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For cosmetic reasons, a 24-year-old man performed subcutaneous autoinjections with a preparation having alpha-MSH-like effects (melanotan II) purchased via the internet. The changes of patient's nevi were documented by sequential videodermoscopy before and during treatment. The observed dermoscopic changes made it difficult to differentiate a nevus from a melanoma.

We present a 54-year old man with generalized pustular psoriasis who developed a paraneoplastic pemphigus due to a non Hodgkin lymphoma for the first time while being treated with infliximab. The progress of the lymphoma was lethal.

Lipoedema is a fat distribution disorder causing massive, bilaterally symmetrical enlargement of the lower and in some cases the upper extremities in women. The atraumatic, anatomically appropriate procedure of water jet-assisted liposuction available today represents a prom- ising treatment for these patients who generally suffer from severe subjective and objective impairment. Liposuction treatment can bring long-term improvement if the operative technique focuses on lymph vessel preservation. Immuno- histologic analyses show minimal evidence of lymph vessel structures in lipoaspirates. The histologic analysis of the aspirates documents a relatively specific removal (''apheresis'') of primarily intact lipocytes with low vas- cular amount.

Hidradenitis suppurativa (HS) - a rather common, very chronic and debilitating inflammatory skin appendage disorder with a notoriously underestimated burden of disease - has long been a playground for the high priests of nomenclature: Ask a bunch of eminent dermatologists and skin pathologists to publicly share their thoughts on what causes HS, and they will soon get entrenched in a heated debate on whether this historical term is a despicable misnomer. Fortunately, the recently founded Hidradenitis Suppurativa Foundation (HSF; http://www. hs-foundation.org), to which EXP DERMATOL serves as home journal, has broken with this unproductive tradition and has encouraged publication of the current CONTROVERSIES feature. This is exclusively devoted to discussing the pathobiology of this chronic neutrophilic folliculitis of unknown origin. Although traces of terminological bickering remain visible, it does the HS experts in our virtual debate room credit that they engage in a constructive and comprehensive dissection of potential pathogenesis pathways that may culminate in the clinical picture we know under the competing terms HS or acne inversa. These experts sketch more often complementary than mutually exclusive pathogenesis scenarios, and the outlines of a conceivable consensus on the many open pathobiology questions begin to emerge in these CONTROVERSIES. Hopefully, this heralds a welcome new tradition: to get to the molecular heart of HS pathogenesis, which can only be achieved by a renaissance of solid basic HS research, as the key to developing more effective HS therapy.

A 33 year-old woman presented with a 4-months history of a granulating ulcer on the right index finger. Paronychia was suspected and nail extraction with subsequent histopathologic examination of the removed tissue was performed. Two months later, it became known that the patient's sexual partner had been treated for syphilis. The patient's serology was also positive. Subsequent examination of the original tissue sample by polymerase chain reaction, immunohistochemistry using Treponema pallidum-specific antibodies, and silver staining revealed large numbers of syphilis bacteria, confirming the diagnosis of extragenital chancre.

Multiple clear cell acanthomas are an uncommon clinical presentation with the same histopathologic picture as the solitary form. The reproducable finding of a psoriasiform inflammatory component has stimulated the discussion about a primary neoplastic versus inflammatory etiology which might be regarded as end points of a clinical manifestation spectrum.

For cosmetic reasons, a 24-year-old man performed subcutaneous autoinjections with a preparation having alpha-MSH-like effects (melanotan II) purchased via the internet. The changes of patient's nevi were documented by sequential videodermoscopy before and during treatment. The observed dermoscopic changes made it difficult to differentiate a nevus from a melanoma.

Morphoeic basal cell carcinoma (BCC) and desmoplastic trichoepithelioma can often be difficult to differentiate on routine sections and few reliable immunohistochemical markers are currently available. Recent cDNA microarray studies revealed the pleckstrin homology-like domain, family A, member 1 protein (PHLDA1) as a highly reliable marker of the hair follicle stem cells. Given the differentiation of trichoepithelioma along the follicular lineage and the proposed role of PHLDA1 as a follicular stem cell marker, we examined the staining pattern of PHLDA1 in the desmoplastic variant of trichoepithelioma and in its differential diagnostic conundrum, morphoeic BCC.To describe the expression pattern of PHLDA1 in morphoeic BCC and desmoplastic trichoepithelioma.Evaluation of the staining pattern for PHLDA1 was performed using standard immunohistochemical techniques. For comparison reasons, we analysed staining for PHLDA1 in normal skin structures with particular reference to the hair follicle.With the exception of one case, all 16 desmoplastic trichoepitheliomas were immunoreactive with more than 80% of the cells stained, whereas all 14 morphoeic BCCs were PHLDA1-negative with the exception of ulcerated tumours. In the latter, the tumour islands close to the ulcer were PHLDA1-positive whereas the deeper located tumour portions remained immunonegative. PHLDA 1 was prominently expressed in the hair follicle bulge of terminal and vellus hair follicles.The hair follicle bulge marker PHLDA1 differentiates between desmoplastic trichoepitheliomas and nonulcerated examples of morphoeic BCCs. We suggest incorporating PHLDA1 in the diagnostic work-up of difficult to differentiate basaloid tumours.

Within the next decade stem cell-based therapies can be expected to be part of clinical medicine. In regard to the skin, the focus of stem cell research is on the epidermis and the hair follicle. In 2001, mesenchymal stem cells residing within the dermis were first isolated which have the capacity to differentiate into adipocytes, smooth muscle cells, osteocytes, chondrocytes and even neurons and glia as well as hematopoietic cells of myeloid and erythroid lineage. The perifollicular connective tissue sheath and the papilla represent the likely anatomical niche for these multipotent dermal cells. They have the potential to function as an easily accessible, autologous source for future stem cell transplantation. Potential therapeutic applications include the treatment of acute and steroid-refractory graft-versus-host disease, systemic lupus erythematosus, idiopathic pulmonary fibrosis and arthritis. The neuronal differentiation potential of cutaneous mesenchymal stem cells may also be exploited in the treatment of neurodegenerative disorders and traumatic spinal injury. The most immediate impact can be expected in the field of wound healing.

Tumour development is frequently described in the basic pathology literature as a recapitulation of embryogenesis. However, a link between the embryology of the skin and the histogenesis of adnexal tumours has been largely overlooked. The low-affinity p75 neurotrophin receptor (p75NTR) has a profound role in hair follicle biology. We therefore speculated that it is involved in the histogenesis of follicular adnexal tumours. One of the most challenging diagnoses in dermatopathology is differentiating morphoeic basal cell carcinoma from desmoplastic trichoepithelioma.To describe the expression pattern of p75NTR during cutaneous embryogenesis, in the adult hair follicle and in morphoeic basal cell carcinoma and desmoplastic trichoepithelioma.Evaluation of the staining pattern for p75NTR was performed using standard immunohistochemical techniques. For comparison, we examined staining for cytokeratin 20 which highlights Merkel cells.All 17 desmoplastic trichoepitheliomas were immunoreactive with80% of the cells stained, whereas 12 of the 14 (86%) morphoeic basal cell carcinomas were p75NTR negative. In the two positive cases of morphoeic basal cell carcinoma30% of cells were labelled. In the late bulbous hair peg stage and in the postnatal anagen hair follicle p75NTR highlights the outer root sheath.Our results support the classification of desmoplastic trichoepithelioma as a follicular hamartoma mimicking the outer root sheath. In contrast, the lack of p75NTR expression in morphoeic basal cell carcinoma favours a concept of this tumour as a more primitive follicular lesion with the characteristics of a carcinoma and not a hamartoma. We suggest including p75NTR as a tool in the differential diagnosis between morphoeic basal cell carcinoma and desmoplastic trichoepithelioma.

The current classification schemes of adnexal tumours are predominantly based on morphological and immunophenotypical similarities to adult skin structures, whereas a link between the embryology of the skin and the histogenesis of adnexal tumours has been largely neglected.To describe the expression patterns of two proteins with proven relevance for hair follicle homeostasis (SOX9 and β-catenin) during human cutaneous embryogenesis and to compare the findings with their expression in basal cell carcinoma (BCC) and pilomatrixoma.Immunohistochemical evaluation with monoclonal antibodies against SOX9 and β-catenin was carried out in embryonic and adult human scalp skin, and BCC and pilomatrixoma samples.We found that the expression patterns of SOX9 and β-catenin during human hair follicle embryogenesis mirror the patterns in BCC and pilomatrixoma in spatial distribution within the various follicular subcompartments. Beginning with the hair peg stage, nucleocytoplasmic immunoreactivity of β-catenin is exclusively confined to the emerging matrix (comparable to pilomatrixoma), whereas SOX9 is restricted to the primordial outer root sheath (comparable to BCC). An appropriate immunophenotyping validated within the conceptual framework of cutaneous developmental biology allows a logical classification of adnexal neoplasms. Expanding this approach further has the potential to revise the current classification schemes so that not only BCC and pilomatrixoma but all adnexal tumours can be categorized logically.

Chronic external otitis may be divided into several diagnostic categories. Disposition for psoriasis, seborrhoeic and atopic eczema are main endogenous reasons. Exogenous pathogens for external otitis are microbes and allergens. There are numerous interrelations by coincidence of dispositional diseases, e.g. psoriasis and atopic eczema and by combination of exogenous and endogenous pathogens. This holds good for the yeast Pityrosporum ovale vs. orbiculare in seborrhoeic eczema and for the susceptibility to contact (type IV) and respiratory (type I) allergy in atopic individuals as well. Mycotic and bacterial, especially gram negative external otitis are linked to predisposing factors like eczema, long-term microbicidal therapy, hot and humid environment. Contact allergic external otitis may occur during long lasting local therapy with various substances including vehicles, the most common allergen being neomycin. Mucosal allergic reactions (Type I) in the upper respiratory tract may impair ventilation of the Eustachian tube and middle ear and therefore epithelial migration, as a drainage mechanism of the auditory canal. Examination should include functional assessment of the Eustachian tube and middle ear and allergy testing (patch, prick test). Preparations for local therapy should contain a limited number of constituents and avoid common allergens. Surgical procedures to reestablish ventilation of the middle ear are also a therapy for chronic external otitis.

Charge-coupled device (CCD) technology is now widely used to record electron-optical images. In order to optimize the transfer of an image to the CCD sensor the properties of the transmission screen (efficiency, pulse height distribution, point-spread function) and the light-optical transfer by fiber optics must be taken into consideration. We discuss the performance of a low-noise CCD camera (Photometrics PM512) which can detect single electron signals. The electron density distribution in the final plane of the transmission electron microscope is converted by a P20 or a YAG single-crystal scintillator and transferred via a 1:1 fiber optic or a 2:1 fiber-optic reduser to the CCD sensor.

Die vielseitigen Einsatzmoglichkeiten eines abbildenden Energiefilters fur die Untersuchung materialkundlicher Proben in einem Transmissionselektronenmikroskop (Kontrast- und Auflosungsverbesserung bei Abbildung dicker Objekte, EELs- und Mapping-Analysentechnik, die Untersuchung elastischer und unelastischer Streuprozesse in kristallinen Proben und deren Bedeutung fur die Kontrastentstehung) stehen heute der materialkundlichen Forschung, die auf Beschleunigungsspannungen uber 100 kV angewiesen ist, leider nicht zur Verfugung. Es ware wunschenswert, das kunftig auch kommerzielle Hochleistungsgerate im Mittelspannungsbereich mit abbildenden Energiefiltern ausgestattet wurden. Der hohe instrumentelle Aufwand ist sicher durch die zahlreichen Anwendungsmoglichkeiten, von denen nur einige vorgestellt wurden, zu rechtfertigen.

A 33-year-old woman presented with a 4-months history of a granulating ulcer on the right index finger. Paronychia was suspected and nail extraction with subsequent histopathologic examination of the removed tissue was performed. Two months later, it became known that the patient's sexual partner had been treated for syphilis. The patient's serology was also positive. Subsequent examination of the original tissue sample by polymerase chain reaction, immunohistochemistry using Treponema pallidum-specific antibodies, and silver staining revealed large numbers of syphilis bacteria, confirming the diagnosis of extragenital chancre.

This paper presents an overview of Extend, a multidomain, hierarchical simulation modeling tool. Extend is designed around a modern graphical user interface and is extensible into many different areas of application including both discrete event and continuous systems.

Malaise and fatigue are common symptoms of advanced malignant disease. Nevertheless, a specific cause--requiring specified treatment--for this symptom should be ruled out. We report on a patient with a complex endocrine dysfunction that developed due to a tiny metastasis of a breast carcinoma in the pituitary stalk.A 46- year-old woman presented with general ill feeling 3 years after operation for a breast carcinoma. She was diagnosed to have hepatic and peritoneal metastases and malignant pleural effusion. For the application of chemotherapy, an i.v.-port system in the right brachiocephalic vein was inserted. In the postoperative period, an emergency situation developed due to demasked cortisol deficiency and hypernatremia. Careful laboratory investigations revealed hypofunction of the anterior lobe of the pituitary gland and diabetes insipidus centralis. By MRI imaging of the parasellar region, a 4 x 5 mm metastatic lesion in the pituitary stalk was found--notable only in knowledge of the clinical diagnosis. The patient's condition and quality of life improved markedly with hormone replacement therapy.Metastatic cancer may present as endocrine disease, either by release of hormone-like substances or by tumorous destruction of endocrine structures. Metastases of solid tumors to the pituitary gland are often asymptomatic or present with diabetes insipidus. The presentation with a hypofunction of the anterior and posterior lobe of the pituitary gland is a rare event. It is recommended to consider endocrine dysfunction as potential cause of 'malaise' in a cancer patient.

The Extend simulation environment provides the tools for all levels of modelers to efficiently create accurate and credible models. Extend's modem, advanced design and rich feature set reduce the amount of time developing, validating, verifying, and analyzing simulation models. Model builders can use Extend's pre-built modeling components to quickly build and analyze systems with little or no programming. Simulation tool developers can use Extend's built-in, compiled language, ModL, to develop new reusable modeling components. All of this is done within a single, self-contained software program that does not require external interfaces, compilers, or code generators.

This document presents an overview of the Extend modeling environment. Extend is a general-purpose, graphically-oriented, discrete event and continuous simulation application with an integrated authoring environment and development system. Examples of applications will illustrate the product's broad appeal. Specific features will be demonstrated by examining a simple model of a single server, single queue system to which detail and enhancements will be added.

A 60-years old female patient developed juxta-articular fibroid nodules and erythrocyanotic lesions of acrodermatitis chronica atrophicans after several tick bites. The woman was treated with ceftriaxon (Rocephin) 2 g daily parenterally without adverse reactions.

Between September 1991 and May 1996, 56 patients with refractory or relapsed acute myeloid leukemia (AML) were treated with one cycle of timed sequential chemotherapy (TSC) consisting of intermediate-dose (ID) ara-C (1.0 g/m2 every 12 h) on days 1, 2, 8, and 9, and idarubicin (IDA, 10 mg/m2) on days 3, 4, 10, and 11. The study population included 22 patients with refractory AML, 33 patients with late first relapse occurring after a first complete remission of ≥ 6 months, and 1 patient for whom the clinical course before salvage therapy was unknown. Of the 56 patients entered onto the study, 25 (45%) achieved a complete remission (CR), 8 (14%) a partial remission (PR), 11 patients (20%) were classified as treatment failure due to resistant disease, and 12 patients (21%) died within the first 42 days after the initiation of salvage therapy, mainly due to infections. Response to salvage therapy was strongly influenced by disease status with 55% of patients with late first relapse achieving a CR as compared with 32% of patients with refractoryAML. Severe myelosuppression was observed in most patients resulting in fever or documented infections in 70–90% of them whereas nonhematologic toxicity was tolerable. Among the 25 patients who achieved a CR, 6 patients received no postremission therapy, 10 patients were treated with 1 or 2 cycles of IDA (8 mg/m2) and etoposide (150 mg/m2) on days 1 to 3 as consolidation, 8 patients underwent an allogeneic or autologous bone marrow transplantation (BMT), and 1 patient was lost for follow-up. Overall, after a median follow-up of 44 months, the median remission duration is 9 months, and the median survival 9 months as well. We conclude that this chemotherapy regimen has significant antileukemic efficacy, especially in AML patients who relapsed after a durable first CR (≥ 6 months). The short duration of remission in patients not eligible for BMT, however, emphasizes the need for optimizing early postinduction therapy.

This paper presents a message-based discrete event simulation architecture. It will examine each of the different types of messages used to schedule events, transfer items through the model, and resolve logic issues. Additional information is also presented on the supporting data structures.

We report on seven examples of this rare, only recently described benign tumor, which presented clinically as solitary elevated nodules on the lower (n = 5) and upper (n = 2) extremity, measuring between 0.6 and 1.1 cm in diameter. Histologically, all tumors were well-defined with a characteristic epidermal collarette. There were abundant (60-80%) epithelioid cells with prominent cytoplasm, a vesicular nucleus and inconspicuous nucleolus, as well as a number of dilated blood vessels. Immunohistologically, tumor cells did not react with monocyte/macrophage antibodies (KP1, MAC387). In addition, there was no evidence of myofibroblastic differentiation (alpha-smooth muscle actin and desmin negative). Thus, while immunohistological markers are helpful to exclude the diagnosis of other tumors, they do not shed light on the differentiation of epithelioid cell histiocytomas. The present cases are identical to those described originally. Recently similar lesions have been described in deeper parts of the corium as well as more cellular forms. Epithelioid cell histiocytoma represents a characteristic, poorly known variant within the spectrum of benign fibrous histiocytomas; it needs to be distinguished clinically and histopathologically especially from Spitz nevus.

Since interleukin-2 (IL-2) has been shown to induce lysis of autologous AML blasts, maintenance therapy with IL-2 could be of value in AML. However, IL-2 normally is given at high doses, and side effects commonly occur. Low-dose regimens have been described [1]. Cytokines are capable of inducing other biological active mediators, and it is not known whether the in-vivo effects of low-dose IL-2 can be augmented by the addition of γ-IFN. We studied the biological effects of low-dose IL-2 alone or in combination with γ-interferon in the maintenance phase. AML patients were first treated using idarubicin and ara-C. 27 patients (25 de novo, 2 relapses) were enrolled in this study. Median age was 53γ (range 21–81). 10/27 patients were investigated using standard cytogenetics, of which 6 were abnormal (4 of these 6 revealed del (5q). 13 (48%) patients entered CR. As maintenance treatment 4-week cycles of either low-dose IL-2 alone or IL-2 in combination with γ-IFN were alternated. Patients were randomized to start with IL-2 cycles, or with IL-2 + γ-IFN. After each cycle, patients were crossed over to the other arm. By this method, 23 immunological and 9 molecular markers of 13 cycles with IL-2 alone and of 14 cycles of IL-2 + γ-IFN could be compared. No side effects were observed. Immunological analysis using two-color flow cytometry showed activation of T-cells in single patients. No difference between cycles with IL-2 alone as compared to IL-2 plus IFN-γ was observed with regard to activation of T-cells. However, an increase of B-cells was demonstrated when using the combination treatment compared to IL-2 alone. Polymerase chain reaction using primers specific for various human cytokines and the respective receptors (IL-2; IL-2 receptor; IL4; IL6; IFN-γ; GM-CSF) revealed no correlation with treatment. In conclusion, maintenance with low-dose IL-2 seems to be safe and is well tolerated; the only difference observed between the two cycles was an increase of B-cells in the cycles with IL-2 plus IFN-γ as compared to IL-2 alone.

Die chirurgische Forderung nach spannungsfreiem Wundverschlus wurde bei verschiedenen dermatologischen Wundverschlusverfahren uberpruft. Mit einer sterilisierbaren Prazisionsfederwaage wurden die zu verschiebenden Wundrander bei unterschiedlichen Arten von Defektverschlussen nach Tumorexzisionen unter Verlagerung in die Position bei Wundverschlus auf die entstehende Spannung hin untersucht. Im einzelnen wurden 5 Dehnungsplastiken, 2 U-Lappen, 4 subkutan gestielte Lappen, 3 Rotationslappen und 2 Transpositionslappen einbezogen. Spannungen zwischen 700 und uber 1 000 mp traten bei GewebeverSchiebungen mit uberwiegend longitudinalem Spannungsvektor (Dehnungsplastik, U-Lappen, subkutan gestielter Lappen) auf. Bei Gewebeverschiebungen im Sinne einer Kreissektorbewegung (Rotationslappen, Transpositionslappen) waren die erforderlichen Spannungen mit 300–500 mp geringer. Offensichtlich ist die Forderung nach spannungsfreiem Wundverschlus unrealistisch und sollte durch die erfullbare Forderung einer moglichst geringen Spannung ersetzt werden. Moglichkeiten, uber vorliegende semiquantitative Aussagen zu verfeinerten Ergebnissen zu kommen, sind an speziell angepaste Mesapparaturen gebunden. Die Berucksichtigung von zu erwartender Spannung bei Wundverschlussen kann helfen, Komplikationen wie Lappenspitzenne- krosen, Dehiszenzen oder hypertrophische Narben zu vermeiden.

Erythrokeratolysis hiemalis, keratolytic winter erythema or Oudtshoorn skin has been reported from the South African district of Oudtshoorn as a dominantly inherited dermatosis beginning in early childhood, in some cases with circinar scaling erythemas. Seasonal manifestation in winter-time and a characteristic multi-form histology distinguish this dermatosis from other childhood scaling erythemas. We present clinical, histological and preliminary immunohistological data of a 4-year-old girl with the attributes of erythrokeratolysis hiemalis. No ancestors from the endemic region were traced. The lack of further cases in the family is interpreted as indicative of a spontaneous dominant new mutation.

Auxotype/serovar (A/S) classification enables precise characterisation of Neisseria gonorrhoeae. In the present study we evaluated whether sex and sexual preference of the patient influence the auxotype/serovar class of the infecting gonococcal strain. In male patients prototrophic/IB-3 was the most frequently isolated A/S class. By contrast, in female patients the A/S class (P)AH(U)/IA-1/2 was significantly (p0.005) more frequently isolated than in male patients. Analysis of our data according to sexual preference of the patients showed that in heterosexual patients the two mentioned A/S classes were leading, whereas in homo- and bisexual patients A/S classes prototrophic/IB-2 (p0.0001) and Pro/IB-2/16 (p0.0001) were isolated significantly more often. Our data are a strong indication that the host environment is also responsible for the selection of N. gonorrhoeae strains with certain typing characteristics.

Targetoid haemosiderotic haemangioma (THH) can be differentiated from other angiomatous lesions by the characteristic findings on clinical and histological examination. Clinically the solitary lesion is suggestive of a melanocytic or angiomatous origin, surrounded by a haemorrhagic halo in the acute phase. Histological findings vary depending on the duration of the alteration. The pattern has a superficial and a deep dermal component. In the papillary body lesional capillaries are lined by prominent endothelial cells. The surrounding tissue is oedematous and contains masses of erythrocytes or haemosiderin and a lymphocytic infiltrate. Vessels in the deeper dermis have a lymphatic appearance and surround adnexal structures. Further possible similarities with Kaposi sarcoma are dissecting vascular lumina between collagen bundles and spindle cell areas. However, has no atypical cells, eosinophilic globules or apoptotic endothelial cells. Immunohistochemical investigations, which have now revealed BMA 120 for the first time in THH as well as factor VIII-R antigen and Ulex europaeus I lectin, have not so far made any substantial contribution to the differential diagnosis and histogenesis of THH, because markers distinguishing lymphatic from vascular endothelia are still lacking.

Chronic external otitis may be divided into several diagnostic categories. Disposition for psoriasis, seborrhoeic and atopic eczema are main endogenous reasons. Exogenous pathogens for external otitis are microbes and allergens. There are numerous interrelations by coincidence of dispositional diseases, e.g. psoriasis and atopic eczema and by combination of exogenous and endogenous pathogens. This holds good for the yeast Pityrosporum ovale vs. orbiculare in seborrhoeic eczema and for the susceptibility to contact (type IV) and respiratory (type I) allergy in atopic individuals as well. Mycotic and bacterial, especially gram negative external otitis are linked to predisposing factors like eczema, long-term microbicidal therapy, hot and humid environment. Contact allergic external otitis may occur during long lasting local therapy with various substances including vehicles, the most common allergen being neomycin. Mucosal allergic reactions (Type I) in the upper respiratory tract may impair ventilation of the Eustachian tube and middle ear and therefore epithelial migration, as a drainage mechanism of the auditory canal. Examination should include functional assessment of the Eustachian tube and middle ear and allergy testing (patch, prick test). Preparations for local therapy should contain a limited number of constituents and avoid common allergens. Surgical procedures to reestablish ventilation of the middle ear are also a therapy for chronic external otitis.

Sterile eosinophilic pustulosis (Ofuji's disease) is very rare in Europe compared with Japan. We describe a Turkish and a German case. Clinical and histopathological findings do not allow a clearcut diagnosis. Many differential diagnoses have to be excluded, mainly by histopathological investigations. Careful examination of the heart and other internal organs is also necessary, since Ofuji's disease belongs to the group of hypereosinophilic diseases. Transitions from cutaneous to internal manifestations of hypereosinophilic disease may exist.

SUMMARY The principles in design and operation of TV electron-image recording systems are elucidated. Using the ‘detection quantum efficiency’ (DQE) as a figure of merit, the influence of various parameters is discussed, such as single electron response, read-out noise and saturation of the camera tubes as well as the properties of digital frame stores. The analogue signal processing mode gives a DQE of about 0·8 and can be adapted to a wide range of operating conditions. Counting of normalized electron signals in digital storages allows an almost ideal image detection, which can, however, at best only be applied with a current density below 10−13 A cm−2. Compared to photographic recording, electronic systems offer real-time response, compatibility with computers and great flexibility of stored information. Their DQE is similar in the analogue mode but superior in the counting mode. The storage capacity, on the other hand—particularly the number of pixels—is presently still inferior to the photoplate.

Channelling imaging of thick single-crystal specimens and improvement of the resolution by energy-loss filtering is demonstrated for a 350 nm thick gold film in a Zeiss 902 energy-filter microscope with 80 keV electrons. Image intensity and contrast are explained in the Bloch-wave picture.

EXAFS-like features in energy loss spectra (known as EXELFS) were observed by using an imaging energy filter built into an electron microscope. Single crystal micro-platelets of MgO were used as test samples. Extended fine structures were obtained reproducibly in the energy range up to 150 eV beyond the O-K, Mg-K and Mg-L edges. Comparison with single scattering calculations for the K edges showed a fair agreement, indicating the feasibility of this type of analysis.

Describes a simple device to cool the target of a SIT camera tube. The simplicity rests on the use of cold nitrogen gas. Since cooling of detectors, multipliers and camera tubes is a common problem, the authors provide a detailed description of the design and performance so that it may be duplicated and modified in any regularly equipped physics laboratory.

Fernseh-Bildverstarkeranlagen mit Speichergeraten lassen sich fur die Auslesung und Verarbeitung von EM-Bildern in Echtzeit einsetzen. Anhand des Einzelelektronensignals und der Detection Quantum Efficiency (DQE) werden die Dimensionierungsgrundsatze fur den Aufbau derartiger Anlagen erlautert und fur verschiedene spezielle Systeme gepruft. Wahrend bei hohen Endbildstromdichten ein vom Dynamikumfang der Kamerarohre abhangiger Abfall der DQE in Kauf genommen werden mus, konnen mit ausreichender optoelektronischer Vorverstarkung bei mittleren Stromdichten Werte von mehr als 0.80 erzielt werden. Der Idealdetektor (DQE = 1) wird bei kleinen Stromdichten mit digitaler Verarbeitung und Speicherung erreicht. TV image intensifiers with storage devices can be utilized for the read-out and processing in real-time of electron microscopic images. By means of the single electron response and the detection quantum efficiency (DQE) the dimensioning principles for the design of such devices are explained and studied for various special systems. Whereas at high final image current densities a DQE decay depending on the dynamic range of the camera tube must be accepted, with sufficient optoelectronic preamplification at medium current densities values of about 0.80 are obtained. The ideal detector (DQE = 1) is realized at small current densities with digital processing and storage.

An image processing system for a CTEM is described which is particularly suited for the imaging of radiation-sensitive objects. It consists of an image intensifier device for single electron counting, a digital storage unit and a video recorder for intermediate storage of low-dose image series. During on-line operation the information can be transferred to a computer for further processing. The output can be transferred onto a second digital storage unit and observed on a monitor. The influence on the DQE of the pulse height distribution of the single electron video signals and of a multiple counting are eliminated by means of special electronic components. Various modes of operation and application possibilities of the image processing system are discussed.

41 males at the age from 20 to 40 years with chronic obstruction of the arteries of the extremities were on the basis of anamnestic and clinical findings subdivided into the groups obliterating endangiitis (group I = 20 patients) and obliterating arteriosclerosis (group II = 11 patients). In 10 patients in this way no decision for one of the two diagnoses could be made (group III). By multidimensional variance and discriminance analysis of various clinico-chemical parameters the separation of the groups I and II could be proved. The efficiency was 93.6% in the discrimination with 10 characteristics. With the help of the calculated non-elementary, linear characteristics of discriminance the patients could be classified into the group III. 7 patients could be classified into the group II and 3 patients into the group I. Thus we succeeded in differing 23 patients with obliterating endangiitis from 18 patients who as arteriosclerotics belong to the metabolic syndrome.

A digital system is described which allows on-line recording and processing of CTEM images. For rapid recording a low light level camera is used. The processed data are fed - via a special TV image storage - into a disc memory of a PDP 11/03 computer and stored as a series of single images thus allowing aposteriori processing.