A randomized controlled clinical trial of topical photodynamic therapy with methyl aminolaevulinate in the treatment of actinic keratoses in transplant recipients

BACKGROUND

Transplant recipients have an increased propensity to develop multiple actinic keratoses, which demonstrate an increased transformation rate into invasive squamous cell carcinoma.

OBJECTIVE

To evaluate the efficacy and tolerability of topical photodynamic therapy with the new highly tumour-selective photosensitizer methyl aminolaevulinate vs. placebo in the treatment of actinic keratoses in transplant recipients.

METHODS

Seventeen transplant recipients with a total number of 129 mild to moderate actinic keratoses were enrolled in a prospective, randomized, double-blind, placebo-controlled study. Two lesional areas within a patient were randomized for two consecutive treatments of topical photodynamic therapy 1 week apart using either methyl aminolaevulinate or placebo cream. Sites were illuminated with 75 J cm(-2) of visible light delivered at 80 mW cm(-2) by a noncoherent light source. Complete resolution and reduction in the number or size of actinic keratoses within the lesional area relative to the initial findings were evaluated at weeks 4, 8 and 16 after treatment.

RESULTS

The lesional areas treated with methyl aminolaevulinate were clinically cleared in 13 of 17 patients at 16 weeks. A partial response was recorded in a further three. No reduction in the size or number of actinic keratoses was observed in one area treated with methyl aminolaevulinate and in all placebo-treated areas. Adverse events, such as erythema, oedema and crust formation, were mild to moderate, and treatment was well tolerated by all patients.

CONCLUSION

Photodynamic therapy using methyl aminolaevulinate is a safe and effective treatment for actinic keratoses in transplant recipients. It may also reduce the risk of transformation of actinic keratoses to invasive, potentially fatal, squamous cell carcinoma.

The Spectrum of Mesenchymal Skin Neoplasms Reflected by the New WHO Classification

Mesenchymal tumors are a heterogeneous group of tumors often arising in the skin and soft tissue. The tumors have been reclassified by the WHO in 2002. Benign mesenchymal tumors are about a hundred times more frequent than malignant mesenchymal tumors. Clinically, mesenchymal tumors often present as skin-colored nodes. Overall, elderly persons are more affected than younger individuals. The etiology is often unknown, sometimes there is an association with insults such as radiation, scars, or lymphedematous or venous stasis. Whereas some years ago a wide excision with a margin of 3-5 cm was performed for malignant variants, today micrographic surgery is preferred, as it can avoid mutilating procedures. Early detection and removal is critical since mesenchymal skin tumors often cannot be cured by radiation or chemotherapy.

Adsorption and vibrational spectroscopy of ammonia at mordenite: Ab initio study

The adsorption of ammonia at various active centers at the outer and inner surfaces of mordenite, involving Brønsted acid (BA) sites, terminal silanol groups, and Lewis sites has been investigated using periodic ab initio density-functional theory. It is shown that ammonia forms an ammonium ion when adsorbed at strong BA sites. The calculated adsorption energies for different BA sites vary in the interval from 111.5 to 174.7 kJ/mol depending on the local environment of the adduct. The lowest adsorption energy is found for a monodentate complex in the main channel, the highest for a tetradentate configuration in the side pocket. At weak BA sites such as terminal silanol groups or a defect with a BA site in a two-membered ring ammonia is H bonded via the N atom. Additional weak H bonds are formed between H atoms of ammonia and O atoms of neighboring terminal silanol groups. The calculated adsorption energies for such adducts range between 61.7 and 70.9 kJ/mol. The interaction of ammonia with different Lewis sites is shown to range between weak (DeltaE(ads)=17.8 kJ/mol) and very strong (DeltaE(ads)=161.7 kJ/mol), the strongest Lewis site being a tricoordinated Al atom at the outer surface. Our results are in very good agreement with the distribution of desorption energies estimated from temperature-programmed desorption (TPD) and microcalorimetry experiments, the multipeaked structure of the TPD spectra is shown to arise from strong and weak Brønsted and Lewis sites. The vibrational properties of the adsorption complexes are investigated using a force-constant approach. The stretching and bending modes of NH(4) (+) adsorbed to the zeolite are strongly influenced by the local environment. The strongest redshift is calculated for the asymmetric stretching mode involving the NH group hydrogen bonded to the bridging O atom of the BA site, the shift is largest for a monodentate and smallest for a tetradentate adsorption complex. The reduced symmetry of the adsorbate also leads to a substantial splitting of the stretching and bending modes. In agreement with experiment we show that the main vibrational feature which differentiates coordinatively bonded ammonia from a hydrogen-bonded ammonium ion is the absence of bending modes above 1630 cm(-1) and in the region between 1260 and 1600 cm(-1), and a low-frequency bending band in the range from 1130 to 1260 cm(-1). The calculated distribution of vibrational frequencies agrees very well with the measured infrared adsorption spectra. From the comparison of the adsorption data and the vibrational spectra we conclude that due to the complex adsorption geometry the redshift of the asymmetric stretching is a better measure of the acidity of an active sites than the adsorption energy.

Density-functional study of the cycloaddition of acrylonitrile on the Si(100) surface

Using a density functional approach, we have explored the cycloaddition of acrylonitrile on the Si(100) surface. The buckling of the surface dimers characteristic for the (2x1) reconstructed surface is shown to favor structures with a dipolar moment such as the resonant form of acrylonitrile with cumulative double bonds. The bond of acrylonitrile via a single C atom is a possible intermediate leading to the nitrile structure of the adsorbed molecule.

Baseline staging in cutaneous malignant melanoma

BACKGROUND

Baseline staging in patients with primary cutaneous malignant melanoma (MM) is routine, but the diagnostic accuracy and the impact on clinical outcome are still unclear.

OBJECTIVES

To evaluate the sensitivity and specificity of baseline staging in the early detection of regional lymph node metastases or distant metastases in patients with MM.

METHODS

One hundred consecutive patients with MM of Breslow's tumour thickness over 1.0 mm were enrolled. All patients had an extensive baseline staging including physical examination, ultrasound (US) of the abdomen and regional lymph nodes, chest X-ray, whole-body positron emission tomography (PET) and sentinel lymph node biopsy. The sensitivity and specificity of detection of macroscopic or microscopic metastases in the regional lymph nodes or at distant sites were calculated for each method.

RESULTS

Sentinel lymph node biopsy was positive in 26 patients. US detected two of 26 histologically tumour-positive sentinel nodes (sensitivity 8%, specificity 88%) and PET two of 26 (sensitivity 8%; specificity 100%). There were three lymph node metastases with a diameter > 4 mm. All of them were found suspect at physical examination. Two of them were detectable with US, two with PET, and all were identified with either US or PET. Nine patients had suspect findings at distant sites, which were all false positive on further investigation (specificity of the combined staging procedures 91%). At 18 (6-37) months' follow-up, five of 26 (19%) patients with a positive sentinel node and four of 74 (5%) of patients with a negative sentinel node had recurrent or progressive disease.

CONCLUSIONS

The combination of physical examination and lymph node US detects the great majority of patients with macroscopic lymph node metastasis (approximately 3% of patients at baseline). Only 10% of patients who have a histologically tumour-positive sentinel node are macroscopically detectable. Altogether, approximately 25% of patients have a positive sentinel node biopsy, among 90% microscopic. The value of whole body staging at baseline remains limited, since distant metastases can hardly ever be detected. The survival benefit of baseline staging and surveillance in patients with cutaneous MM remains to be established by comparative prospective trials.

Polysaccharides from Hibiscus sabdariffa flowers stimulate proliferation and differentiation of human keratinocytes

Raw polysaccharides, previously described in detail, were isolated from the flowers of Hibiscus sabdariffa L. and fractionated by ion exchange chromatography into one neutral and three acidic subfractions. Raw polysaccharides and all acidic subfractions caused a strong induction of proliferation of human keratinocytes (HaCaT) of up to 40 %, while the neutral polymers were ineffective. While mitochondrial activity was not influenced, raw polysaccharides induced early differentiation of primary natural human keratinocytes, as determined by involucrin formation.

Imiquimod in basal cell carcinoma: how does it work?

Imiquimod is a topical immune response modifier that binds to Toll-like receptor-7 and -8, inducing interferon-alpha. We treated superficial basal cell carcinomas (BCC) with imiquimod 5% cream daily for 5-8 days. The BCC lesions were biopsied before treatment and following imiquimod treatment, when the lesion showed the signs of erosion. We applied histology, immunohistochemistry and gene array technology (Affymetrix) to gain further insight into the mode of action of imiquimod. Our findings demonstrate that imiquimod-induced BCC regression is associated with a strong activity of the innate immune response, mediated by cells of macrophage-monocyte origin and is associated with the induction of apoptosis.

Treatment of verrucous carcinoma with imiquimod and CO2 laser ablation

An 82-year-old female patient presented with a large perianal hyperkeratotic tumor extending into the anal canal. Staging did not reveal any metastatic spread. Diagnosis of verrucous carcinoma or Buschke-Löwenstein tumor, respectively, was based on typical clinical and histologic features. Moreover, human papillomavirus 6b DNA sequences could be detected by PCR. Surgical excision could not be performed due to the general health status of the patient; thus, alternative therapy methods were necessary. Treatment with imiquimod cream 5% (Aldara), a topical immune response modifier applied once a day and left for 12 h, led to significant partial tumor regression and clear demarcation of the tumor. The remaining tumor, now feasible for treatment with CO2 laser, was removed in two sessions in local anesthesia. In a third session, tumor parts in the anal canal were vaporized. This case demonstrates that the combination of imiquimod and CO2 laser ablation is an effective treatment option for verrucous carcinoma.

Proteus Syndrom

A 34-year-old male patient was referred with a recalcitrant leg ulcer overlying an extensive vascular malformation, which had led several times to septic soft tissue infections. During his infancy he had been diagnosed to have Klippel-Trenaunay syndrome. Clinical examination revealed asymmetric hypertrophy of the lower extremities, an extensive portwine stain on the more severely affected left limb as well as prominent venous varicosities of both legs. Hands and feet showed striking cerebriform palmoplantar hypertrophy, and macrodactily with syndactily of several fingers. All toes had been amputated in early childhood due to extreme overgrowth and currently the patient walked on his forefeet in a prominent pes equinus deformity. Further symptoms consisted in several lipomas at both arms, another portwine stain at the left hemithorax and a single café-au-lait spot at the left scapula. Angio-magnetic resonance imaging scans of both legs showed an extensive venous-lymphatic vascular malformation involving the whole subcutis and infiltrating the muscle. The chronic wound was interpreted as venous stasis ulceration. Local percutaneous sclerotherapy of the dilated veins underneath the ulcer was discussed, but considered to carry a relevant risk of skin necrosis with consecutive progression of the wound. A conventional split-skin graft led to complete wound healing. Since, the patient consequently wears custom-made compression stockings and remained free from recurrences. The syndromatic constellation of palmoplantar overgrowth, multiple lipomas, giant fingers and toes, limb overgrowth, venous-lymphatic malformation and a café-au-lait spot led to the diagnosis of Proteus syndrome. The possible aetiology, clinical manifestations, differential diagnosis and management of this rare disorder are discussed.

Shear instability of gamma-Fe in bulk and in ultrathin films

Using ab initio local-spin-density calculations we demonstrate that along the Bain path describing the transformation of face-centered-cubic (fcc) gamma-Fe into body-centered-cubic (bcc) alpha-Fe, tetragonal Fe is unstable against monoclinic shear deformations producing a nearly bcc structure. In the limit of a monolayer adsorbed on a fcc substrate, the epitaxial constraint suppresses the shear instability, but in ultrathin films with three to six monolayers a striped pattern of near-bcc domains develops, confirming recent observations by scanning tunneling microscopy. A strong correlation between the shear instability and the magnetic state is reported.

[Epstein-Barr virus genome positive lymphoepithelioma-like carcinoma of the stomach]

EBV is associated with a high number of tumours and non-tumourous conditions. The rare lymphoepithelioma like carcinoma of the stomach,--just as similar tumours of foregut origin (thymus, lung, salivary gland)--are frequently EBV genom positive with the expression of only a few genes (EBV nuclear antigen 1, EBV encoded ribonucleoproteins/EBER/, latency I). On the basis of the clinicopathological analysis of two cases and literature data the authors point out the male predominance and the relatively favourable prognosis of the patients, furthermore the frequent cardial-subcardial localization of these tumours. Since the frequent non-lymphoepithelioma like stomach tumours,--adenocarcinomas,--show EBV genom positivity in about 1% of the cases, it is concluded that the characteristic lymphoepithelioma like histological pattern is not a sine qua non condition of EBV genom positivity. It may also be assumed, that the CD8 and TIA 1 cytotoxic lymphocytes are not virus but tumour cell specific, however not efficient, perhaps not activated. The low level of apoptotic tumour cells supports this assumption. In one of the cases a double tumour, a genom positive lymphoepithelioma like carcinoma and a genom negative adenocarcinoma, adjacent to each other was seen which speaks in favour of common carcinogenetic factors and shows that microscopic neighbourhood is not a necessary condition in viral association. The origin of the possible oncogenic effect of EBV in the absence of the transforming gene products latent membrane protein 1 and EBNA 2 in genom positive stomach carcinomas is uncertain. The significance of the presence in both cases of CD 5+ tumour cells is not clear, the study of further cases is indicated.

Skin cancers in organ transplant recipients: two cases of virus-induced neoplasms

Immunosuppression profoundly influences the prevalence of skin disorders in transplant recipients. Skin tumors occur with high incidence and constitute a major part of transplantation-related morbidity and mortality. We report on 2 immunosuppressed patients presenting with rapidly growing epithelial and mesenchymal neoplasms after renal transplantation. The diagnostic approach, differential diagnosis and treatment options are discussed emphasizing the characteristics of cutaneous lesions in immunosuppressed transplant recipients.

Coexistence of atomic and molecular chemisorption states: H(2)/Pd(210)

A novel H(2) molecular adsorption state on metal surfaces has been detected by temperature-programmed desorption and electron energy loss spectroscopy experiments of the H(2)/Pd(210) system. The molecular nature of this state has been verified by isotope exchange experiments. This molecular state leads to a decrease of the surface work function while atomic hydrogen on Pd(210) causes an increase. Ab initio total-energy calculations have confirmed all experimental findings. Through these calculations the microscopic nature of this novel molecular adsorption state could be identified; it turns out that this state is stabilized by the presence of atomic hydrogen on the Pd(210) surface.

A periodic DFT study of intramolecular isomerization reactions of toluene and xylenes catalyzed by acidic mordenite

A periodic density functional theory (DFT) study of the isomerization reactions of toluene and xylene catalyzed by acidic mordenite is reported. Monomolecular isomerization reactions have been considered and analyzed. The different reaction pathways have been discussed in detail. The use of periodic structure calculations allows consideration and analysis of zeolite electrostatic contributions and steric constraints that occur within zeolite micropores. Major differences in the details of protonation reaction pathways are found when periodic structures are used rather than small cluster models of the Brønsted acidic site. Complex relationships are found between zeolite topology and reaction pathways.

Stability of Zn(II) cations in chabazite studied by periodical density functional theory

The location of the Zn(2+) cation in Zn-exchanged chabazite has been studied by the periodical density functional method. Chabazite was chosen as a zeolite model, because it contains three different types of rings commonly found in the zeolite structures: four-, six-, and eight-membered rings. Two aluminum atoms have been employed to substitute the silicon atoms in the same D6R unit cell of the zeolite framework. This leads to different arrangements for the Brønsted site pair and the Zn(II) cation. The two Brønsted sites are found to be more stable when placed in the small ring (4T ring) than in the other rings. This suggests that the most reactive Brønsted sites are located in the large rings. Two Brønsted sites are most stable when the O(H)-Al-O-Si-O(H)-Al sequence is followed in the same ring instead of being located in two different rings. This resembles the aluminum distribution in the small four-membered ring and agrees with bond order conservation rules. The cation stability is markedly influenced by the distortions of the framework. Other factors that also contribute to the stabilization are the aluminum content near the cation and the stability of the original Brønsted sites. The Zn(2+) cation is more stable in the large rings than in the small ones, the six-membered one being the most stable configuration. In the small rings, the cation is, therefore, more reactive. Two different probe molecules have been used to study the interaction with the Zn(II) cation: water and methane. These probe molecules can extract the active center from its original position. For the water molecule, this effect is large and leads to a high framework relaxation. The value of the binding energy of this molecule to the active sites is influenced by these framework relaxations as well as by the cationic position environment. For weakly interacting methane, these effects are significantly less.

Factor V Leiden mutation in postthrombotic and non-postthrombotic venous ulcers

OBJECTIVE

To determine the prevalence of the factor V Leiden mutation in patients with postthrombotic and non-postthrombotic venous ulcers.

DESIGN

Case-control study.

SETTING

Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland.

PARTICIPANTS

Seventy-three consecutive outpatients and inpatients with venous ulcers and 45 age- and sex-matched control subjects (matched to the 42 patients with postthrombotic syndrome).

MAIN OUTCOME MEASURES

Frequency of postthrombotic and non-postthrombotic findings in patients with venous ulcers. Prevalence of the factor V Leiden mutation in these different subgroups.

RESULTS

Postthrombotic syndrome was identified as the cause of 42 (58%; 95% confidence interval [CI], 45%-69%) of 73 venous ulcers, and the remainder were caused by primary valvular insufficiency. In postthrombotic ulcers, the prevalence of the factor V Leiden mutation was 38% (95% CI, 24%-54%) (16/42), which corresponds to an odds ratio of 13.2 (95% CI, 2.8-62.3; P<.001). In non-postthrombotic venous ulcers, the prevalence was 16% (95% CI, 5%-34%) (5/31), which corresponds to an odds ratio of 3.2 (95% CI, 1.0-10.0; P =.07).

CONCLUSIONS

The factor V Leiden mutation is highly prevalent in patients with postthrombotic venous ulcers. Even patients with non-postthrombotic venous ulcers show a moderately elevated prevalence of the factor V Leiden mutation. Some of the latter might be misclassified because of near-to-perfect revascularization after asymptomatic deep venous thrombosis. However, as long as the therapeutic consequences of the factor V Leiden mutation are not established, systematic screening cannot be recommended in patients with venous ulcers.

[Case report on therapy with granulocyte stimulating factor in diabetic foot]

Several pathogenetic factors such as peripheral neuropathy, vasculopathy and infection are responsible for the development of diabetic foot ulcerations. An important factor contributing to the high infection risk in diabetic patients is a defect in neutrophil granulocytes. Deficiencies in neutrophil chemotaxis, phagocytosis and respiratory burst activity with the decrease of the super- and peroxids are known to be associated with diabetes. Granulocyte-colony stimulating factor (G-CSF) increases the release of neutrophils from the bone marrow and improves neutrophil function. A 78-year old patient with non-insulin-dependent diabetes presented with ulcerations of both big toes and a malum perforans on the right sole. He also had generalized arteriosclerosis as well as a polyneuropathy with a dry foot and typical foot deformation as well as decreased in sensitivity. Intensive local care for 35 days led to no improvement of the ulcerations. Then G-CSF (Neupogen) was administered in a total dose of 165 million IU over 11 days; the daily dose varied between 15-30 million IU depending on the absolute leucocyte count. In addition 500 mg of oral ciprofloxacin (Ciproxin) was given b.i.d. This treatment led to a significant improvement of the lesions. Within 11 days cost analysis suggests G-CSF may be a cost-effective addition to antimicrobial therapy in diabetic foot infection.

A theoretical study of the alkylation reaction of toluene with methanol catalyzed by acidic mordenite

A theoretical study of the alkylation reaction of toluene with methanol catalyzed by the acidic Mordenite (Si/Al = 23) is reported. Cluster DFT as well as periodical structure DFT calculations have been performed. Full reaction energy diagrams of the elementary reaction steps that lead to the formation of the three xylene isomers are given. The use of periodical structure calculations allows one to account for zeolite framework electrostatic contributions and steric constraints that take place in zeolitic catalysts. Especially the steric constraint energy contribution has a significant effect on the energies and bond formation paths. The activation energy barrier of p-xylene formation is found to be approximately 20 kJ/mol lower than the corresponding values for the formation of its isomers. Computed host-guest binding energies according to the DFT method need a correction due to the absence of the dispersive interaction with the zeolite wall. Apparent activation energies obtained with this correction are in good agreement with experimental data.

[Conservative therapy in varicose symptom complex]

This article deals with the conservative management of light and severe forms of varicosities as well as chronic venous insufficiency along with subjective symptoms and trophic skin changes. Approximately 40% of the population shows minor forms and another 10% shows major forms of varicosities. The prevalence of advanced stages of chronic venous insufficiency is approximately 3%. Compression therapy represents the mainstay of anti-edema treatment. Elastic bandages are mainly used during the acute phase, and compression stockings are rather recommended to maintain the result. The differences of short stretch and long stretch bandages, as well as the classes of compression therapy are discussed. Physical therapy, such as joint mobilization, ambulation exercises, and lymph drainage may further support edema reduction in severe cases. Edema-protective drugs can be justified as adjuvant treatment. The pharmacology and action of these substances has been further elucidated by both laboratory and clinical studies. It has been shown that the continuous use of these substances during 8-12 weeks can reach the anti-edematous effect of class II-stockings. Sclerotherapy is especially useful in the treatment of smaller caliper reticular varicosities and teleangiectatic veins. The development of new vascular lasers with a long pulse duration has added to the options in the treatment of leg teleangiectasias, although these expensive techniques cannot be regarded a standard therapy. Advanced stages of chronic venous insufficiency are also amenable to conservative treatment. In these cases, an exact vascular examination is highly recommended. Interventional treatment of relevant peripheral arterial disease and of superficial venous insufficiency can impressively improve the quality of life of these patients, even at an elderly age. Moreover, the role and differential indication of synthetic dressings in the local therapy of chronic leg ulcers is explained in-depth.

Leg ulcers in peripheral arterial disease (arterial leg ulcers): impaired wound healing above the threshold of chronic critical limb ischemia

BACKGROUND

Peripheral arterial disease is the only identifiable etiology in approximately 10% of leg ulcers. Clinical data on the management of these chronic wounds are scarce.

OBJECTIVE

We attempted to outline the threshold of systolic ankle pressure and ankle-brachial-index (ABI) below which arterial leg ulcers can occur and to outline the indication for revascularization in arterial leg ulcers.

METHODS

Diagnostic and outcome analysis was performed for 26 consecutive patients with arterial leg ulcers. We calculated sensitivities, specificities, and receiver operating characteristic (ROC) curves for the identification of arterial leg ulcers among all 223 consecutive leg ulcer patients within a 3-year period, as well as the ROC curve for patients who required revascularization.

RESULTS

The systolic ankle pressure was 88 (18-130) mm Hg (median; 95% confidence interval) and the ABI was 0.60 (0.15-0.86), respectively. Eighteen patients (69%) were subjected to revascularization. By the end of the study, 24 patients (92%) healed completely, 1 improved (90% wound closure), and 1 patient had to undergo below-knee amputation for chronic osteomyelitis. During this study, the ankle pressure and ABI were poor in distinguishing those patients who required revascularization from those who healed without revascularization.

CONCLUSION

Most arterial leg ulcers do not meet the criteria of chronic critical limb ischemia, but they do not heal under conservative measures, either. A majority of these patients benefit from revascularization and should, therefore, be referred for arterial duplex ultrasound investigation or angiography. In our study, an ankle pressure below 110 mm Hg identified all patients (100%) who were subjected to revascularization procedures. However, controlled clinical studies are required to find the systolic ankle pressure and ABI below which revascularization can be recommended to speed up the healing time.