Specific growth rates calculated from CTs in patients with head and neck squamous cell carcinoma: a retrospective study performed in Austria

OBJECTIVE

To provide data on specific growth rates (SGRs) of primary tumours (PT-SGR) and largest pathological cervical lymph nodes (LN-SGR) for head and neck squamous cell carcinoma (HNSCC). To explore PT-SGR's and LN-SGR's correlation with selected biomarkers epidermal growth factor receptor (EGFR), Ki67 and CD44.

DESIGN AND SETTING

Retrospective study performed at a tertiary oncological referral centre in Innsbruck, Austria.

PARTICIPANTS

Adult patients with incident HNSCC treated with primary radiotherapy (RT) or radiochemotherapy (RCT).

OUTCOME MEASURES

Volumes of the primary tumour (PT-volume) and largest pathological cervical lymph node (LN-volume) were measured in CT scans obtained at time of diagnosis and subsequent planning CTs immediately prior to RT or RCT. SGRs were calculated assuming an exponential growth function. PT-SGR's and LN-SGR's correlation with EGFR, Ki67 and CD44 were explored.

RESULTS

In 123 patients, mean interval between diagnostic and planning CT was 29±21 days. PT-SGR was 1.8±1.8% (mean±SD) per day and was positively correlated with EGFR, Ki67 and CD44 expression (p=0.02; p=0.02; p=0.03). LN-SGR was 1.7±2.0% per day and increased with larger initial LN-volume, was lower in laryngeal cancer (p=0.003) and slowed down with time. LN-SGR was not correlated with EGFR, Ki67 or CD44 expression in primary tumours (p>0.12). New cartilage or bone infiltration occurred in 10 patients and new central lymph node necrosis in 8 patients.

CONCLUSIONS

HNSCCs are fast-growing tumours for which treatment must not be delayed. Clinical tumour growth rates are influences by EGFR, KI67 and CD44 expression.

Persistent Head and Neck Cancer Following First-Line Treatment

Background: Following first-line treatment of head and neck cancer (HNC), persistent disease may require second-line treatment. Methods: All patients with HNC treated between 2008 and 2016 were included. Second-line treatment modalities and survival of patients were analyzed. Results: After first-line therapy, 175/741 patients had persistent disease. Of these, 112 were considered eligible for second-line treatment. Second-line treatment resulted in 50% complete response. Median overall survival of patients receiving second-line therapy was 24 (95% CI: 19 to 29) months; otherwise survival was 10 (9 to 11; p < 0.0001) months. Patients receiving second-line surgery had a median overall survival of 45 (28 to 62) months, patients receiving second-line radiotherapy had a median overall survival of 37 (0 to 79; p = 0.17) months, and patients receiving systemic therapy had a median overall survival of 13 (10 to 16; p < 0.001) months. Patients with persistent HNC in the neck had a better median survival (45 months; 16 to 74 months; p = 0.001) than patients with persistence at other sites. Conclusion: Early treatment response evaluation allows early initiation of second-line treatment and offers selected patients with persistent disease a realistic chance to achieve complete response after all. If possible, surgery or radiotherapy are preferable.

Prognostic value of tumor volume in patients with head and neck squamous cell carcinoma treated with primary surgery

BACKGROUND

Tumor volume in head and neck squamous cell carcinoma (HNSCC) was mainly measured in nonsurgically treated patients. We analyzed the influence of tumor volume on complete response (CR), overall survival (OS), and clear surgical margins also in primarily surgically treated patients.

METHODS

In contrast-enhanced CTs, the tumor volumes of patients with incident HNSCC were measured.

RESULTS

The tumor volumes of 259 patients were measured, of which 125 patients (48%) underwent primary surgery and 102 patients (84%) had clear margins. The tumor volume was not an independent factor for CR at the primary tumor site. Risk of death increased by 1.4% per mL of tumor volume (95% confidence interval [CI] 0.8%-2.0%; P < .001). The OS was better in patients treated with primary surgery, if the tumor volume was ≤12 mL (P < .001). Risk of involved margins increased by 4.5% per mL of tumor volume (95% CI 0.9%-8.3%; P = .003). The predicted probability of clear margins was ≥80% in tumor volumes ≤ 16 mL.

CONCLUSION

The tumor volume had an impact on CR, OS, and clear margins. The tumor volume may also aid in selecting HNSCC treatment.

Optimized Conformal Paraaortic Lymph Node Irradiation is not Associated with Enhanced Renal Toxicity

BACKGROUND AND PURPOSE

For patients with gynecologic carcinomas, irradiation of paraaortic lymph nodes (PLNs) is a routine treatment concept. Planning target volumes (PTVs) individually optimized by radiation field delineations along the big vessels permit the inclusion of at least 97% of potentially involved PLNs. However, this novel treatment technique might increase radiation-induced nephrotoxicity. Therefore, the actual incidence of kidney damage after PLN irradiation has to be assessed in order to validate the safety of this treatment concept.

PATIENTS AND METHODS

19 patients were treated with irradiation alone (50.4 Gy; 5 x 1.8 Gy/week) and monitored for up to 90 months. Functional renal parameters, namely renal plasma flow (RPF) and glomerular filtration rate (GFR), were assessed by dynamic renal scintigraphy. Additionally, patients were clinically observed (i.e., hypertension, proteinuria) and calculations of normal-tissue complication probability (NTCP) values for nonuniform kidney irradiation were performed using the Lyman-Wolbarst algorithm.

RESULTS

Two patients with anticipated moderate NTCP values (12.6% and 8.7%) showed slightly impaired RPF rates at 12, 24, and after 48 months of follow-up. Only one patient in the subgroup showing NTCP values > 50% (n = 9) developed a notable impairment of renal RPF. However, all patients including those with elevated complication probabilities exhibited neither impaired GFR nor clinically apparent symptoms related to a loss of functioning renal tissue from 12 to > 48 months post irradiation.

CONCLUSION

Conformal irradiation of retroperitoneal lymph nodes with individual PTV delineation appears not to be associated with clinically relevant functional impairment of the kidneys.

Competing irradiation techniques for para-aortic lymph nodes: Dose distribution and NTCP for the kidney

PURPOSE

Partial coirradiation of both kidneys is an unavoidable consequence of adequate dose delivery in radiation therapy of para-aortic lymph nodes (PLN). Depending on total dose anteroposterior/posteroanterior (AP/PA), opposed-fields or multifield techniques are used. To optimize the treatment of potentially tumor-affected PLN with minimal kidney involvement, we calculated normal tissue complication probabilities (NTCPs) of coirradiated kidneys for four common irradiation techniques used in the PLN area.

METHODS AND MATERIALS

Planning target volume (PTV) delineation was performed in computed tomography scans of 21 patients with a lateral safety margin of 3 cm from the aorta and 2 cm aside the vena cava. Ventral and dorsal margins of the PTV were delineated 2 cm from the vessels. As previously shown (Nevinny-Stickel M, et al. Int J Radiat Oncol Biol Phys 2000;48:147-151), PTVs optimized by these altered delineations permit inclusion of at least 97% of potentially involved PLN in contrast to standard delineations based on bony structures that are more likely to miss affected lymph nodes. The present study compared NTCPs for individual PTV-based treatment planning with NTCPs for standard planning based on bony structures. For each patient, four hypothetical treatment plans were created: (A) standard AP/PA opposed fields technique with lateral field margins along the tips of the transverse processes of the vertebral bodies; (B) individually planned AP/PA opposed fields with lateral field margins according to the optimized PTV; (C) standard four-field box technique with lateral width as described for (A), with dorsal borders at the center of the vertebral bodies and ventral margins 3 cm in front of the vertebrae; and (D) individually planned four-field box with lateral field margins according to the optimized PTV. Calculation of irradiation-induced complication probability values for nonuniform kidney irradiation was performed for model doses 19.8 Gy, 30.6 Gy, and 50.4 Gy according to the Lyman-Wolbarst model.

RESULTS

No dose showed a statistically significant difference (p < 0.00833, corrected for six multiple interrelated comparisons) in the median of total organ kidney NTCPs between techniques A, C, and D, with technique D intermediately ranging between technique A and C (e.g., for 50.4 Gy: A: median, 0.39; range, 0.01-0.83; C: median, 0.27 range; 0.05-0.68; D: 0.36; range, 0.03-0.72). In comparison to techniques A, C, and D, the individually planned AP/PA opposed-fields technique (B) was accompanied by significantly higher and intolerable overall kidney NTCP rates (e.g., for 50.4 Gy: median, 0.68; range, 0.01-0.99).

CONCLUSION

Conformal four-field planning with individually optimized PTVs (D) resulted in only moderate tissue complication probabilities in both kidneys with the advantage of providing significantly greater inclusion of potentially involved PLNs in comparison to accepted standard procedures (A and C).

Reproducibility of Patient Positioning for Fractionated Extracranial Stereotactic Radiotherapy Using a Double-Vacuum Technique

BACKGROUND AND PURPOSE

Precise reproducible patient positioning is a prerequisite for conformal fractionated radiotherapy. A fixation system based on double-vacuum technology is presented which can be used for conventional as well as hypofractionated stereotactic extracranial radiotherapy.

MATERIAL AND METHODS

To form the actual vacuum mattress, the patient is pressed into the mattress with a vacuum foil which can also be used for daily repositioning and fixation. A stereotactic frame can be positioned over the region of interest on an indexed base plate. Repositioning accuracy was determined by comparing daily, pretreatment, orthogonal portal images to the respective digitally reconstructed radiographs (DRRs) in ten patients with abdominal and pelvic lesions receiving extracranial fractionated (stereotactic) radiotherapy. The three-dimensional (3-D) vectors and 95% confidence intervals (CI) were calculated from the respective deviations in the three axes. Time required for initial mold production and daily repositioning was also determined.

RESULTS

The mean 3-D repositioning error (187 fractions) was 2.5 +/- 1.1 mm. The largest single deviation (10 mm) was observed in a patient treated in prone position. Mold production took an average of 15 min (10-30 min). Repositioning times are not necessarily longer than using no positioning aid at all.

CONCLUSION

The presented fixation system allows reliable, flexible and efficient patient positioning for extracranial stereotactic radiotherapy.

Latex type I sensitization and allergy in children with atopic dermatitis. Evaluation of cross-reactivity to some foods

Recent studies have demonstrated that allergy to natural rubber latex (NRL) is associated with cross-reactivity to certain foods. The aim of this study was to investigate the prevalence of NRL sensitization and allergy in children with atopic dermatitis (n=74). We also examined cross-reactions between latex and foods, and compared the frequency of suspected latex cross-reacting fruits in children with and without NRL-specific immunoglobulin E (IgE). Twelve of the 74 atopic children studied (16.2%; 95% confidence interval (CI), 8.7-26.6%) had circulating IgE antibodies to latex. These NRL-sensitized children were older and they showed significantly higher total IgE values (p<0.003) when compared with the group of children without NRL sensitization. Of the specific food IgE evaluations, 18.4% (93 out of 505) were positive, and 69.9% were observed in the group of children with latex-specific IgE, most frequently to potato, tomato, sweet pepper, and avocado. An isolated latex-specific IgE response without food-specific IgE was never observed. Exclusively in the latex-positive group, conformity with the report of allergic symptoms after ingestion of food and increased food-specific IgE was found. Twenty children without proven latex sensitization showed increased food-specific IgE, most frequently to potato, banana, and chestnut. Avocado-specific IgE was never determined in this patient group. No significant differences were detected concerning the sensitization to potato, banana, and kiwi between NRL-sensitized children and the group of 20 children without latex-specific IgE. The competitive CAP inhibition using sera from children with specific IgE to both latex and food showed different cross-reactivities between latex and the specific food. A close relationship existed between latex and avocado (median inhibition: 100%), whereas sensitization to latex and kiwi seemed to be independent in our study group (inhibition: <25%). In particular, for potato, cross-reactivity and co-sensitization existed. Our study demonstrated that children with atopic dermatitis are a high-risk group for latex sensitization. Increasing age, additional sensitization to ubiquitous inhaled allergens, and enhanced total serum IgE values seemed to be important variables for latex sensitization and further sensitization to the latex-associated foods. Cross-reactivity and, in some cases, co-sensitization to specific fruits and vegetables, were observed.

Class I endochitinase containing a hevein domain is the causative allergen in latex-associated avocado allergy

BACKGROUND

In the medical literature immunoglobulin (Ig)E-mediated sensitization to avocado is rarely reported. On the other hand, more than 50% of subjects having IgE-mediated natural rubber latex allergy are sensitized to avocado fruit as demonstrated by skin-prick testing and/or specific IgE measurements and about 10-20% report hypersensitivity reactions after ingesting avocado.

OBJECTIVE

The underlying pathomechanism of latex-associated avocado allergy is still unknown. The conserved hevein domain of the major latex allergen prohevein (Hev b 6.01) is a ubiquitous chitin-binding protein structure that can be found in several plant proteins and may be responsible for the observed cross-reactivity between latex and avocado fruit.

METHODS

Chitin-binding avocado proteins (CBAPs) were isolated by affinity-chromatography and their IgE-binding characteristics were studied by immunoblotting using the sera from 15 avocado-sensitized latex patients. Inhibition experiments using isolated hevein and CBAPs as inhibitor solutions were performed to study the immunological cross-reactivity between both protein species and to assess the role of the CBAPs as mediators in latex-associated avocado allergy.

RESULTS

In 80% of avocado-sensitized subjects (n = 15), IgE antibodies directed against a 31-kDa allergen were detected by immunoblotting. This IgE-binding protein was identified by protein sequencing to be a class I endochitinase containing a hevein domain at the N-terminus. Purified native and digested (using simulated gastric fluid) endochitinase were able to completely block all avocado-specific IgE antibodies in six out of seven avocado patients.

CONCLUSIONS

Sensitization to endochitinase class I containing a hevein domain is the main underlying pathomechanism in latex-mediated avocado allergy.

Baker's asthma due to the enzyme xylanase -- a new occupational allergen

The asthmatic baker showed IgE-mediated sensitization to xylanase of Aspergillus niger used as a baking additive. Inhalative challenge with approximately 0.5 microg of the enzyme resulted in an immediate-type asthmatic reaction. This case, as well as a preliminary screening of symptomatic bakers, shows that xylanase is a further relevant type I-sensitizer in the baking industry.

Cloning, expression and characterization of the major latex allergen prohevein

BACKGROUND

About 70-80% of latex allergic health care workers are sensitized to prohevein (Hev b 6.01), a 20 kDa cysteine-rich chitin-binding protein of Hevea latex.

OBJECTIVE

This study reports on the bacterial cloning, expression and immunochemical characterization of rHev b 6.01.

METHODS

Prohevein was expressed in the periplasmatic space of Escherichia coli as maltose binding protein (MBP) fusion protein and purified to homogeneity after factor Xa cleavage. The IgE binding capacity of both rHev b 6.01 and prohevein isolated from fresh Hevea latex was compared by immunoblotting experiments using sera of latex-allergic patients. The diagnostic value of rHev b 6.01 was analysed by enzyme allergosorbent test (EAST).

RESULTS

Two different cDNA clones of rHev b 6.01 were established. The deduced amino acid sequence of both clones revealed two and three amino acid differences in the C-terminal domain of prohevein compared with the original database entry. Purified rHev b 6.01 bound with high affinity to chitin as its natural counterpart isolated from natural latex. In IgE-immunblotting using sera of affected subjects binding intensity to both proteins was comparable indicating a very high antigenic similarity. The diagnostic value of MBP-prohevein was tested in EAST using sera of 33 latex-allergic subjects. The in vitro test showed high sensitivity and specificity and proved the diagnostic value of uncleaved MBP-prohevein.

CONCLUSIONS

The production of recombinant latex key allergens with defined quality like prohevein is a straightforward strategy for the development of standardized in vitro test systems.

Identification of hevein (Hev b 6.02) in Hevea latex as a major cross-reacting allergen with avocado fruit in patients with latex allergy

BACKGROUND

Recent studies demonstrated that allergy to natural rubber latex is frequently associated with hypersensitivity to avocado fruit. The responsible cross-sensitizing allergen has not been identified.

OBJECTIVE

The purpose of this study was to investigate the cross-reactivity of a latex major allergen, hevein, with avocado proteins.

METHODS

Serum samples from 118 health care workers (HCWs) allergic to latex (HCW group) and 78 patients with spina bifida (SB) allergic to latex (SB group) were included in this study. Anti-hevein and anti-avocado IgE antibodies were measured by enzyme-linked allergosorbent assay. Cross-reactivity of hevein to avocado proteins was assessed by inhibition of the IgE binding in individual patients' sera containing IgE antibodies to both hevein and avocado.

RESULTS

The prevalence of seropositive IgE antibodies to avocado was found to be strongly associated with the presence of hevein-specific IgE antibodies in subjects of both groups (P < .001). Sixty-seven of 91 (73%) subjects from the HCW group and all 19 subjects in the SB group with positive IgE antibodies to hevein also had elevated IgE values to avocado. Competitive RAST inhibition with 42 sera showed that IgE binding to avocado could be completely inhibited in 27 (64%) sera by preincubation with hevein. By contrast, the degrees of inhibition of IgE to hevein by avocado extract ranged from 0% to 36% (n = 16). These results indicate that sensitization to avocado in most patients allergic to latex is caused exclusively by IgE-binding epitopes present in hevein. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kd protein in avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by hevein in all sera tested.

CONCLUSION

Hevein is the major cross-reacting allergen with avocado in subjects with latex allergy.

Characterized allergens causing bakers' asthma

Although airborne allergens in bakeries and confectioneries cause one of the most common forms of occupational asthma, namely, bakers' asthma, only a few of them are known in detail so far. Here we summarize current knowledge of bakery allergens and describe our own two-dimensional (2-D) immunoelectrophoresis studies of wheat-flour allergens as well as the allergenic baking enzyme Asp o 2. Out of approximately 700 soluble wheat polypeptides, 70 show IgE binding; the following wheat-flour allergens could be identified and characterized: members of the alpha-amylase inhibitor family (14-18 kDa), acyl-CoA oxidase (26 kDa), peroxidase (36 kDa), and fructose-bisphosphate aldolase (37 kDa). However, the great majority of the soluble wheat-flour allergens, mainly located in the 27-, 55-, and 70-kDa areas of the 2-D immunoblots with pI values of 5.8-6.8, 5.9-6.5, and 5.5-6.1, respectively, are not known at present. Asp o 2, to which approximately 25% of all bakers with respiratory symptoms are sensitized, is a well-characterized starch-cleaving enzyme. We conclude that great effort is still needed to describe all major wheat-flour allergens. As shown by Asp o 2, knowledge of the causative allergens and their characteristics enables us to initiate very effective preventive measures such as the introduction of granulated allergenic products.

Latex allergen database

Two-dimensional (2-D) electrophoresis followed by immunoblotting and N-terminal protein microsequencing were used to characterize and identify the IgE-reactive proteins of Hevea latex that are the main cause of the latex type I allergy affecting especially health care workers and spina bifida children. This approach generated a comprehensive latex allergen database, which facilitated the integration of most of the latex allergen data presented in the literature. The major latex allergens Hev b 1, Hev b 3, Hev b 6 and Hev b 7 have been localized on our 2-D maps. Moreover, we were able to identify six previously undescribed IgE-binding latex proteins, namely enolase, superoxide dismutase, proteasome subunit C5, malate dehydrogenase, triosephosphate isomerase and endochitinase. The generated latex 2-D maps will provide valuable information to develop strategies for the isolation of the novel IgE binding proteins in order to study the frequency of sensitization among both risk groups. Detailed knowledge of all proteins involved in latex allergy will allow better diagnosis of latex allergy and to monitor the success of prevention strategies that are needed to reduce the high prevalence of latex allergy among both risk groups.

[Latex allergens: review of current knowledge]

Both health care workers and spina bifida patients are at risk to develop type I latex allergy since allergenic proteins of natural rubber latex are present in a variety of latex products. Natural latex contains more than 250 polypeptides and approximately 60 of them show IgE-binding characteristics. A multitude of these latex allergens has been identified, and their sensitization potency for both risk groups has been determined. While hevein (Hev b 6.02) is the major allergen in latex-allergic health care workers, 80% of latex sensitized-spina bifida children have IgE antibodies to the "rubber elongation factor" (Hev b 1). Almost all relevant latex allergens have been identified in natural latex products: however, no data on the allergen profiles of individual latex products exist. The knowledge of the major latex allergens enables improved diagnosis and to monitor the success of prevention strategies for decreasing the high prevalence of latex allergies.

Cross-reactivity between natural rubber latex and food allergens

Immediate-type hypersensitivity to latex is a growing problem, especially among health care workers (HCWs) and patients requiring long-term catheterization and multiple operations. The responsible allergens are latex proteins, which are found in raw latex, as well as in various latex-containing products. More than 200 polypeptides can be discerned in latex sap and of these, 60 proteins showed reactivity with IgE antibodies from patients with latex allergy. Several of these proteins have been characterized at the molecular level and their role in latex allergy has been elucidated. Latex allergy is often associated with hypersensitivity to certain fruits and vegetables like avocado, kiwi, banana, sweet pepper, and tomato. Several case reports demonstrate a potential for serious allergic reactions to foods in latex allergic patients. Nevertheless, comprehensive studies on the clinical significance and relevance of this co-sensitization are missing. Although some of the latex allergens are ubiquitous plant proteins or share structural features with plant proteins, the molecular bases of these cross-reactivities have not yet been clarified.

On the allergenicity of Hev b 1 among health care workers and patients with spina bifida allergic to natural rubber latex

BACKGROUND

Recent studies have caused much controversy about the prevalence of IgE antibodies to Hev b 1 among health care workers (HCWs) and patients with spina bifida (SB) who are allergic to latex. This investigation was carried out to verify the results reported.

METHOD

Serum samples from 140 patients with SB as well as from 105 HCWs allergic to latex were tested by enzyme allergosorbest test (EAST) and EAST-inhibition assay to evaluate the rate and degree of sensitization to highly purified Hev b 1.

RESULTS

Eighty-one percent of patients with SB who were allergic to latex had IgE antibodies against Hev b 1. The prevalence of anti-Hev b 1 antibodies among HCWs allergic to latex was 52.3%. In 15 of 33 serum samples from patients with SB that were randomly tested, the IgE binding to commercial latex allergens could be completely inhibited by Hev b 1; in only six cases was the maximum inhibition of IgE binding to latex by Hev b 1 less than 50%. Testing two monoclonal anti-Hev b 1 antibodies with extracts of five brands of latex gloves revealed a predominant presence of Hev b 1 protein as a monomer or its aggregates. Molecular analysis of human leukocyte antigen-D region genes DRB and DQB1 suggested no statistically significant correlation between the human leukocyte antigen alleles tested and IgE responsiveness to Hev b 1.

CONCLUSIONS

Our results indicate that Hev b 1 not only makes significant contributions to the IgE binding to latex, but it is also the unique sensitizer in about 45% of patients with SB who are allergic to latex.

Characterization and identification of latex allergens by two-dimensional electrophoresis and protein microsequencing

BACKGROUND

Proteins of natural rubber latex cause IgE-mediated sensitization in 3% to 18% of health care workers and in up to 50% of patients with spina bifida.

OBJECTIVE

This study was aimed at the generation of a comprehensive latex protein database by two-dimensional electrophoresis (2-DE).

METHODS

Proteins extracted from fresh Hevea brasiliensis latex were separated by 2-DE. IgE-reactive proteins were analyzed by immunoblotting with sera of health care workers with latex allergy. Protein microsequencing and monoclonal antibodies were used to identify the latex allergens.

RESULTS

The latex C-serum 2-DE map was very complex and exhibited about 200 distinct polypeptides. The proteins eluted from the latex particles consisted primarily of two groups of acidic proteins located in the 8 to 14 kd and 22 to 24 kd areas of the 2-DE map. Major IgE-reactivity was detected with C-serum proteins in the 56, 45, 30, 20, 14, and <6.5 kd areas of the immunoblots. The 8 to 14 kd particle proteins exhibited distinct IgE reactivity, whereas the 22 to 24 kd proteins were not stained. Seven of the soluble IgE-reactive protein spots showed high homology with enolase, superoxide dismutase, triosephosphate isomerase, proteasome subunit, and chitinase and represent previously undescribed latex allergens; whereas nine protein spots corresponded to known latex allergens, namely prohevein, hevein, prohevein C-domain, and hevamine. As identified by monoclonal antibodies, the IgE-reactive latex particle proteins mainly represent the allergenic rubber elongation factor.

CONCLUSIONS

Two-dimensional electrophoresis, followed by immunoblotting and protein microsequencing, can rapidly identify a large number of IgE-binding latex proteins. The 2-DE latex maps generated will provide valuable information for the development of strategies to isolate the relevant latex allergens. Because the novel latex allergens are common plant enzymes, they may also act as cross-reacting proteins in various foods.

Isolation and identification of hevein as a major IgE-binding polypeptide in Hevea latex

BACKGROUND

Polypeptides in Hevea latex are known as the major cause of latex type I sensitivities. So far, only a few of them have been characterized.

METHODS

Proteins with a molecular weight lower than 10 kd in fresh Hevea latex were separated by ultrafiltration and further characterized by liquid chromatography on-line-coupled electrospray mass spectrometry. Hevein in this fraction was then purified by preparative reverse-phase high-performance liquid chromatography and characterized by matrix-assisted laser desorption ionization mass spectrometry and protein sequencing. Skin prick tests, enzyme-linked allergosorbent tests, and inhibition immunoblotting were performed to show the allergenicity of the purified hevein.

RESULTS

Hevein, a 4.7 kd polypeptide, is the predominant component in the fraction with latex proteins of smaller than 10 kd. Specific IgE antibodies to hevein were detected by enzyme-linked allergosorbent test in 48 of 64 (75%) sera from health care workers allergic to latex and in three of 11 (27%) sera from patients with spina bifida and hypersensitivity reactions to latex. Inhibition immunoblotting demonstrated that the preincubation of 14 sera and a serum pool from patients allergic to latex with purified hevein completely inhibited IgE binding to the 20 kd protein, which has been recently reported to be a major allergen in latex (prohevein). Skin prick testing showed a positive reaction to hevein in 17 of 21 (81%) patients with latex allergy.

CONCLUSIONS

The results clearly demonstrate that hevein is an important latex allergen, and the IgE-binding capacity of prohevein in latex is mostly attributed to hevein, the N-terminal domain of prohevein.

EAST and CAP specificity for the evaluation of IgE and IgG antibodies to diisocyanate-HSA conjugates

Sera of 54 symptomatic workers showing sensitization to isocyanate-human serum albumin (HSA) conjugates were subjected to parallel enzyme allergosorbent test (EAST) and CAP measurements to determine IgE antibodies to diphenyl-methane diisocyanate-HSA, toluene diisocyanate-HSA and hexamethylene diisocyanate-HSA. Results of both methods correlated rather well with each other. In comparison to the EAST results, the CAP values were twice as high, and 4, 17 and 13% more frequently positive findings were obtained with the three different antigens. Autoinhibition performed with both methods proved the specificity of IgE binding in 92% of sera in EAST and in 89% of sera in CAP if values of > or = 0.35 kU/l were considered. The total IgE level in sera influenced the antibody results. Four of 20 sera studied by autoinhibition had a total IgE of > 700 kU/l, and two of them did not show significant autoinhibition with all conjugates by CAP and one serum by EAST. In addition, three of these sera showed an elevated binding to control HSA only (0.31-0.5 kU/l), and two revealed only a slightly increased IgE binding when compared with the HSA control (ratio of isocyanate-HSA to HSA, < 2). Only 2 of the 16 sera with a total IgE level of < 700 kU/l yielded a noninhibitory positive CAP result, whereas all positive EAST values of these sera could be significantly blocked by autoinhibition. Therefore, we suggest regarding EAST and CAP IgE results to isocyanate-HSA as positive if they exceed HSA control by 100% and are above 0.35 kU/l. Weak positive CAP results (< or = kU/l), especially of sera with total IgE > 700 kU/l, should by confirmed by inhibition experiments. Twelve of 40 symptomatic isocyanate workers exhibited borderline or weakly increased IgG values for diisocyanate-HSA conjugates in the CAP system and IgG-EAST. HSA tested in EAST as a reference showed nearly the same results as the isocyanate-HSA conjugates. In the 23 inhibition experiments, IgG-binding specificity was not confirmed. These findings imply IgG measurement to be of no diagnostic value in isocyanate-induced airway disorders.

Increased radiosensitivity by a combination of 9-cis-retinoic acid and interferon-y in breast cancer cells

Interferons (IFNs) and retinoic acid (RA) are known to possess antiproliferative effects in various human cancer cell lines, including squamous cervix carcinoma and breast cancer cell lines. Frequently synergistic effects could be observed by the combination of both, and in clinical trials high response rates could be achieved by IFN-alpha in combination with 13-cis-RA in patients with squamous carcinoma of the uterine cervix. Since radiation-potentiating effects of IFNs and RA were described, we evaluated the additional impact of irradiation on three human breast cancer cell lines and investigated the antiproliferative effects of single, double, or triple treatments with IFN-gamma, 9-cis-RA, and irradiation. Antiproliferative effects were observed in all cell lines by any single treatment. When combining IFN-gamma with 9-cis-RA, synergism could be observed in all experiments. The combination of either IFN-gamma or 9-cis-RA with irradiation resulted mostly in additive effects. Irradiation contributed additive or further synergistic effects to the already synergistic effects of the combination of these two drugs. Thus synergism of IFN-gamma and 9-cis-RA always at least persisted fully. These results suggest that a regimen of IFN, RA, and radiotherapy (RT) might be a promising combination in the therapy of solid tumors, where RT is part of the conventional treatment.

Compression characteristics of CPR manikins

We evaluated the force-depth compression characteristics of 8 different CPR manikins during mechanical cardiopulmonary resuscitation by a thumper. The force required to compress the manikin's thorax of 1, 2, 3, 4 and 5 cm was measured. It ranged between 6.3 and 14 kp at a depth of 1 cm, 11.6-30 kp at 2 cm, 17-38 kp at 3 cm, 22.5-54 kp at 4 cm and 28.5-69 kp at 5 cm. The manikins with a spring in the thorax (Ambu Man, Ambu MultiMan, Dräger CPR-Max, Laerdal Resusci Anne) as well as one without (Ambu CPR Pal) showed a rather linear relationship between depth and force required to compress the chest. Ambu Man, set at 'High', Laerdal Resusci Anne and Dräger CPR-Max revealed a slight increase in resistance, whereas 2 manikins without a spring (Laerdal Little Anne, Laerdal Family Trainer) and 1 manikin with a plastic spring-like construction (Actar 911) exhibited less resistance with increasing depth. According to our results, the manikins are not uniform in their compression characteristics; some become nonlinear when 3 cm of compression is exceeded. For correct CPR it is of utmost importance that the CPR trainee learns to compress in a sufficiently strong manner, but simultaneously to avoid an exceedingly high depth of compression irrespective of the thorax resistance. In order to prepare the CPR student for the varying chest resistances of the human body, we recommend to train CPR on manikins with different chest resistances.

Interlaboratory reproducibility of yeast protein patterns analyzed by immobilized pH gradient two-dimensional gel electrophoresis

An interlaboratory comparison was conducted on the positional and quantitative reproducibility of yeast proteins resolved by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) using isoelectric focusing with immobilized pH gradient (pH 4-7) in the first dimension. The basic experimental set-up was as follows: one laboratory prepared and distributed a [35S]methionine-labeled total yeast protein extract (Göteborg, Sweden), another laboratory prepared the IPG strips to be used by all labs in this study (Munich, Germany), the third laboratory (Aarhus, Denmark) circulated the protocols and coordinated the modest attempts to unify them. Samples were run horizontally in the first dimension and vertically in the second. The gels were sent to Göteborg for processing by phosphoimager technology and computerized image analysis (PDQuest), and the 2-D PAGE resolved proteins were located and quantified automatically. A subset of 470 spots was manually matched in all gels out of an average of 1328 resolved proteins. The positional interlaboratory comparison revealed great pattern reproducibility, the correlation coefficient in no case being less than 0.9994. In absolute terms an average deviation of 2.8 mm (x-position) and 1.8 mm (y-position) were obtained for all nine gels (three gels per lab). The interlaboratory comparison of protein quantitation displayed higher variability, and the best correlation coefficient generated was 0.975. An average standard deviation of 34.5% was calculated for protein quantitation including all three labs, a value slightly higher than the intralaboratory variation (range 20-28%). Thus, despite differences in protocols, chemicals and equipment, the immobilized pH gradient technology gave extremely high positional and quantitative reproducibility. This will greatly facilitate the exchange of data and the establishment of multi-user image-based 2-D gel databases.

Sequence analysis of wheat grain allergens separated by two-dimensional electrophoresis with immobilized pH gradients

Micropreparative two-dimensional (2-D) gel electrophoresis with immobilized pH gradients (4-8) in the first dimension (IPG-DALT) was optimized for the separation of salt-soluble wheat grain proteins, associated with bakers' asthma disease. The resolved polypeptides were electroblotted onto a polyvinylidene difluoride (PVDF) membrane and incubated with the pooled sera from four asthmatic bakers. Bound IgE was demonstrated by alkaline phosphatase conjugated anti-human IgE. Major IgE binding was detected in the 27 kDa, 37 kDa and, to a lesser extent, in the 14-18 kDa area of the 2-D immunoblots, respectively. Since the main purpose of our study was to determine the N-terminal amino acid sequences of the major wheat grain allergens, N-terminal sequencing was performed for six out of a total of eleven major allergens located in the 27 kDa area, for one out of two 37 kDa allergens, and for two out of four 14-18 kDa allergens. Our results revealed that two of the 27 kDa polypeptides are clearly related to several Acyl-CoA oxidase variants of barley and rice, whereas no significant homologies were found for the remaining four 27 kDa allergens analyzed. The N-terminus of the 37 kDa allergen appeared to be blocked so that no sequence information was obtained, while the two 14-18 kDa allergens analyzed were identified as members of the wheat alpha-amylase-inhibitor family.

Genetic variability of carrot seed proteins analyzed by one- and two-dimensional electrophoresis with immobilized pH gradients

The genetic variability of eight carrot populations representing commercially important morphological types was analyzed for seed protein polymorphism by one- and two-dimensional electrophoresis using immobilized pH gradients (IPG) in order to assess the potential of both techniques in carrot hybrid breeding as well as genetic quality testing of carrot trade seeds. The digitized silver-stained one- and two-dimensional gels of the urea/detergent-soluble seed proteins were subjected to computer analysis to estimate both the inter- and intrapopulation genetic variability. The results indicated that isoelectric focusing (IEF-IPG) of seed proteins is a powerful tool for quick screening of the genetic variability present between and within carrot populations, while two-dimensional polyacrylamide gel electrophoresis (IPG-DALT) can be employed to establish detailed genetic relationships of carrot populations selected by initial IEF-IPG screening in order to use genetic distant and homogeneous populations for successful carrot hybrid breeding. However, the applicability of IEF-IPG in genetic quality testing of carrot seeds seems to be restricted to hybrid purity testing. IPG-DALT is a far more powerful tool to profile unambiguously all carrot varieties commercially used in order to test the genetic quality of trade seeds, because this technique exhibits protein spots or spot combinations exclusively found in each of the eight varieties investigated.

Two-dimensional polyacrylamide gel electrophoresis with immobilized pH gradients in the first dimension (IPG-Dalt): the state of the art and the controversy of vertical versus horizontal systems

After having established the basic protocol of two-dimensional electrophoresis with immobilized pH gradients in the first dimension (IPG-Dalt) in 1988 (A. Görg et al., Electrophoresis 1988, 9, 531-546), some critical parameters of the actual IPG-Dalt protocols as well as the results obtained with horizontal and vertical second-dimensional sodium dodecyl sulfate-electrophoresis are demonstrated and discussed.

Association of protein polymorphism among pepper (Capsicum annuum L.) inbred lines with agronomic performance of their crosses

The genetic variation of 10 morphologically similar pepper (Capsicum annuum L.) inbred lines has been analyzed by two-dimensional electrophoresis with immobilized pH gradient (IPG-DALT) of seed proteins. For all pairs of inbred lines genetic distance indices were calculated on the basis of the IPG-DALT analysis and a genetic tree was constructed. The protein polymorphism data of the 10 inbred lines were integrated into a pepper breeding program to validate the assumption that there is a higher chance of achieving better hybrid performance when the genetic distance between the parents is as great as possible. Field trials were performed in Turkey and consisted of a total of 27 crossings based on 9 inbred lines. Fifteen hybrids exceeded the crop yield of the better parent and 8 additional hybrids exceeded the mean crop yield of both parents. The genetic distance indices of the parental inbred lines based on protein polymorphism data were not significantly correlated to heterosis performance of the experimental hybrids (r = 0.20), indicating that protein polymorphism data add little to the prediction of single cross hybrid performance. Nevertheless, protein polymorphism data support the breeder in being more effective in finding out the best inbred combinations, because most of the less promising crossings can be omitted from the expensive and time-consuming performance tests. Those hybrids whose distance indices exceeded the mean of all 27 distance values (0.52) were superior to the mean value of all heterosis performances by 19%.(ABSTRACT TRUNCATED AT 250 WORDS)

Pallister-Hall syndrome and McKusick-Kaufmann syndrome: one entity?

The Pallister-Hall syndrome is characterised by specific facial anomalies, postaxial polydactyly, imperforate anus, and brain anomalies including a diencephalic hamartoblastoma. The hallmarks of the McKusick-Kaufmann syndrome are hydrocolpos owing to vaginal atresia, postaxial polydactyly, imperforate anus, and congenital heart defects. We report a patient with the unique features of hydrocolpos, postaxial polydactyly, and hypothalamic hamartoblastoma and discuss the different aetiological considerations of both syndromes and implications for clinical management.

Positional reproducibility of protein spots in two-dimensional polyacrylamide gel electrophoresis using immobilised pH gradient isoelectric focusing in the first dimension: an interlaboratory comparison

An intra- and interlaboratory comparison of positional reproducibility of protein spots in two-dimensional electrophoresis using immobilised pH gradients (IPG) in the first dimension (IPG-DALT) was made. Aliquots of two different samples, human cardiac and barley leaf proteins, were separated in two different laboratories (London and Munich), using 180 mm long IPG gel strips, pH 4-8, for the first dimension and homogeneous SDS-PAGE gels (12% T) for the second dimension. Subsets of 340 (cardiac) and 200 (barley) well-resolved spots distributed across the 2-D gel patterns were selected for computer analysis (PDQUEST) of positional reproducibility. The IPG-dimension was highly reproducible in each laboratory, with a mean standard deviation of about 1 mm for both types of sample. Interlaboratory comparisons revealed identical results for barley with a mean standard deviation along the x-axis of about 1 mm, whereas the cardiac matchset showed slightly more variability (mean standard deviation approximately 1.5 mm). Nevertheless, IPG-DALT provides significantly improved reproducibility of spot positions compared to conventional isoelectric focusing with synthetic carrier ampholytes.

Polymorphism of pepper (Capsicum annuum L.) seed proteins studied by two-dimensional electrophoresis with immobilized pH gradients: methodical and genetic aspects

A population of ten morphologically similar inbred lines of pepper (Capsicum annuum L.) has been investigated for polymorphism of seed proteins by two-dimensional (2-D) electrophoresis with immobilized pH gradients. To reveal as much variation as possible, both the water- and the urea/detergent-soluble protein fraction were electrophoretically analyzed and subsequently visualized by silver staining. The 2-D patterns were subjected to computer analysis to be able to establish genetic variation. A high number of the seed proteins were found to be variable as to presence/absence: these were 68 out of 184 reproducible water-soluble proteins and 34 out of 419 reproducible urea/detergent-soluble proteins. Comparison of the 2-D data of the water-soluble and the urea/detergent-soluble proteins, which represent the biggest part of all extractable seed proteins, showed that both protein fractions have proteins in common, but the variable proteins found in both fractions were non-identical. The difference of variability scored in both solubility fractions was discussed. Genetic distances between all pairs of inbred pepper lines were calculated and a genetic tree was constructed. A correlation analysis was carried out to correct for genetic linkage and for secondary modifications, to have a more proper estimate of genetic distances. In both cases the dendrograms showed two distinct genetic groups of five inbred lines. This electrophoretic study was done in order to utilize the genetic distance data in breeding for heterosis. The genetic distance data presented will be used to validate the assumption that there is a higher chance to achieve better hybrid performance when the genetic distance between the parents is as great as possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous collapse of posttraumatic syringomyelia: serial magnetic resonance imaging

The case of a 30-year-old man with posttraumatic syringomyelia involving the cervical and upper thoracic spine is reported. The patient was followed clinically and with magnetic resonance (MR) imaging over a 3-year period. Spontaneous complete remission of the syrinx-related symptoms correlated with a partial collapse of the syrinx, as proved by serial MR imaging.

Genetic variability of pepper (Capsicum annuum L.) seed proteins studied by 2-D electrophoresis with immobilized pH gradients

Ten pepper (Capsicum annuum L.) inbred lines were successfully differentiated by two-dimensional electrophoresis with immobilized pH gradients. Qualitative polymorphism of water-soluble and urea/detergent-soluble seed proteins, respectively, was investigated by computer analysis and used for establishing a dendrogram derived from maximum-parsimony analysis. The dendrogram calculated from urea/detergent-soluble proteins shows four types of distance indices, whereas water-soluble proteins show two sets of inbred lines with similar intraset distance indices. The validity of the dendrograms with respect to quantitative inherited traits, such as cold tolerance and earliness, will be tested by field trials.

Elimination kinetics of maternally derived thyrotropin receptor-blocking antibodies in a newborn with significant thyrotropin elevation

OBJECTIVE

To determine the course of maternally derived elevations in thyrotropin-binding inhibitory immunoglobulins in a neonate.

DESIGN

Case report.

SETTING

University pediatric endocrinology clinic and endocrine immunology laboratory in Ohio.

PARTICIPANTS

An infant with elevated thyrotropin levels but near-normal total thyroxine levels, and her mother.

INTERVENTIONS

None.

MEASUREMENTS/MAIN RESULTS

Thyroid hormone, thyrotropin, and thyrotropin-blocking immunoglobulin concentrations were serially measured in a woman and her infant, who was found to have elevated thyrotropin levels (234 mU/L) and borderline low thyroxine levels (95 nmol/L). As infant thyroxine concentrations remained normal (125 to 145 nmol/L), no thyroxine supplementation was given. Thyrotropin levels decreased concomitantly with thyrotropin-blocking inhibitory immunoglobulin levels, and normalized by day 56 of life. The apparent elimination half-life of thyrotropin-blocking immunoglobulins was 7.5 days.

CONCLUSIONS

The observed parallel elimination kinetics suggest that the thyrotropin receptor antibody acts as a thyrotropin antagonist, resulting in compensatory thyrotropin elevations. The duration of such elevations may be predicted on the basis of such elimination.