassay. Progesterone production from cells was the indicator used to evaluate the action of IA. All tested doses of IA significantly inhibited progesterone production in both basal and oLH stimulating conditions. Also those dosages inhibited cyclic adenosine-3',5'- monophosphate (cAMP) stimulation, suggesting a post-cAMP mechanism is involved in the IA action. We concluded that IA can induce pregnant cows to abort partly through blocking luteal function and may be identified as a new abortifacient chemical.

Triplet-to-singlet exciton formation in poly(p-phenylene-vinylene) light-emitting diodes

The triplet to singlet exciton formation ratio in a MEH-PPV light-emitting diode is measured by comparing the triplet-induced absorptions with optical and electric excitations at the same singlet exciton density. The ratio is a strong universal decreasing function of the averaged electric field. Using 4 ns for singlet to triplet intersystem crossing time, the ratio is significantly larger than the spin-independent value 3 at intermediate field but is reduced to about 2 for higher field.

The effect of humic acid on the uptake of mercury(II), cadmium(II), and zinc(II) by Chinook salmon (Oncorhynchus tshawytscha) eggs

The Chinook salmon (Oncorhynchus tshawytscha) is endangered or threatened in several of its ranges. The uptake of metals by Chinook salmon eggs and how humic acid (HA) affects the uptake is a subject of interest. Humic acid (0, 0.001, 0.01, and 0.05g/l) reduces the uptake of the metal ions Hg(II), Cd(II), and Zn(II), (1.0 microM) by eggs. HA is more effective in reducing the uptake of Hg than that of Cd or Zn. At [HA] = 0.001 g/L Hg uptake is reduced by 44% compared to no HA, while Cd and Zn uptakes are slightly or not reduced. Once the metals are taken up by the eggs, Hg migrates more slowly from the chorion to the yolk than either Zn or Cd. In experiments in which the metal contents of the chorion and yolk were measured at up to 24 h and five days after uptake, the order of migration was Cd > Zn > Hg. This observation is important when discussing the effects of metals on biological processes in the yolk because when Hg is taken up by eggs, a smaller percentage reaches the yolk than does Cd and Zn.

Prevalence and clinical implications of hepatitis B virus genotypes in southern Taiwan

BACKGROUND

Hepatitis B virus (HBV) infection is a major health problem. HBV genotypes may be associated with progression of liver disease. The distribution and clinical implications of HBV genotypes in southern Taiwan are evaluated.

METHODS

We used a polymerase chain reaction-restriction fragment length polymorphism genotyping method to determine HBV genotypes.

RESULTS

The genotype distribution for 265 patients with chronic HBV infection was as follows: A, 3 (1%); B, 158 (60%); C, 90 (34%); D, 7 (2.5%); E, 0: F, 0; and unclassified, 7 (2.5%). Compared with genotype B patients, genotype C patients had a higher hepatitis B e antigen positive rate and higher fibrosis score. There was no significant difference in the mean age between genotype B and genotype C patients with hepatocellular carcinoma (HCC). However, when patients were stratified by age, the prevalence of genotype C was significantly higher in young HCC patients (<50 years of age) than in age-matched asymptomatic carriers (40% versus 10%, P < 0.001). Using multivariate analysis, the significant risk factors for advanced liver disease (cirrhosis or HCC) for patients with chronic HBV infection were old age, male gender and genotype C.

CONCLUSIONS

These results suggest that genotype C is associated with more severe liver diseases than the B variant.

Effect of enantiomeric excess on surface structures and phase sequences in free-standing liquid-crystal films

We present differential optical reflectivity and null transmission ellipsometry data from several mixtures of MHPBC enantiomers. From this data, we have determined the chiral smectic phase sequence as a function of enantiomeric excess. The data suggest a change in the structure of the smectic-C(*)(alpha) phase and the surface tilt state as the enantiomeric excess is reduced. The results also show that the intermediate phases, smectic C(*)(FI2), smectic C(*)(FI1), and smectic C(*)(alpha), disappear sequentially on reducing the net chirality.

Characterization of two regulatory genes of the mercury resistance determinants from TnMERI1 by luciferase-based examination

The broad-spectrum mercury resistance transposon, TnMERI1, of Bacillus megaterium strain MB1, contains three proposed operator/promoter (O/P) transcriptional start sites and two regulatory genes (merR1 and merR2). A series of luciferase (lux)-based transcriptional fusion plasmids were studied in Escherichia coli to show that both merR1 and merR2 gene products repressed transcription from O/PmerB3, O/PmerR1, and O/PmerR2 under uninduced conditions. Derepression occurred when the merR1 gene was present and Hg(2+) functioned as an inducer. In the presence of organomercurial compounds, basal transcription of merB3 was needed to produce inorganic Hg(2+) as the inducer of expression regulated by MerR1 at O/PmerB3. The presence of merR2 repressed transcription from all three O/Pmer sites under both non-induced conditions and when inorganic Hg(2+) or organomercurials were added. These results show that MerR1 functions as a repressor in the absence of Hg(2+) and as an activator in the presence of Hg(2+), while MerR2 functions as a repressor.

Nonplanar structure of molecular tilt planes in the surface layers of smectic-A free-standing liquid crystal films

We present ellipsometric results from thin free-standing films of one chiral liquid crystal compound. In the bulk SmA range with surface-induced molecular tilt, a nonplanar arrangement of the molecular orientations of the tilted surface layers is found under a small applied electric field.

Levels of interferon-gamma and interleukin-2 receptor-alpha for bronchoalveolar lavage fluid and serum were correlated with clinical grade and treatment of pulmonary tuberculosis

OBJECTIVE

We investigated possible correlations for interferon-gamma (IFN-gamma) and soluble interleukin-2 receptor-alpha (sIL-2R-alpha) levels in bronchoalveolar lavage fluid (BALF), and clinical grade of pulmonary tuberculosis (TB), which is determined by factors such as extent of pulmonary involvement, fever and loss of body weight.

DESIGN

In order to explore these correlations and address associated questions, BALF was collected from 45 patients presenting with active pulmonary TB and 14 healthy controls. Repetitive BALF was collected in 17 patients after 3 months of anti-tuberculosis chemotherapy. The epithelial lining fluid (ELF) levels for IFN-gamma and sIL-2R-alpha were measured using enzyme-linked immunosorbent assay (ELISA) after standardization with urea.

RESULTS

Patients with higher-grade pulmonary TB (i.e., with more advanced pulmonary involvement, fever or body weight loss), revealed significantly higher ELF levels for IFN-gamma and sIL-2R-alpha compared to those with lower grade pulmonary TB. Similar results were also determined for sIL-2R-alpha serum levels, but not for IFN-gamma serum levels. After anti-tuberculosis chemotherapy the elevated cytokine levels for ELF and serum significantly decreased in accordance with radiographic improvement.

CONCLUSIONS

ELF levels of IFN-gamma and sIL-2R-alpha were correlated with disease grading of pulmonary TB and decreased after anti-tuberculosis chemotherapy.

Molecular orientation arrangements in the smectic-C* variant liquid-crystal phases

Recent experiments have identified three-layer and four-layer distorted helical structures in the smectic liquid-crystal phases Sm C*(FI1) and Sm C*(FI2), respectively. However, no theories have explained the existence of all these phases. A discrete phenomenological model of the free-energy is analyzed and found to predict the stability of distorted three-layer and four-layer structures, as well as simple helical solutions in smectic liquid crystals. A simple physical picture is provided to explain the stability of the phases exhibiting distorted helical structures.

Interlayer structures of the chiral smectic liquid crystal phases revealed by resonant X-ray scattering

The structures of the liquid crystalline chiral subphases exhibited by several materials containing either a selenium or sulphur atom have been investigated using a resonant x-ray scattering technique. This technique provides a unique structural probe for the ferroelectric, ferrielectric, antiferroelectric, and SmC(*)(alpha) phases. An analysis of the scattering features allows the structural models of the different subphases to be distinguished, in addition to providing a measurement of the helical pitch. This paper reports resonant scattering features in the antiferroelectric hexatic phase, the three- and four-layer intermediate phases, the antiferroelectric and ferroelectric phases and the SmC(*)(alpha) phase. The helicoidal pitch has been measured from the scattering peaks in the four-layer intermediate phase as well as in the antiferroelectric and ferroelectric phases. In the SmC(*)(alpha) phase, an investigation into the helical structure has revealed a pitch ranging from 5 to 54 layers in different materials. Further, a strong resonant scattering signal has been observed in mixtures of a selenium containing material with as much as 90% nonresonant material.

Combined bronchoalveolar lavage and polymerase chain reaction in the diagnosis of pulmonary tuberculosis in smear-negative patients

SETTING

The polymerase chain reaction (PCR) may be sensitive and specific for the diagnosis of tuberculosis, but most reports are of studies conducted in well-controlled laboratories. A study to evaluate the clinical value of bronchoalveolar lavage (BAL) combined with PCR was necessary.

OBJECTIVE

One hundred and thirty one patients were recruited into the study from March 1994 to February 1997.

DESIGN

Patients with a positive acid-fast stain on sputum smear were recruited into group A as positive controls, patients with lung cancer and a negative acid-fast stain on sputum smear were put into group B as negative controls, and patients who had clinical symptoms of pulmonary TB without sputum or with negative smear results were the investigating group. PCR was performed on the sputum samples from group A and B patients and on the BAL fluid from those in group C.

RESULTS

The sensitivity of PCR was 96% in group A, and the specificity was 100% in group B. The sensitivity of PCR in the BAL fluid from the group C patients was 36% and the specificity was 96%; the positive predictive value was 94% and the negative predictive value was 45%.

CONCLUSION

BAL plus PCR is useful in the rapid diagnosis of pulmonary TB in non-productive or smear-negative patients.

Dramatic effect of an additional CH2 group on the temperature variation of the Sm-C(*)(alpha) short helical pitch

High-resolution differential optical reflectivity was used to study the temperature evolution of the short helical pitch in the Sm-C(*)(alpha) phase of successive members from two liquid-crystal homologous series. With the addition of one CH2 group, the magnitude and temperature evolution of the pitch change dramatically, and the molecular arrangements between consecutive surface layers found in free-standing films change from being anticlinic to synclinic.

Observation of unusual surface ordering in a uniaxial Sm-A phase formed by a highly biaxial compound

We have studied one banana-shaped compound using null-transmission ellipsometry. By studying free-standing films of various thicknesses we confirm that this compound exhibits the Sm-A phase. This is the first banana-shaped compound with a relatively small bend angle (approximately 140 degrees) in which a uniaxial phase has been observed. At the lower temperature end of the Sm-A phase we observe unusual ordering at the surface of the film.

Unusual thickness-dependent heat-capacity anomalies in free-standing hexatic liquid-crystal films

High-resolution heat-capacity and optical-reflectivity measurements have been conducted near the smectic-A to hexatic-B transition in thin free-standing films of the liquid-crystal compound 64COOBC. We find an unexpected dependence on film thickness of the integrated magnitude of the heat-capacity anomalies as the films undergo layer-by-layer transitions. We measure the penetration depths of the ordering from the surface and next-to-surface layers which are pertinent to the highly correlated thermal behavior.

Baicalein, a novel apoptotic agent for hepatoma cell lines: a potential medicine for hepatoma

This study has demonstrated that baicalein has anticancer effectiveness against human hepatoma cells. The dose response of baicalein in Hep G2 and Hep J2 cells indicates that baicalein decreased viability >90%. In comparison, baicalein had only minimal effects on the viability of control Chang liver cells. Flow cytometric analysis showed that baicalein inhibited the cell cycle of Hep G2 cells in the S phase. In addition, baicalein treatment resulted in a decreased mitochondrial transmembrane potential and damaged the integrity of the cell membrane. The TdT-mediated dUTP-biotin nick end labeling assay results indicated that baicalein elicited a significant increase of DNA fragmentation in Hep G2 cells after incubation for 48 hours. These results indicate that baicalein is an effective antihepatoma agent with minimal influence on noncancer cells. The effects of baicalein on Hep G2 cells include inhibition of the S phase of the cell cycle, dysfunction of mitochondria, and initiation of apoptosis.

Surface structures and transitions in the smectic-C* phase of one chiral liquid crystal compound

Three optical probes have been employed on free-standing films to study surface structure and transitions of the SmC* phase of one liquid crystal compound. While the interior layers show the SmC* structure, the tilt in adjacent surface layers is found to be anticlinic. The number of anticlinic surface layers grows rapidly as the transition to the SmC*(FI2) phase is approached.

Characterization of the mechanism underlying the reversal of long term potentiation by low frequency stimulation at hippocampal CA1 synapses

Reversal of long term potentiation (LTP) may function to increase the flexibility and storage capacity of neuronal circuits; however, the underlying mechanisms remain incompletely understood. We show that depotentiation induced by low frequency stimulation (LFS) (2 Hz, 10 min, 1200 pulses) was input-specific and dependent on N-methyl-d-aspartate (NMDA) receptor activation. The ability of LFS to reverse LTP was mimicked by a brief application of NMDA. This NMDA-induced depotentiation was blocked by adenosine A(1) receptor antagonist. However, the reversal of LTP by LFS was unaffected by metabotropic glutamate receptor antagonism. This LFS-induced depotentiation was specifically prevented by protein phosphatase (PP)1 inhibitors, okadaic acid, and calyculin A but not by the PP2A or PP2B inhibitors. Furthermore, by using phosphorylation site-specific antibodies, we found that LFS-induced depotentiation is associated with a persistent dephosphorylation of the GluR1 subunit of amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor at serine 831, a protein kinase C and calcium/calmodulin-dependent protein kinase II (CaMKII) substrate, but not at serine 845, a substrate of cAMP-dependent protein kinase. This effect was mimicked by bath-applied adenosine or NMDA and was specifically prevented by okadaic acid. Also, the increased phosphorylation of CaMKII at threonine 286 and the decreased PP activity seen with LTP were overcome by LFS, adenosine, or NMDA application. These results suggest that LFS erases LTP through an NMDA receptor-mediated activation of PP1 to dephosphorylate amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and CaMKII in the CA1 region of the hippocampus.

Molecular analysis of diabetes mellitus-associated A3243G mitochondrial DNA mutation in Taiwanese cases

Investigation of the clinical manifestations of MELAS-specific A3243G mitochondrial DNA (mtDNA) point mutation has suggested that the A3243G mutation of mtDNA can cause certain subtypes of diabetes mellitus (DM) and contributes about 0.15% of the overall incidence of diabetes. However, a relationship between the diabetic syndrome and the proportion of mutant mtDNA in affected tissues remains unclear. In this article, we report the results of our investigation of 14 diabetic and 23 non-diabetic patients who had the A3243G mutant mtDNA. The proportions of mutant mtDNA in different tissues were noted to change variably and neither heteroplasmy of mutant mtDNA in various tissues nor the proportion of mutated mtDNA in a specific tissue showed a correlation with the clinical phenotype of DM. Generation of a diabetic syndrome was not predictable from either the content of mutant mtDNA in leukocytes, hair follicles, or in muscle tissues. Further study showed that muscle tissue has the highest proportion of mutant mtDNA followed by hair follicles and by blood cells. Moreover, we observed that as the patient's age increased, all tissue showed a declining proportion of mutant mtDNA. These findings suggest that age may play a role in the manifestation of diabetes in patients with A3243G mutation of mtDNA.

Effects of calcium, calmodulin, protein kinase C and protein tyrosine kinases on volume-activated taurine efflux in human erythroleukemia cells

The effects of calcium, calmodulin, protein kinase C (PKC) and protein tyrosine kinase (PTK) modulators were examined on the volume-activated taurine efflux in the erythroleukemia cell line K562. Exposure to hypoosmotic solution significantly increased taurine efflux and intracellular calcium concentration ([Ca2+]i). The Ca2+ channel blockers La3+ (1 mM), verapamil (200 microM) and nifedipine (100 microM) inhibited the hypoosmotically-induced [Ca2+]i increase by more than 90%, while the volume-activated taurine efflux was inhibited by 61.3 +/- 9.5, 74.1 +/- 9.3 and 38.0 +/- 1.5%, respectively. Furthermore, the calmodulin inhibitors W7 (50 microM) and trifluoperazine (10 microM) and the Ca2+/calmodulin-dependent protein kinase II inhibitor KN-62 (2 microM) significantly blocked the volume-activated taurine efflux by 93.4 +/- 2.7, 77.9 +/- 3.5 and 61.3 +/- 15.8%, respectively. In contrast, the PKC inhibitor staurosporine (200 nM) or the PKC activator phorbol 12-myristate 13-acetate (100 nM) did not have significant effects on the volume-activated taurine efflux. However, pretreatment with PTK inhibitors genistein, tyrphostin A25, and tyrphostin A47 blocked the volume-activated taurine efflux. These results suggest that the volume-activated taurine efflux in K562 cells may not directly involve Ca2+, but may require the presence of calmodulin and/or PTK.

Maximization of injection volumes for DNA analysis in capillary electrophoresis

We report concentration and separation of DNA in the presence of electroosmotic flow (EOF) using poly(ethylene oxide) (PEO) solution. DNA fragments migrating against EOF stacked between the sample zone and PEO solution. To maximize the injection volume, several factors, such as concentrations of Tris-borate (TB) buffer and PEO solution, capillary size, and matrix, were carefully evaluated. The use of 25 mM TB buffers, pH 10.0, containing suitable amounts (less than 10 mM) of salts, such as sodium chloride, sodium phosphate, and sodium acetate, to prepare DNA is essential for the concentration of large-volume samples. In the presence of salts, the peaks also became sharper and the fluorescence intensity of DNA complexes increased. Using 2.5% PEO and a 150 microm capillary filled with 400 mM TB buffer, pH 10.0, up to 5 microL DNA samples (phiX 174 RF DNA-HaeIII digest or the mixture of pBR 322/HaeIII, pBR 328/Bg/I, and pBR 328/HinfI digests) have been analyzed, resulting in more than 400-fold improvements in the sensitivity compared to that by conventional injections (ca. 36 nL). Moreover, this method allows the analysis of 3.5 microL PCR products amplified after 17 cycles without any sample pretreatment.

Orientational ordering in the chiral smectic-C*FI2 liquid crystal phase determined by resonant polarized x-ray diffraction

High-resolution resonant polarized x-ray diffraction experiments near the sulfur K edge have been performed on free-standing liquid crystal films exhibiting the chiral smectic-C*FI2 phase. It is widely accepted that this phase has a four-layer repeat unit, but the internal structure of the repeat unit remains controversial. We report different resolved features of the resonant x-ray diffraction peaks associated with the smectic-C*FI2 phase that unambiguously demonstrate that the four-layer repeat unit is locally biaxial about the layer normal and that the measured angle, describing the biaxiality, is in good agreement with optical measurements.

Ticlopidine-induced thrombotic thrombocytopenic purpura: two case reports treated with plasma exchange plus steroids

Thrombotic thrombocytopenic purpura (TTP) has a high mortality rate if left untreated with plasma exchange promptly. We report two cases of ticlopidine-induced TTP, which lesser dosages of ticlopidine (200-250 mg/day) were prescribed and were treated with plasma exchange (PE) plus steroids. The first case was treated successfully, but the second case did not respond to our treatment and died of a progressive disease complicated with pneumonia. In sum, we recommend careful use of ticlopidine, regardless of the dosages prescribe and regardless of how long the drug is used. Moreover, the adverse effect of ticlopidine should be closely monitored.

Evidence for the involvement of dopamine D(1) and D(2) receptors in mediating the decrease of food intake during repeated treatment with amphetamine

Repeated treatment with amphetamine (AMPH), a well-known anorectic agent, into animals could induce anorexia on day 1 and produce a gradual reversion of food intake (tolerant anorexia) on the following days. It is unknown whether these feeding changes are related to dopamine (DA) and/or noradrenergic neurotransmission. Thus, the present study investigated the subtype of receptor mediating AMPH-induced anorexia. Daily food intake was measured after various drugs were given. Pretreatment with haloperidol, an antagonist of DA receptors, may lead to inhibition of AMPH-induced anorexia. However, pretreatment with the alpha-adrenoceptor antagonist phentolamine, and the beta-adrenoceptor antagonist propranolol, failed to modify the action of AMPH, suggesting the involvement of DA receptors but not adrenoceptors in the action of AMPH-induced anorexia. Furthermore, pretreatment with SCH 23390 at a dose sufficient to block D(1) receptors or pimozide at a dose sufficient to inhibit D(2) receptors blocked AMPH-induced anorexia, indicating the involvement of D(1) and D(2) receptors. In a study of tolerant anorexia, repeated treatment with the D(1)/D(2) agonist apomorphine, but not the D(1) agonist SKF 38393 or D(2) agonist quinpirole, induced an AMPH-like tolerant feeding response, providing evidence for conjoint action of D(1) and D(2) receptors in the effect. The present results suggest that both D(1) and D(2) receptors are involved in anorexia and tolerant anorexia induced by chronic intermittent administration of AMPH.

Spontaneous rupture of hepatocellular carcinoma during pregnancy

BACKGROUND

Hepatocellular carcinoma associated with pregnancy is unusual.

CASE

A 33-year-old woman presented at 25 weeks' gestation with sudden, severe epigastric pain for 6 hours. Abdominal ultrasonography and magnetic resonance imaging showed multiple liver tumors with a small amount of ascites. Exploratory laparotomy revealed an unresectable ruptured liver tumor that was treated by packing. Although a biopsy was nondiagnostic, ultrasound-guided needle biopsy 6 days after cesarean delivery at 41 weeks' gestation showed hepatocellular carcinoma, which was treated with transarterial embolization. At 3.5 years posttherapy, both mother and infant are well.

CONCLUSION

Ruptured hepatocellular carcinoma during pregnancy is rare but should be included in the differential diagnosis of sudden, severe epigastric pain.