Metformin shows anti-neoplastic properties by inhibition of oxidative phosphorylation and glycolysis in epidermolysis bullosa-associated aggressive cutaneous squamous cell carcinoma.

BACKGROUND: While most cutaneous squamous cell carcinomas (cSCCs) are treatable, certain high-risk cSCCs, such as those in recessive dystrophic epidermolysis bullosa (RDEB) patients, are particularly aggressive. Owing to repeated wounding, inflammation and unproductive healing, RDEB patients have a 68% cumulative risk of developing life-threatening cSCCs by the age of 35, and a 70% risk of death by the age of 45. Despite aggressive treatment, cSCC represents the leading cause of premature mortality in these patients, highlighting an unmet clinical need. Increasing evidence points to a role of altered metabolism in the initiation and maintenance of cSCC, making metabolism a potential therapeutic target. OBJECTIVES: We sought to determine the feasibility of targeting tumour cell energetics as a strategy to selectively hinder the growth advantage of aggressive cSCC. METHODS: We evaluated the cell energetics profiles of RDEB-SCC cells by analysing available gene expression data against multiple gene signatures and single-gene targets linked to metabolic reprogramming. Additionally, we employed real-time metabolic profiling to measure glycolysis and respiration in these cells. Furthermore, we investigated the anti-neoplastic properties of the metformin against human and murine high-risk cSCCs in vitro and in vivo. RESULTS: Gene expression analyses highlighted a divergence in cell energetics profiles between RDEB-SCC and non-malignant RDEB keratinocytes, with tumour cells demonstrating enhanced respiration and glycolysis scores. Real-time metabolic profiling supported these data and additionally highlighted a metabolic plasticity of RDEB-SCC cells. Against this background, metformin exerted an anti-neoplastic potential by hampering both respiration and glycolysis, and by inhibiting proliferation in vitro. Metformin treatment in an analogous model of fast-growing murine cSCC resulted in delayed tumour onset and slower tumour growth, translating to a 29% increase in median overall survival. CONCLUSIONS: Our data indicate that metformin exerts anti-neoplastic properties in aggressive cSCCs that exhibit high-risk features by interfering with respiration and glycolytic processes.

[Comparison of four identical electronic noses and three measurement set-ups]. / Vergleich von vier baugleichen elektronischen Nasen und drei Messaufbauten.

BACKGROUND: Volatile organic compounds (VOCs) can be used as biomarkers in exhaled air. VOC profiles can be detected by an array of nanosensors of an electronic nose. These profiles can be analysed using bioinformatics. It is, however, not known whether different devices of the same model measure identically and to which extent different set-ups and the humidity of the inhaled air influence the VOC profile. METHODS: Three different measuring set-ups were designed and three healthy control subjects were measured with each of them, using four devices of the same model (Cyranose 320™, Smiths Detection). The exhaled air was collected in a plastic bag. Either ambient air was used as reference (set-up Leipzig), or the reference air was humidified (100% relative humidity) (set-up Marburg and set-up Munich). In the set-up Marburg the subjects inhaled standardised medical air (Aer medicinalis Linde, AGA AB) out of a compressed air bottle through a demand valve; this air (after humidification) was also used as reference. In the set-up Leipzig the subjects inhaled VOC-filtered ambient air, in the set-up Munich unfiltered room air. The data were evaluated using either the real-time data or the changes in resistance as calculated by the device. RESULTS: The results were clearly dependent on the set-up. Apparently, humidification of the reference air could reduce the variance between devices, but this result was also dependent on the evaluation method used. When comparing the three subjects, the set-ups Munich and Marburg mapped these in a similar way, whereas not only the signals but also the variance of the set-up Leipzig were larger. CONCLUSION: Measuring VOCs with an electronic nose has not yet been standardised and the set-up significantly affects the results. As other researchers use further methods, it is currently not possible to draw generally accepted conclusions. More systematic tests are required to find the most sensitive and reliable but still feasible set-up so that comparability is improved.

[Smelling diseases? A short review on electronic noses]. / Krankheiten erriechen? Eine kurze Übersicht über elektronische Nasen.

Non-invasive pulmonary diagnostics is a promising and interesting field in respiratory medicine. Beside exhaled breath condensate, there is an increasing interest in alternative and faster techniques such as electronic noses (EN). EN aim to mimic or improve the sense of smelling. Different types of EN have been employed in research so far. In addition to ion mobility spectrometry and mass spectrometry, ENs that consist of various biopolymer sensors for the sensing of volatile organic compounds (VOCs) have been tested. VOCs bind to the sensors depending on size, structure, hydrogen binding and polarity. This leads to physical alterations, e. g., swelling resulting in a change of resistance. The smell print represents composite patterns in contrast to single compounds, and the distinction between different categories is achieved by pattern recognition algorithms. Other types of EN like mass spectrometry and ion mobility spectrometry are capable of identifying even single analyte fractions provided that their characteristics have been saved in data repositories. The non-invasive nature, onsite availability and relatively cheap sampling are advantages of ENs that underly the increasing interest in their use for medical purposes. Some promising results have already been published. This review aims to describe the state of the art in brief form.

B-cell activating factor BAFF reflects patients' immunological risk profile after kidney transplantation.

The B-cell activating factor BAFF plays an important role in the development and maturation of B-lymphocytes, which can contribute to the generation of donor-specific antibodies and thus may influence graft function and graft survival. Inconsistent data on the role of BAFF levels after renal transplantation for the formation of donor-specific antibodies and the contribution for allograft rejection exist. The aim of the current study was to determine to what extent the degree of pre-immunization is reflected by each patient's BAFF levels before transplantation and in the follow-up. Furthermore, the impact of BAFF on allograft rejection frequency as well as severity and resulting allograft function over time was analyzed. Additionally, the impact of viral infections on BAFF levels after transplantation - as a potential confounder - was examined. For this purpose, a group of pre-sensitized patients (PRA>0%, (52±24% on average), n=40) was compared with non-sensitized patients (PRA=0%, n=62) and in a subsequent analysis stratification in accordance to the detected BAFF level was performed. Pre-sensitized patients had significantly higher BAFF levels before transplantation and suffered significantly more often from early steroid-resistant, mainly antibody-mediated rejections. A result which was confirmed also in highly sensitized patients with PRA levels >50%. Additionally, in the follow-up patients with either rising BAFF levels over time or BAFF levels above the median also had significantly more often antibody mediated rejections. Additionally, patients with BAFF levels above detected median even displayed impaired creatinine values as well as an induced eGFR slope up to month 48 after transplantation. The occurrence of viral infections (CMV, BKV) was only an additional influencing factor in the absence of concomitant allograft rejections. Therefore, the B-cell proliferation factor BAFF appears not only to reflect the immunological risk profile of patients in the context of kidney transplantation, it may possibly be further developed as a predictor of patients with an increased risk profile for subsequent allograft rejection and impaired allograft function.

Recombinant peptides derived from the env-gene of HIV-2 in the serodiagnosis of HIV-2 infections.

We produced recombinant envelope-derived peptides of HIV-2 for use in a diagnostic enzyme-linked immunosorbent assay (ELISA) or Western blot by expressing several restriction enzyme fragments from the env gene of HIV-2 in the bacterial fusion vector pEX-3. On Western blots, 17 out of 18 anti-HIV-2-positive sera available to us reacted strongly with those recombinant peptides which were derived from, or extended into, the transmembrane protein of HIV-2. In contrast, recombinant peptides derived from the external envelope glycoprotein were only weakly recognized by two sera. We observed a cross-reactivity of some human sera containing antibodies to HIV-1 with the HIV-2 peptides derived from the transmembrane protein of HIV-2. In spite of this cross-reactivity, a serological distinction between anti-sera to HIV-1 and HIV-2 can be attempted by simultaneous testing in ELISA on recombinant peptides derived from the transmembrane protein of HIV-1 and HIV-2.

Expression of the C3d/EBV receptor and of other cell membrane surface markers is altered upon HIV-1 infection of myeloid, T, and B cells.

Human cell lines (the T-cell lines H9, Jurkat, and HUT102, the myeloid lines U937 and HL60, and the Raji B cell line) were infected with HIV-1. HIV-1 antigen could be detected by immunofluorescence analysis in more than 50% of T cells and myeloid cells 15 days after infection. Infection of Raji cells took more than 2-3 months. Studies of cell surface marker expression revealed remarkable changes after HIV-1 infection of Raji cells: expression of CR2 (C3d/EBV receptor, CD19, CD20, CD22, CD23, CD10, and surface IgM) were highly reduced, in the case of CR2 and membrane-IgM from 100 to 0%, whereas levels of CD37 and CD38 remained unaltered by HIV-1 infection. U937 cells showed a reduction of CD4 expression from 14 to 5% after HIV-1 infection; the CR3 expression slightly increased from 25 to 30%. In contrast, HLA-DR was only expressed (21%) after HIV-1 infection but not in uninfected U937 cells. Expression of HLA-DR could be detected also in HL60 cells (33%) after HIV-1 infection. In H9 cells, CD4 was reduced from 60 to 30% after HIV-1 infection, whereas HLA-DR and CD25/IL-2 receptor expression increased from 16 to 90% and from 0 to 50%, respectively. CD4 was reduced from 70 to 0% from Jurkat cells after HIV-1 infection, whereas expression of CR2 was only slightly diminished from 8 to 4%. Expression of CR1 and HLA-DR was slightly increased in these cells (1 to 3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Value of repeated analyses of 24-hour urine in recurrent calcium urolithiasis.

OBJECTIVES: The value of repeated analyses of 24-hour urine collections for daily excretion of calcium, uric acid, citrate, phosphorus, and creatinine and for volume and pH performed to detect and classify metabolic disorders in a selected group of calcium stone formers with striking recurrence rates was assessed in a retrospective study. METHODS: A total of 441 urinalyses made over a mean period of 80.4 months of samples obtained from 49 patients were reviewed. Fifty-nine percent of patients were initially found to have metabolic disorders (absorptive hypercalciuria types I and II, hyperuricuria, hypocitraturia) and therefore received specific drug therapy (allopurinol, thiazide, alkali citrate, orthophosphate) for a mean of 45.7 months (group I). The remaining patients were classified as metabolically inactive and were given general metaphylactic instructions (group II). RESULTS: In 73% of patients recurrent stones developed, with no statistically significant difference between the two groups (79% vs 65%). In 55% of group I patients, urinalyses continued to yield abnormal findings during follow-up; however, subsequent abnormal findings were also seen in 40% of the metabolically inactive group II patients. Overall, metabolic disorders were observed at some point in 75% of patients. Only 27% remained recurrence free, and 62% thereof also had pathologic urinary findings. CONCLUSIONS: It does not appear that drug treatment in recurrent calcium urolithiasis based on urinary findings is superior to simple general metaphylactic recommendations, nor that repeated analyses of 24-hour urine collections furnish additional information on the risk of recurrent stone formation or on the presence of risk factors leading to recurrence in the long-term course of disease.

Multifocality of transitional cell carcinoma results from genetic instability of entire transitional epithelium.

OBJECTIVES: Multifocality of transitional cell carcinoma (TCC) has been attributed to seeding of exfoliated tumor cells or to a general sensitivity of the entire urothelium to carcinogenic stimuli. By contrast, TCC has been shown to evolve as a consequence of genetic defects and chromosomal instability. We analyzed chromosomal patterns, total DNA content, and p53 and Ki67 expression in malignant and normal transitional cells to evaluate their relationship to the development of multifocal TCC. METHODS: Included in the study were 47 patients, 16 women and 31 men, with a mean age of 70.04 years (range 37 to 83). Of 47 patients, 45 had TCC of the urinary bladder and 7 of those had synchronous ureteral involvement. Two patients had ureteral TCC and a history of TCC of the bladder. Using fluorescence in situ hybridization, numerical aberrations of chromosomes 7, 9, and 17 were detected in imprint specimens of histologically verified tumor and "normal" urothelium and were compared with static ploidy and p53 and Ki67 expression. RESULTS: Chromosome 7 was altered in 93.6%, chromosome 9 in 63.8% (including monosomy), and chromosome 17 in 87.2% of the 47 analyzed tumor and normal imprints. Differences between tumor and normal epithelium were observed in aberrational frequencies (number of cells showing chromosomal aberrations calculated on 200 cells counted, given in percentages). DNA content was aneuploid in all tumor specimens, but diploid in 20 (42.5%) of 47 normal specimens, according to lower aberration frequencies in these patients. p53 detection was positive in 82.9% of the tumor specimens and 76.6% of the normal specimens. Ki67 was positive in 87.2% of the tumor imprints and in 72.3% of the normal specimens. CONCLUSIONS: These data suggest a general genetic instability as a reason for multifocality in the entire transitional epithelium.

Mooren's ulcer after penetrating keratoplasty.

Seventeen months after penetrating keratoplasty for pseudophakic bullous keratopathy, a patient developed severe pain and a peripheral corneal ulcer that had the characteristic clinical appearance of a Mooren's ulcer. We performed a 10-mm penetrating keratoplasty that extended from the superior margin of the previously placed graft to the inferior corneoscleral limbus to encompass the ulcerated cornea. Histopathologic examination of tissue removed at surgery disclosed that the peripheral corneal ulcer extended nearly through the entire stromal thickness and that the donor corneal stroma adjacent to the ulcer was infiltrated with lymphocytes, plasma cells, and neutrophils. The conjunctiva adjacent to the peripheral corneal ulcer was packed with plasma cells and also showed some lymphocytes and neutrophils.

Corneal ulcers associated with extended-wear soft contact lenses.

We treated nine myopic and nine aphakic eyes in patients who developed corneal ulcers while wearing extended-wear soft contact lenses. Bacteria were recovered from the corneal ulcers of 13 of 18 patients with Pseudomonas aeruginosa being the pathogen most frequently isolated. Chemical disinfection was used by seven of the nine patients with myopia and eight of the nine with aphakia. Two of nine patients in the myopic group had visual loss to 20/200 and hand movements; five of nine patients in the aphakic group had visual loss to 20/50 or worse. Invasion of the corneal stroma by bacteria may occur after breakdown of the epithelial barrier by contact lens manipulation or after chronic overnight anoxic stress. Thus, the use of soft contact lenses on an extended-wear basis may be complicated by the development of corneal ulcers. Both aphakic and myopic eyes are at risk.

Corneal edema related to accidental Hibiclens exposure.

Five patients developed corneal edema presumably caused by accidental preoperative ocular exposure to Hibiclens. In all cases, the patients complained of ocular pain after surgery. Conjunctival inflammation and corneal epithelial defects were found in all patients. Between two and ten weeks after exposure, stromal and epithelial edema, with a predilection for the inferior cornea initially, developed in all patients. The corneal edema resolved in three patients in approximately six months, leaving mild stromal scarring and reduced endothelial cell counts. The corneal edema in the other two patients progressed to diffuse bullous keratopathy, which eventually required penetrating keratoplasty. We recommend that Hibiclens be avoided in preoperative preparation of the facial skin to prevent accidental ocular exposure.

Mycobacterium fortuitum keratitis.

Two of four cases of Mycobacterium fortuitum keratitis occurred after corneal surgery with contact lens wear, one was associated with extended contact lens wear alone, and one occurred after a foreign body injury. All cases were characterized by pain, conjunctival hyperemia, stromal inflammation, and ulceration. Diagnosis was made by culture and acid-fast staining of corneal scrapings. On the basis of published experience with amikacin for the treatment of nonocular M. fortuitum infections, three patients were treated with topical amikacin. Two patients responded clinically, but histopathologic examination of a penetrating keratoplasty specimen in one of the two disclosed persistent infection. One patient was cured of early disease by debridement alone. Rapid diagnosis and absence of corticosteroid use were the two most important determinants of successful therapy. In advanced cases, infection may be cured and useful vision restored by penetrating keratoplasty.

Keratoconus detected by videokeratography in candidates for photorefractive keratectomy.

BACKGROUND: Patients with corneal shape abnormalities should be identified prior to photorefractive keratectomy (PRK). We used videokeratography screening to detect subclinical corneal abnormalities, including keratoconus, which might have been missed by conventional clinical evaluation. METHODS: One hundred forty-six apparently normal myopic eyes (-1.00 to -7.00 diopters [D] with less than 1.50 D of cylinder) of 91 consecutive patients who were candidates for PRK were screened by videokeratography. RESULTS: In 6 of 91 patients (7 of 146 eyes), unsuspected corneal shape abnormalities were detected by videokeratography. Two patients had definite keratoconus and three were classified as keratoconus suspects by inferior corneal steepening (Rabinowitz I-S index ranging from 1.62 to 6.20 D). One patient had early pellucid marginal degeneration. CONCLUSIONS: Keratoconus suspects and contact lens-induced changes resembling keratoconus are present in the "normal" myopic population that presents for refractive surgery. Videokeratographic screening is the only effective means of identifying these and other corneal shape abnormalities.

Evaluation on HIV serology and immune-stimulation on patients in Tanzania.

Antibodies against human immunodeficiency virus, other infectious agents and neopterin levels were determined in 253 patients in a rural area of North-West Tanzania. Seroprevalence for HIV was 3.2%. In one case serology was positive for HIV-1 and HIV-2 antibodies and questions whether there was a real double infection or a cross reaction not only concerning core region proteins but also transmembrane protein. The specificity in the diagnosis of HIV-infection is markedly increased with newer serological methods using recombinant peptides but did not improve sensitivity on African sera. Neopterin was determined as a sensitive indirect marker for the activation of T-cells and is therefore correlated with the susceptibility of HIV infection and with progression of disease. High seroprevalence rates for various infectious agents were determined and may explain the high rate of elevated neopterin levels in 80% of the Africans. Neopterin levels were even higher in HIV patients. Viral p24 antigen was found only in two persons, one of whom had no antibodies detectable.

[Value of sonography, computed tomography and angiography in adrenal diagnosis]. / Wertigkeit von Sonographie, Computertomographie und Angiographie in der Nebennierendiagnostik.

Between 1979 and 1982, 47 patients with pathological process of the adrenals were surgically treated after preceding thorough non-evasive angiographic diagnosis (6 phaeochromocytomas, 20 adrenal adenomas, 8 adrenal hyperplasias, 5 adrenal carcinomas, 5 adrenal cysts and 3 adrenal metastases). The most consistently accurate results were obtained via adrenal phlebography with an accuracy of 94%. This was followed by non-evasive computed tomography (87%). Compared with the data given in literature, hormone determination in the adrenal venous blood was less favourable (79%). Selective adrenal arteriography, which was used less often, yielded correct results in 83% of the cases, whereas the number of accurate diagnoses achieved via sonography was lowest with 54%.

Multiple limit cycles for predator-prey models.

We construct a Gause-type predator-prey model with concave prey isocline and (at least) two limit cycles. This serves as a counter-example to the global stability criterion of Hsu [Math. Biosci. 39:1-10 (1978)].

Orbital extension of retinoblastoma: a clinicopathological study.

We have studied all cases of orbital extension of retinoblastomas at the Edward S. Harkness Eye Institute in New York since 1925. Only 9.4% of the patients lived more than 2 years after diagnosis. Orbital retinoblastoma is frequently associated with systemic metastases. We emphasize the significance of massive choroidal involvement and periemissarial extension. Careful handling of the enucleation specimen at the time of surgery and during histologic preparation is important to avoid cell spillage and artifacts. Treatment should be early, multidisciplinary and include adjuvant chemotherapy.

Invasion of the optic nerve by retinoblastoma: a clinicopathological study.

We have studied all cases of optic nerve invasion in retinoblastoma seen at the Edward S. Harkness Eye Institute in New York since 1925. Since 1959 optic nerve invasion has been less extensive--suggesting earlier diagnosis and management. Since 1959 there has also been an increase in the number surviving. Survival correlates with the extent of spread to optic nerve, choroid and extrabulbar tissues. Current and future therapy are discussed. The importance of subpial extension of retinoblastoma is noted and its relationship to the mode of therapy is emphasized.