Comparative diagnostic accuracy of magnetic resonance imaging and immunoscintigraphy for detection of bone marrow involvement in patients with malignant lymphoma.

PURPOSE: To compare the diagnostic accuracy of magnetic resonance imaging (MRI) and immunoscintigraphy (IS) for detection of bone marrow infiltration in malignant lymphoma. PATIENTS AND METHODS: In 32 patients with Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL), MRI of the axial skeleton and whole-body IS using technetium-99m (99mTc)-labeled monoclonal antibodies were reviewed and compared with iliac crest biopsies. Criterion for marrow infiltration was a positive biopsy or concordant positive results of MRI and IS. RESULTS: In 16 patients (50%), MRI, IS, and iliac crest biopsies were negative for marrow infiltration. Iliac crest biopsy showed infiltration in only four patients (13%). Infiltration was missed in two of 32 patients with IS and in one patient with MRI. In one additional patient, MRI was false-positive because of pelvic hematopoietic hyperplasia. A subset of nine patients (28%) with negative biopsies had bone marrow involvement according to MRI and IS with identical location and pattern of infiltration. In eight of these nine patients, diagnostic imaging indicated marrow involvement only in noncrest marrow. Subsequent biopsy confirmed infiltration in five patients. The clinical course suggested true-positive imaging results in the remaining four patients. Two patients (6%) remained equivocal. Overall concordance of MRI and IS for marrow infiltration was 88% (28 of 32 patients). CONCLUSION: Diagnostic imaging is essential for optimal staging in malignant lymphoma, as blind biopsies appear to have low sensitivity for bone marrow infiltration because of frequent involvement in noncrest marrow. both imaging modalities show a high rate of detection of bone marrow infiltration.

Total chemical synthesis, characterization, and immunological properties of an MHC class I model using the TASP concept for protein de novo design.

The design, total chemical synthesis, and immunological properties of a four-alpha-helix bundle template-assembled synthetic protein (TASP) mimicking some of the structural features of the major histocompatibility complex (MHC) class I is described. In a first approach, the native sequence 58-74 of the alpha 1 heavy chain domain of HLA-A2 was modeled in order to increase helix stability and amphiphilicity of the 17-mer peptide, preserving the residues for potential T-cell receptor (TcR) binding properties. According to the TASP concept, these helical segments were covalently attached to a cyclic template molecule designed for the induction of a four-helix-bundle topology of the assembled peptide blocks. After extensive HPLC purification, stepwise solid-phase synthesis resulted in a TASP molecule of high chemical purity as demonstrated by analytical HPLC, mass spectrometry, and amino acid analysis. CD spectroscopic investigations are consistent with the onset of a partial alpha-helical conformation in aqueous buffer as well as in TFE. Antibodies raised directly against this four-alpha-helix bundle TASP molecule (without prior conjugation to a carrier molecule) were detected by ELISA. Flow cytometry studies showed that these antibodies recognize the native MHC class I molecule on the surface of HLA-A2-positive cells. The results indicate that the TASP approach represents a versatile tool for mimicking conformational epitopes.

Invasive pulmonary aspergillosis. MRI, CT, and plain radiographic findings and their contribution for early diagnosis.

A prospective study was conducted in 38 patients with nodular lesions on plain chest radiographs and the clinical suspicion of invasive pulmonary aspergillosis (IPA) to assess the diagnostic accuracy of magnetic resonance imaging (MRI) and computed tomography (CT). For early diagnosis of IPA (clinical signs and symptoms < 10 days), CT scans with demonstration of the halo sign had a high sensitivity (16/22) and specificity (8/8). Magnetic resonance imaging performed at the same time revealed a relatively higher sensitivity (22/22), but a very poor specificity (0/8). Gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA) enhanced images did not improve specificity. In the later course of infection (clinical signs and symptoms > 10 days), MRIs showed typical nodular target-like lesions with Gd-DTPA enhancement of the rim area that was not seen in the early course of the disease or in patients with Pseudomonas or staphylococcal infection. In conclusion, MRI findings are not as characteristic as the CT halo sign in diagnosing IPA in the early course of the disease, but the MRI target sign with Gd-DTPA enhancement of the rim area and the "reverse target" on T2-weighted images are strongly suggestive of IPA at a later stage of the disease.

Studies on the release of histamine from isolated guinea pig mast cells stimulated by ionophore A23187 or by the anaphylactic reaction.

The divalent cation ionophore A23187 was found to produce a dose-dependent release of histamine from isolated mesenteric mast cells of the guinea pig. The process showed a specific requirement for calcium ions and was blocked by inhibitors of glycolysis. The effect of cAMP, theophylline, sympathomimetic amines and DSCG on the histamine release induced by the ionophore or by the antigen-antibody reaction was compared. In both cases, the release was inhibited by Bu2cAMP and by theophylline but higher concentrations were required with the ionophore. Adrenaline, isoprenaline and DSCG were effective only in the anaphylactic system. These results are compared with those previously reported for human leucocytes and rat peritoneal mast cells in which the release produced by the ionophore was found not to be inhibited by cAMP and its analogues. On the basis of these findings, the possible role of cAMP in the modulation of histamine release is discussed.

Vitamin B6 responsive growth of human tumors.

The model of human malignant tumors, heterotransplanted and passaged into athymic nude mice, proved to be a valuable tool for nutritional oncology. It showed that several human tumors proliferate in distinct dependence on the available vitamin B6. A surplus of the vitamin causes enhancement of growth. Proliferation is retarded in cases of reduced availability. The amount of vitamin B6 available does not only depend on the dietary supply. The contribution of the intestinal flora may be considerable. Therefore the adverse effect of a diet free of vitamin B6 is distinctly increased by additional application of a vitamin antagonist such as D-penicillamine for instance. It should be emphasized that this happens even in situations in which no clinical symptoms of vitamin deficiency could be observed at all. Our experimental findings may have consequences for those human patients who are stricken with vitamin B6 responsive tumors. A shifting supply of vitamin B6 should at least be avoided. Dietary guidance and a careful use of vitamin antagonists, such as D-penicillamine for instance, may be helpful.

Preoperative CT and MR imaging of inferior vena cava leiomyosarcoma.

We investigated the radiological findings of five patients with primary leiomyosarcoma of the inferior vena cava (IVC) comparing cavography, computed tomography (CT), and magnetic resonance imaging (MRI). The radiographic presentation ranged from an intraluminal lesion with obstruction of the IVC to a tumor mass extending from the media musculature into the surrounding perivascular tissue with only slight protrusion into the lumen. The lesions were associated with late or few symptoms. Pathognomonic radiological findings could not be established. In cases with an extraluminal growth a lobulated, well-defined, encapsulated tumor with an inhomogeneous contrast uptake is characteristic in CT studies. Additional information was provided by MRI. Leiomyosarcomas with extraluminal involvement showed homogeneous intermediate signal intensity (SI) on T1-, and mixed intermediate/high SI on T2-weighted images. In cases with predominantly intraluminal growth, both CT and MRI demonstrated the IVC to be dilatated and allowed to differentiate between tumor extent and obliterating thrombosis. Modern imaging modalities allow an early and accurate pre-operative diagnosis resulting in a higher rate of surgical resection and improvement of survival.

[Castleman's lymphoma. Differential diagnosis of mediastinal tumors]. / Das Castleman-Lymphom. Zur Differentialdiagnose der Mediastinaltumoren.

This report describes two cases of Castleman's disease (male 48 yrs, female 33 yrs). Two intrathoracic lymphomas were accidentally discovered during routine x-ray examination. Histologically, follicular hyperplasia, prominent interfollicular vascularity and sheets of mature plasma cells (intermediate variant) were seen. The etiology of this benign lymphoma remains unknown. Its significance lies in its differential diagnosis from malignant tumours.

[Early postoperative control of internal thoracic artery-coronary artery anastomoses using intra-arterial DSA]. / Frühe postoperative Kontrolle von Arteria-thoracica-interna-Anastomosen mit Koronararterien durch intraarterielle DSA.

Early postoperative angiographic control is important for prognosis and medical therapy for patients undergoing coronary bypass surgery. Grafts from the internal mammary artery had been shown to be superior to venous bypasses for anastomoses to the left anterior descending coronary artery. Thus, the need for angiographic demonstration of graft patency and function is increasing. We report on the angiographic analyses of 73 patients after left internal mammary artery (LIMA) bypass surgery by filling of the graft via retrograde injection of contrast medium into the left brachial artery. In all cases the bypass, anastomosis and downstream vessel were clearly visualised. No complications or side effects were observed.

[Pseudolymphoma of the stomach]. / Das Pseudolymphom des Magens.

Gastric pseudolymphoma is an uncommon benign lesion which poses a difficult problem in diagnosis and management. Lymphoid hyperplasia of the stomach, however, may occasionally precede true gastric lymphoma. Endoscopic, radiologic and pathological findings are not generally helpful in establishing the diagnosis preoperatively. Benign gastric lymphoid hyperplasia could be mistaken radiologically for ulcerated gastric carcinoma and pathologically for malignant lymphoma. Recognition of this condition is important to prevent unnecessary treatment by surgery or radiotherapy. About 140 case reports have been published to date. This paper describes the cases of two further patients.

[Traction injuries of the brachial plexus: radiologic diagnosis using myelo-CT and MR]. / Traktionsverletzungen des Plexus brachialis: radiologische Diagnostik mit Myelo-CT und MR.

The exact radiographic localisation of supraganglionic lesions of the brachial plexus provides important information for the prognosis and clinical management of these injuries. The authors report on the results of enhanced CT scanning and MRI of the cervical spine in five patients with surgically proven root avulsions caused by traction injuries. All lesions were correctly diagnosed by enhanced CT scanning. MRI, by comparison, identified only about 70% of the neural lesions.

[Pulmonary changes in AIDS]. / Lungenveränderungen bei AIDS.

We reviewed retrospectively the clinical records of 28 patients with AIDS staged group IV according to CDC-criteria. Among these, 19 had pulmonary disease: most of them (n = 17) had pneumocystis carinii pneumonia (Pcp). 12/17 patients with proven Pcp displayed typical x-ray findings with diffuse perihilar interstitial infiltration sparing lung periphery. 3/17 had atypical features and 2 normal chest x-ray findings. These data are important to identify patients with pulmonary complications of AIDS.

[Radiologic differential diagnosis of inflammatory round pulmonary infiltrates in immunocompromised patients. A prospective study using CT and MRT]. / Radiologische Differentialdiagnose des entzündlichen pulmonalen Rundinfiltrates bei immungeschwächten Patienten. Eine prospektive Studie mit CT und MRT.

In a prospective study we examined the diagnostic ranking of CT and MR in 52 immunocompromised patients with nodular pulmonary lesions and clinical suspicion of invasive pulmonary aspergillosis (IPA). For early diagnosis of IPA (clinical symptoms having existed for less than 10 days) the CT halo sign proved highly sensitive and specific. MRT showed at this time a comparatively high sensitivity but only low specificity that could not be improved upon after Gd-DTPA. At a later stage of the aspergillosis infection (clinical symptoms manifested for more than 10 days) MR identified aspergillus-specific lesions with on-target characteristics (marked enhancement of margins after Gd-DTPA) or the so-called "reverse" target phenomenon (T2-weighted sequences). Such lesions were never seen in the early stage of the disease in patients with nodular pulmonary lesions of different aetiology (pseudomonal or staphylococcal pneumonia).

[Endoluminal therapy of infrarenal abdominal aortic aneurysms: a new interventional technique]. / Die endoluminale Therapie des infrarenalen Bauchaorten-aneurysmas--ein neues interventionelles Verfahren.

PURPOSE: With a series of 31 transluminal stent-graft procedures, we assessed the feasibility and clinical effectiveness of a new stent-graft for the treatment of infrarenal abdominal aortic aneurysms (AAAs). METHODS: We treated the patients (male; mean age 71 years) with straight or bifurcated nitinol stents covered with woven dacron graft material for infrarenal eccentric saccular AAA (n = 4) or AAA involving the bifurcation and the common iliac arteries (n = 27). The 18-F delivery system was advanced via a surgical arteriotomy and the stent-graft was placed under fluoroscopic control. Follow-up period ranged from 8 days to 9 months. RESULTS: The implantation of the stent-grafts was technically successful in 30/31 cases. Procedure-related complications were acute hepatic failure due to gastric bleeding in a patient with liver cirrhosis, graft occlusion due to emboli originating from the left atrium (n = 1), macro-embolisation (n = 3), local haematoma (n = 1) and av-fistula (n = 1) requiring surgery. A post-implantation syndrome with leukocytosis and elevated C-reactive protein was observed in all patients. CONCLUSIONS: Endoluminal repair of infrarenal AAA with use of dacron covered nitinol stent-grafts is feasible, safe and clinically effective. However, careful long-term evaluation is necessary.

Renal artery occlusion model in dogs for the evaluation of thrombolytic agents.

The purpose of this study was to develop a model of renal artery occlusion and to investigate the effects of various thrombolytic agents on an acute occlusion of the renal artery with respect to ischemic tolerance of renal parenchyma. In order to do this, a thrombosis model in dogs (n = 36) was established and a total of 72 dorsal renal arteries occluded using autologous clot material. For the in vitro preparing of a clot, autologous blood (20 mL) was withdrawn and 100 U thrombin immediately added. Then 1 mL of the clot material was injected into the dorsal branch of the exposed renal artery. The dogs were divided into 8 groups (2 control groups, 6 therapy groups with local and systemic thrombolytic therapy). Thrombolysis was performed using urokinase, single-chain urokinase, and recombinant tissue-plasminogen activator. In all cases the clot preparation technique allowed complete and stable occlusion of the renal arteries. Local and systemic application of the thrombolytic agents, however, resulted in complete recanalization of the clot material in all study groups. Recombinant tissue-plasminogen activator turned out to be the most effective agent in terms of recanalization time. The technique described allowed effective and reproducible artery occlusion for in vivo experimental work to study comparatively thrombolytic agents with respect to fibrin specificity, lytic efficacy, and side effects.

Lowering of blood glucose in athymic nude mice and rats, grafted with human lung cancers.

Human tumors were transplanted into athymic nude mice. From blood samples in the final stage of their passages we observed that in some of these lines, human lung cancer lines mostly, blood glucose generally decreased with increasing size of the tumor grafts. This observation was the reason for further investigations. Eight out of 13 human lung cancer lines caused a decrease of blood glucose in grafted mice. The extent of decrease was directly correlated with the proliferation of grafts. The results raise hope that the model of human malignant tumors, xenotransplanted and passaged into athymic nude mice, could be helpful in research on IGF and related substances.

Cystic adventitial degeneration and entrapment syndrome of the popliteal artery as a differential diagnosis of popliteal stenosis or occlusion in the younger age group.

Differential diagnosis in angiographically found popliteal artery stenosis or occlusion comprises some distinct and clinically important entities that should be considered as management and prognosis may vary considerably. We present two patients with the final diagnosis of cystic adventitial disease of the popliteal artery and popliteal artery entrapment syndrome. Angiographic findings and the value of additional diagnostic imaging are discussed.

Screening for colorectal carcinoma.

Since the introduction in the Federal Republic of Germany of free routine screening for colorectal carcinoma (digital examination of the rectum in 1971; test for occult blood in the faeces in 1977), the number of Dukes' stage A cases diagnosed at one hospital has increased by 30%. The average interval between onset of symptoms and diagnosis has shortened from 5 to 3.8 months, and the proportion of inoperable carcinomas has decreased by 10%.

[Surgical correction of chest wall abnormalities]. / Zur operativen Korrektur von Thoraxwandmissbildungen.

Cosmetic aspects often are the indication for operation in funnel chest or pigeon breast. Cardial or respiratory symptoms are only noticed in a few patients. The operative procedure according to Brunner is technically a simple method with low risk, which reaches good cosmetic and long-term results (the recurrence rate is 16,6%). Because of the higher recidivation liability after surgery in early childhood, we recommend surgical correction of the chest wall deformities after the age of 12.

Allelopathic interactions involving phenolic acids.

A major concern regarding allelopathic interactions involving phenolic acids in no-till systems pertains to the fact that concentrations of individual phenolic acids recoverable from field soils are well below levels required for inhibition of germination and seedling growth in laboratory bioassays. Field soils contain a variety of phenolic acids as well as other toxic and nontoxic organic compounds that are available to interact with seeds and roots; whereas in laboratory bioassays, with few exceptions, single phenolic acids have been tested. Studies of mixtures of phenolic acids and other toxic (e.g., methionine) and nontoxic (e.g., glucose) organic compounds in laboratory bioassays indicate that the action of a single phenolic acid is not representative of the actions of such mixtures. Specifically, as the number of phenolic acids added to soil increased, concentrations of the individual phenolic acids required to bring about a growth inhibition declined. The addition of other organic compounds (e.g., glucose, methionine) to the soil also reduced the concentration of a phenolic acid (e.g., p-coumaric acid) required for growth inhibition. These results support the hypothesis that in the field mixtures of phenolic acids and other organic compounds can cause inhibitory effects even though the concentrations of individual compounds are well below their inhibitory levels.

[Loco-regional lysis with thrombosis older than 10 days: experiences and outcome]. / Erfahrungen mit der lokoregionalen Fibrinolysetherapie bei Thrombosealter über 10 Tage.

Successful treatment of deep vein thrombosis by lysis therapy leads to recanalisation of the occluded vessel saving the venous flaps, thus limiting postthrombotic syndrome. Systemic lysis therapy carries an increased risk of fatal complications (1-2%). However, loco-regional lysis therapy with rtPA stands out as a method of recanalisation without increased complications compared to compression and anticoagulation therapy. According to the leading opinion about systemic lysis therapy it should only be performed if thrombotic age does not exceed 10 days. In this study we examined whether loco-regional lysis therapy is successful with older thrombosis, too. We showed that in thromboses older than 10 days lysis success was slightly decreased whereas postthrombotic syndrome doubled (up to 50%). These results point out loco-regional lysis as a method suitable for thromboses with age up to 10 days only.