The formation of a covalent complex between a dipeptide ligand and the src SH2 domain

The X-ray crystal structure of the src SH2 domain revealed the presence of a thiol residue (Cys 188) located proximal to the phosphotyrosine portion of a dipeptide ligand. An aldehyde bearing ligand (1) was designed to position an electrophilic carbonyl group in the vicinity of the thiol. X-ray crystallographic and NMR examination of the complex formed between (1) and the src SH2 domain revealed a hemithioacetal formed by addition of the thiol to the aldehyde group with an additional stabilizing hydrogen bond between the acetal hydroxyl and a backbone carbonyl.

[Orbital decompression in treatment of endocrine orbitopathy]

Graves' ophthalmopathy (Graves' disease) is a grave, rare immunological inflammatory reaction of the postorbital connective, adipose and ocular muscle tissue. Graves' disease occurs only within the scope of immunothyropathies and constitutes the most frequently encountered extrathyroidal manifestation. Typical symptoms are a result of the volume increase of the postbulbar connective and adipose tissue and of the interstitial swelling of the ocular muscles. Clinically, we find a spectrum of increasingly grave changes in the orbita, such as infiltration of the eyelid and connective tissue, exophthalmos, swelling of the muscles, damage to the cornea and involvement of the optic nerve with loss of vision. Regarding functional impairment of the optic nerve (optic nerve compression), orbita decompression represents an operative ultima ratio. Between January 1992 and April 1997, 11 patients (22 orbitae) from a group of more than 600 patients with Graves' disease with vision involvement were treated surgically. All treatment data were documented prospectively. Surgical intervention was performed only in cases where a progressive loss of vision existed in spite of retrobulbar irradiation and high-dose glucocorticoid therapy. Surgical therapy consisted of decompression of the medial, inferior and lateral orbital wall and of the orbital contents via combined bi-coronary and anterior access. The long-term results demonstrated improved vision conditions with 17 of the 22 eyes operated on. Parameters such as vision, exophthalmos, VEP, motility, double vision and field of vision were documented pre- and post-operatively. The prediction of post-operative deviations of the bulb axis was limited, and these were rectified through secondary displacements of the ocular muscle. No complications worth mentioning were encountered. In extreme events of therapy-resistant Graves' ophthalmopathies with progressive loss of vision, the three-wall decompression method has proved to be the correct one.

[Interdisciplinary surgical therapy of tumors of the frontal skull base]

Most tumors of the anterior cranial base invade both the intra- and extracranial regions at the borderline of the cranial and facial skeleton. In surgical treatment of these lesions, combined craniofacial approaches are applied in accordance with the anatomical conditions. Surgery is performed by an interdisciplinary team of neurosurgeons and maxillofacial surgeons. To evaluate the effectiveness and the complications of this surgical concept, the data of 58 patients treated over a 10-year period were collected. In these patients, 60 operations were performed, including two operations for tumor recurrence. In 38 cases, complete tumor removal was achieved. One patient died in the early postoperative period because of pulmonary embolism. Significant neurological deficits occurred in three patients. In most cases, postoperative complications and functional disability were both due to intradural invasion of the tumor. Nevertheless, in the majority of the cases radical tumor removal is achieved with acceptable morbidity when microsurgical techniques are applied for the resection of the intradural tumor. Both the meticulous repair of dural defects and the reconstruction of the anterior cranial base and orbit contribute distinctly to a reduction in the rate of postoperative complications and to acceptable cosmetic results.

[Reconstruction of the frontobasal skull after tumor operations and trauma. Transplant selection and functional outcome]

Defects of the frontoorbital complex subsequent to extensive tumor surgery or severe trauma often result in aesthetic and functional disharmonies. The long-term results of rehabilitation related to different materials and techniques are the subject of this study. From 1974 to 1996 altogether 127 patients with bony defects of the orbit and/or the skull base underwent surgery. All patients' data were documented prospectively from 1984 onwards. The results following reconstruction with autologous calvarian transplants in 52 patients were compared to those of a control group which received iliac bone or PMMA implants. Eighty-one bony defects (64%) resulted from tumor resection; 37 patients (29%) suffered from the effects of trauma. In 67 cases (53%) reconstruction was performed primarily, in 51 cases (40%) secondarily. Free or pedicled soft-tissue transplants were necessary in order to separate the orbit and the neurocranium in 26% of the defects. On the other hand, small, isolated defects of the orbital roof (7%) were left without any reconstructive procedure. Contrary to the iliac bone grafts, the calvarian transplants resisted secondary resorption. Postoperative infections appeared in two cases; loss of transplants was avoided entirely in the group of calvarian reconstructions in contrast to the alloplasts. The selection of a suitable donor site area and rigid fixation with microplates led to excellent esthetic results even in cases with large defects.

An efficient motion estimator with application to medical image registration

Image registration is a very important problem in computer vision and medical image processing. Numerous algorithms for registering single and multi-modal image data have been reported in these areas. Robustness as well as computational efficiency are prime factors of importance in image data registration. In this paper, a robust/reliable and efficient algorithm for estimating the transformation between two image data sets of a patient taken from the same modality over time is presented. Estimating the registration between two image data sets is formulated as a motion-estimation problem. We use a hierarchical optical flow motion model which allows for both global as well as local motion between the data sets. In this hierarchical motion model, we represent the flow field with a B-spline basis which implicitly incorporates smoothness constraints on the field. In computing the motion, we minimize the expectation of the squared differences energy function numerically via a modified Newton iteration scheme. The main idea in the modified Newton method is that we precompute the Hessian of the energy function at the optimum without explicitly knowing the optimum. This idea is used for both global and local motion estimation in the hierarchical motion model. We present examples of motion estimation on synthetic and real data (from a patient acquired during pre- and post-operative stages) and compare the performance of our algorithm with that of competing ones.

[Suppurative abscess-forming mediastinitis after tooth extraction. Consequences for therapeutic approach]

Purulent mediastinitis is a rare but serious complication of a descending odontogenic infection with a high mortality. Diagnosis is difficult and frequently delayed. Physical examination is often nondiagnostic, but may include pronounced edema of the neck and chest. CT scan is the single most important tool for early diagnosis. The treatment is always is surgical, in combination with an extremely high dose of combined antibiotics. Ultimately, we only could save our patient with this therapy.

[Early detection of threatened implant loss in tumor patients]

After resection of an oropharyngeal tumor, 157 dental implants were placed in 17 irradiated (44 Gy on average) and 20 non-irradiated patients. Within a control period of 37 months, 15 implants had failed. The reason for implant failure was analyzed, whereby indicative parameters were revealed. Eleven implants in four irradiated and one non-irradiated oral cancer patients showed no primary osseointegration during the healing period because of mandible fracture, overloading or for unknown reasons. Four implants in one irradiated and three non-irradiated oral-cancer patients were lost subsequently on average 39 months after second-stage surgery due to biomechanical overloading or bacterial infection. No osteoradionecrosis development due to implant failure was observed in irradiated patients. In all cases, peri-implant pocket depth, implant stability and peri-implant bone resorption increased before definitive implant failure. Therefore, these findings seem to be useful as indicative parameters in the prediction of implant failure.

Identification of the fliI and fliJ components of the Caulobacter flagellar type III protein secretion system

Caulobacter crescentus is motile by virtue of a polar flagellum assembled during the predivisional stage of the cell cycle. Three mutant strains in which flagellar assembly was blocked at an early stage were isolated. The mutations in these strains mapped to an operon of two genes, fliI and fliJ, both of which are necessary for motility. fliI encodes a 50-kDa polypeptide whose sequence is closely related to that of the Salmonella typhimurium FliI protein, an ATPase thought to energize the export of flagellar subunits across the cytoplasmic membrane through a type III protein secretion system. fliJ encodes a 16-kDa hydrophilic protein of unknown function. Epistasis experiments demonstrated that the fliIJ operon is located in class II of the C. crescentus flagellar regulatory hierarchy, suggesting that the gene products act at an early stage in flagellar assembly. The expression of fliIJ is induced midway through the cell cycle, coincident with other class II operons, but the FliI protein remains present throughout the cell cycle. Subcellular fractionation showed that FliI is present both in the cytoplasm and in association with the membrane. Mutational analysis of FliI showed that two highly conserved amino acid residues in a bipartite ATP binding motif are necessary for flagellar assembly.

[Primary soft tissue coverage and specific after-care of endosseous implants in pre-irradiated orbits]

After orbital exenteration and high- dose irradiation (60 Gy on average), 17 endosseous implants were placed periorbitally in 5 patients. No hyperbaric oxygen therapy was performed. All implants were primarily covered with regional or free flaps. After second-stage surgery and aesthetic rehabilitation with an external maxillofacial prosthesis, the pocket depth and implant stability (periotest) were checked, an occipitonasomental radiograph was taken and the soft tissue assessed in short recall intervals. When the implant was uncovered, osseointegration was stable. Within a follow-up period of 35 months, no fixation had failed. In two patients, peri-implant inflammation (microbiologically confirmed Staphylococcus aureus) occurred, which was clinically only determined by soft tissue oedema and rubor. The results demonstrate primary soft tissue covering as essential for non-irritating implant osseointegration in the irradiated orbita. In extraoral implants the clinical estimation of the peri-implant soft tissue, including a microbiological examination, is required for early detection of peri-implant inflammation in order to avoid secondary implant failure. In contrast, periotest and pocket depth are not relevant in recognizing an ensuing peri-implant inflammation.

[Outcome of Van der Meulen columellar extension in bilateral lip-jaw-palate clefts]

A total of 42 patients were operated on for secondary columellar elongation at the Department for Cranio-maxillofacial Surgery in Essen, Germany, from 1990 to 1996. The procedures were carried out because of nasal deformity in bilateral cleft lips (n = 35) or unilateral cleft lips (n = 7). The well-established drawbacks of Millard's forked flap technique, especially the resulting unfavourable scars at the lip columellar angle and the unpredictable, more conspicuous scar formations within the upper lip gave rise to an intensive search for an alternative surgical technique in our clinic. Since 1995 we have undertaken 14 secondary columellar elongations by means of Van der Meulen's three dimensional Z-plasty at the alar rim. Avoiding reopening of the lip we were able to lengthen the columella and project the nasal tip forward between 3 mm and 8 mm in all patients without introducing additional visible scars. The procedure led to an improved contour of the nasal tip, the alar rims and the nostrils. Nevertheless, we observed secondary broadening and shortening of the elongated columella in two children. This complication could subsequently be avoided by postoperative application of a nostril splint. The results confirm the effectiveness of the described technique for moderate columellar lengthening. The postoperative application of nostril splints is mandatory.

Peptide ligands of pp60(c-src) SH2 domains: a thermodynamic and structural study

Thermodynamic measurements, structural determinations, and molecular computations were applied to a series of peptide ligands of the pp60(c-src) SH2 domain in an attempt to understand the critical binding determinants for this class of molecules. Isothermal titration calorimetry (ITC) measurements were combined with structural data derived from X-ray crystallographic studies on 12 peptide-SH2 domain complexes. The peptide ligands studied fall into two general classes: (1) dipeptides of the general framework N-acetylphosphotyrosine (or phosphotyrosine replacement)-Glu or methionine (or S-methylcysteine)-X, where X represents a hydrophobic amine, and (2) tetra- or pentapeptides of the general framework N-acetylphosphotyrosine-Glu-Glu-Ile-X, where X represents either Glu, Gln, or NH2. Dipeptide analogs which featured X as either hexanolamine or heptanolamine were able to pick up new hydrogen bonds involving their hydroxyl groups within a predominantly lipophilic surface cavity. However, due to internal strain as well as the solvent accessibility of the new hydrogen bonds formed, no net increase in binding affinity was observed. Phosphatase-resistant benzylmalonate and alpha,alpha-difluorobenzyl phosphonate analogs of phosphotyrosine retained some binding affinity for the pp60(c-src) SH2 domain but caused local structural perturbations in the phosphotyrosine-binding site. In the case where a reversible covalent thiohemiacetal was formed between a formylated phosphotyrosine analog and the thiol side chain of Cys-188, deltaS was 25.6 cal/(mol K) lower than for the nonformylated phosphotyrosine parent. Normal mode calculations show that the dramatic decrease in entropy observed for the covalent thiohemiacetal complex is due to the inability of the phosphotyrosine moiety to transform lost rotational and translational degrees of freedom into new vibrational modes.

Implant-supported telescopic restorations in maxillofacial prosthetics

Eight partially irradiated oral cancer patients were treated using either mandibular implant and mucosa-supported telescopic coping prostheses or a restoration that was completely implant-supported with telescopic copings. Both types of restorations provided sufficient positional stability and peri-implant hygiene, and functional and esthetic improvement. However, only the completely implant-supported telescopic prosthesis avoided soft tissue ulcers that had the potential for the development of osteoradionecrosis. This type of restoration can especially be recommended for irradiated patients.

Orbital exenteration: surgical and reconstructive strategies

BACKGROUND

Radical exenteration procedures, which include the removal of orbital content and eyelids, result in serious functional limitations, especially with respect to eating and speaking. Therefore we have recently changed our surgical concept.

METHODS

Seventy-seven patients underwent orbital exenteration during the 20-year period from 1974 to 1995 at the Department of Maxillofacial Surgery, Essen University. The simultaneous removal of periorbital bone was performed in 45 of these cases.

RESULTS

The 1-year survival rate was 89%, the 5-year rate was 63% and the 10-year rate was 48%. The surgical approach, the amount of resected orbital tissue and the reconstructive procedure have been adapted to the individual needs, depending on the location and extent of the tumor. Subsequently, the surgical morbidity has decreased.

DISCUSSION

Detailed consideration of all clinical and histological findings is essential before surgery, in order to prevent a higher rate of recurrence following these modified operations.

"Latex-fruit syndrome": frequency of cross-reacting IgE antibodies

An association between allergies to latex proteins and to various foods has been reported and confirmed by RAST and immunoblotting inhibition. However, no significant data had been collected on the frequency of specific IgE antibodies to fruits in these patients and the frequency of a history of fruit intolerance. Serum samples of 136 patients with well-documented, clinically relevant, immediate-type hypersensitivity against latex proteins were analyzed for IgE antibodies against a panel of different fruits. Patient history of food intolerance was documented by a standardized questionnaire. Fruit-specific IgE antibodies were detected in 69.1% of serum samples. Cross-reacting IgE antibodies recognizing latex and fruit allergens (papaya, avocado, banana, chestnut, passion fruit, fig, melon, mango, kiwi, pineapple, peach, and tomato) were demonstrated by RAST-inhibition tests. Of our patients, 42.5% reported allergic symptoms after ingestion of these fruits and a total of 112 intolerance reactions were recorded. However, fruit-specific IgE antibodies were detected only in serum samples from 32.1% of the patients who perceived symptoms due to these fruits. Thus, serologic tests seem to be of low significance for prediction o food allergy in latex-allergic patients.

Titanium implants in the zygoma as retaining elements after hemimaxillectomy

Obturator prostheses require anchoring elements in the partially resected maxilla to provide stability and oronasal separation. Anchoring elements are usually overstressed because of the lack of collateral support. Intraoral titanium implants can provide additional retention and avoid mechanical overstress of the anchoring elements in the residual maxilla. Treatment with intraoral implants into the zygoma for the support of an obturator prosthesis is reported.

Evaluation of oro-coecal transit time: a comparison of the lactose-[13C, 15N]ureide 13CO2- and the lactulose H2-breath test in humans

OBJECTIVE

The lactulose H2-breath test is the most widely used non-invasive approach for evaluation of orocoecal transit time (OCTT). In the present study, doubly-labelled lactose-[13C, 15N]ureide (DLLU) was synthesized to investigate the OCTT in comparison to the conventional lactulose H2-breath test. Additionally the bacterial breakdown rate (BBR) and rate of elimination and the metabolic pathways of the cleavage products of DLLU (13CO2, [15N]urea, and 15NH3) were investigated.

DESIGN AND SUBJECTS

In a first study, DLLU was administered as a single oral-pulse-labelling (dosage: one gram) either without and after pretreatment of five grams of unlabelled lactoseureide (LU) on the day prior to the study to twelve healthy adult volunteers after breakfast. Breath and urine were collected in one and two hour-intervals, respectively, over a one-day period. 13C-enrichment in breath as well as 15N-enrichment in urine fractions were measured by continuous flow-isotope ratio mass spectrometry (CF-IRMS). In a second study, lactulose was administered to the same subjects (dosage: ten grams). Breath was collected in quarter, half and one hour-intervals over a ten hour-period. Hydrogen concentration in breath was analysed using an electrochemical detector.

RESULTS

The comparison of the lactose-[13C]ureide 13CO2-breath test and the lactulose H2-breath test showed that the mean increase of the 13C-enrichment in CO2 occurred 1.18 h later than the mean increase of H2 in breath. The resulting OCTTs derived from the two methods were 3.02 +/- 1.4 and 1.84 +/- 0.5 h (P < 0.05) and the corresponding BRs were 9.63 +/- 3.4 and 6.07 +/- 1.7 h (P < 0.01), respectively. The 15N-enrichment of urinary urea and ammonia without and after pretreatment with LU started between two and three hours after DLLU-administration. The cumulative percentage urinary excretion of the 15N- and 13C-tracer was 29.9% and 13.6% respectively, and was slightly increased after LU-pretreatment to 32.1% and 14.6% of the dose administered. A total of 35.2% of the 13C was found to be exhaled and remained approximately constant after LU-pretreatment (36.2%).

CONCLUSIONS

The use of the lactulose H2-breath test for evaluation of the OCTT showed a statistically significant shortening of 1.18 h in comparison to the lactose-[13C]ureide 13CO2-breath test in healthy adults. The most important limitations of the lactulose H2-breath test are its low specificity and sensitivity due to dose-dependent accelerations of OCTT, interfering H2-rise from malabsorbed dietary fibre and H2-non-producers. In contrast, our lactose-[13C]ureide 13CO2-breath test was confirmed to avoid these disadvantages and to yield reliable results. This test is recommended especially if higher sensitivity and specificity is required, if IRMS-technique is available and if lactulose H2-tests lead to insufficient results.

Concept of surgical and implant-supported prostheses in the rehabilitation of patients with oral cancer

Thirteen irradiated and 14 nonirradiated patients were treated after resection of a malignant oral lesion. With a follow-up period of 26 months, 3 of 48 implants in nonirradiated patients and 4 of 57 implants in irradiated patients failed. In comparison to implant-tissue-supported prostheses, exclusively implant-supported prostheses demonstrated better results with regard to soft tissue trauma and function of the prosthesis.

Suppression of LPS-induced tumor necrosis factor-alpha gene expression by microtubule disrupting agents

Microtubule disrupting agents such as colchicine have been shown to reduce TNF-alpha production in macrophages. To examine molecular mechanisms underlying the action of colchicine, TNF-alpha gene expression was studied in the murine macrophage cell line PU5-1.8. An LPS stimulation caused an intense up-regulation of TNF-alpha gene expression which was followed by a high TNF-alpha protein production. Simultaneous addition of colchicine (10 microM) suppressed LPS-induced TNF-alpha mRNA accumulation by one-third and TNF-alpha protein release by two-thirds. This effect was shared by vinblastine and vincristine, chemically different agents that also disrupt microtubule polymerization. For full suppressive activity on TNF-alpha gene expression, colchicine had to be present for 3 h in LPS-stimulated macrophage cultures. With nuclear run-on transcription experiments we could demonstrate that colchicine primarily inhibited de novo gene transcription and did not accelerate degradation of TNF-alpha mRNA in actinomycin D-treated macrophages. Thus, the well-known antiinflammatory action of microtubule depolymerizing agents may be largely due to a reduced TNF-alpha gene expression.

Inhibition of LPS-induced tumor necrosis factor-alpha production by colchicine and other microtubule disrupting drugs

Colchicine has been shown to act as an antiinflammatory agent. In this study, we examined whether colchicine and other microtubule-depolymerizing drugs affected the production of TNF-alpha. When rat peritoneal macrophages were stimulated by LPS, addition of colchicine, vincristine, vinblastine or nocodazole was found to inhibit TNF-alpha release in a concentration-dependent manner. Suppression of TNF-alpha release was not due to interference with secretion as the cytokine did not accumulate intracellularly following colchicine treatment. Colchicine markedly enhanced PGE2 release from LPS-stimulated macrophages. However, addition of the cyclooxygenase inhibitor indomethacin only partially reversed the suppressive effect of colchicine on TNF-alpha production. Colchicine caused a strong reduction of LPS-induced TNF-alpha mRNA accumulation, suggesting that a pretranslational effect may represent the primary mechanism by which colchicine reduced TNF-alpha production. These observations could have clinical relevance in ameliorating undesirable effects due to excessive TNF-alpha production, for example following LPS stimulation of monocytes/macrophages in gram-negative sepsis. Furthermore, these drugs may provide useful tools to study the apparent involvement of the microtubular system in cytokine gene expression and cytokine production.

[Molluscum contagiosum-like papules within the scope of disseminated infection with Mycobacterium avium complex in an AIDS patient]

A 38-year-old HIV-positive man had several attacks of high fever associated with extensive perspiration over a 10-week period. Simultaneously, he developed molluscum contagiosum-like papules and an erythematous plaque on the face, ulcerated papules on both shoulders and buttocks and subcutaneous nodules on the arms. Histological examination of biopsy specimens revealed a diffuse, histiocytic infiltrate with abundant rod-shaped bacteria. Mycobacterium avium complex was cultured from the tissue and Mycobacterium avium complex DNA was detected by the polymerase chain reaction. The diagnosis of disseminated disease was additionally confirmed by culturing Mycobacterium avium complex from blood, sputum and stool. The skin lesions healed completely within 10 weeks by a multiagent as the patient was treated with a drug therapy. We describe the differential diagnosis, diagnostic procedures and therapy of disseminated infection with Mycobacterium avium complex.

Innervation patterns of the lateral line stitches of the clawed frog, Xenopus laevis, and their reorganization during metamorphosis

We quantitatively examined the afferent innervation pattern of the lateral line stitches of both larval and postmetamorphotic clawed frogs, Xenopus laevis, using a silver staining technique. We also studied the relevance of the number of neuromasts in a stitch to physiological properties, recording afferent activity with an electrode inserted directly into the neuromast. The innervation pattern changed during early metamorphosis, the fiber thickness increasing after the reorganization. We found three different innervation patterns: in type A stitches, the same two afferent fibers innervate all neuromasts; in type B stitches, one or two fibers innervate more than one stitch; in type C stitches, three to six fibers innervate a stitch. The distribution of the different types of stitches varied in different parts of the body. The frequency of type A stitches differed between larval trunk and larval head. For both larvae and juveniles, type B stitches were more frequent on ventral than dorsal areas, while type C stitches were more frequent on the head than on the trunk. Electrophysiological experiments indicated that the sensitivity of an afferent fiber increases with the number of neuromasts it innervates. This increase and the variation in innervation patterns shows that the single afferent fiber, not the stitch, is the functional unit of the lateral line periphery.

Enhancement of lysozyme trypsin-mediated decay of intestinal bifidobacteria and lactobacilli

Lysozyme-mediated lysis of Bifidobacteria and Lactobacilli was studied in in vitro tests using the agar gel plate and turbidometric Micrococcus luteus (lysodeikticus) procedure as a standard. Suspensions of the strains Bifidobacterium infantis, B. infantis liberorum, B. breve, B. longum, B. ssp, and Lactobacillus acidophilus proved to be resistant to egg white lysozyme and human milk lysozyme when incubated at 37 degrees C in concentrations of 5, 50, and 500 mg lysozyme/L, respectively, through 30 and 60 min. Heat treatment at 100 degrees C for 1 h and pretreatment with ether, acetone, ascorbic acid, and hydrogen peroxide failed to incline the bacteria to the lytic effects of lysozyme. Consecutive incubation of the lysozyme-pretreated bacteria with trypsin resulted in a significantly enhanced bacteriolysis in all strains of bacteria, with the exception of B. longum. The mode of action of lysozyme and proteolytic enzymes on Bifidobacteria and Lactobacilli offers an explanation for the release of microbial building blocks and their colonic absorption and retention in the breast-fed baby.

Successful treatment of epidermolysis bullosa acquisita using intravenous immunoglobulins

We report a 55-year-old man with severe inflammatory epidermolysis bullosa acquisita. The skin lesions did not respond to various immunosuppressive treatments. The combined administration of prednisone, azathioprine, dapsone and colchicine resulted only in a transient and incomplete resolution of the lesions. The bullae and increased skin fragility were successfully controlled by the addition of high-dose intravenous immunoglobulin therapy.

Eosinophilic pustular folliculitis: successful treatment with interferon-alpha

Eosinophilic pustular folliculitis (Ofuji's disease) is a rare skin disease of unknown etiology characterized by infiltrated circinate plaques with sterile follicular pustules in primarily seborrheic areas. Several therapeutic regimens have been reported to control the disease with inconsistent results. We here report on a patient with Ofuji's disease, who was successfully treated with interferon-alpha 2b.

Preoperative radiochemotherapy and radical surgery in comparison with radical surgery alone. A prospective, multicentric, randomized DOSAK study of advanced squamous cell carcinoma of the oral cavity and the oropharynx (a 3-year follow-up)

A multicentric, randomized study of squamous cell carcinoma (SCC) of the oral cavity and the oropharynx has been undertaken by DOSAK. The results after radical surgery alone have been compared with the results of combined preoperative radiochemotherapy followed by radical surgery. Patients with primary (biopsy proven) SCC of the oral cavity or the oropharynx with tumor nodes metastasis (TNM) stages T2-4, N0-3, M0 were included in the study. A total of 141 patients were treated by radical surgery alone, whereas 127 patients were treated by radical surgery preceded by preoperative radiochemotherapy. The preoperative treatment consisted of conventionally fractioned irradiation on the primary and the regional lymph nodes with a total dose of 36 Gy (5 x 2 Gy per week) and low-dose cisplatin chemotherapy with 5 x 12.5 mg cisplatin per m2 of body surface during the first week of treatment. Radical surgery according to the DOSAK definitions (DOSAK, 1982) was performed after a delay of 10-14 days. During the follow-up period, 28.2% of all patients suffered from locoregional recurrence, and 27.2% of the patients died. The percentages were higher after radical surgery alone for locoregional recurrence (31% and 15.6%) and for death (28% and 18.6%). The life-table analysis showed improved survival rates of 4.5% after 1 year and 8.3% after 2 years in the group of patients treated with combined therapy. The demonstrated improvement appeared to be significant with the Gehan-Wilcoxon test as well as with the log rank test below a P value of 5%.

No cultural detection of Helicobacter pylori in dental plaque

Helicobacter pylori causes human type B gastritis and is involved in the etiology of peptic ulcer disease. The routes of transmission of H. pylori are still unclear. The microorganism may be transmitted orally, since H. pylori has been detected in dental plaques. To confirm the hypothesis that dental plaques are a reservoir of H. pylori, 100 dental plaque specimens from 55 dental surgery patients were incubated on one nonselective and up to four selective agar media for the detection of H. pylori. In addition, urease activity of the plaque material was tested, and the gingival status of the patients was assessed. H. pylori was not cultivated from any of the specimens investigated. Plaque material from 12 patients with moderate and severe gingivitis showed urease activity. The results do not confirm the hypothesis that dental plaques are a relevant reservoir of viable H. pylori cells. However, non-cultivatable forms of H. pylori may survive in dental plaques. Urea cleaving activity of dental plaque may be a marker of gingival inflammation.

[Dyshidrosiform bullous pemphigoid]

Dyshydrosiform bullous pemphigoid is a clinical variant of bullous pemphigoid in which the lesions appear primarily on palms and soles. Knowledge of this unusual manifestation of bullous pemphigoid may be of practical relevance, since it has to be included in the differential diagnosis of blistering palmoplantar dermatoses. The correct diagnosis is confirmed by histological examination and immunofluorescence, which reveal all the characteristic hallmarks of bullous pemphigoid. Three patients with dyshydrosiform bullous pemphigoid are presented; clinical and histological aspects, findings on immunofluorescence, differential diagnosis and therapy are discussed.

Enhancement of Clostridium botulinum C3-catalysed ADP-ribosylation of recombinant rhoA by sodium dodecyl sulfate

The influence of sodium dodecyl sulfate (SDS) on ADP-ribosylation by Clostridium botulinum C3 exoenzyme (C3) was studied. SDS increased the ADP-ribosylation of recombinant rhoA and human platelet cytosolic proteins maximally at 0.01% whereas higher concentrations of the detergent (> 0.01%) inhibited the ADP-ribosylation. In contrast, ADP-ribosylation of human platelet membranes and of recombinant rhoB was inhibited by the detergent. The Km for NAD of the ADP-ribosylation of rhoA was decreased by SDS from about 10 to 0.6 microM. Whereas in the absence of SDS, the C3-induced ADP-ribosylation of recombinant rhoA is not affected by the amphiphilic wasp venom mastoparan, in the presence of SDS (0.01%) mastoparan (100 microM) inhibited the ADP-ribosylation. C3-associated NAD-glycohydrolase activity was maximally and half-maximally inhibited by 0.1 and 0.013% SDS, respectively. Inhibition of NAD-glycohydrolase activity was reversed by diluting out SDS indicating that C3 was not irreversibly denatured by SDS treatment. SDS (0.01%) completely inhibited the [3H]GTP binding of rhoA whereas the release of previously bound nucleotide was not affected. The data indicate that changes in the lipophilicity of rhoA protein largely affect its ability to serve as a substrate for C3-like ADP-ribosyltransferases.

Reduced release of leukotrienes B4 and C4 from alveolar macrophages of rats with silicosis

Silicosis leads to altered release of fibrogenic and immunomodulating mediators from alveolar macrophages (AM). Since 5-lipoxygenase metabolites have been shown to possess proinflammatory effects and to promote the release of cytokines such as tumor necrosis factor-alpha (TNF-alpha) from mononuclear phagocytes, we determined leukotriene secretion from silica-exposed AM. Rats were exposed to an aerosol of silica particles for 8 days and AM were harvested by bronchoalveolar lavage 5 to 7 mo after exposure. AM from both air-sham control and silica-exposed rats displayed minimal spontaneous leukotriene release upon in vitro culture. Stimulation with opsonized zymosan particles induced leukotriene B4 (LTB4) and leukotriene C4 (LTC4) secretion, which was much greater in control AM than in AM from silica-dusted rats. The reverse was found for zymosan-induced TNF-alpha production, which was higher in AM from silica-exposed than from control rats. To study the interrelation between leukotriene and TNF-alpha release, we incubated zymosan-stimulated AM with the 5-lipoxygenase inhibitor VZ 65. VZ 65 suppressed zymosan-induced TNF-alpha release from AM in a dose-dependent manner, and TNF-alpha production could be restored almost completely by addition of LTB4. These experiments demonstrate that silica exposure resulted in a decreased LTB4 and LTC4 production from AM, which may represent a regulatory mechanism to counterbalance enhanced TNF-alpha production during silicosis.

[Phosphate concentration. Does reduction in infant formula feeding modify the micro-ecology of the intestine?]

The potential influence of phosphates in formulas on intestinal microflora was studied in 25 infants, aged 8 days to 12 weeks. The babies were either fed an infant formula with the usual phosphate concentration (n = 10) or an infant formula with reduced phosphate and protein concentrations (n = 7). The microbiological findings were compared with those obtained from breastfed infants (n = 8). Low-phosphate concentrations did not correlate with a predominance of bifidobacteria or suppression of putrefactive bacteria in the feces. The fecal excretion of phosphates and fat was found to be significantly lower with mother's milk compared to formulas both rich and poor in phosphate. Protein synthesis and breakdown rates, as well as the net protein gain, did not have a significant correlation with protein intake.

Posttranslational isoprenylation of rho protein is a prerequisite for its interaction with mastoparan and other amphiphilic agents

The amphiphilic agents melittin, compound 48/80 and mastoparan inhibit ADP-ribosylation of porcine brain rho protein by Clostridium botulinum exoenzyme C3. However, ADP-ribosylation of recombinant rhoA expressed in E.coli was not inhibited by these agents. Accordingly, steady state GTP hydrolysis by recombinant rhoA was not stimulated by mastoparan, whereas GTP hydrolysis by porcine brain rho was stimulated 2.5-fold in the presence of this wasp venom. After microinjection of recombinant rhoA into Xenopus laevis oocytes the inhibitory effect of mastoparan on C3 ADP-ribosylation was restored. The data suggest that the amphiphilic agents tested are only active at the posttranslationally processed form of rho and that they exert their effects via the C-terminal end.

Purification and characterization of an ADP-ribosyltransferase produced by Clostridium limosum

We purified a novel ADP-ribosyltransferase produced by a Clostridium limosum strain isolated from a lung abscess and compared the exoenzyme with Clostridium botulinum ADP-ribosyltransferase C3. The C. limosum exoenzyme has a molecular weight of about 25,000 and a pI of 10.3. The specific activity of the ADP-ribosyltransferase is 3.1 nmol/mg/min with a Km for NAD of 0.3 microM. Partial amino acid sequence analysis of the tryptic peptides revealed about 70% homology with C3. The novel exoenzyme modifies selectively the small GTP-binding proteins of the rho family in human platelet membranes presumably at the same amino acid (asparagine 41) as known for C3. Recombinant rhoA and rhoB serve as substrates for C3 and the C. limosum exoenzyme. Whereas recombinant rac1 protein is only marginally ADP-ribosylated by C3 or by the C. limosum exoenzyme in the absence of detergent, in the presence of 0.01% sodium dodecyl sulfate rac1 is modified by C3 but not by the C. limosum exoenzyme. Recombinant CDC42Hs protein is a poor substrate for C. limosum exoenzyme and is even less modified by C3. The C. limosum exoenzyme is auto-ADP-ribosylated in the presence of 0.01% sodium dodecyl sulfate by forming an ADP-ribose protein bond highly stable toward hydroxylamine. The data indicate that ADP-ribosylation of small GTP-binding proteins of the rho family is not unique to C. botulinum C3 ADP-ribosyltransferase but is also catalyzed by a C3-related exoenzyme from C. limosum.

ADP-ribosylation of rho proteins is inhibited by melittin, mast cell degranulating peptide and compound 48/80

The amphiphilic agents melittin, mast cell degranulating peptide and compound 48/80 inhibit the ADP-ribosylation of the small GTP-binding proteins rho by Clostridium botulinum exoenzyme C3. Half-maximal and maximal inhibition (greater than 90%) of ADP-ribosylation occurred at about 8 and 25 micrograms/ml for compound 48/80, at 10 and 45 microM for mast cell degranulating peptide and at 15 and 50 microM for melittin, respectively. In addition, these compounds increase the steady state GTP hydrolysis and the association and dissociation rate of GTP-binding of rho proteins through an increase of GDP/GTP exchange. The data suggest that the amphiphilic agents tested interact with small GTP-binding proteins of the rho protein family.

Chemical distribution of glycosphingolipids in third-instar larval organs of the blowfly, Calliphora vicina (Insecta: Diptera)

As a first approach to testing the working hypothesis that glycosphingolipids are functionally involved in the ontogeny of insects, their chemical distribution in larval organs was determined and any stadium-correlated differences documented. Selected organs, i.e., the fatbody, striated muscle, intestinal tract, salivary glands, imaginal discs, and central nervous system, were dissected from seven-day-old larvae of the blowfly, Calliphora vicina, and their glycolipids isolated. Two-dimensional, high-performance thin-layer chromatography was used to separate the neutral and acidic glycolipids of each organ. Significantly different total glycolipid component-patterns were obtained for the individual organs, whereby, except for a number of additional uncharacterized components in the intestinal tract, the neutral glycolipids of all organs were found to be qualitatively similar. However, major quantitative differences between the selected organs were found in their total glycolipid-carbohydrate contents, as well as the respective quantitative neutral glycosphingolipid-component distributions. The acidic glycolipids showed pronounced qualitative as well as quantitative organ-dependent variations. Whereas the highest proportion of uncharged glycolipids was characteristic of the fatbody, a high proportion of zwitterionic glycolipid-components was observed to be typical of the central nervous system and imaginal discs, i.e., of organs persisting during larval life and throughout metamorphosis. Imaginal disc glycolipids were distinguished by their high content of acidic glycolipids, a putative reflection of the functional role of these glycoconjugates in regulated cell reorganization during metamorphosis.

Coxsackievirus B3-induced production of tumor necrosis factor-alpha, IL-1 beta, and IL-6 in human monocytes

Infections by coxsackievirus B3 (CVB3) have previously been shown to cause acute and chronic myocarditis characterized by a heavy mononuclear leukocyte infiltration and myocyte necrosis. Because clinical and experimental evidence suggested that cardiac damage may result from immunologic rather than viral mechanisms, we examined in this study the in vitro interaction of CVB3 with human monocytes. CVB3 was capable of infecting freshly harvested monocytes as revealed by immunofluorescence and release of infectious virus particles. Virus infection did not reduce monocyte viability but, on the contrary, enhanced spreading and adherence. In a dose-dependent manner, CVB3 stimulated the release of cytokines from monocytes. Whereas a potent production of TNF-alpha, IL-1 beta, and IL-6 was dependent on exposure to infectious CVB3, IFN release was also induced by UV-inactivated virus. On a molecular level, CVB3 stimulated cytokine gene expression as shown by a marked TNF-alpha, IL-1 beta, and IL-6 mRNA accumulation. Supernatants of CVB3-infected monocytes displayed cytotoxic activity against Girardi heart cells which could be abrogated by an anti-TNF-alpha antiserum. These data suggest that CVB3-induced cytokine release from monocytes may participate in virus-induced organ damage such as myocarditis, which may either occur by a direct cytotoxicity of cytokines or by activation of cytotoxic lymphocytes.

Coxsackievirus B3-induced production of tumor necrosis factor-alpha, IL-1 beta, and IL-6 in human monocytes

Infections by coxsackievirus B3 (CVB3) have previously been shown to cause acute and chronic myocarditis characterized by a heavy mononuclear leukocyte infiltration and myocyte necrosis. Because clinical and experimental evidence suggested that cardiac damage may result from immunologic rather than viral mechanisms, we examined in this study the in vitro interaction of CVB3 with human monocytes. CVB3 was capable of infecting freshly harvested monocytes as revealed by immunofluorescence and release of infectious virus particles. Virus infection did not reduce monocyte viability but, on the contrary, enhanced spreading and adherence. In a dose-dependent manner, CVB3 stimulated the release of cytokines from monocytes. Whereas a potent production of TNF-alpha, IL-1 beta, and IL-6 was dependent on exposure to infectious CVB3, IFN release was also induced by UV-inactivated virus. On a molecular level, CVB3 stimulated cytokine gene expression as shown by a marked TNF-alpha, IL-1 beta, and IL-6 mRNA accumulation. Supernatants of CVB3-infected monocytes displayed cytotoxic activity against Girardi heart cells which could be abrogated by an anti-TNF-alpha antiserum. These data suggest that CVB3-induced cytokine release from monocytes may participate in virus-induced organ damage such as myocarditis, which may either occur by a direct cytotoxicity of cytokines or by activation of cytotoxic lymphocytes.

Enhanced release of prostaglandin E2 from macrophages of rats with silicosis

The pathogenesis of silicosis results, in part, from interactions between silica particles and alveolar macrophages (AM) with release of cytokines and other mediators. Different arachidonic acid metabolites have been shown to promote or to suppress inflammation and fibrosis. We designed experiments to study the production of cyclooxygenase metabolites and tumor necrosis factor-alpha (TNF-alpha) from macrophages during active silicosis. Macrophages were harvested from rats 5 to 7 mo after an 8-day silica aerosol exposure. Upon in vitro culture of AM, the spontaneous release of prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and prostaglandin D2 (PGD2) of silica-exposed animals was higher than that of sham-exposed animals. Moreover, AM from silicotic rats displayed an increased sensitivity to low concentrations of lipopolysaccharide (LPS, 10 ng/ml) and released copious amounts of PGE2 and TXB2. When compared with similarly enhanced release of TNF-alpha from AM of silica-exposed rats, PGE2 production occurred later and started to increase when TNF-alpha production declined. Addition of the cyclooxygenase blocker indomethacin augmented TNF-alpha production, whereas the addition of PGE2 counteracted TNF-alpha release. Also peritoneal macrophages, which did not have direct contact with silica particles, released enhanced levels of PGE2 in response to low LPS doses. We conclude that AM and other macrophages from silica-exposed rats are preactivated and display an enhanced prostanoid production that could serve anti-inflammatory or immunomodulating roles in silicosis.

ADP-ribosylation by Clostridium botulinum C3 exoenzyme increases steady-state GTPase activities of recombinant rhoA and rhoB proteins

ADP-ribosylation of recombinant rhoA and rhoB proteins by Clostridium botulinum C3 exoenzyme increased steady-state GTP hydrolysis by 50 to 80%. ADP-ribosylation and increase in GTP hydrolysis occurred at similar concentrations of C3, depended on the presence of NAD and were prevented by anti-C3 antibody or heat inactivation of C3. In contrast, GTP hydrolysis by Ile-41 rhoA or Ha-ras, which are no substrates for the transferase, were not affected by C3. ADP-ribosylation facilitated the [3H]GDP release and subsequently, the binding of [3H]GTP to rhoA. The data indicate that the increase in the steady-state GTPase activity by ADP-ribosylation is caused by increasing the rate of GDP release which is suggested to be the rate limiting step of the GTPase cycle of the small GTP-binding proteins.

Prospective flow cytometric analysis of head and neck carcinomas. Prognostic relevance of DNA-content and S-fraction

Flow cytometric data were obtained from 142 primary squamous cell carcinomas of the oral cavity or the oropharynx. Aneuploidy was found in 36.8% of the tumours. The DNA indices showed a significant correlation with the S-fraction, tumour size and evidence of suspicious lymphnodes. There was no clear correspondence between the S-fraction and the tumour stage. Tumour size, histopathologically-positive lymphnodes and the mode of treatment were significantly correlated with the survival rates. In contrast, there was no clear correlation between flow cytometric data and the prognosis of the whole group as well as several clinical subgroups. In 40 patients who received preoperative irradiation, DNA indices and S-fractions were compared before and after the preoperative treatment. In 12 of 14 aneuploid tumours irradiation led to a decrease in the DNA indices into the range of euploidy. Only 2 tumours remained aneuploid. After irradiation 26 of 37 tumours showed a decrease in S-fraction, 11 tumours showed an increase. Loss of aneuploidy after irradiation was associated with a histologically-proven increasing devitalization of tumour cells, decrease in S-fraction corresponded to a tendency to a better prognosis.

Clostridium botulinum C3 ADP-ribosyltransferase

C3 and C3-like ADP-ribosyltransferases modify the low-molecular-mass GTP-binding proteins Rho and Rac. ADP-ribosylation occurs in asparagine-41, which is located in the putative effector region of these highly conserved regulatory proteins. First studies indicate that the Rho proteins are somehow involved in the regulation of cytoskeletal proteins, e.g., microfilament proteins. Although the precise mechanism of the interaction of the C3 substrate with cytoskeletal elements is unclear, it appears that the ADP-ribosylation by C3 renders the GTP-binding protein biologically inactive. Thus C3 and/or C3-like ADP-ribosyltransferases may be useful instruments with which to study the physiological functions of its eukaryotic substrates. Moreover, those studies may help to elucidate whether these exoenzymes are of pathophysiological and pathogenetic relevance in diseases caused by clostridia producing these agents.

Interaction of mastoparan with the low molecular mass GTP-binding proteins rho/rac

Mastoparan, which has been shown to active G proteins, inhibits the ADP-ribosylation of 20 kDa human platelet membrane proteins catalyzed by Clostridium botulinum exoenzyme C3 half-maximally and maximally (90%) at 20 and 100 microM concentrations, respectively. Inhibition of ADP-ribosylation was enhanced by GTP-gamma S. Mastoparan increased GTP hydrolysis by porcine brain rho protein and stimulated GTP binding in a concentration dependent manner. The data suggest that mastoparan not only interacts with heterotrimeric G proteins but also with low molecular mass GTP-binding proteins of the rho/rac family.

Systemic macrophage stimulation in rats with silicosis: enhanced release of tumor necrosis factor-alpha from alveolar and peritoneal macrophages

In silicosis, alveolar macrophages (AM) are thought to induce chronic inflammation and fibrosis by release of cytokines. Rats were exposed to aerosols of alpha-quartz and examined 4 to 9 mo later for persistence of silica particles and release of tumor necrosis factor-alpha (TNF-alpha) from macrophages. Silica particles were detected in AM, lung parenchyma, and thoracic lymphoid organs, whereas extrathoracic lymphoid tissues and organs were free of the mineral. When AM were tested functionally, no spontaneous release of TNF-alpha was observed. However, upon in vitro stimulation of AM from silicotic rats with a low concentration of lipopolysaccharide (10 ng/ml), abundant TNF-alpha production was found that was higher and occurred more rapidly than with AM from sham-exposed animals. Peritoneal macrophages, which did not have contact with silica particles, displayed a similarly enhanced TNF-alpha release in response to low doses of lipopolysaccharide. These data demonstrate a state of systemic preactivation ("priming") of macrophages that supports the notion that silicosis is associated with a general immunostimulation.

Long-term treatment effects in patients with bilateral retinoblastoma: ocular and mid-facial findings

A total of 99 patients with bilateral retinoblastoma who had been treated between 1965 and 1982 were reexamined in April 1988 to study the late effects of treatment. Their median age at the follow-up visit in 1988 was 16 years (range, 6-27 years), and the median follow-up was 15 years (range, 6-26 years). All patients underwent a full eye examination, morphometric measurements of the mid-face and genetic counselling. Each eye or orbit and the corresponding side of the patient's mid-face were evaluated separately, resulting in 198 data sets from 99 individuals. Subjects were divided into four treatment groups according to whether photo- and cryo-coagulation, enucleation, radiation therapy or various combinations thereof were used. In all, 81 eyes had a visual acuity of greater than 0.4 (in 23 of these, however, only with low-vision aids). Within a dose range of 36-51 Gy, the location of the tumor (36%) or cataract (15%) were the main factors responsible for poor visual acuity, whereas radiation retinopathy and/or optic neuropathy occurred in only three cases. Cataracts were more frequently observed following orthovoltage as compared with megavoltage therapy (P = 0.012). A total of 72 eyes had been enucleated and had not received radiation therapy at any time. Cosmetic results (as measured by several parameters) in these cases were significantly better then those in 28 subjects who underwent combined radiation therapy and enucleation. As defined by various subjective as well as objective findings, mid-facial hypoplasia occurred significantly more often following orthovoltage as compared with megavoltage therapy.

ADP-ribosylation and de-ADP-ribosylation of the rho protein by Clostridium botulinum exoenzyme C3. Regulation by EDTA, guanine nucleotides and pH

Pretreatment of rho protein purified from pig brain cytosol with EDTA (3 mM) for 10 min at 30 degrees C inhibited its ADP-ribosylation by Clostridium botulinum C3 ADP-ribosyltransferase by more than 90%. The EDTA effect was not caused by alteration of C3. GDP or GDP beta S present during the pretreatment period completely prevented the decrease in ADP-ribosylation with half-maximal and maximal effects at 3 and 300 microM, respectively. GTP or GTP gamma S were less efficacious in preventing the decrease in ADP-ribosylation, but were more potent (half-maximal and maximal effects at 0.1 and 3 microM, respectively). [32P]ADP-ribose incorporated in pig brain rho by C3 was de-ADP-ribosylated by the enzyme in the presence of nicotinamide and at low pH. Concomitantly, [32P]NAD was formed. The pH optima for ADP-ribosylation and de-ADP-ribosylation were pH 7.5 and 5.5, respectively. De-ADP-ribosylation was most efficient with nicotinamide, less effective with 3-acetylpyridine and not observed with 3-aminopyridine, 4-aminopyridine, 4-acetylpyridine and isonicotinic acid. As observed for the ADP-ribosylation, the de-ADP-ribosylation by C3 was maximal with the GDP-bound form of rho and blocked after EDTA treatment.

Symbiotic interactions between colonic microflora and protein metabolism in infants

The utilization of 15N nitrogen from 15N-labelled bifidobacteria for whole body protein synthesis was studied in 4 infants by oral single-pulse labellings and in 3 other infants, who had colostomies, by colonic pulse labellings. The bifidobacteria were harvested from a modified Petuely culture medium containing 15N ammonium chloride and 15N cystine as the only sources of nitrogen. The tracer dose chosen for the balance studies was 3 mg 15N/kg. 15N concentrations in urine and feces collected over 48 hours after the pulse labellings were determined by emission spectrometry. Oral administration of 15N-labelled bifidobacteria resulted in absorption of approximately 90% renal excretion of 15%, and fecal excretion of 12% of the tracer dose, respectively. Retention in the protein pool averaged 73%. After colonic single pulse labelling with 15N-labelled bifidobacteria, the corresponding values were 85.5%, 2.2%, 14.5% and 83.0%, respectively. Absorption and incorporation of the heavy nitrogen into body proteins were directly demonstrated by increased 15N atom percent excess values within the trichloroacetic acid (TCA) supernatants and the proteins of the plasma, 0.25 and 0.04 atom%, respectively, at 24 hours after oral pulse labellings. One half of the total 15N excreted in urine consisted of urea and approximately 8% was eliminated as ammonia.