Mass Measurement of Upper fp-Shell N=Z-2 and N=Z-1 Nuclei and the Importance of Three-Nucleon Force along the N=Z Line

Using a novel method of isochronous mass spectrometry, the masses of ^{62}Ge, ^{64}As, ^{66}Se, and ^{70}Kr are measured for the first time, and the masses of ^{58}Zn, ^{61}Ga, ^{63}Ge, ^{65}As, ^{67}Se, ^{71}Kr, and ^{75}Sr are redetermined with improved accuracy. The new masses allow us to derive residual proton-neutron interactions (δV_{pn}) in the N=Z nuclei, which are found to decrease (increase) with increasing mass A for even-even (odd-odd) nuclei beyond Z=28. This bifurcation of δV_{pn} cannot be reproduced by the available mass models, nor is it consistent with expectations of a pseudo-SU(4) symmetry restoration in the fp shell. We performed ab initio calculations with a chiral three-nucleon force (3NF) included, which indicate the enhancement of the T=1 pn pairing over the T=0 pn pairing in this mass region, leading to the opposite evolving trends of δV_{pn} in even-even and odd-odd nuclei.

First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and β-delayed neutron emission probability, P_{1  n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

[Anterior segment OCT-assisted PTK combined with PRK in the treatment of myopia associated with cornea macula: a case report]

Nowadays, myopia morbidity keeps increasing in China. As the improvements of technique and safety in corneal refractive surgeries, an increasing number of patients with refractive error tend to choose these treatments. The 26-year-old woman with myopia in this case, whose UCVA was 0.1 in OD and 0.2 in OS, had corneal macula in the nasal side of the left eye owing to a corneal trauma occurred more than 10 years ago. After sufficient preoperative examinations, FS-LASIK was performed on the right eye and PTK combined with PRK was performed on the left eye. The UCVA was 1.2 in both eyes 3 months postoperatively, and the corneal macula was mostly cleared in the left eye. It is demonstrated that PTK combined with PRK is an effective and safe way to correct the diopter as well as remove the lesions for the lowly or moderately myopic patients accompanied with superficial corneal opacity. (Chin J Ophthalmol, 2021, 57: 614-617).

SERS-based detection of haptoglobin in ovarian cyst fluid as a point-of-care diagnostic assay for epithelial ovarian cancer

Purpose

To evaluate haptoglobin (Hp) in ovarian cyst fluid as a diagnostic biomarker for epithelial ovarian cancers (EOCs) using surface-enhanced Raman spectroscopy (SERS)-based in vitro diagnostic assay for use in an intraoperative setting.

Methods

SERS-based method was used to detect and quantify Hp in archived ovarian cyst fluids collected from suspicious ovarian cysts and differentiate benign tumors from EOCs. The diagnostic performance of SERS-based assay was verified against the histopathology conclusions and compared with the results of CA125 test and frozen sections.

Results

Hp concentration present in the clinical cyst fluid measured by SERS was normalized to 3.3 mg/mL of standard Hp. Normalized mean values for patients with benign cysts were 0.65 (n=57) and malignant cysts were 1.85 (n=54), demonstrating a significantly (P<0.01) higher Hp in malignant samples. Verified against histology, Hp measurements using SERS had a sensitivity of 94% and specificity of 91%. Receiver operating characteristic curve analysis of SERS-based Hp measurements resulted in area under the curve of 0.966±0.03, establishing the robustness of the method. CA125 test on the same set of patients had a sensitivity of 85% and specificity of 90%, while frozen section analysis on 65 samples had 100% sensitivity and specificity.

Conclusion

With a total execution time of <10 minutes and consistent performance across different stages of cancer, the SERS-based Hp detection assay can serve as a promising intra-operative EOC diagnostic test.

Identification of mycolic acid forms using surface-enhanced Raman scattering as a fast detection method for tuberculosis

Background

Tuberculosis (TB) is the ninth leading cause of death worldwide and the leading cause from a single infectious agent, based on the WHO Global Tuberculosis Report in 2017. TB causes massive health care burdens in many parts of the world, specifically in the resource constrained developing world. Most deaths from TB could be prevented with cost effective early diagnosis and appropriate treatment.

Purpose

Conventional TB detection methods are either too slow as it takes a few weeks for diagnosis or they lack the specificity and accuracy. Thus the objective of this study was to develop a fast and efficient detection for TB using surface enhanced Raman scattering (SERS) technique.

Methods

SERS spectra for different forms of mycolic acids (MAs) that are both synthetic origin and actual extracts from the mycobacteria species were obtained by label-free direct detection mode. Similarly, we collected SERS spectra for γ-irradiated whole bacteria (WB). Measurements were done using silver (Ag) coated silicon nanopillar (Ag SNP) as SERS substrate.

Results

We report the SERS based detection of MA, which is a biomarker for mycobacteria species including Mycobacterium tuberculosis. For the first time, we also establish the SERS spectral characterization of the three major forms of MA - αMA, methoxy-MA, and keto-MA, in bacterial extracts and also in γ-irradiated WB. We validated our findings by mass spectrometry. SERS detection of these three forms of MA could be useful in differentiating pathogenic and nonpathogenic Mycobacterium spp.

Conclusions

We have demonstrated the direct detection of three major forms of MA - αMA, methoxy-MA, and keto-MA, in two different types of MA extracts from MTB bacteria, namely delipidated MA and undelipidated MA and finally in γ-irradiated WB. In the near future, this study could pave the way for a fast and efficient detection method for TB, which is of high clinical significance.

Noninvasive real-time characterization of non-melanoma skin cancers with handheld optoacoustic probes

Currently, imaging technologies that enable dermsurgeons to visualize non-melanoma skin cancers (NMSC) in vivo preoperatively are lacking, resulting in excessive or incomplete removal. Multispectral optoacoustic tomography (MSOT) is a volumetric imaging tool to differentiate tissue chromophores and exogenous contrast agents, based on differences in their spectral signatures and used for high-resolution imaging of functional and molecular contrast at centimeter scale depth. We performed MSOT imaging with two- and three-dimensional handheld scanners on 21 Asian patients with NMSC. The tumors and their oxygenation parameters could be distinguished from normal skin endogenously. The lesion dimensions and depths were extracted from the spectral melanin component with three-dimensional spatial resolution up to 80 μm. The intraclass correlation coefficient correlating tumor dimension measurements between MSOT and ex vivo histology of excised tumors, showed good correlation. Real-time 3D imaging was found to provide information on lesion morphology and its underlying neovasculature, indicators of the tumor's aggressiveness.

Highly sensitive and scalable AAO-based nano-fibre SERS substrate for sensing application

Well-ordered periodic nanostructures are excellent substrates for many surface-enhanced Raman spectroscopy (SERS) applications. Conventional fabrication approaches such as high precision electron beam lithography or focused ion beam produce high resolution nano-features with great reproducibility at the expense of low throughput. In this work, a highly sensitive and scalable AAO-nano-fibre (ANF) SERS substrate is demonstrated by optimising the second anodisation time of the standard two-step anodisation of aluminium and performing an additional wet etching step on the resulting AAO substrate. The optimised ANF substrate exhibits SERS sensitivity that surpasses the AAO nanoholes and the metal-film-on-nanoparticles substrates. A detection limit of 0.1 nM is achieved with a signal-to-noise ratio of 2.6-3 using a low excitation power of 0.1 mW. The ANF substrate exhibits an enhancement factor of 9.28 × 106 and a standard deviation of no more than 8%. The results indicate that the highly sensitive and scalable ANF substrate is a promising substrate for commercial SERS application.

Structural and functional 3D mapping of skin tumours with non-invasive multispectral optoacoustic tomography

BACKGROUND

Recent advances in technology have enabled the development of various non-invasive skin imaging tools to aid real-time diagnosis of both benign and malignant skin tumours, minimizing the need for invasive skin biopsy. Multispectral optoacoustic tomography (MSOT) is a recently developed non-invasive imaging tool, which offers the unique capacity for high resolution three dimensional (3D) optical mapping of tissue by further delivering highly specific optical contrast from a depth of several millimetres to centimetres in living tissues. MSOT enables volumetric, spectroscopic differentiation of tissue, both in vivo and in real time, with and without the application of biomarker-specific probes, and is further able of providing spatial maps of skin chromophores, as well as underlying blood vasculature.

METHODS

Three patients with suspicious skin tumours consented to have their lesions imaged with MSOT prior to excision. The histological findings and measurements were compared.

RESULTS

We demonstrated the first in vivo clinical use of MSOT for 3D reconstruction of skin tumours in three patients with good histological correlation.

CONCLUSION

Our findings confirm the potential benefit of the new imaging method in guiding surgical intervention to achieve a more precise excision with better clearance and lower relapse rates. It can also potentially help to shorten the duration of Mohs' micrographic surgery. Further large-scale studies are necessary to ensure correlation between MSOT and histology.

Identification of the Lowest T=2, J^{π}=0^{+} Isobaric Analog State in ^{52}Co and Its Impact on the Understanding of β-Decay Properties of ^{52}Ni

Masses of ^{52g,52m}Co were measured for the first time with an accuracy of ∼10  keV, an unprecedented precision reached for short-lived nuclei in the isochronous mass spectrometry. Combining our results with the previous β-γ measurements of ^{52}Ni, the T=2, J^{π}=0^{+} isobaric analog state (IAS) in ^{52}Co was newly assigned, questioning the conventional identification of IASs from the β-delayed proton emissions. Using our energy of the IAS in ^{52}Co, the masses of the T=2 multiplet fit well into the isobaric multiplet mass equation. We find that the IAS in ^{52}Co decays predominantly via γ transitions while the proton emission is negligibly small. According to our large-scale shell model calculations, this phenomenon has been interpreted to be due to very low isospin mixing in the IAS.

[Genetic analysis for 5 congenital hypothyroidism patients due to dyshormonogenesis]

OBJECTIVE

To analyze molecular characteristics of 5 congenital hypothyroidism (CH) patients due to dyshormonogenesis.

METHOD

We enrolled 5 CH patients due to dyshormonogenesis who were identified in Newborn Screening Center of Guangxi Zhuang Autonomous Region, China. Blood samples were collected from the patients and their parents, and genomic DNA was extracted from peripheral blood leukocytes. All exons of DUOX2, TG, TPO and NIS gene together with their exon-intron boundaries were screened by next-generation sequencing. Specimens from 100 normal controls were tested for these novel variations.

RESULT

No TPO, NIS or TG gene mutations were identified. Direct sequencing of the DUOX2 gene revealed that patient 1 had a compound heterozygote for c. 3340delC and p. R683L, patient 2 was homozygous for p. K530X and patient 3 was a heterozygote for p. E879K. Both biallelic and monoallelic heterozygous mutations in DUOX2 were associated with transient CH. Novel mutations included c. 3340delC and p. R683L, analysis of 100 healthy subjects without thyroid disease did not show the same change.

CONCLUSION

Genetic analysis of TPO, NIS, DUOX2 and TG gene in 5 unrelated CH patients with thyroid dyshormonogenesis revealed two novel DUOX2 mutations, both were biallelic and monoallelic heterozygous mutations in DUOX2 associated with transient CH.

Duplication polymorphisms in exon 4 of κ-casein gene in yak breeds/populations

The objective of this study was to compare 12 bp-duplication polymorphisms in exon 4 of the κ-casein gene among 3 breeds/populations of yak (Bos grunniens). Genomic DNA was extracted from yak blood or muscle samples (N = 211) and a partial sequence of exon 4 of κ-casein gene was amplified by polymerase chain reaction. A polyacrylamide gel electrophoresis assay of the products (169 bp) revealed 2 variants. These variants differed in a 12-bp duplication of the nucleotide sequence corresponding to amino acids 147-150 (Glu-Ala-Ser-Pro) or 148-151 (Ala-Ser-Pro-Glu). The genotype frequency and gene frequency of the 2 κ-casein variants differed among the 3 yak breeds/populations. The long form of the κ-casein gene was the predominant allele, and the Jiulong yak showed the highest frequency of the short form variant of the κ-casein gene. In addition, 2 nucleotide differences resulting in amino acid substitutions were also identified in yaks. These results are significant for designing a breeding strategy to improve the genetic makeup of yak herds.

Enhancement of early cervical cancer diagnosis with epithelial layer analysis of fluorescence lifetime images

This work reports the use of layer analysis to aid the fluorescence lifetime diagnosis of cervical intraepithelial neoplasia (CIN) from H&E stained cervical tissue sections. The mean and standard deviation of lifetimes in single region of interest (ROI) of cervical epithelium were previously shown to correlate to the gold standard histopathological classification of early cervical cancer. These previously defined single ROIs were evenly divided into layers for analysis. A 10-layer model revealed a steady increase in fluorescence lifetime from the inner to the outer epithelial layers of healthy tissue sections, suggesting a close association with cellular maturity. The shorter lifetime and minimal lifetime increase towards the epithelial surface of CIN-affected regions are in good agreement with the absence of cellular maturation in CIN. Mean layer lifetimes in the top-half cervical epithelium were used as feature vectors for extreme learning machine (ELM) classifier discriminations. It was found that the proposed layer analysis technique greatly improves the sensitivity and specificity to 94.6% and 84.3%, respectively, which can better supplement the traditional gold standard cervical histopathological examinations.

Quantitative diagnosis of cervical neoplasia using fluorescence lifetime imaging on haematoxylin and eosin stained tissue sections

The use of conventional fluorescence microscopy for characterizing tissue pathological states is limited by overlapping spectra and the dependence on excitation power and fluorophore concentration. Fluorescence lifetime imaging microscopy (FLIM) can overcome these limitations due to its insensitivity to fluorophore concentration, excitation power and spectral similarity. This study investigates the diagnosis of early cervical cancer using FLIM and a neural network extreme learning machine classifier. A concurrently high sensitivity and specificity of 92.8% and 80.2%, respectively, were achieved. The results suggest that the proposed technique can be used to supplement the traditional histopathological examination of early cervical cancer.

New frontier in hypericin-mediated diagnosis of cancer with current optical technologies

Photosensitizers (PSs) have shown great potentials as molecular contrast agents in photodynamic diagnosis (PDD) of cancer. While the diagnostic values of PSs have been proven previously, little efforts have been put into developing optical imaging and diagnostic algorithms. In this article, we review the recent development of optical probes that have been used in conjunction with a potent PS, hypericin (HY). Various fluorescence techniques such as laser confocal microscopy, fluorescence urine cytology, endoscopy and endomicroscopy are covered. We will also discuss about image processing and classification approaches employed for accurate PDD. We anticipate that continual efforts in these developments could lead to an objective PDD and complete surgical clearance of tumors. Recent advancements in nanotechnology have also opened new horizons for PSs. The use of biocompatible gold nanoparticles as carrier for enhanced targeted delivery of HY has been attained. In addition, plasmonic properties of nanoparticles were harnessed to induce localized hyperthermia and to manage the release of PS molecules, enabling a better therapeutic outcome of a combined photodynamic and photothermal therapy. Finally, we discuss how nanoparticles can be used as contrast agents for other optical techniques such as optical coherence tomography and surface-enhanced Raman scattering imaging.

Analysis of antigen epitopes and molecular pathogenic characteristics of the 2009 H1N1 pandemic influenza A virus in China

In order to further predict the epidemic trend and develop vaccines for 2009 H1N1 virus, we monitored its epitopes and molecular pathogenic characteristics during the epidemic process. We also analyzed the similarity of antigenic and genetic characteristics among the novel 2009 H1N1, representative seasonal H1N1 strains, and vaccine strains. 2009 H1N1 isolates had high similarity of hemagglutinin (HA) antigenic sites with H1N1 viruses isolated before 1940 and up to 80.0% similarity with 1918 H1N1. The elderly people born before 1940 have relatively low 2009 H1N1 infection rate, which might be responsible for their previous infection with either 1918 H1N1 virus or an early progeny. Compared to seasonal H1N1 vaccine strains from 1999 to 2010, the HA, neuraminidase (NA), and nucleoprotein (NP) proteins of the isolates had highly conserved CTL epitopes (60.5-65.8%, 69.6-82.6%, and 76.7%, respectively). The seriousness and mortality rate of 2009 H1N1 infections were similar to seasonal influenza, which may be related to the molecular characteristics of low toxicity of 2009 H1N1 and cross-T-cell immunity, due to vaccination or exposure to seasonal H1N1 virus. Some strains of 2009 H1N1 acquired mutations at antigenic and glycosylation sites. It is of particular interest that Haishu/SWL110/10 and Beijing/SE2649/09, isolated after November 2009, gained a new glycosylation site at the position 179 of HA protein, near the RBD. Thus, in the future, vaccination with glycosylated 2009 H1N1 virus may prevent the seasonal epidemic caused by strains with glycosylation site mutation near the receptor binding domain (RBD).

Clinical SERS: are we there yet?

Surface Enhanced Raman Spectroscopy or SERS has witnessed many successes over the past 3 decades, owing particularly to its simplicity of use as well as its highly-multiplexing capability. This article provides an overview of SERS and its applicability in the field of bio-medicine. We will preview recent developments in SERS substrate designs, and the various sensing technologies that are based on the SERS phenomenon. An overview of the clinical applications of SERS is also included. Finally, we provide an opinion on the future trends of this unique spectroscopic technique.

The relationship between acid-suppressing drugs and phytobezoar formation: a retrospective analysis and discussion of phytobezoar formation

OBJECTIVES

Although phytobezoars are a rare cause of gastrointestinal obstruction, they are most commonly found in patients with previous gastric surgery. It is well known that predisposing factors of phytobezoar formation are ingestion of fruits containing soluble tannin, presence of dilute hydrochloric acid in the stomach, and gastric stasis or delayed emptying. We investigated whether intake of acid-suppressing drugs that neutralize gastric acidity or inhibit gastric acid secretion to constitute a hypo-acidic condition, increases the risk of phytobezoar formation.

MATERIALS AND METHODS

Between September 1992 and October 2008, 32 patients (24 male and 8 female) with gastrointestinal phytobezoars were diagnosed either surgically or endoscopically at the Tri-Service General Hospital, Taipei, Republic of China. The data were collected from hospital records and analyzed retrospectively.

RESULTS

Eighteen (56.25%) of all patients had previous gastric surgery and 6 (42.9%) of the 14 patients who had not undergone surgery had diabetes mellitus. The majority of admissions were during winter and spring (between October and March) (P < 0.01) and none of the patients had taken acid-suppressing drugs during the 6 months before detection of gastrointestinal phytobezoars.

CONCLUSIONS

In our study, intake of acid-suppressing drugs did not increase the risk of phytobezoar formation in patients with normal gastric motility. Moreover, we believe that the major factor in phytobezoar formation is gastric stasis or delayed emptying, which sufficiently prolongs the retention period of materials in the stomach, while dilute hydrochloric acid is a minor factor.

Monitoring and evaluation of removal of pathogens at municipal wastewater treatment plants

The concentrations and removal of Cryptosporidium, Giardia, and microbial indicators, including somatic coliphages and fecal coliforms were investigated through the wastewater treatment processes at three municipal wastewater treatment plants in Beijing, China. The experimental results showed that the concentrations of Cryptosporidium in untreated wastewater, primary treatment effluent, secondary treatment effluent, tertiary treatment effluent were 33-600, 67-333, 0-9 and 0-0.4 oocysts L(-1), and that of Giardia were 130-3,600, 533-2,033, 0-32 and 0-2.1 cysts L(-1), respectively. The reduction ratios of Cryptosporidium and Giardia by the primary treatment process were 0.12 log and 0.18 log, respectively. Oxidation ditch process had higher reduction efficiency to Cryptosporidium and Giardia than anaerobic-anoxic-oxic process and conventional activated sludge process, probably because of longer retention time and higher sludge concentration. Membrane ultrafiltration had a notably better efficiency to reduce microorganisms, especially Cryptosporidium and Giardia, than conventional flocculation sedimentation and sand filtration process, as the tertiary treatment. Comparing with total coliforms, fecal coliforms and heterotrophic bacteria, concentration of somatic coliphages was correlated better with that of Cryptosporidium and Giardia in untreated wastewater and secondary treatment effluent.

Combinatorial synthesis of a triphenylmethine library and their application in the development of surface enhanced Raman scattering (SERS) probes

The first synthesis of a triphenylmethine (TM) library of compounds and screening of their Surface Enhanced Raman Scattering (SERS) capability was carried out to identify novel Raman reporters with high sensitivity. We identified three novel SERS reporters (B2, B7, and C7) with higher signal intensity than that of commonly used crystal violet (CV). These reporters may find potential applications in developing sensitive SERS based biosensors.

Fluorescence lifetime discrimination using expectation-maximization algorithm with joint deconvolution

The fluorescence lifetime technique offers an effective way to resolve fluorescent components with overlapping emission spectra. The presence of multiple fluorescent components in biological compounds can hamper their discrimination. The conventional method based on the nonlinear least-squares technique is unable to consistently determine the correct number of fluorescent components in a fluorescence decay profile. This can limit the applications of the fluorescence lifetime technique in biological assays and diagnoses where more than one fluorescent component is typically encountered. We describe the use of an expectation-maximization (EM) method with joint deconvolution to estimate the fluorescence decay parameters, and the Bayesian information criterion (BIC) to accurately determine the number of fluorescent components. A comprehensive simulation and experimental study is carried out to compare the performance and accuracy of the proposed method. The results show that the EM-BIC method is able to accurately identify the correct number of fluorescent components in samples with weakly fluorescing components.

Effects of N-methyl pyrrolidone on the uptake of hypericin in human bladder carcinoma and co-staining with DAPI investigated by confocal microscopy

Photodynamic diagnosis (PDD) using hypericin (HY), a natural photosensitizer, detects bladder cancer significantly better than white light endoscopy. However, the lipophilicity of HY complicates its administration for clinical applications. Currently, pharmaceutical preparations for HY without plasma protein are being developed. Formulations containing a biocompatible solvent, N-methyl pyrrolidone (NMP) have been shown to enhance the photodynamic therapeutic effects of HY. It was recently reported that, NMP formulations of HY were able to produce significantly higher contrast for fluorescence detection of tumors than albumin-containing HY formulations. This present work hypothesizes that NMP acts both as a solvent and penetration enhancer to improve the delivery of HY into cells by increasing the permeability of cell membranes. This paper reports the use of 3-D confocal microscopy to monitor real-time uptake of HY in human carcinoma. 3-D confocal microscopy was used to investigate the possibility of nuclear localization of HY in MGH cells. The fluorescence of HY was confirmed to be emitted from HY containing cells using spectrometry. The localization of a DNA fluorescent probe 4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) was used to confirm the possibility of colocalization of DAPI and HY. The colocalization analysis in the present study suggests that it was very unlikely that HY colocalized in the nucleus that was stained by DAPI. Fluorescein leakage tests showed that 1% NMP changes the permeability of cell membranes, and enhanced the delivery of HY into cells resulting in lower cell survival ratios. Thus, NMP was able to enhance the photodynamic therapeutic effects of HY on cancer cells.

Fluorescence detection of bladder cancer using urine cytology

Bladder cancer is the fourth most common malignant disease worldwide, accounting for 4% of all cancer cases. In Singapore, it is the ninth most common form of cancer. The high mortality rate in bladder cancer can be reduced by early treatment following pre-cancerous screening. Currently, the gold standard for screening bladder tumors is histological examination of biopsy specimens, which is both invasive and time-consuming. In this study, ex vivo urine fluorescence cytology was investigated to offer an alternative timely and biopsy-free means for detecting bladder cancers. Sediments in patient urine samples were extracted and incubated with a novel photosensitizer, hypericin. Laser confocal microscopy was used to capture the fluorescence images at an excitation wavelength of 488 nm. Images were subsequently processed to single out the exfoliated bladder cancer cells from the other cells based on the cellular size. Intensity histograms of each targeted cell and feature vectors, derived from the histogram moments, were used to represent each sample. A difference in the distribution of the feature vectors of normal and low-grade cancerous bladder cancer cells were observed. A diagnostic algorithm for discriminating between normal and low-grade cancerous cells is elucidated in this report. This study suggests that the fluorescence intensity profiles of hypericin in bladder cells can potentially provide an automated quantitative means of early bladder cancer diagnosis.

Integration of optical fiber light guide, fluorescence detection system, and multichannel disposable microfluidic chip

A combination of fluorescence detection and microfluidic technology provides promising applications in life sciences. A prototype of an integrated fluorescence detection system and optical fiber light guide on a laminate-based multichannel microfluidic chip has been developed and tested. A blue LED, plastic optical fiber, photodiode, Mylar and PMMA, and fluorescein and BSA-FITC were used as an excitation source, light coupler and guide, detector, microfluidic substrate and sample, respectively. The results show that the system is capable of detecting weak fluorescence emission from a fluorescein solution at concentration down to 0.01 ng/ml, and gives linear response. The results were also reproducible, and no cross-talk between adjacent channels was observed. The test using BSA as a model analyte demonstrates its feasibility for on-chip immunosensor applications. The performance and applications can be developed further. This prototype can be used as a platform to develop a simple and compact bio-fluorescence detection system integrated with an inexpensive and disposable multichannel microfluidic chip for biomedical devices.

Constitutive expression of human angiostatin in Pichia pastoris by high-density cell culture

A high-density cell culture method to produce human angiostatin has been successfully established by constitutive expression of the protein in Pichia pastoris. The fermentation was carried out in a 20 l bioreactor with a 10 l working volume, using a high-density cell culture method by continuously feeding with 50% glycerol-0.8% PTM4 to the growing culture for 60 h at 30 degrees C. Dissolved oxygen level was maintained at 25-30% and pH was controlled at 5 by the addition of 7 M NH4OH. Angiostatin was constitutively expressed during the fermentation by linking its expression to the P. pastoris constitutive GAP promoter (pGAP). But after 36 h of fermentation, the peak biomass growth was 305 as measured by absorption of 600 nm, while the peak angiostatin expression was 176 mg/l. Similar to the product expressed from inducible system [24], angiostatin produced from constitutive system also inhibited the angiogenesis on the CAM and suppressed the growth of B16 melanoma in C57BL/6J mouse. The above results suggest that GAP promoter is more efficient than AOX1 promoter for the expression of angiostatin in P. pastoris by shake flask culture or high-density cell fermentation and is likely to be an alternative to AOX1 promoter in large-scale expression of angiostatin and other heterologous proteins.

Compact fluorescence detection using in-fiber microchannels-its potential for lab-on-a-chip applications

This paper reports a compact and practical fluorescence sensor using an in-fiber microchannel. A blue LED, a multimode PMMA or silica fiber and a mini-PMT were used as an excitation source, a light guide and a fluorescence detector, respectively. Microfluidic channels of 100 microm width and 210 microm depth were fabricated in the optical fibers using a direct-write CO(2) laser system. The experimental results show that the sensor has high sensitivity, able to detect 0.005 microg L(-1) of fluorescein in the PBS solution, and the results are reproducible. The results also show that the silica fiber sensor has better sensitivity than that of the PMMA fiber sensor. This could be due to the fouling effect of the frosty layer formed at the microchannel made within the PMMA fiber. It is believed that this fiber sensor has the potential to be integrated into microfluidic chips for lab-on-a-chip applications.

Subnanosecond-resolution phase-resolved fluorescence imaging technique for biomedical applications

Characterization of fluorescence emissions from cells often leads to conclusive results in the early detection of cellular abnormalities. Cellular abnormalities can be characterized by their difference in the fluorescence lifetime, which may be less than nanoseconds. A sensitive frequency domain technique, also called a phase-resolved fluorescence imaging technique, is proposed in which fluorescence emissions at the same wavelengths can more effectively be separated with subnanosecond resolution in their lifetime difference. The system configuration is optimized by incorporating even-step phase shifting in the homodyne-assisted signal-processing concept along with the phase-resolved fluorescence technique to eliminate the dc offsets of emission. Experiments are carried out with simulated samples composed of two fluorescence emissions of the same wavelength but with different lifetime values. Suppression of either of the fluorescence emissions by selective imaging of the other validates the superiority of the proposed technique. Hence, this technique can potentially be applied in the early detection of cellular abnormalities.

A simple predictive model for blood-brain barrier penetration

A simple two-descriptor model to predict blood-brain barrier penetration is derived from a training set of 79 compounds: log BB = - 13.31V2 + 9.601V - 2.231PSA - 0.5290 (n = 79, r2 = 0.83) where log BB is the logarithm of the ratio of the steady-state concentration of the compound in the brain to in the blood, V (nm3) is the molecular volume, PSA (nm2) is the polar surface area which is defined as the sum of the van der Waals surface areas of oxygen atoms, nitrogen atoms, and attached hydrogen atoms in a molecule, n is the number of compounds, and r is the correlation coefficient. The model is validated by a leave-one-out procedure and an external test set (25 compounds). The results indicate that the model developed is statistically sound and is sufficiently reliable and robust for predictive use. The descriptors in the model can be easily computed and it is suitable for the rapid prediction of the blood-brain barrier penetration for a wide range of drug candidates.

A mathematical model to predict the release of water-soluble drugs from HPMC matrices

A mathematical model to predict the fraction of water-soluble drug released as a function of release time (t, h), HPMC concentration (CH, w/w), and volume of drug molecule (V, nm3) was derived with ranitidine hydrochloride, diltiazem hydrochloride, and ribavirin as model drugs. The model is log (M(t)/M(infinity)) = 0.5 log t-0.3322CH-0.2222V-0.2988 (n = 140, r = 0.9848), where M(t) is the amount of drug released at time t, M(infinity) is the amount of drug released over a very long time, which corresponds in principle to the initial loading, n is the number of samples, and r is the correlation coefficient. The model was validated using isoniazid and satisfactory results were obtained. The model can be used to predict the release fraction of various soluble drugs from HPMC matrices having different polymer levels.

Changes in VP2 gene during the attenuation of very virulent infectious bursal disease virus strain Gx isolated in China

Very virulent (vv) infectious bursal disease virus (IBDV) Gx strain with high pathogenicity was attenuated through replication in specific-pathogen-free (SPF) chicken embryos and in chicken embryo fibroblast (CEF) cell cultures. The changes in VP2 nucleotide and the deduced amino acid sequences were obtained during attenuation of vvIBDV in CEF culture. Sequence analysis of selected passages from numbers 0 to 20 in CEFs (designated here Gx to CEF-20) showed that no changes were detectable in the VP2 gene before CEF-7. There were a few changes in the nucleotide sequence of the VP2 gene but no amino acid substitutions at CEF-8. The virus of CEF-9 was an intermediate with some amino acid changes that possibly were related to virulence. CEF-10 virus had become similar to CU-1 strain. The VP2 gene sequence remained the same from CEF-10 to CEF-20. The results of pathogenicity tests showed that the mortalities of Gx, CEF-5, CEF-8, and CEF-9 in 4-wk-old SPF chickens were 64%, 60%, 60%, and 32%, respectively; whereas CEF-10, CEF-15, and CEF-20 were nonpathogenic. Virus neutralization tests with Gx strain showed that the antigenicities are similar from Gx to CEF-20.

Type III tympanoplasty with cartilage obliteration for cholesteatoma surgery

BACKGROUND

The main objective of cholesteatoma surgery is complete eradication of the disease. Another goal is to preserve hearing acuity. We reviewed type III tympanoplasty with cartilage obliteration for cholesteatomatous ears. To evaluate the role of ossiculoplasty, the functional results of classic and modified type III tympanoplasties were compared.

METHODS

Thirty-six cholesteatomatous ears undergoing type III tympanoplasty with cartilage obliteration were reviewed. The same operator performed these operations from 1984 until 1995. According to the CAO staging system, there were five early, 16 moderate and 15 advanced-stage cases of cholesteatoma. Using the anterior approach, all operations were canal-wall-down type III tympanoplasties with "tailored" open cavity and cartilage obliteration. There were 24 classic and 12 modified type III tympanoplasties.

RESULTS

The average follow-up duration was 7.2 years. Neither recidivistic cholesteatoma nor retraction pocket was observed postoperatively. There was an improvement in atelectatic score after surgery. The mean postoperative air-bone gap (ABG) was 15.8 +/- 10.7 dB and the mean closure of the ABG was 4.0 +/- 14.3 dB. After the disease stage and preoperative hearing status were adjusted using regression analysis, there was no significant difference in hearing results between ears that underwent classic or modified type III tympanoplasties.

CONCLUSIONS

We performed the canal-wall-down tympanoplasty with cartilage obliteration using the anterior approach for treatment of cholesteatoma. Such surgical techniques eradicate the cholesteatoma, prevent its recurrence and create a clean ear. Hearing reconstruction can also be accomplished in a single-stage procedure offering a serviceable hearing acuity.

Decreasing levels of anti-Nef antibody correlate with increasing HIV type 1 viral loads and AIDS disease progression

To study the association between anti-Gag and anti-Nef antibody reactivities and their correlations with disease progression, 174 HIV-1/AIDS patients were followed up for 1 year after they received triple therapy. The antibody reactivities were analyzed using a Western blot test with recombinant Gag and Nef proteins. The results showed that decreasing levels of anti-Gag or anti-Nef antibody correlate with disease progression defined by HIV-1 viral loads or T4 cell counts. After receiving triple treatment for 1 year, 8 of 38 (21.1%) Nef antibody-negative patients became positive, while only 9 of 125 (7.2%) Nef antibody-positive persons lost the antibody reactivity (p < 0.01). Therefore, HIV-1 Nef may serve as a clinical marker of disease progression.

Antibody reactivities to tumor-suppressor protein p53 and HTLV-I Tof, Rex and Tax in HTLV-I-infected people with differing clinical status

Since the presence of anti-p53 antibody has been correlated with the mutation and accumulation of p53, the aim of this study was to detect anti-p53 antibody and understand its correlations with anti-Tof, -Rex, or -Tax antibody reactivity in HTLV-I infected people differing in their clinical status. A plasmid (pGEX-Tof) was constructed to express Tof recombinant protein (RP) in Escherichia coli. Serum samples from 50 asymptomatic carriers (ACs), 50 adult T-cell leukemia (ATL) and 50 HTLV-I-associated myelopathyltropical spastic paraparesis (HAM/TSP) patients were assayed for reactivity with different RPs by Western immunoblotting. The results showed that 2% of ACs, 4% of ATL patients and 6% of HAM/TSP patients had anti-p53 antibody. Therefore, anti-p53 antibody is not a useful serological marker for clinical management of HTLV-I infected people. Only 1 HAM/TSP patient had anti-Tof antibody whose specificity was further confirmed by antibody competition enzyme immunoassay. This study demonstrates that Tof protein is immunogenic in vivo, suggesting that it plays a role in the life cycle and pathogenesis of HTLV-I. The rate of anti-Rex antibody among HAM/TSP patients was significantly higher than that of ACs or ATL patients. In addition, 50% of ACs, 42% of ATL and 98% of HAM/TSP patients had anti-Tax antibody. McNemar's test showed that the presence of anti-p53 antibody did not have any correlation with the anti-Tax antibody in HTLV-I-infected people, while the correlation between anti-p53 and anti-Rex antibodies or anti-p53 and anti-Tof antibodies cannot be ruled out in this study.

The joint action of two mixed stimuli with a bivariate threshold

The general mathematical statistical theory of a mixture of two stimuli in quantal bioassay or other binary response is investigated assuming the existence of thresholds. Univariate thresholds have long been studied. Different serious attempts on bivariate threshold theory have emerged since the late 1940s. Some have been based on biologically established fact mixed with analysis, while others have been more heuristic. In this paper we investigate the properties of correlations of thresholds. Joint actions are then interpreted according to those correlations and deviations from independence. Isoboles are lines, curves, planes, or surfaces of constant probability. They are also investigated, and their properties are used in proofs of important theorems. It is proved that additivity or additivism of two stimuli is present if and only if the thresholds of the two stimuli are perfectly correlated. Furthermore, additivity requires univariate dose-response functions to be everywhere concave on the nonnegative real numbers (doses). Finally, threshold theory, itself, dictates cumulative distributions of marginal thresholds that are everywhere nondecreasing and concave on the nonnegative reals. That is, they cannot have points of inflection. Such popular distributions as the normal and logistic have points of inflection at their respective medians. This does not invalidate their usefulness. They are simply modeling phenomena other than those which are the subject of this paper, namely, threshold theory.

[Improvement of coronary flow by artificial decending the intrathoracic pressure]

In simulating the changes of intrathoracic pressure during deep inhalation, the intrathoracic pressure was descended by repeated aspiration from thoracic cavity in 8 dogs. The volume of coronary flow was observed simultaneously. It was found that when intrathoracic pressure was dropping the coronary flow volume showed an increase as a result of decrease of right atrium pressure and increase of aorta pressure, thus creating an increased pressure difference between inflow and outflow of coronary circulation.

[The characteristic of lymphokine-activated killer cells induced from tumor draining lymph-node cell]

A short time lymphocyte culture for lymphokine activated killer (LAK) cells was presented, the lymphocytes being collected from the tumor draining regional lymph nodes in seven patients with gynecologic malignant tumors. The results showed different cytotoxic activities of LAK cells against Lewis pulmonary cancer cells, CAOV, cells and the new separated ovarian cancer cells. And the cytotoxic activity of the LAK cells increased with the rise of the effecter cell-target cell ratio and maintained at a certain level when the rise of the latter's increase reached a certain extent. The cytotoxic activity of the LAK cells against autologous tumor cells (as from ovarian cancer) were shown to be much stronger than against the others. As the culture days lengthened, the cytotoxicities of the LAK cells from interleukin-2/OKT 3 culture became stronger than from interloukin-2 alone. Large quantities of lymphocytes could be collected from tumor-draining lymphe nodes. This is a preliminary investigation on the inducing of LAK cells from lymphocytes of the draining regional lymph nodes of malignant gynecologic tumors. The quantitative increase of LAK cells and the effect of their cytotoxic activities are to be further explored.

[Urinary gonadotropin fragment measurement in the monitoring of trophoblastic disease]

Urinary gonadotropin fragment (UGF) is a small peptide which is present in the urine of pregnant women and of women with trophoblastic diseases as well as with certain nontrophoblastic malignancies. 275 samples each of urine and blood from 46 patients with trophoblastic diseases were taken for UGF and hCG measurements and compared. 24 samples from 12 healthy, nonpregnant women were taken as control. Cut-off values of UGF and hCG used for measuring the sensitivity of trophoblastic diseases were respectively > 0.2 microgram/L and above 20 micrograms/L. It was found that 64.0% of the urine samples gave UGF values > 0.2 microgram/L and 66.5% of the blood samples showed hCG levels above 20 micrograms/L (P > 0.1). No false-positive rate was observed in the control group. However, among patients who were found to have low or negative hCG values, 57.6% showed positive UGF levels. These findings suggest that in patients with positive levels of both UGF and hCG, the UGF measurement may not be necessary. But for patients with low or negative blood hCG values, certain percentage of urine UGF could still be detected.

[An in vitro and in vivo study of antitumor effects of rHTNF-alpha on human ovarian cancer]

We examined the cytotoxic activities of recombinant human tumor necrosis factor (rHTNF-alpha) and five chemotherapeutic agents, CTX, 5-Fu, VCR, DDP, KSM, against two human ovarian cancer cell lines, OVCAR3 and CAOV3, using the MTT assay. The results showed that cytotoxicities of rHTNF-alpha at 5 x 10-5 x 10(4) u/ml against OVCAR3 cell line for 24 h exposure were from 14.2 +/- 6.8% to 67.2 +/- 3.0%, and those against CAOV3 cell line were from 8.2 +/- 4.3% to 60.9 +/- 1.3%. The cytotoxic effects of all five chemotherapeutic agents against the two cell lines were much lower than that of rHTNF-alpha. Further, we studied the combined anticancer potential of rHTNF-alpha with chemotherapeutic agents against the two cell lines. Various degrees of synergism in cytotoxicities of DDP or KSM in combination with rHTNF-alpha were observed. The cytotoxic effect of rHTNF-alpha on CAOV3 cell were also morphologically observed under phase contrast and electron microscope. Based on experiment in vitro, the in vivo anticancer activity of rHTNF-alpha alone or in combination with KSM was examined against human ovarian cancer OVCAR3 subcutaneously transplanted in nude mice. After 8 weeks of treatment, a statistically significant difference of mean tumor volume was found between the control group and groups that received rHTNF-alpha or rHTNF-alpha plus KSM (P < 0.01).

[Three-dimensional motion of the radial artery and attributes of position, rhythm, shape and variance of pulse diagnosis]

In using the sophisticated colour Doppler image-forming technique, and analysis with the self-made cardioelectric phasic mark fixed point as well as the limb minus/plus pressure bathtub, 44 healthy youths were observed.

THE RESULTS

(1) The superficial arteries in the limbs have their motion forms of radial expansion, axial extension and axis shifting. (2) These three motions, together with the pulsation present periodical changes. (3) Compared with the results on the survey of the topographical autopsy of a cadaver, the scope and forms of aforementioned artery motion were related to the anatomical positions of cadaver in which they were located. (4) The above-mentioned axial position shifting of the arteries constitute the whole body shifting or revolving of the blood vessels through plain observations on two dimensions and provide three-dimensional signals. (5) A systematic study was made between the relationship of the vascular motion pattern in human body and the form attributes of position, rhythm, shape and variance. It is significant to study the individuality of vascular activities as well as to elucidate the mechanism in forming the pulse conditions of TCM.