Nonphotochemical hole-burning study of selectively stained normal and cancerous human ovarian tissues

Results are presented of nonphotochemical hole-burning (HB) experiments on cancerous ovarian and analogous normal peritoneal in vitro tissues stained with the mitochondrial-selective dye rhodamine 800. A comparison of fluorescence excitation spectra, hole-growth kinetics data, and external electric field (Stark) effects on the shape of spectral holes burned in cancerous and normal tissues stained with rhodamine 800 revealed significant differences only in the dipole moment change (fDeltamu) measured by a combination of HB and Stark spectroscopies. It is shown that the permanent dipole moment change for the S0--> S1 transition of the rhodamine 800 molecules in cancerous tissue is higher than that of normal tissue by a factor of about 1.4. The finding is similar to the HB results obtained earlier for human ovarian surface epithelial cell lines, i.e., OV167 carcinoma and OSE(tsT)-14 normal cells stained with the same mitochondria-specific dye (Walsh et al. Biophys. J. 2003, 84, 1299). We propose that the observed difference in the permanent dipole moment change in cancerous ovarian tissue is related to a modification in mitochondrial membrane potential.     

Spectrometry supports fluorescence staging laparoscopy after intraperitoneal aminolaevulinic acid lavage for gastrointestinal tumours

Conventional staging laparoscopy in combination with fluorescence diagnosis has proven to be an effective modality in the detection of macroscopically occult intraperitoneal tumours and metastases. Rats with induced peritoneal carcinosis are photosensibilized by intraperitoneal aminolaevulinic acid (ALA) lavage. After visualization of the tumour foci, the emission from the lesions is measured spectrometrically and the fluorescence analysed quantitatively ('optical biopsy'). There is a considerable accordance between imaging by fluorescence diagnosis laparoscopy and point spectrometry in the detection of peritoneal malignancies. Compared with surrounding healthy peritoneum, tumour-positive areas show significantly higher fluorescence intensities in spectrometry.     

Photodynamic Diagnosis Using 5‐Aminolevulinic Acid in 41 Biopsies for Primary Central Nervous System Lymphoma

We evaluated the feasibility of 5‐aminolevulinic acid (5‐ALA)‐mediated photodynamic diagnosis (PDD) in the biopsy for primary central nervous system lymphoma (PCNSL). 5‐ALA (20 mg kg^?1) was administered orally 4 hours preoperatively. Forty‐one biopsies obtained under PDD in 47 consecutive biopsies (46 patients) that were finally pathologically diagnosed as PCNSL were evaluated. Positive fluorescence was observed in 34 of those 41 biopsies (82.9%). An intraoperative pathological diagnosis (IOD) of suspected PCNSL was made in 21 of the biopsies with positive fluorescence (61.8%). However, the eight IODs in the remaining 13 biopsies (23.5%) were not correct (atypical cell, 4; high‐grade glioma, 1; gliosis, 1; unremarkable, 2). In those 8 biopsies, PCNSL was confirmed by the final pathological diagnosis. There was no difference in the mean Mib‐1 labeling index between the biopsies with positive fluorescence (86.5%) and those without positive fluorescence (90.0%). IOD was not performed in 6 biopsies; however, 5 of those biopsies (83.3%) showed positive fluorescence and were finally pathologically diagnosed as PCNSL. Use of PDD in biopsies for patients with suspected PCNSL is a reliable way of obtaining specimens of adequate quality for the final pathological diagnosis and may lead to improved diagnostic yield in the biopsy of PCNSL.     

Characterisation of liposomes containing aminolevulinic acid and derived esters

Liposomes of different compositions have been designed to improve delivery of aminolevulinic acid (ALA) and its esterified derivatives ALA-Hexyl ester (He-ALA) and ALA-Undecanoyl ester (Und-ALA) for its use in photodynamic therapy (PDT). Egg yolk phosphatidyl choline (PC), phosphatidic acid (PA) and phosphatidyl glycerol (PG) were employed in the preparation of the liposomes. Sonicated vesicles composed of PC, PC-PG (80:20) or PC-PA (80:20) containing ALA or derivatives were obtained and purified by a minicolumn centrifugation method. PC liposomes presented encapsulation percentages around 6% for 2 mM ALA, 13% for 2 mM He-ALA and 51% for 2 mM Und-ALA. The addition of PG or PA to the formulation, resulted in an increased entrapment: 19% for 2 mM ALA, 69% for 2 mM He-ALA and 87% for 2 mM Und-ALA in PC-PG liposomes and 21% for 2 mM ALA, 60% for 2 mM He-ALA and 87% for 2 mM Und-ALA in PC-PA liposomes. Higher concentrations of ALA or derivatives resulted in lower percentages of entrapment. The three formulations containing ALA or derivatives were stable up to 1 week upon storage at 4 degrees C. However, upon dilution with medium, ALA leaked from the liposomes, while on the contrary, He-ALA was highly retained, being therefore a good choice for its use in PDT. The stability of Und-ALA upon dilution could not be tested, but Und-ALA proved to have the highest entrapment efficacy.     

White-light toxicity, resulting from systemically administered 5-aminolevulinic acid, under normal operating conditions

This study has investigated damage to the intraperitoneal organs of the rat after systemic (intraperitoneal and intravenous) administration of low doses of 5-aminolevulinic acid (ALA) and illumination with a standard white-light operating-room (o.r.) lamp. The study has been done within the framework of a larger study in which the possibility of using ALA for localization of small-volume macroscopically nonvisible peritoneal metastasis of ovarian tumors is being investigated. Fluorescence diagnostics are done in addition to the standard staging and localization procedures, either through a laparoscope or during laparotomy. In these circumstances, fluorescence diagnostics involve some risk of photosensitization of critical organs since a broad-band (o.r.) light source is used during the surgical procedures for illumination of the operating area. The drug dose and the time interval between administration of ALA and illumination are varied and normal tissues are examined both macroscopically and microscopically for damage. A relationship is demonstrated between the maximum tolerable dose (MTD) of ALA (defined as the dose that does not cause any tissue damage) and the time interval between administration and illumination. The white light that is used for illumination of the operating area is sufficient to induce damage to the peritoneal organs at relatively low ALA doses. The MDTs for 2, 6 and 16 h intervals are found to be respectively 1, 10 and 100 mg kg⁻¹. The results are similar for both intraperitoneal and intravenous administration.     

Light Dosimetry for Intraperitoneal Photodynamic Therapy in a Murine Xenograft Model of Human Epithelial Ovarian Carcinoma

Few studies have been published to date measuring spatially resolved fluence rates in complex tissue geometries. Here the light distributions of three different intraperitoneal light delivery geometries in a murine ovarian cancer model were investigated to assess their influence on the tumorcidal efficacy of photodynamic therapy (PDT). In vivo fluence rate measurements in the peritoneal cavities of mice, with the light intensity being mapped in three transverse planes, were performed using fiber-optic detectors. Three different source fiber designs and placements were tested for their ability to provide uniform irradiation of the peritoneal cavity. The biological response to a PDT protocol comprising three separate treatments administered at 72 h intervals, each consisting of a 0.25 mg kg intraperitoneal injection of benzopor-phyrin derivative-mono acid ring A followed 90 min later by delivery of 15 J of 690 nm light, was measured. The tissue response was evaluated by measuring the number of remaining visible lesions and the total residual tumor mass. Fluence rate measurements showed large variations in the fluence rate distribution for similar intended treatments. The most uniform and reproducible illumination was achieved using two 18 mm long cylindrical emitting optical fibers. The biological response was comparable to that produced when a flat-cleaved end optical fiber is used to illuminate the four quadrants of the abdomen sequentially. While a good reproducibility in tumor induction in this animal model exists, no correlation was found between the fluence rate distribution measured in one group of animals and the biological response in a separate group of similarly treated animals. Due to the large intra-animal variability in fluence rate distribution, representative fluence rate mapping in complex tissue geometries is of limited value when applied to an individual PDT treatment. Thus, surveillance of the fluence rate during individual treatments will be required for acceptable PDT dosimetry. To improve the versatility of this particular animal model for PDT research, a large number of extended sources are required to increase uniformity of the illumination in order to reduce unwanted cytotoxic side effects resulting from foci of high fluence rates. In this way, subsequent increase of the total energy delivered to the tumor may be possible.     

Optical diagnosis of peritoneal metastases by infrared microscopic imaging

Fourier transform infrared (FTIR) spectroscopy is nowadays widely accepted as a technique with high potential for diagnosis of cancerous tissues. This study presents an example of the investigation of peritoneal metastases by FTIR microimaging. Peritoneal malignancies are generally secondary localizations of primary visceral cancers such as ovarian, stomach or colon cancers. By analysing simultaneously both formalin-fixed paraffin-embedded and frozen specimens, we examined malignant and non-malignant (i.e. fibrotic and cicatricial) peritoneal lesions. Paraffin-embedded tissues were analysed without any previous dewaxing. Multivariate statistical approaches, based on the classification of infrared data by hierarchical cluster analysis, allowed the discrimination of these various samples. Microimaging also permits the revelation of the heterogeneity of the tissue: it was possible to localize precisely the cancerous areas, and to distinguish, on the basis of their spectral signatures, the peritumoral neighbouring connective tissue close to the carcinomatous areas from the connective tissue distant from the cancerous areas. These spectral differences could be useful as complementary information to study molecular changes associated with the malignancy.     

Fluorescence staining of oral cancer using a topical application of 5-aminolevulinic acid: fluorescence microscopic studies

INTRODUCTION: Topical application of 5-aminolevulinic acid (5-ALA) by means of a rinsing solution has been shown to be a promising new procedure in the diagnosis of oral malignancies. However, for assessing the reliability of this method regarding fluorescence-guided tumor resections and photodynamic therapy, further information on the distribution and penetration depth of 5-ALA-induced protoporphyrin IX (PPIX) in the tissue is needed. METHODS: 24 patients suffering from oral cancer were included in this investigation. Biopsies were taken immediately after fluorescence examination and either used as native sections for immediate fluorescence microscopic examination (n = 3) or shock frozen in liquid nitrogen and prepared as frozen sections (n = 46). Fluorescence imaging and digital image processing were utilized in order to determine the presence of PPIX in regions of various histologies as well as the penetration depth of PPIX into solid tumor. RESULTS: PPIX fluorescence in the tissue was limited to the epithelium. Both normal and dysplastic epithelium showed PPIX fluorescence. In the stroma, no PPIX fluorescence was found. In some cases (n = 3/4) invasive carcinomas did not show PPIX fluorescence, while the adjacent or overlying normal epithelium was strongly fluorescent. The penetration depth of PPIX after topical application of 5-ALA was found to be limited to less than 1 mm. CONCLUSION: PPIX fluorescence induced by topical application of 5-ALA can be very useful in the determination of superficial tumor margins. However, due to the limited penetration depth there is a risk of not accurately recognizing the infiltration depth of solid tumors. The aim of further investigations will be to assess the tissue distribution and depth of penetration of PPIX following systemic application of 5-ALA.     

Enhanced ALA-induced fluorescence in hyperparathyroidism

INTRODUCTION: Intraoperative localization of parathyroid glands can be challenging especially in minimally invasive surgery. Fluorescence diagnosis using the photosensitizer aminolevulinic acid (ALA) has been described to identify normal parathyroid glands during experimental bilateral neck exploration. The present study evaluated fluorescence differences between hyperplastic and normal parathyroid glands as a precondition for a clinical application of the technique. MATERIALS AND METHODS: Polycystic kidney disease (PKD) rats with hyperparathyroidism due to hyperplastic parathyroid glands and Wistar rats with normal parathyroid glands were photosensitized by peritoneal lavage with ALA solution. After surgical exposure of thyroid and parathyroid glands the operative site was observed under blue light conditions using the d-light system to assess fluorescence characteristics of each tissue. Fluorescence intensities of parathyroid glands and surrounding thyroid tissue were measured by spectrometry. Parathyroid hormone in serum of the rats was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Observation of the exposed thyroid site showed a subjectively stronger red fluorescence of the parathyroid glands in the PKD rats in comparison to the Wistar rats, whereas thyroid tissue appeared equally fluorescent. In the PKD animals, spectrometric fluorescence intensity was 10 times higher in the parathyroid glands than in the thyroid gland, whereas in the Wistar rats the ratio was 3.2:1. Fluorescence intensity in the parathyroid glands was more than twice in the PKD rats than in the Wistar rats, however slightly lower in the thyroid tissue. ELISA confirmed the pathophysiological change of a hyperparathyroidism with significantly increased serum levels of parathyroid hormone in the PKD rats. DISCUSSION: Hyperparathyroidism enhances ALA-induced fluorescence of the parathyroid glands. A combined surgical fluorescence strategy may justify a unilateral, minimally invasive approach in selected patients and serve to improve the capability of the surgeon to safely and efficiently manage parathyroid diseases.     

In vivo skin absorption dynamics of topically applied pharmaceuticals monitored by fiber-optic diffuse reflectance spectroscopy

A simple non-invasive ultra-violet/visible (UV/vis) diffusive reflectance spectroscopy combined with fiber-optics was investigated to elicit the dynamics of skin penetration in vivo of a pharmaceutical, aminolevulinic acid polyethylene glycol cream (5-ALA-PEG cream). Temporal data of the reflectance, R(lambda), were measured from a bare skin region and from a skin region treated with 5-ALA cream. The difference in apparent optical density [(DeltaAOD)=Deltalog[1/R(lambda)]] between the treated and untreated regions of the skin was gradually increased to a local maximum value with an increasing time of measurement, and then it was decreased in an oscillatory manner. This temporal increase in DeltaAOD was interpreted as a diminution of total reflectance by an increased scattering inside the skin tissue as topically applied materials penetrated gradually and temporally accumulated into the skin. A following decrease in DeltaAOD was attributed to diminished scattering effects as the penetrated materials gradually cleared out by cellular uptake of 5-ALA and circulation by epidermal capillary. In conclusion, it was possible to measure the skin absorption kinetics of the topically treated materials, including the penetration time and clearing out from the temporal course of the differential AOD.     

Plasma Exosomes of Patients with Breast and Ovarian Tumors Contain an Inactive 20S Proteasome

Exosomes are directly involved in governing of physiological and pathological conditions of an organism through the transfer of information from producing to receiving cells. It can be assumed that exosomes are one of the key players of tumor dissemination since they are very stable and small enough to penetrate from various tissues into biological fluids and then back, thus interacting with tissue target cells. We evaluated the enzymatic activity and the level of 20S proteasome in tissue and exosomes of healthy females (n = 39) and patients with ovarian (n = 50) and breast (n = 108) tumors to reveal the critical role of exosomal cargo in the mediation of different types of metastases. Exosomes from plasma and ascites were isolated and characterized in according to International Society for Extracellular Vesicles guidelines. The level of 20S proteasome in tissue and exosomes was determined using Western blot analysis. Chymotrypsin- and caspase-like (ChTL and CL, respectively) peptidase activities of the proteasomes were determined using fluorogenic Suc-LLVY-AMC and Cbz-LLG-AMC substrates, respectively. We observed increased levels of 20S proteasome in ovarian cancer tissue and luminal B subtype breast cancer tissue as well as in plasma exosomes from cancer patients. Moreover, the level of the 20S proteasome in plasma exosomes and ascites exosomes in patients with ovarian tumors is comparable and higher in ovarian cancer patients with low volume ascites than in patients with moderate and high-volume ascites. We also found increased ChTL and CL activities in breast cancer and ovarian cancer tissues, as well as in peritoneal metastases in ovarian cancer, while proteasomal activity in exosomes from plasma of healthy females and all patients, as well as from ascites of ovarian tumor patients were lower than detection limit of assay. Thus, regardless of the type of tumor metastasis (lymphogenous or peritoneal), the exosomes of cancer patients were characterized by an increased level of 20S proteasome, which do not exhibit enzymatic activity.     

NIR‐II Fluorescent Self‐Assembled Peptide Nanochain for Ultrasensitive Detection of Peritoneal Metastasis

Fluorescence‐guided cytoreductive surgery is one of the most promising approaches for facile elimination of tumors in situ, thereby improving prognosis. Reported herein is a simple strategy to construct a novel chainlike NIR‐II nanoprobe (APP‐Ag₂S‐RGD) by self‐assembly of an amphiphilic peptide (APP) into a nanochain with subsequent chemical crosslinking of NIR‐II Ag₂S QDs and the tumor‐targeting RGD peptide. This probe exhibits higher capability for cancer cell detection compared with that of RGD‐functionalized Ag₂S QDs (Ag₂S‐RGD) at the same concentration. Upon intraperitoneal injection, superior tumor‐to‐normal tissue signal ratio is achieved and non‐vascularized tiny tumor metastatic foci as small as about 0.2 mm in diameter could be facilely eliminated under NIR‐II fluorescent imaging guidance. These results clearly indicate the potential of this probe for fluorescence‐guided tumor staging, preoperative diagnosis, and intraoperative navigation.     

Photodetection with 5-Aminolevulinic acid-induced protoporphyrin IX in the rat abdominal cavity: drug-dose-dependent fluorescence kinetics

In 75% of cases, ovarian carcinoma has already metastasized in the abdominal cavity at the time of diagnosis. For determination of the necessity for a supplementary therapy, in addition to surgical resection, it is important to localize and stage microscopical intraperitoneal metastases of the tumor. Intraperitoneal photodetection of tumor metastases is based on preferential tumor distribution of a fluorescent tumor marker. The time-dependent differences in drug concentration between tumor and normal (T/N) tissues can be used to visualize small tumors. We performed fluorescence measurements on abdominal organs and tumor in the peritoneal cavity of rats. 5-Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) was used as the fluorescent marker. Three different drug doses (100, 25 and 5 mg/kg) were used and PpIX fluorescence profiles were followed up to 24 h after intravenous administration. Maximum T/N ratios were found 2-3 h after administration of ALA with all drug doses. A significant T/N tissue contrast was obtained for all abdominal organs tested after administration of 5 mg/kg.     

Use of 5‐Fluorouracil Loaded Micelles and Cisplatin in Thermosensitive Chitosan Hydrogel as an Efficient Therapy against Colorectal Peritoneal Carcinomatosis

Colorectal peritoneal carcinomatosis (CRPC) is a common systemic metastasis of intra‐abdominal cancers. Intraperitoneal chemotherapy against CRPC is at present the preferred treatment. The aim of this study is to develop a novel hydrogel drug delivery system through the combination of 5‐fluorouracil (5‐FU) loaded polymeric micelles and cisplatin (DDP) in biodegradable thermosensitive chitosan (CS) hydrogel. The prepared CS hydrogel drug is a free‐flowing solution at room temperature and forms a stationary gel at body temperature. Therefore, a CRPC mouse model is established to investigate the antitumor activity of CS hydrogel drug system. The results suggest that intraperitoneal administration of CS hydrogel drug can inhibit tumor growth and metastasis, and prolong survival time compared with other groups, thus improving the chemotherapeutic effect. Ki‐67 immunohistochemical analysis reveals that tumors in the CS hydrogel drug group has lower cell proliferation in contrast to other groups (P < 0.001). Furthermore, hematoxylin‐eosin staining of liver and lung tissue indicates that the CS hydrogel drug has also a certain inhibitory effect on colorectal cancer metastasis to the liver and lung. Hence, the work highlights the potential clinical applications of the CS hydrogel drug.

     

Depth Profile of Protoporphyrin IX Fluorescence in an Amelanotic Mouse Melanoma Model

Protoporphyrin IX (PpIX) fluorescence was measured at different depths in a subcutaneous amelanotic melanoma model (LOX) in mice. PpIX was induced by topical application of 5‐aminolevulinic acid (ALA) and two of its derivatives, the methylester (MAL) and hexylester (HAL) onto the normal skin covering the tumor. The PpIX fluorescence intensity on the surface of the tumors was the highest for HAL, followed by ALA and MAL. Using equimolar concentrations (0.5 mmol g^?1), HAL induced nearly twice as much fluorescence as ALA did. The depth profile of PpIX fluorescence was measured at different layers of the tumor, which was carefully sliced and controlled in situ ex vivo. The PpIX fluorescence was mainly localized within the upper 2 mm of the tissue for ALA and within 1 mm for MAL and HAL. There were no significant differences in the shape of the fluorescence excitation spectra, but the long wavelength excitation peak (633 nm) was so weak that these results are unreliable for depth estimation. When considering the low fluorescence intensity (around 5% of the intensity at the tumor surface), the actual penetration depth of HAL was comparable to that of ALA. The fluorescence after topical application of ALA and HAL was significantly above the background level down to a depth of around 6 mm, and there were traces of PpIX fluorescence even at the tumor base (10 mm). The fluorescence after topical application of MAL was detectable down to 1 mm. In the depth of 2–6 mm, the fluorescence was slightly higher for HAL than for ALA. Using the estimated diffusion coefficients for topically applied ALA (0.16 ± 0.03 mm² h^?1), MAL (0.045 ± 0.005 mm² h^?1) and HAL (0.037 ± 0.003 mm² h^?1), the behavior of the drugs after different application times could be estimated in this tumor model.     

An HPLC and EPR investigation on the stability of DMPO and DMPO spin adducts in vivo

Application of the spin trapping technique in intact animals requires an understanding of the stability and distribution of the spin traps and their spin adducts in vivo. We studied the stability of DMPO in vivo in mice using HPLC and the stability of spin adducts of DMPO by EPR in plasma, whole blood, peritoneal fluid, and homogenized heart tissue of the rat. At 15 minutes after intraperitoneal injection DMPO had similar concentrations in the liver, heart, and blood of the mice and 40% remained in the organs 2 hours after the injection. In contrast, the spin adduct DMPO-OH was short lived, with a half-life of 3.0 minutes in plasma, and was not detectable 1 minute after formation in whole blood and homogenized heart tissue. The carbon centered spin adduct DMPO-CH(OH)CH₃ was more stable, having half-lives of 16, 11, 3.6, and 0.79 minutes in plasma, peritoneal fluid, whole blood, and homogenized heart tissue, respectively. The spin adduct DMPO-SO₃ was sufficiently stable for the adduct to be observed directly from living mice.     

Pharmacokinetics of 5-aminolevulinic acid-induced protoporphyrin IX in skin and blood

The fluorescence and photosensitivity of endogenously synthesized protoporphyrin IX (PPIX) is increasing used for the diagnosis and treatment of malignant and certain non-malignant diseases. A selective accumulation of PPIX can be induced by application of 5-aminolevulinic acid (5-ALA), which is a precursor of PPIX in the cellular biosynthetic pathway of heme.

The purpose of this study was to monitor the in vivo accumulation of PPIX in different locations of the skin after oral ingestion and to determine the pharmacokinetics of 5-ALA and PPIX in human blood plasma for various routes of application. At the same time we wanted to achieve an optimal treatment scheme but also study possible side-effects of 5-ALA administration.

After oral application of 5-ALA in a concentration of 40 mg kg⁻¹ body weight, the fluorescence intensities of PPIX in the skin showed maxima between 6.5 and 9.8 h depending on the location and decreased to values lower than 5% related to the maximum after a mean time of about 40 h. The measured absolute intensities of PPIX fluorescence varied strongly between different patients and different locations on one patient. In the plasma of blood samples, PPIX could be detected via its fluorescence for all studied routes of application with the exception of the ointment, where PPIX levels were below the detection limit of 1 μg l⁻¹. The highest mean concentration of 742 μg l⁻¹ PPIX in the plasma was measured 6.7 h after oral application. For inhalation of 5-ALA, a mean maximum concentration of 12 μg l⁻¹ could be detected 4.1 h after application, for intravesical instillation, the mean maximum concentration was found to be 1 μg l⁻¹ 2.9 h after application. The kinetics of 5-ALA in the plasma peaked much earlier with a maximum concentration of 32 mg l⁻¹ about 30 min. after oral administration. The 5-ALA levels did not exceed normal reference values after topical application.

The results of our experiments suggest that for a systemic application of 5-ALA side-effects in sensitive patients cannot be excluded.     

18F-FDG PET/CT显像联合肿瘤标志物检查对女性不明原因腹腔积液的诊断价值

本文探讨了18 F-脱氧葡萄糖(18 F-FDG)正电子发射计算机断层显像(PET/CT)联合肿瘤标志物检查对女性不明原因腹腔积液的鉴别诊断价值。选取95例不明原因腹腔积液女性患者的18 F-FDG PET/CT影像资料及肿瘤标志物资料进行回顾性分析,并与病理诊断结果进行对照。结果显示:95例患者中,经病理证实恶性腹腔积液74例,良性腹腔积液21例。PET/CT对良恶性腹腔积液的诊断灵敏度为98.65%,特异度为19.05%,准确度为81.05%。恶性腹腔积液的SUV max与良性腹腔积液比较,差异无统计学意义(P>0.05)。将患者按病因进一步细分后发现,卵巢癌组的SUV max明显高于其他良性原因组(P<0.05),但与结核组和其他恶性肿瘤组比较,差异无统计学意义(P>0.05)。肿瘤标志物中以CA125检测效率最高,其对卵巢癌及结核所致腹腔积液的诊断灵敏度为98.2%,特异度为7.7%,准确度为81.4%。PET/CT和CA125联合诊断对卵巢癌及结核所致腹腔积液的灵敏度、特异度及准确度与单一PET/CT或CA125诊断比较差异均无统计学意义(P>0.05)。本实验表明18 F-FDG PET/CT诊断女性不明原因腹腔积液的良恶性有较高的灵敏度和准确度,但特异性较差,联合肿瘤标志物检查并不能提高对卵巢癌及结核所致腹腔积液的诊断效能。     

Photodynamic destruction of Haemophilus parainfluenzae by endogenously produced porphyrins

Bacterial resistance against antibiotic treatment is becoming an increasing problem in medicine. Therefore methods to destroy microorganisms by other means are being investigated, one of which is photodynamic therapy (PDT).

It has already been shown that a variety of Gram-positive and Gram-negative bacteria can be killed in vitro by PDT using exogenous sensitizers. An alternative method of photosensitizing cells is to stimulate the production of endogenous sensitizers. The purpose of this study was to investigate the bactericidal efficacy of PDT for Haemophilus parainfluenzae with endogenously produced porphyrins, synthesized in the presence of δ-aminolaevulinic acid (δ-ALA). H. parainfluenzae incubated with increasing amounts of δ-ALA showed decreased survival after illumination with 630 nm light. No photodynamic effect on the bacterial viability was found when H. parainfluenzae was grown without added δ-ALA. H. influenzae, grown in the presence of δ-ALA, but not capable of synthesizing porphyrins from δ-ALA, was not affected by PDT. Of the range of incident wavelengths, 617 nm appeared to be the most efficient in killing the bacteria. Spectrophotometry of the bacterial porphyrins demonstrated that the maximum fluorescence occurred at approximately 617 nm, with a much lower peak around 680 nm. We conclude that a substantial killing of H. parainfluenzae by PDT in vitro after endogenous sensitization with δ-ALA can be achieved.