Influence of vitamins and food on the fluorescence spectrum of human urine.

OBJECTIVES: Fluorescence spectroscopy of human urine is a method with the potential to gain importance as a diagnostic tool in the medical field, e.g., for measuring Coproporphyrin III (CPIII) as an indicator of cancer and acute types of porphyria. Food can change human urine's color, which could influence the urine fluorescence spectrum and the detection of CPIII in urine. To determine if there is a noticeable influence on the urine fluorescence spectrum or on the detection of CPIII in urine, 16 vitamin supplements, and three food items were tested. Such investigation may also prevent false interpretation of measured data. METHODS: Urine samples were collected before and after (overnight, ca. 8 h) intake of each test substance. Samples were investigated by fluorescence spectrum analysis. At excitation wavelengths from 300 to 500 nm and emission wavelengths from 400 to 700 nm excitation-emission-matrices were measured. Data obtained from urine before intake were compared to the data from overnight urine. Furthermore, the investigation of any interference with the CPIII concentration was performed at an excitation wavelength of 407 ± 3 nm and emission wavelengths of 490-800 nm. RESULTS: Only vitamin B2, but none of the other tested substances, showed noticeable influence on the urine fluorescence spectrum. None of the tested substances showed noticeable interference with the recovery rate of CPIII. CONCLUSIONS: The correct interpretation of measured data by fluorescence spectroscopy is possible with the exception if vitamin B2 supplementation was performed; thus, the consumption of vitamin B2 supplements before fluorescence testing of the patient's urine should be avoided and/or must be requested. CPIII concentrations could reliably be measured in all cases.

Non-Invasive Zinc Protoporphyrin Screening Offers Opportunities for Secondary Prevention of Iron Deficiency in Blood Donors.

Background: Frequent blood donors are at high risk of developing iron deficiency. Currently, there is no potent screening during blood donation to detect iron deficient erythropoiesis (IDE) before anemia develops and deferral from donation is inevitable. Study Design and Methods: In addition to capillary and venous hemoglobin, the iron status of 99 frequent blood donors was assessed by various venous blood parameters and zinc protoporphyrin IX (ZnPP). ZnPP was determined by high-performance liquid chromatography (HPLC) and a new prototype fiber-optic device was employed for non-invasive measurements of ZnPP through the blood collection tubing (NI-tubing) and on lip tissue (NI-lip). We aimed to evaluate the feasibility and diagnostic value of the NI-tubing measurement for early detection of severe iron deficiency in blood donors. Results: NI-tubing and HPLC reference measurements of ZnPP showed narrow limits of agreement of 12.2 µmol ZnPP/mol heme and very high correlation (Spearman's Rho = 0.938). Using a cutoff of 65 µmol ZnPP/mol heme, NI-tubing measurements (n = 93) identified 100% of donors with iron deficiency anemia (IDA) and an additional 38% of donors with IDE. Accordingly, NI-tubing measurements would allow detection and selective protection of particularly vulnerable donors. Conclusion: NI-tubing measurements are an accurate and simple method to implement ZnPP determination into the routine blood donation process. ZnPP was able to identify the majority of subjects with IDE and IDA and might therefore be a valuable tool to provide qualified information to donors about dietary measures and adjustments of the donation interval and thereby help to prevent IDA and hemoglobin deferral in the future.

Interstitial Photodynamic Therapy of Glioblastomas: A Long-Term Follow-up Analysis of Survival and Volumetric MRI Data.

BACKGROUND: The treatment of glioblastomas, the most common primary malignant brain tumors, with a devastating survival perspective, remains a major challenge in medicine. Among the recently explored therapeutic approaches, 5-aminolevulinic acid (5-ALA)-mediated interstitial photodynamic therapy (iPDT) has shown promising results. METHODS: A total of 16 patients suffering from de novo glioblastomas and undergoing iPDT as their primary treatment were retrospectively analyzed regarding survival and the characteristic tissue regions discernible in the MRI data before treatment and during follow-up. These regions were segmented at different stages and were analyzed, especially regarding their relation to survival. RESULTS: In comparison to the reference cohorts treated with other therapies, the iPDT cohort showed a significantly prolonged progression-free survival (PFS) and overall survival (OS). A total of 10 of 16 patients experienced prolonged OS (≥ 24 months). The dominant prognosis-affecting factor was the MGMT promoter methylation status (methylated: median PFS of 35.7 months and median OS of 43.9 months) (unmethylated: median PFS of 8.3 months and median OS of 15.0 months) (combined: median PFS of 16.4 months and median OS of 28.0 months). Several parameters with a known prognostic relevance to survival after standard treatment were not found to be relevant to this iPDT cohort, such as the necrosis-tumor ratio, tumor volume, and posttreatment contrast enhancement. After iPDT, a characteristic structure (iPDT remnant) appeared in the MRI data in the former tumor area. CONCLUSIONS: In this study, iPDT showed its potential as a treatment option for glioblastomas, with a large fraction of patients having prolonged OS. Parameters of prognostic relevance could be derived from the patient characteristics and MRI data, but they may partially need to be interpreted differently compared to the standard of care.

Interstitial photodynamic therapy for newly diagnosed glioblastoma.

PURPOSE: Innovative, efficient treatments are desperately needed for people with glioblastoma (GBM). METHODS: Sixteen patients (median age 65.8 years) with newly diagnosed, small-sized, not safely resectable supratentorial GBM underwent interstitial photodynamic therapy (iPDT) as upfront eradicating local therapy followed by standard chemoradiation. 5-aminolevulinic acid (5-ALA) induced protoporphyrin IX was used as the photosensitizer. The tumors were irradiated with light at 635 nm wavelength via stereotactically implanted cylindrical diffuser fibers. Outcome after iPDT was retrospectively compared with a positively-selected in-house patient cohort (n = 110) who underwent complete tumor resection followed by chemoradiation. RESULTS: Median progression-free survival (PFS) was 16.4 months, and median overall survival (OS) was 28.0 months. Seven patients (43.8%) experienced long-term PFS > 24 months. Median follow-up was 113.9 months for the survivors. Univariate regression revealed MGMT-promoter methylation but not age as a prognostic factor for both OS (p = 0.04 and p = 0.07) and PFS (p = 0.04 and p = 0.67). Permanent iPDT-associated morbidity was seen in one iPDT patient (6.3%). Patients treated with iPDT experienced superior PFS and OS compared to patients who underwent complete tumor removal (p < 0.01 and p = 0.01, respectively). The rate of long-term PFS was higher in iPDT-treated patients (43.8% vs. 8.9%, p < 0.01). CONCLUSION: iPDT is a feasible treatment concept and might be associated with long-term PFS in a subgroup of GBM patients, potentially via induction of so far unknown immunological tumor-controlling processes.

Bronchoscopic Probe-Based Confocal Laser Endomicroscopy to Diagnose Diffuse Parenchymal Lung Diseases.

Background: Diagnosis of diffuse parenchymal lung disease (DPLD) is based on clinical evaluation, radiological imaging and histology. However, additional techniques are warranted to improve diagnosis. Aims and objective: Probe based confocal laser endomicroscopy (pCLE) allows real time in vivo visualisation of the alveolar compartment during bronchoscopy based on autofluorescence of elastic fibres. We used pCLE (Cellvizio®, Mauna Kea Technology. Inc, Paris, France) to characterise alveolar patterns in patients with different types of DPLD. Methods: In this pilot study we included 42 therapy naive patients (13 female, age 72.6 +/- 2.3 years), who underwent bronchoscopy for workup of DPLD. pCLE images were obtained during rigid bronchoscopy in affected lung segments according to HR-CT scan, followed by cryobiopsies in the identical area. Diagnoses were made by a multidisciplinary panel. The description of pCLE patterns was based on the degree of distortion of the hexagonal alveolar pattern, the density of alveolar structures, the presence of consolidations or loaded alveolar macrophages (AM). The assessment was performed by 2 investigators blinded for the final diagnosis. Results: The normal lung showed a typical alveolar loop pattern. In amiodarone lung disease loaded AM were predominant. COP showed characteristic focal consolidations. IPF was characterized by significant distortion and destruction, NSIP showed significant increase in density, and chronic HP presented with consolidations, mild distortion and density. Conclusion: pCLE shows potential as an adjunctive bronchoscopic imaging technique in the differential diagnosis of DPLD. Structured and quantitative analysis of the images is required.

The role of Shikonin in improving 5-aminolevulinic acid-based photodynamic therapy and chemotherapy on glioblastoma stem cells.

Glioblastoma multiforme is a malignant neoplasia with a median survival of less than two years and without satisfactory therapeutic options. The so-called glioblastoma stem cells escape the established radio- and chemotherapies and lead to tumor recurrence in most cases. The alkaloid Shikonin with its various anti stem cell properties and the interstitial photodynamic therapy with 5-aminolevulinic acid seem to be promising new options in the therapy of glioblastoma. In this study, in vitro investigations were performed to observe the influence of Shikonin on viability, proliferation, induction of apoptosis and the capability of forming tumor spheres in U-87 MG and the primary glioblastoma cell line GB14. The combined effect with the chemotherapeutic temozolomide and photodynamic treatment on the mRNA expression of glioma specific stem cell markers and further examined intracellular protoporphyrin IX accumulation under Shikonin treatment was analyzed. Shikonin effectively inhibited the capability of forming tumor spheres and enhanced temozolomide effectiveness in the reduction of proliferation and in the induction of apoptosis. Additionally, Shikonin increased the mRNA expression of the tumor suppressing Neurofibromatosis type 1 (NF1) gene and showed modulating effects on intracellular protoporphyrin IX.

Development and validation of a triple-LED surgical loupe device for fluorescence-guided resections with 5-ALA.

OBJECTIVE: Fluorescence-guided resections performed using 5-aminolevulinic acid (5-ALA) have been studied extensively using the BLUE400 system. The authors introduce a triple-light-emitting diode (LED) headlight/loupe device for visualizing fluorescence, and compare this to the BLUE400 gold standard in order to assure similar and not more or less sensitive protoporphyrin-IX visualization. METHODS: The authors defined the spectral requirements for a triple-LED headlight/loupe device for reproducing the xenon-based BLUE400 module. The system consisted of a white LED (normal surgery), a 409-nm LED for excitation, a 450-nm LED for background illumination, and appropriate observation filters. The prototype's excitation and emission spectra, illumination and detection intensities, and spot homogeneity were determined. The authors further performed a prospectively randomized and blinded study for fluorescence assessments of fresh, marginal, fluorescing and nonfluorescing tumor samples comparing the LED/loupe device with BLUE400 in patients with malignant glioma treated with 20 mg/kg body weight 5-ALA. Tumor samples were immediately assessed in turn, both with a Kinevo and with a novel triple-LED/loupe device by different surgeons. RESULTS: Seven triple-LED/loupe devices were analyzed. Illumination intensities in the 409- and 450-nm range were comparable to BLUE400, with high spot homogeneity. Fluorescence intensities measured distally to microscope oculars/loupes were 9.9-fold higher with the loupe device. For validation 26 patients with malignant gliomas with 240 biopsies were analyzed. With BLUE400 results as the reference, sensitivity for reproducing fluorescence findings was 100%, specificity was 95%, positive predictive value was 98%, negative predictive value was 100%, and accuracy was 95%. This study reached its primary aim, with agreement in 226 of 240 (94.2%, 95% CI 0.904-0.968). CONCLUSIONS: The authors observed only minor differences regarding spectra and illumination intensities during evaluation. Fluorescence intensities available to surgeons were 9.9-fold higher with the loupe device. Importantly, the independent perception of fluorescence achieved using the new system and BLUE400 was statistically equivalent. The authors believe the triple-LED/loupe device to be a useful and safe option for surgeons who prefer loupes to the microscope for resections in appropriate patients.

Interstitial Photodynamic Therapy Using 5-ALA for Malignant Glioma Recurrences.

Interstitial photodynamic therapy (iPDT) using 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) as a cytotoxic photosensitizer could be a feasible treatment option for malignant gliomas. In a monocentric cohort of consecutive patients treated between 2006 and 2018, a risk profile analysis of salvage iPDT for local malignant glioma recurrences and associated outcome measures are presented here. It was considered indicated in patients with circumscribed biopsy-proven malignant glioma recurrences after standard therapy, if not deemed eligible for safe complete resection. A 3D treatment-planning software was used to determine the number and suitable positions of the cylindrical diffusing fibers placed stereotactically to ensure optimal interstitial irradiation of the target volume. Outcome measurements included the risk profile of the procedure, estimated time-to-treatment-failure (TTF), post-recurrence survival (PRS) and prognostic factors. Forty-seven patients were treated, of which 44 (median age, 49.4 years, range, 33.4-87.0 years, 27 males) could be retrospectively evaluated. Recurrent gliomas included 37 glioblastomas (WHO grade IV) and 7 anaplastic astrocytomas (WHO grade III). Thirty (68.2%) tumors were O-6-methylguanine-DNA methyltransferase (MGMT)-methylated, 29 (65.9%)-isocitrate dehydrogenase (IDH)-wildtype. Twenty-six (59.1%) patients were treated for their first, 9 (20.5%)-for their second, 9 (20.5%)-for the third or further recurrence. The median iPDT target volume was 3.34 cm3 (range, 0.50-22.8 cm3). Severe neurologic deterioration lasted for more than six weeks in one patient only. The median TTF was 7.1 (95% confidence interval (CI), 4.4-9.8) months and the median PRS was 13.0 (95% CI, 9.2-16.8) months. The 2- and 5-year PRS rates were 25.0% and 4.5%, respectively. The treatment response was heterogeneous and not significantly associated with patient characteristics, treatment-related factors or molecular markers. The promising outcome and acceptable risk profile deserve further prospective evaluation particularly to identify mechanisms and prognostic factors of favorable treatment response.

Interrelation between Spectral Online Monitoring and Postoperative T1-Weighted MRI in Interstitial Photodynamic Therapy of Malignant Gliomas.

In a former study, interstitial photodynamic therapy (iPDT) was performed on patients suffering from newly diagnosed glioblastoma (n = 11; 8/3 male/female; median age: 68, range: 40-76). The procedure includes the application of 5-ALA to selectively metabolize protoporphyrin IX (PpIX) in tumor cells and illumination utilizing interstitially positioned optical cylindrical diffuser fibers (CDF) (2-10 CDFs, 2-3 cm diffusor length, 200 mW/cm, 635 nm, 60 min irradiation). Intraoperative spectral online monitoring (SOM) was employed to monitor treatment light transmission and PpIX fluorescence during iPDT. MRI was used for treatment planning and outcome assessment. Case-dependent observations included intraoperative reduction of treatment light transmission and local intrinsic T1 hyperintensity in non-contrast-enhanced T1-weighted MRI acquired within one day after iPDT. Intrinsic T1 hyperintensity was observed and found to be associated with the treatment volume, which indicates the presence of methemoglobin, possibly induced by iPDT. Based on SOM data, the optical absorption coefficient and its change during iPDT were estimated for the target tissue volumes interjacent between evaluable CDF-pairs at the treatment wavelength of 635 nm. By spatial comparison and statistical analysis, it was found that observed increases of the absorption coefficient during iPDT were larger in or near regions of intrinsic T1 hyperintensity (p = 0.003). In cases where PpIX-fluorescence was undetectable before iPDT, the increase in optical absorption and intrinsic T1 hyperintensity tended to be less. The observations are consistent with in vitro experiments and indicate PDT-induced deoxygenation of hemoglobin and methemoglobin formation. Further investigations are needed to provide more data on the time course of the observed changes, thus paving the way for optimized iPDT irradiation protocols.

ABCG2 influence on the efficiency of photodynamic therapy in glioblastoma cells.

BACKGROUND: Photodynamic therapy with 5-aminolevulinic acid (5-ALA PDT) is a promising novel therapeutic approach in the therapy of malignant brain tumors. 5-ALA occurs as a natural precursor of protoporphyrin IX (PpIX), a tumor-selective photosensitizer. The ATP-binding cassette transporter ABCG2 plays a physiologically significant role in porphyrin efflux from living cells. ABCG2 is also associated with stemness properties. Here we investigate the role of ABCG2 on the susceptibility of glioblastoma cells to 5-ALA PDT. METHODS: Accumulation of PpIX in doxycycline-inducible U251MG glioblastoma cells with or without induction of ABCG2 expression or ABCG2 inhibition by KO143 was analyzed using flow cytometry. In U251MG cells, ABCG2 was inducible by doxycycline after stable transfection with a tet-on expression plasmid. U251MG cells with high expression of ABCG2 were enriched and used for further experiments (sU251MG-V). PDT was performed on monolayer cell cultures by irradiation with laser light at 635 nm. RESULTS: Elevated levels of ABCG2 in doxycycline induced sU251MG-V cells led to a diminished accumulation of PpIX and higher light doses were needed to reduce cell viability. By inhibiting the ABCG2 transporter with the efficient and non-toxic ABCG2 inhibitor KO143, PpIX accumulation and PDT efficiency could be strongly enhanced. CONCLUSION: Glioblastoma cells with high ABCG2 expression accumulate less photosensitizer and require higher light doses to be eliminated. Inhibition of ABCG2 during photosensitizer accumulation and irradiation promises to restore full susceptibility of this crucial tumor cell population to photodynamic treatment.

MOP-dependent enhancement of methadone on the effectiveness of ALA-PDT for A172 cells by upregulating phosphorylated JNK and BCL2.

BACKGROUND: Methadone, as a long-acting opioid analgesic, shows an ability to sensitize the treatment of ALA-PDT for glioblastoma cells (A172) in vitro by promoting apoptosis. However, the mechanisms how methadone enhances the effectiveness of ALA-PDT for tumor cells remains to be clarified. METHODS: The expression of mu opioid receptor (MOP), apoptosis, phosphorylated c-Jun N-terminal kinase (JNK) and phosphorylated apoptosis regulator B cell lymphoma 2 (BCL2) were measured by flow cytometry. Cytotoxicity was determined using Cell Counting Kit-8 (CCK-8). A MOP antagonist, naloxone, was used to evaluate the role of MOP in the above process. RESULTS: It was found that A172 cells show the expression of MOP and that naloxone inhibits the enhancement of the methadone effect on apoptosis following ALA-PDT (p < 0.05). Phosphorylated JNK and BCL2 induced by ALA-PDT were promoted in the presence of methadone (p < 0.05). These methadone effects were also inhibited by naloxone (p < 0.05). CONCLUSIONS: The results suggest that apoptosis induced by ALA-PDT is enhanced by methadone, mostly MOP-mediated, through the upregulation of accumulation of phosphorylated JNK and BCL2, leading to a promotion of cytotoxicity of ALA-PDT for A172 cells.

Indocyanine green fluorescence imaging during partial adrenalectomy.

BACKGROUND: Indocyanine green (ICG) fluorescence imaging represents an emerging technology that facilitates the assessment of tissue vascularity, tissue distinction, and tumor localization during surgery. The aim of this study was to investigate the potential role of ICG imaging during laparoscopic partial adrenalectomy. METHODS: Indocyanine fluorescence imaging was carried out during laparoscopic partial adrenalectomy for bilateral pheochromocytoma and bilateral Cushing's syndrome. A first bolus of 5 mg ICG was applied intravenously upon exposure of the retroperitoneal plane to identify the adrenal borders. The fluorescence was visualized using a Storz® NIR/ICG endoscopic system. As the camera of this system detects NIR light as a blue signal, the well-vascularized adrenal tissue was expected to show a strong fluorescence in the blue color channel in contrast to the surrounding adipose tissue. Following partial adrenalectomy, a second bolus of 5 mg ICG was applied intravenously to evaluate the vascularity of the remaining adrenal tissue. RESULTS: We investigated six adrenal glands from three patients undergoing bilateral partial adrenalectomy. The indication for surgery was pheochromocytoma in two patients and Cushing's syndrome with bilateral adenomas in one patient. Regarding left adrenalectomies, ICG imaging was helpful in visualizing the adrenal borders and the adrenal vein. Further, it facilitated the identification of the hypofluorescent pheochromocytoma and to resect the entire tumor. On the right side, due to the more apparent anatomy, ICG imaging did not contribute to the conduct of the operation. Four adrenal remnants showed a strong vascularization and two remnants were only reasonably vascularized. CONCLUSION: ICG fluorescence may be helpful in guiding partial adrenalectomy and assessing the vascularity of remaining adrenal tissue.

Fluorescence and Treatment Light Monitoring for Interstitial Photodynamic Therapy.

In interstitial photodynamic therapy, light is distributed to the tumor via light diffusers. The light dose and the related phototoxic effect achieved throughout the target volume critically depend on absorption, scattering and diffuser positioning. Using liquid tissue phantoms, we investigated the dependencies of treatment light transmission and protoporphyrin IX (PpIX) fluorescence on these parameters. This enabled monitoring hemoglobin oxygenation and methemoglobin formation during irradiation (635 nm, 200 mW cm-1 diffuser length). Starting with two parallel cylindrical diffusers at 10 mm radial separation, the light transmitted between the fibers was largely determined by the minimal distance between the diffusers, but rather insensitive to an additional axial displacement or tilting of one fiber with respect to the other. For fixed distance between the diffusor centers, however, tilting up to direct contact resulted in a 10-fold signal increase. For hemoglobin within erythrocytes, irradiation leads to photobleaching of PpIX without marked change in hemoglobin oxygenation until hemolysis occurs. Afterward, hemoglobin is rapidly deoxygenized and methemoglobin is formed, leading to a dramatic increase in absorption. For lysed blood, these effects start immediately. A comparison of intraoperative monitoring of the signals with the experimental results might help prevent insufficient treatment by reconsidering treatment planning or prolonging irradiation.

Screening for iron deficiency in surgical patients based on noninvasive zinc protoporphyrin measurements.

BACKGROUND: Approximately every third surgical patient is anemic. The most common form, iron deficiency anemia, results from persisting iron-deficient erythropoiesis (IDE). Zinc protoporphyrin (ZnPP) is a promising parameter for diagnosing IDE, hitherto requiring blood drawing and laboratory workup. STUDY DESIGN AND METHODS: Noninvasive ZnPP (ZnPP-NI) measurements are compared to ZnPP reference determination of the ZnPP/heme ratio by high-performance liquid chromatography (ZnPP-HPLC) and the analytical performance in detecting IDE is evaluated against traditional iron status parameters (ferritin, transferrin saturation [TSAT], soluble transferrin receptor-ferritin index [sTfR-F], soluble transferrin receptor [sTfR]), likewise measured in blood. The study was conducted at the University Hospitals of Frankfurt and Zurich. RESULTS: Limits of agreement between ZnPP-NI and ZnPP-HPLC measurements for 584 cardiac and noncardiac surgical patients equaled 19.7 µmol/mol heme (95% confidence interval, 18.0-21.3; acceptance criteria, 23.2 µmol/mol heme; absolute bias, 0 µmol/mol heme). Analytical performance for detecting IDE (inferred from area under the curve receiver operating characteristics) of parameters measured in blood was: ZnPP-HPLC (0.95), sTfR (0.92), sTfR-F (0.89), TSAT (0.87), and ferritin (0.67). Noninvasively measured ZnPP-NI yielded results of 0.90. CONCLUSION: ZnPP-NI appears well suited for an initial IDE screening, informing on the state of erythropoiesis at the point of care without blood drawing and laboratory analysis. Comparison with a multiparameter IDE test revealed that ZnPP-NI values of 40 µmol/mol heme or less allows exclusion of IDE, whereas for 65 µmol/mol heme or greater, IDE is very likely if other causes of increased values are excluded. In these cases (77% of our patients) ZnPP-NI may suffice for a diagnosis, while values in between require analyses of additional iron status parameters.

Intraoperative Near-Infrared Autofluorescence and Indocyanine Green Imaging to Identify Parathyroid Glands: A Comparison.

OBJECTIVE: To investigate the feasibility of near-infrared autofluorescence (AF) and indocyanine green (ICG) fluorescence to identify parathyroid glands intraoperatively. METHODS: Fluorescence imaging was carried out during open parathyroid and thyroid surgery. After visual identification, parathyroid glands were exposed to near-infrared (NIR) light with a wavelength between 690 and 770 nm. The camera of the Storz® NIR/ICG endoscopic system used detects NIR light as a blue signal. Therefore, parathyroid AF was expected to be displayed in the blue color channel in contrast to the surrounding tissue. Following AF imaging, a bolus of 5 mg ICG was applied intravenously. ICG fluorescence was detected using the same NIR/ICG imaging system. Well-vascularized parathyroid glands were expected to show a strong fluorescence in contrast to surrounding lymphatic and adipose tissue. RESULTS: We investigated 78 parathyroid glands from 50 patients. 64 parathyroid glands (82%) displayed AF showing the typical bluish violet color. 63 parathyroid glands (81%) showed a strong and persistent fluorescence after application of ICG. The sensitivity of identifying a parathyroid gland by AF was 82% (64 true positive and 14 false negative results), while ICG imaging showed a sensitivity of 81% (63 true positive and 15 false negative results). The Fisher exact test revealed no significant difference between both groups at p < 0.05. Neither lymph nodes nor adipose tissue revealed substantial AF or ICG fluorescence. CONCLUSION: AF and ICG fluorescence reveal a high degree of sensitivity in identifying parathyroid glands. Further, ICG imaging facilitates the assessment of parathyroid perfusion. However, in the current setting both techniques are not suitable as screening tools to identify parathyroid glands at an early stage of the operation.

Parathyroid Autofluorescence-How Does It Affect Parathyroid and Thyroid Surgery? A 5 Year Experience.

Injury to parathyroid glands during thyroid and parathyroid surgery is common and postoperative hypoparathyroidism represents a serious complication. Parathyroid glands possess a unique autofluorescence in the near-infrared spectrum which could be used for their identification and protection at an early stage of the operation. In the present study parathyroid autofluorescence was visualized intraoperatively using a standard Storz laparoscopic near-infrared/indocyanine green (NIR/ICG) imaging system with minor modifications to the xenon light source (filtered to emit 690 nm to 790 nm light, less than 1% in the red and green above 470 nm and no blue light). During exposure to NIR light parathyroid tissue was expected to show autofluorescence at 820 nm, captured in the blue channel of the camera. Over a period of 5 years, we investigated 205 parathyroid glands from 117 patients. 179 (87.3%) glands were correctly identified by their autofluorescence. Surrounding structures such as thyroid, lymph nodes, muscle, or adipose tissue did not reveal substantial autofluorescence. We conclude that parathyroid glands can be identified by their unique autofluorescence at an early stage of the operation. This may help to preserve these fragile structures and their vascularization and lower the rate of postoperative hypocalcemia.

Methadone enhances the effectiveness of 5-aminolevulinic acid-based photodynamic therapy for squamous cell carcinoma and glioblastoma in vitro.

Although having shown promising clinical outcomes, the effectiveness of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) for squamous cell carcinoma (SCC) and glioblastoma remains to be improved. The analgesic drug methadone is able to sensitize various tumors to chemotherapy. In this in vitro study, the influence of methadone to the effectiveness of ALA-PDT for SCC (FADU) and glioblastoma (A172) was investigated on the protoporphyrin IX (PpIX) fluorescence, survival rates, apoptosis, and cell cycle phase, each with or without the presence of methadone. The production of PpIX was increased by methadone in FADU cells while it was decreased in A172 cells. The survival rates of both cell lines treated by ALA-PDT were significantly reduced by the combination with methadone (P < .05). Methadone also significantly increased the percentage of apoptotic cells and improved the effect of ALA-PDT on the cell cycle phase arrest in the G0/G1 phase (P < .05). This study demonstrates the potential of methadone to influence the cytotoxic effect of ALA-PDT for both SCC and glioblastoma cell lines.

Non-invasive measurement of erythrocyte zinc protoporphyrin in children.

BACKGROUND: Reliable screening for iron deficiency (ID) has required a blood sample and cost-intensive laboratory measurements. A novel method to non-invasively measure erythrocyte zinc protoporphyrin (ZnPP), an established marker for ID, is evaluated in children. METHODS: ZnPP was determined non-invasively by fluorescence measurements on the wet vermillion of the lower lip in 99 hospitalized children aged 9 months to 5 years. For comparison, conventional ID parameters and ZnPP were determined from blood samples. RESULTS: The non-invasively measured ZnPP values had limits of agreement (LoA) of 14 µmol ZnPP/mol heme (95% confidence interval: 9-20) compared to fluorescence measurements directly in blood. Repeated high-performance liquid chromatography reference determinations had comparable LoA of 14 µmol ZnPP/mol heme (9-17). Non-invasive ZnPP measurements had sensitivity and specificity of 67% (39-88%) and 97% (91-99%), and negative and positive predictive value of 94% (90-97%) and 80% (55-93%), for detecting ID as defined by the soluble transferrin receptor (sTfR). In groups with more severe ID as defined by serum ferritin and sTfR, higher ZnPP values were found, with the highest ZnPP values for the group with ID anemia. CONCLUSION: Non-invasive ZnPP measurements are reliably feasible in children. The simple and fast method has the potential to enable wide-spread screening for ID.

Photothermal therapy enhanced the effectiveness of imiquimod against refractory cutaneous warts through boosting immune responses.

Refractory cutaneous warts are difficult to eliminate. In situ photo-immunotherapy (ISPI) is an innovative treatment concept combining local photothermal therapy (PTT) and topical immunotherapy using imiquimod. To compare the efficacy of ISPI vs topical imiquimod alone, a prospective randomized controlled trial was performed with patients suffering from refractory cutaneous warts. In both groups, approximately 50% of the skin surface containing warts was treated for 6 weeks. On the basis of topical imiquimod, ISPI includes an additional 808 nm laser irradiation. Treatment response, temperatures during irradiation and histopathologic examination were evaluated. The complete response rate in the ISPI-group (22/36, 61.1%) was significantly higher than in the imiquimod alone group (11/34, 32.4%). In the ISPI-group, the mean maximum temperature was 44.5 ± 5.1°C, and obvious lymphocytic infiltration was found in the perivasculature of the dermis. There was no recurrence or worsening in both groups during the 12-month follow-up. No obvious adverse reaction was observed. This study demonstrates that ISPI can be used as an effective and safe treatment modality for refractory cutaneous warts.