Optical coherence tomography: a potential tool for unsupervised prediction of treatment response for Port-Wine Stains

BACKGROUND

Treatment of Port-Wine Stains (PWS) suffers from the absence of a reliable real-time tool for monitoring a clinical endpoint. Response to treatment varies substantially according to blood vessel geometry. Even though optical coherence tomography (OCT) has been identified as a modality with potential to suit this need, it has not been introduced as a standard clinical monitoring tool. One reason could be that - although OCT acquires data in real-time - gigabyte data transfer, processing and communication to a clinician may impede the implementation as a clinical tool.

OBJECTIVES

We investigate whether an automated algorithm can address this problem.

METHODS

Based on our understanding of pulsed dye laser treatment, we present the implementation of an unsupervised, real-time classification algorithm which uses principal components data reduction and linear discriminant analysis. We evaluate the algorithm using 96 synthesized test images and 7 clinical images.

RESULTS

The synthesized images are classified correctly in 99.8%. The clinical images are classified correctly in 71.4%.

CONCLUSIONS

Principal components-fed linear discriminant analysis (PC-fed LDA) may be a valuable method to classify clinical images. Larger sampling numbers are required for a better training model. These results justify undertaking a study involving more patients and show that disease can be described as a function of available treatment options.

Cost-effectiveness of clinical interventions for AIDS wasting

Economic studies of HIV/AIDS interventions are important for providing cost-effective care. This paper presents a costeffectiveness study of a three-arm clinical trial conducted at Tufts University School of Medicine/New England Medical Center in Boston, Massachusetts that treated 50 patients with AIDS wasting from March 1998 through January 2001. This study compared the costs and impacts of a nutritional counseling intervention alone (NC arm), the nutrition intervention with oxandrolone (OX arm), and the nutrition intervention with progressive resistance training (PRTarm) for the treatment of AIDS wasting. The cost of each intervention was derived for both the three-month clinical trial and a six-month estimated community model (ECM), its projected adaptation to community-based medical care. The cost determination involved obtaining and multiplying unit economic costs and quantities expended of each resource within each study arm. The ECM average cost per client in the cost-effectiveness analysis incorporated both institutional and societal perspectives. The costeffectiveness analysis compared the cost of each intervention to its quality-adjusted life-year (QALY) gain (Zeckhauser and Shepard, 1976). From a societal perspective, for the NC arm, the cost per client totaled US dollars 983 for the actual and US dollars 596 under the ECM. For the OX arm, the cost per client totaled US dollars 3,772 for the actual study and US dollars 3,385 under the ECM. For the PRT arm, the cost per client totaled US dollars 3,189 for the actual study and US dollars 2,987 under the ECM. Under the societal perspective the cost per QALY was US dollars 55,000 (range: US dollars 51,000 to US dollars 83,000) for the NC arm, US dollars 151,000 (range: US dollars 149,000 to US dollars 171,000) for the OX arm, and US dollars 65,000 (range: US dollars 44,000 to US dollars 104,000) for the PRTarm. When using only an institutional perspective, the cost per QALY was US dollars 45,000 (range: US dollars 42,000-US dollars 64,000) for the NC arm, US dollars 147,000 (range: US dollars 147,000 to US dollars 163,000) for the OX arm, and US dollars 31,000 (US dollars 21,000 to US dollars 44,000) for the PRTarm. This paper shows that cost and cost-effectiveness analyses can be adapted to a community setting by combining information from community practice and costs with data from a randomized trial. Compared to other AIDS treatments, such as highly active antiretroviral therapies, all three interventions were affordable, but their cost-effectiveness was intermediate. Oxandrolone was the least cost effective of the interventions, even compared to nutrition alone, as it included similar or somewhat greater costs for less of an increase in quality of life. PRT was the most cost-effective treatment for AIDS wasting, particularly from an institutional perspective. Third party payers should consider coverage of PRT.

Optical adjuncts for enhanced colonoscopic diagnosis

Background

Optical techniques using previously unexploited properties of light interaction with tissue may be valuable in the detection, diagnosis and staging of colorectal neoplasia.

Methods

A Medline search (1990 to present) was conducted on optical diagnostics in the detection of colorectal neoplasia. The reference list of each identified article was reviewed for further relevant papers.

Results and conclusion

Chromoendoscopy is the only optical adjunct to colonoscopy that has been tested in large randomized clinical trials. It improves the detection of small and flat colorectal adenomas, and of neoplasia in chronic ulcerative colitis and hereditary non-polyposis colorectal cancer. All other techniques are the subject of ongoing research and the practicality of population screening with any of the methods has yet to be established. Optical techniques may, however, permit immediate clinical diagnosis, removing the need for histological analysis. They may also improve the diagnosis of early colonic neoplasia.

Estimating population size of endangered brush-tailed rock-wallaby (Petrogale penicillata) colonies using faecal DNA

The brush-tailed rock-wallaby (Petrogale penicillata) is an endangered species in southeastern Australia and many of the remaining populations are declining. The steep rocky habitat and shy nature of the species make it difficult to obtain data on population parameters such as abundance and recruitment. Faecal pellet counts from scat plots are commonly used to monitor population trends but these are imprecise and difficult to relate to absolute population size. We conducted a noninvasive genetic sampling 'mark-recapture' study over a 2-year period to identify individuals from faecal DNA samples and estimate the population size of four brush-tailed rock-wallaby colonies located in Wollemi National Park, New South Wales. Scat plots in rock-wallaby colonies were used as sample collection points for this study. Two separate population estimates were carried out for three of the colonies to determine if we could detect recruitment and changes in population size. We determined that there was one large colony of an estimated 67 individuals (95% confidence interval: 55-91) and three smaller colonies. Monitoring of the smaller colonies also detected possible population size increases in all three. Our results indicate that faecal DNA analysis may be a promising method for estimating and monitoring population trends in this species particularly when used with a traditional field survey method.

Coulomb blockade anisotropic magnetoresistance effect in a (Ga,Mn)As single-electron transistor

We observe low-field hysteretic magnetoresistance in a (Ga,Mn)As single-electron transistor which can exceed 3 orders of magnitude. The sign and size of the magnetoresistance signal are controlled by the gate voltage. Experimental data are interpreted in terms of electrochemical shifts associated with magnetization rotations. This Coulomb blockade anisotropic magnetoresistance is distinct from previously observed anisotropic magnetoresistance effects as it occurs when the anisotropy in a band structure derived parameter is comparable to an independent scale, the single-electron charging energy. Effective kinetic-exchange model calculations in (Ga,Mn)As show chemical potential anisotropies consistent with experiment and ab initio calculations in transition metal systems suggest that this generic effect persists to high temperatures in metal ferromagnets with strong spin-orbit coupling.

How, not just if, condoms are used: the timing of condom application and removal during vaginal sex among young people in England

OBJECTIVE

To assess the prevalence of, and factors associated with, vaginal penetration before condom application and following condom removal among young people in education in England.

METHOD

A large cross sectional survey (n = 1373) was conducted in educational establishments in England and sexual event diaries were completed by a subsample of young people over a 6 month period.

RESULTS

Of the 375 survey respondents who reported having used a condom on the most recent occasion of vaginal sex, 6% had applied the condom after penetration and 6% had continued penetration after condom removal. Of the 74 diary respondents, 31% applied a condom late and 9% removed a condom early at least once over a 6 month period. The odds of "imperfect" condom use were found to decrease with overall consistency of condom use, confidence in correct condom use, positive reported relationship with mother, non-use of other contraception, and desire to use a condom.

CONCLUSION

Given that late application and early removal of condoms fail to maximise their effectiveness as a method of STI prevention, it is important to address "imperfect" condom use and the factors associated with such use in public health policies and programmes. It is essential that young people understand the importance of using condoms consistently and correctly, and are also equipped with the skills and knowledge to do so.

Raman spectroscopy: elucidation of biochemical changes in carcinogenesis of oesophagus

Several techniques are under development to diagnose oesophageal adenocarcinoma at an earlier stage. We have demonstrated the potential of Raman spectroscopy, an optical diagnostic technique, for the identification and classification of malignant changes. However, there is no clear recognition of the biochemical changes that distinguish between the different stages of disease. Our aim is to understand these changes through Raman mapping studies. Raman spectral mapping was used to analyse 20-microm sections of tissue from 29 snap-frozen oesophageal biopsies. Contiguous haematoxylin and eosin sections were reviewed by a consultant pathologist. Principal component analysis was used to identify the major differences between the spectra across each map. Pseudocolour score maps were generated and the peaks of corresponding loads identified enabling visualisation of the biochemical changes associated with malignancy. Changes were noted in the distribution of DNA, glycogen, lipids and proteins. The mean spectra obtained from selected regions demonstrate increased levels of glycogen in the squamous area compared with increased DNA levels in the abnormal region. Raman spectroscopy is a highly sensitive and specific technique for demonstration of biochemical changes in the carcinogenesis of Barrett's oesophagus. There is potential for in vivo application for real-time endoscopic optical diagnosis.

Eltrombopag, a novel, oral platelet growth factor, increases platelet counts in thrombocytopenic patients and healthy subjects

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Background: Eltrombopag (SB-497115) is a novel, first in class, orally bioavailable, thrombopoietin receptor agonist that induces differentiation and proliferation of megakaryocyte progenitors and has been shown to increase platelet counts in preclinical and clinical studies. Methods: In two randomized, placebo-controlled trials, eltrombopag was administered as oral tablets, once daily for 10 days to 73 healthy male subjects at doses of 5–75mg in an ascending dose cohort study, and to 103 (64 female/39 male) adult chronic immune thrombocytopenic purpura (ITP) patients, with a platelet count of <30×109/L, once daily for 6 weeks at doses of 30–75mg in a parallel dose cohort study. The primary efficacy endpoint in the Phase II ITP trial was the proportion of subjects with a platelet count >50×109/L after 6 weeks of dosing. Results: In healthy subjects, eltrombopag induced a dose dependent increase in the platelet counts. Mean maximal platelet count increases were 24.1 % at 30mg, 42.9 % at 50mg, and 50.4 % at 75mg. In 95 eligible ITP patients, platelet counts increased from <30 to >50×109/L in 16% (4/25) of subjects on placebo, and in the eltrombopag groups in 28% (7/25, p=ns) on 30mg, 67% (16/24, p<0.001) on 50mg and 86% (18/21, p<0.001) on 75mg eltrombopag. The median platelet counts in each treatment arm after 6 weeks of dosing were 16×109/L on placebo, 29×109/L on 30mg, 132×109L on 50mg, and 202×109/L on 75mg. The dose dependent effect was not significantly affected by the splenectomy status, background immunosuppressant use, or baseline platelet count (greater than or less than 15×109/L). Conclusions: The platelet count data from these clinical studies suggests that eltrombopag could be an effective therapy for the treatment of thrombocytopenia. Eltrombopag is being tested in further studies involving patients with ITP and chronic liver disease, and cancer patients receiving thrombocytopenic chemotherapy.

[Table: see text]

The safety profile of eltrombopag, a novel oral platelet growth factor, in thrombocytopenic patients and healthy subjects

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Background: Eltrombopag (SB-497115) is an oral, non-peptide, small molecule, thrombopoietin receptor agonist being tested as a potential treatment for thrombocytopenia. Eltrombopag has been shown to increase platelet counts in both healthy subjects and thrombocytopenic patients. Methods: Safety and tolerability data for eltrombopag (3–75 mg for up to 6 weeks) is presented from randomized, placebo-controlled, parallel group clinical trials involving 115 healthy subjects and 104 immune thrombocytopenic purpura (ITP) patients. Safety and tolerability endpoints involved assessment of adverse events (AE) and clinical laboratory parameters, including ECGs and platelet function. Results: In 3 Phase I trials, 98 healthy males received active eltrombopag QD for up to 10 days at 3–75 mg. In the Phase II dose ranging study, 78 chronic ITP patients (28 male/50 female) received active eltrombopag QD for 6 weeks at doses of 30–75 mg. There was no apparent relationship between active and control arms, the dose of eltrombopag and the incidence or severity of AEs, changes in laboratory values, platelet function or cardiac parameters in any of the studies. There were no serious adverse events (SAEs) reported by subjects in the 3 Phase I studies. 5 SAEs were reported in 1 patient in the ITP study that were considered by the investigator as possibly associated with administration of 50 mg eltrombopag. No SAEs were related to 30 mg or 75 mg eltrombopag, and 2 SAEs in 2 patients were related to placebo. Conclusions: There was no apparent relationship between eltrombopag dose and safety endpoints in these studies. These encouraging safety and tolerability data support the further testing of eltrombopag in phase II and III studies involving patients with ITP and chronic liver disease, and cancer patients receiving thrombocytopenic chemotherapy.

[Table: see text]

Assessment of fiberoptic near-infrared raman spectroscopy for diagnosis of bladder and prostate cancer

OBJECTIVES

To determine whether a fiberoptic Raman system, suitable for in vivo use, is able to differentiate between benign and malignant bladder and prostate pathologic findings in vitro. Raman spectroscopy is an optical technique that provides a measure of the molecular composition of tissue by analyzing the way that tissue scatters laser light. Laboratory studies have shown that the technique can be used to identify and characterize transitional cell carcinoma and prostate adenocarcinoma in vitro.

METHODS

A total of 220 Raman spectra were recorded from 29 snap-frozen bladder samples collected at cystoscopic procedures, and 197 Raman spectra were recorded from 38 snap-frozen prostate samples collected at transurethral resection of the prostate. The spectra were correlated with the histologic features and used to construct separate diagnostic algorithms for the bladder and prostate. These algorithms were tested as to their ability to determine the pathologic finding of a sample from its Raman spectrum.

RESULTS

The bladder algorithm was able to differentiate benign samples (normal and cystitis) from malignant samples (transitional cell carcinoma), with an overall accuracy of 84%. The prostate algorithm was able to differentiate benign samples (benign prostatic hyperplasia and prostatitis) from malignant samples (prostate cancer), with an overall accuracy of 86%.

CONCLUSIONS

The results of this study have demonstrated that the clinical Raman system can provide an accurate and objective method to diagnose prostate and bladder cancer in vitro. Because the Raman probe is suitable for use during endoscopic, laparoscopic, or open procedures, this work paves the way for in vivo studies.

The use of Raman spectroscopy to differentiate between different prostatic adenocarcinoma cell lines

Raman spectroscopy (RS) is an optical technique that provides an objective method of pathological diagnosis based on the molecular composition of tissue. Studies have shown that the technique can accurately identify and grade prostatic adenocarcinoma (CaP) in vitro. This study aimed to determine whether RS was able to differentiate between CaP cell lines of varying degrees of biological aggressiveness. Raman spectra were measured from two well-differentiated, androgen-sensitive cell lines (LNCaP and PCa 2b) and two poorly differentiated, androgen-insensitive cell lines (DU145 and PC 3). Principal component analysis was used to study the molecular differences that exist between cell lines and, in conjunction with linear discriminant analysis, was applied to 200 spectra to construct a diagnostic algorithm capable of differentiating between the different cell lines. The algorithm was able to identify the cell line of each individual cell with an overall sensitivity of 98% and a specificity of 99%. The results further demonstrate the ability of RS to differentiate between CaP samples of varying biological aggressiveness. RS shows promise for application in the diagnosis and grading of CaP in clinical practise as well as providing molecular information on CaP samples in a research setting.

Atorvastatin inhibits calcification and enhances nitric oxide synthase production in the hypercholesterolaemic aortic valve

OBJECTIVE

To study in a rabbit model the expression of endothelial nitric oxide synthase (eNOS) in association with the development of calcification of the aortic valve, and to assess the effects of atorvastatin on eNOS expression, nitrite concentration, and aortic valve calcification.

METHODS

Rabbits (n = 48) were treated for three months: 16, forming a control group, were fed a normal diet; 16 were fed a 0.5% (wt/wt) high cholesterol diet; and 16 were fed a 0.5% (wt/wt) cholesterol diet plus atorvastatin (2.5 mg/kg/day). The aortic valves were examined with eNOS immunostains and western blotting. Cholesterol and high sensitivity C reactive protein (hsCRP) concentrations were determined by standard assays. Serum nitrite concentrations were measured with a nitric oxide analyser. eNOS was localised by electron microscopy and immunogold labelling. Calcification in the aortic valve was evaluated by micro-computed tomography (CT).

RESULTS

Cholesterol, hsCRP, and aortic valve calcification were increased in the cholesterol fed compared with control animals. Atorvastatin inhibited calcification in the aortic valve as assessed by micro-CT. eNOS protein concentrations were unchanged in the control and cholesterol groups but increased in the atorvastatin treated group. Serum nitrite concentrations were decreased in the hypercholesterolaemic animals and increased in the group treated with atorvastatin.

CONCLUSION

These data provide evidence that chronic experimental hypercholesterolaemia produces bone mineralisation in the aortic valve, which is inhibited by atorvastatin.

First nuclear moment measurement with radioactive beams by the recoil-in-vacuum technique: the g factor of the 2+1 state in 132Te

Following Coulomb excitation of the radioactive ion beam (RIB) 132Te at HRIBF we report the first use of the recoil-in-vacuum (RIV) method to determine the g factor of the 2(+)(1) state: g(973.9 keV 2(+) 132Te) = (+)0.35(5). The advantages offered by the RIV method in the context of RIBs and modern detector arrays are discussed.

The use of Raman spectroscopy to identify and characterize transitional cell carcinoma in vitro

OBJECTIVE

To determine whether Raman spectroscopy can be used to differentiate between normal, inflammatory and malignant bladder pathologies in vitro, and secondly if it can used to grade and stage transitional cell carcinoma (TCC).

MATERIALS AND METHODS

In all, 1525 Raman spectra were measured from 75 bladder samples comprising normal bladder, cystitis, carcinoma in situ (CIS), TCC and adenocarcinoma. Multivariate analysis was applied to the spectral dataset to construct diagnostic algorithms; these were then tested for their ability to determine the histological diagnosis of each sample from its Raman spectrum.

RESULTS

The diagnostic algorithms could be used to accurately differentiate among the pathological groups, in particular, a three-group algorithm differentiated among normal bladder, cystitis and TCC/CIS with sensitivities and specificities of > 90%. Algorithms could also accurately characterize TCC in terms of splitting them into low (G1/G2) or high (G3) grade and superficial (pTa) or invasive (pT1/pT2) stage.

CONCLUSION

Raman spectroscopy can be used to accurately identify and grade/stage TCC in vitro. The technique therefore shows promise for use as an objective method to assist the pathologist in assessing bladder pathologies. Raman spectroscopy also has potential to provide immediate pathological diagnoses during surgical procedures. Following the promising results of this in vitro study, in vivo cystoscopic studies are planned.

Effects of CaCl2 and MgCl2 on Fourier transform infrared spectra of lung cancer cells

The cations Ca2+ and Mg2+ are two important factors in the growth and maintenance of living cells. The addition of Ca2+ to living cells can cause a change in the three-dimensional (3D) structure of calcium binding proteins. Therefore, we decided to study whether the addition of CaCl2 and MgCl2 to three in vitro growing lung cancer cell lines could cause changes that could be measured by Fourier Transform Infrared Spectroscopy. The addition of CaCl2 or MgCl2 to lung cancer cells caused an increase in absorbance of the trough at 1410 cm(-1). This translated into an inversion of the 1410/1395 cm(-1) ratio following the addition of CaCl2 or MgCl2 for all three lung cancer cell lines. Also, the amide I peak shifted from around 1631 cm(-1) to lower wavenumbers when CaCl2 or MgCl2 was added to cancer cells. Furthermore, the addition of these two substances caused a shift of the peak between 3290 and 3395 cm(-1). Finally, while the addition of CaCl2 to lung cancer cells was associated with an increased cell death, this was not the case following the addition of MgCl2. This would confirm that the changes seen in the spectra of all three cell lines are due to metabolic and ionic shifts rather than cell death.

Raman spectral mapping in the assessment of axillary lymph nodes in breast cancer

This paper is the first reported description of Raman Spectroscopy in the assessment of axillary lymph nodes in breast cancer patients. Raman Spectroscopy is an inelastic scattering spectroscopic technique appropriate for the assessment of unprocessed complex biological tissues. Spectra represent biochemical signatures of the tissue under scrutiny. The described method of Raman spectral mapping produces false-color spectral images of lymph node sections. These can be compared with standard histopathology slides and white light images of nodal tissue. This method has the potential to allow the detailed biochemical assessment of heterogeneous lymph node features, and to contribute towards the development of an optical diagnostic tool for use in a clinical setting.

The use of Raman spectroscopy to identify and grade prostatic adenocarcinoma in vitro

Raman spectroscopy is an optical technique, which provides a measure of the molecular composition of tissue. Raman spectra were recorded in vitro from both benign and malignant prostate biopsies, and used to construct a diagnostic algorithm. The algorithm was able to correctly identify each pathological group studied with an overall accuracy of 89%. The technique shows promise as a method for objectively grading prostate cancer.