Salvage lymph node dissection with adjuvant radiotherapy for nodal recurrence of prostate cancer.

PURPOSE: We evaluated the impact of salvage lymph node dissection with adjuvant radiotherapy in patients with nodal recurrence of prostate cancer. By default, nodal recurrence of prostate cancer is treated with palliative antihormonal therapy, which causes serious side effects and invariably leads to the development of hormone refractory disease. MATERIALS AND METHODS: A total of 47 patients with nodal recurrence of prostate cancer based on evidence of (11)C-choline/(18)F-choline ((18)F-fluorethylcholine) positron emission tomography-computerized tomography underwent primary (2 of 52), secondary (45 of 52), tertiary (4 of 52) and quaternary (1 of 52) salvage lymph node dissection with histological confirmation. Of 52 salvage lymph node dissections 27 were followed by radiotherapy. Biochemical response was defined as a prostate specific antigen less than 0.2 ng/ml after salvage therapy. The Kaplan-Meier method, binary logistic regression and Cox regression were used to analyze survival as well as predictors of biochemical response and clinical progression. RESULTS: Mean prostate specific antigen at salvage lymph node dissection was 11.1 ng/ml. A mean of 23.3 lymph nodes were removed per salvage lymph node dissection. Median followup was 35.5 months. Of 52 salvage lymph node dissections 24 resulted in complete biochemical response followed by 1-year biochemical recurrence-free survival of 71.8%. Gleason 6 or less (OR 7.58, p = 0.026), Gleason 7a/b (OR 5.91, p = 0.042) and N0 status at primary therapy (OR 8.01, p = 0.011) were identified as independent predictors of biochemical response. Gleason 8-10 (HR 3.5, p = 0.039) as a preoperative variable, retroperitoneal positive lymph nodes (HR 3.76, p = 0.021) and incomplete biochemical response (HR 4.0, p = 0.031) were identified as postoperative predictors of clinical progression. Clinical progression-free survival was 25.6% and cancer specific survival was 77.7% at 5 years. CONCLUSIONS: Based on (11)C/(18)F-choline positron emission tomography-computerized tomography as a diagnostic tool, salvage lymph node dissection is feasible for the treatment of nodal recurrence of prostate cancer. Most patients experience biochemical recurrence after salvage lymph node dissection. However, a specific population has a lasting complete prostate specific antigen response.

New tracers beyond FDG in head and neck oncology.

Positron emission tomography with the glucose analogue 2-deoxy-2-[18F]fluoro-D-glucose (FDG-PET) is frequently used for staging and re-staging of squamous cell carcinomas of the head and neck region (HNSCC). HNSCCs generally demonstrate intense FDG uptake and FDG-PET has been found to be clinically useful in many situations. Nevertheless, several limitations of FDG-PET have also been identified. These include the physiologic uptake of FDG in several normal structures in the head and neck region as well as the unspecific FDG uptake by inflammatory processes. In order to overcome the limitations of FDG-PET tracers targeting amino acid transport, thymidine metabolism, hypoxia and antigen expression have been developed and tested in preclinical, as well as in initial clinical studies. While encouraging results have been obtained in small series of patients, none of the studied agents are likely to replace FDG-PET for staging and re-staging of HNSCCs, since their sensitivity for tumor detection appears limited. Nevertheless, they may provide complementary information on FDG-PET. Amino acid tracers may allow more specific detection HNSCC as compared to FDG-PET, and PET with [18F]fluorothymidine has shown encouraging results for monitoring changes in tumor proliferation during therapy. Using markers of hypoxia PET can potentially improve the efficacy of radiotherapy by increasing the radiation dose to hypoxic and thus more radioresistant tumors. Radiolabeled antibodies hold great potential for imaging drug targets and monitoring antibody therapy. Imaging of alpha(v)beta(3) integrins may allow characterization of tumor angiogenesis and monitoring of anti-angiogenic therapies. All these promising new applications of PET do, however, require more systematic clinical studies before they can be used for patient management.

[German guidelines for brain tumour imaging by PET and SPECT using labelled amino acids]. / PET- und SPECT-Untersuchungen von Hirntumoren mit radioaktiv markierten Aminosäuren.

For the primary diagnosis of brain tumours, morphological imaging by means of magnetic resonance imaging (MRI) is the current method of choice. The complementary use of functional imaging by positron emitting tomography (PET) and single photon emitting computerized tomography (SPECT) with labelled amino acids can provide significant information on some clinically relevant questions, which are beyond the capacity of MRI. These diagnostic issues affect in particular the improvement of biopsy targeting and tumour delineation for surgery and radiotherapy planning. In addition, amino acid labelled PET and SPECT tracers are helpful for the differentiation between tumour recurrence and non-specific post-therapeutic tissue changes, in predicting prognosis of low grade gliomas, and for metabolic monitoring of treatment response. The application of dynamic PET examination protocols for the assessment of amino acid kinetics has been shown to enable an improved non-invasive tumour grading. The purpose of this guideline is to provide practical assistance for indication, examination procedure and image analysis of brain PET/SPECT with labelled amino acids in order to allow for a high quality standard of the method. After a short introduction on pathobiochemistry and radiopharmacy of amino acid labelled tracers, concrete and detailed information is given on the several indications, patient preparation and examination protocols as well as on data reconstruction, visual and quantitative image analysis and interpretation. In addition, possible pitfalls are described, and the relevant original publications are listed for further information.

Fatty acid composition of milk from multiparous Holstein cows treated with bovine somatotropin and fed n-3 fatty acids in early lactation.

Multiparous cows (n = 59) were blocked by expected calving date and previous milk yield and assigned randomly to treatments to determine effects of bovine somatotropin (bST; Posilac, Monsanto Animal Agricultural Group, St. Louis, MO) and source of dietary fat on milk fatty acid composition during the first 140 d in milk. Diets were provided from calving and included whole, high-oil sunflower seeds (SS; 10% of dietary dry matter; n-6/n-3 ratio of 4.6) as a source of linoleic acid or a mixture of Alifet-High Energy and Alifet-Repro (AF; Alifet USA, Cincinnati, OH; 3.5 and 1.5% of dietary dry matter, respectively; n-6/n-3 ratio of 2.6) as a source of protected n-3 fatty acids (15.7% 18:3, 1.3% 20:5, and 1.3% 22:6). Treatments were derived from a 2 x 2 combination of supplemental fat source (SS, AF) and with 0 (SSN, AFN) or 500 (SSY, AFY) mg of bST administered every 10 d from 12 to 70 d in milk and at 14-d intervals thereafter. Milk fatty acid composition was determined in samples collected from 32 cows (8 complete blocks) during wk 2, 8, and 20 of lactation. Data were analyzed as repeated measures using mixed model procedures to determine the effects of diet, bST, week of lactation, and their interactions. Proportions of 18:3 (4.02 vs. 3.59 +/- 0.16%), 20:5 (0.52 vs. 0.41 +/- 0.02%), and 22:6 (0.11 vs. 0.02 +/- 0.02%) were greater and the n-6/n-3 fatty acid ratio (7.40 vs. 8.80 +/- 0.30) was reduced in milk from cows fed AF compared with SS. Proportions of de novo-synthesized fatty acids increased and preformed fatty acids decreased as lactation progressed, but bST administration delayed this shift in origin of milk fatty acids. Transfer efficiency of 18:3, 20:5, and 22:6 from AF to milk fat averaged 36.2, 4.9, and 5.2%, respectively. These efficiencies increased as lactation progressed, but were delayed by bST. Apparent mammary Delta(9)-desaturase activity and milk conjugated linoleic acid (cis-9, trans-11 conjugated linoleic acid) content increased through the first 8 wk of lactation. Based on the product-to-substrate ratio of 14:1/14:0 fatty acids in milk, there was an interaction of diet and bST because bST decreased apparent Delta(9)-desaturase activity in SSY cows but increased it in AFY cows (0.10, 0.09, 0.08, and 0.09 +/- 0.01 for SSN, SSY, AFN, and AFY, respectively). Feeding Alifet-Repro increased n-3 fatty acids in milk and bST prolonged the partitioning of dietary fatty acids into milk fat.

Postpartum ovarian activity in multiparous Holstein cows treated with bovine somatotropin and fed n-3 fatty acids in early lactation.

Multiparous cows (n = 59) were blocked by expected calving date and previous 305-d mature-equivalent milk yield and assigned randomly to a 2 x 2 factorial design to determine the effects of bovine somatotropin (bST; Posilac, Monsanto Animal Agricultural Group, St. Louis, MO) and dietary fat on ovarian activity during the first 90 d in milk (DIM). Diets that included whole, high-oil sunflower seeds [SS; 10% of dietary dry matter; rich in linoleic acid (18:2)] or a mixture of Alifet-High Energy and Alifet-Repro [AF; Alifet USA, Cincinnati, OH; 3.5 and 1.5% of dietary dry matter, respectively; protected source of linolenic (18:3), eicosapentaenoic, and docosahexaenoic fatty acids] were provided from calving. Diets were isocaloric at equal intakes, but AF provided more net energy for lactation at actual intakes (1.54 vs. 1.66 Mcal/kg of dry matter). Cows received 0 or 500 mg of bST (N, Y) every 10 d from 12 to 70 DIM and at 14-d intervals from 70 to 280 DIM. Breeding was initiated after 90 DIM. Follicular dynamics, luteal growth and development (15 to 90 DIM), and plasma progesterone concentrations (1 to 90 DIM) were evaluated (3 times per week). Days to first ovulation (33.6 +/- 1.4) and incidence of anovulation at 45 or 70 DIM did not differ among treatments. Interovulatory intervals were similar among treatments (22.1 +/- 0.9 d). Incidence of estrous cycles with 2 follicular waves was greater for SSY (71.0%) and AFN (80.0%) than for other groups, but more 3-wave cycles occurred with AFY (83.3%). Growth rate of the ovulatory follicle was greater for AF than SS (1.9 vs. 2.2 +/- 0.11 mm/d) and diameter of ovulatory follicles was larger for AFN than the other treatments (17.9 vs. 15.7 +/- 0.7 mm). Area under the progesterone curve was reduced for SSY (63.2, 48.1, 55.5, and 61.4 +/- 5.1 ng.d/mL for SSN, SSY, AFN, and AFY, respectively). The number of class 1 (3 to 5 mm) follicles was decreased and the number of class 2 (6 to 9 mm) follicles was increased by bST. The number of class 2 follicles was reduced by AF. Initiation of bST administration at 12 DIM and dietary n-3 fatty acids altered ovarian activity during the first 90 DIM and could benefit reproductive performance. Dietary n-3 fatty acids interacted with bST administration in early lactation to increase the incidence of estrous cycles with 3 follicular waves. Although these changes could benefit reproductive performance, evaluation with a larger number of cows is needed to determine if these alterations improve fertility.

Hepatic gene expression in multiparous Holstein cows treated with bovine somatotropin and fed n-3 fatty acids in early lactation.

Multiparous cows were fed supplemental dietary fat and treated with bST to assess effects of n-3 fatty acid supply, bovine somatotropin (bST), and stage of lactation on hepatic gene expression. Cows were blocked by expected calving date and previous milk yield and assigned randomly to treatment. Supplemental dietary fat was provided from calving as either whole high-oil sunflower seeds (SS; 10% of dietary dry matter; n-6/n-3 ratio of 4.6) as a source of linoleic acid or a mixture of Alifet-High Energy and Alifet-Repro (AF; 3.5 and 1.5% of dietary dry matter, respectively; n-6/n-3 ratio of 2.6) as a source of protected n-3 fatty acids. Cows were treated with 0 (SSN, AFN) or 500 (SSY, AFY) mg of bST every 10 d from 12 to 70 d in milk (DIM) and at 14-d intervals thereafter. Liver biopsies were collected on -12, 10, 24, and 136 DIM for gene expression analysis. Growth hormone receptor (GHR), insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP3), hepatic nuclear factor 4alpha (HNF4alpha), fibroblast growth factor-21 (FGF-21), and peroxisome proliferator-activated receptor alpha (PPARalpha) were the target genes and hypoxanthine phosphoribosyltransferase (HPRT) was used as an endogenous control gene. Expression was measured by quantitative real-time reverse transcription-PCR analyses of 4 samples from each of 32 cows (8 complete blocks). Amounts of hepatic HPRT mRNA were not affected by bST or diet but were increased by approximately 3.8% in early lactation (3.42, 3.52, 3.54, and 3.41 x 10(4) message copies for -12, 10, 24, and 136 DIM, respectively). This small change had little detectable impact on the ability of HPRT to serve as an internal control gene. Amounts of hepatic GHR, IGF-I, and IGFBP3 mRNA were reduced by 1.5 to 2-fold after calving. Expression of GHR and IGF-I increased and IGFBP3 tended to increase within 12 d (by 24 DIM) of bST administration. These effects of bST persisted through 136 DIM. Hepatic HNF4alpha mRNA was not altered by DIM or any of the treatments. Abundance of PPARalpha mRNA was unchanged through 24 DIM but increased by 136 DIM. There was a trend for an interaction of bST, diet, and DIM on PPARalpha mRNA abundance from 24 to 136 DIM because the amount of PPARalpha mRNA increased in SSN, SSY, and AFN cows but was not altered in AFY cows. The amount of FGF-21 mRNA increased markedly in early lactation but, like HNF4alpha mRNA, was not affected by bST, diet, or their interactions. These results indicate 1) that bST induced increases in hepatic expression of GHR, IGF-I, and IGFBP3 when cows were in negative energy balance in early lactation, 2) there was no effect of reduced dietary n-6/n-3 content on hepatic gene expression, and 3) there was support for a potential homeorhetic role of hepatic FGF-21 via uncoupling the somatotropin-IGF-axis in early lactation.

[Integrated health care at Recklinghausen]. / Recklinghäuser Arztnetz für Information und Qualität.

This paper reports in detail on a project of Integrated Health Care in cardiology at Recklinghausen, Germany. Information on the structure of the contract, the participants, the agreed claiming of benefits and provision of services are provided as well as relevant figures and contact data.

Spinal cord stimulation in complex regional pain syndrome: cervical and lumbar devices are comparably effective.

BACKGROUND: Spinal cord stimulation (SCS) has been used since 1967 for the treatment of patients with chronic pain. However, long-term effects of this treatment have not been reported. The present study investigated the long-term effects of cervical and lumbar SCS in patients with complex regional pain syndrome type I. METHODS: Thirty-six patients with a definitive implant were included in this study. A pain diary was obtained from all patients before treatment and 6 months and 1 and 2 years after implantation. All patients were asked to complete a seven-point Global Perceived Effect (GPE) scale and the Euroqol-5D (EQ-5D) at each post-implant assessment point. RESULTS: The pain intensity was reduced at 6 months, 1 and 2 years after implantation (P<0.05). However, the repeated measures ANOVA showed a statistically significant, linear increase in the visual analogue scale score (P=0.03). According to the GPE, at least 42% of the cervical SCS patients and 47% of the lumbar SCS patients reported at least 'much improvement'. The health status of the patients, as measured on the EQ-5D, was improved after treatment (P<0.05). This improvement was noted both from the social and from the patients' perspective. Complications and adverse effects occurred in 64% of the patients and consisted mainly of technical defects. There were no differences between cervical and lumbar groups with regard to outcome measures. CONCLUSION: SCS reduced the pain intensity and improves health status in the majority of the CRPS I patients in this study. There was no difference in pain relief and complications between cervical and lumbar SCS.

[The Advanced Breast Biopsy Instrumentation (ABBI) for evaluation of mammographically suspicious, non-palpable findings of the breast: a reliable diagnosis with minor therapeutic potential]. / Die Advanced Breast Biopsy Instrumentation (ABBI) für die Evaluation mammographisch verdächtiger, nicht-palpabler Befunde der Brustdrüse: Eine zuverlässige Diagnostik mit geringem therapeutischen Potential.

BACKGROUND: Stereotactic biopsy techniques supersede conventional hook-wire localization followed by open excision to clarify the dignity of nonpalpable mammographic lesions. The advanced breast biopsy instrumentation (ABBI) allows stereotactically guided excision of a specimen up to 20 mm in diameter on an outpatient basis under local anaesthesia. METHODS: Demographic information, mammographic and pathological findings, complications, subsequent interventions and sensitivity as well as efficiency of a series of 144 planned ABBI procedures were documented (largest published single institution series). RESULTS: The ABBI procedure was successfully performed in 93.8% (135/144); accurate diagnosis was made in 99.3% (134/135), sensitivity for malignant lesions was 96.9% (31/32) and morbidity was 1.5%. Consistent with other published series margins of the biopsy cylinder containing a malignant lesion were involved in 83.9% (26/31). CONCLUSIONS: Excisional biopsy using the ABBI system is a reliable diagnostic tool with a low incidence of morbidity. The therapeutic use is of limited potential.

Biosynthetic origin of hydrogen atoms in the lipase inhibitor lipstatin.

The lipase inhibitor lipstatin is biosynthesized in Streptomyces toxytricini via condensation of a C(14) precursor and a C(8) precursor, which are both obtained from fatty acid catabolism. To study the mechanism of this reaction in more detail, S. toxytricini was grown in medium containing a mixture of U-(13)C,U-(2)H-lipids and unlabeled sunflower oil or in a medium containing 70% D(2)O. Lipstatin was isolated and analyzed by (1)H,(2)H, and (13)C NMR spectroscopy. Hydrogen atoms at C-2, C-3, and C-4 of lipstatin were found to be derived from solvent protons. The formation of the lipstatin precursor 3-hydroxy-Delta(5,8)-tetradecadienoyl-CoA by beta oxidation of linoleic acid explains the incorporation of solvent hydrogen into the 4 position of lipstatin. The hydrogen in position 3 of lipstatin is most probably introduced from solvent by proton/deuterium exchange of a redox cofactor involved in the reduction of the keto group in the branched chain beta keto acid arising by a decarboxylative condensation. The incorporation of solvent hydrogen at position 2 can be explained by epimerization of a chiral intermediate at C-2 and C-3. Epimerization may involve a dehydration-rehydration mechanism.

Are there acid base changes during transurethral resection of the prostate (TURP)?

UNLABELLED: Acid base status during transurethral resection of the prostate (TURP) has been almost neglected. We therefore measured the acid base status and interpreted the observed changes according to the Stewart approach. The Stewart model focuses more on the influence of serum electrolyte concentrations on acid base changes than does the conventional Henderson-Hasselbalch approach. In 20 patients undergoing TURP, the following variables were determined: PaO(2), PaCO(2), pH(a), actual bicarbonate, standard base excess, serum concentration of sodium, potassium, chloride, lactate, and total protein. A study group (n = 11) and a control group (n = 9) were built, depending on the maximal amount of fluid absorption estimated with the aid of ethanol concentration monitoring in the expired gas. The study group developed a mild acidosis with a decrease in pH from 7.41 to 7.37 (P = 0.037), compared with a very discrete pH decrease from 7.44 to 7.42 in the control group. We found that moderate irrigant absorption during TURP leads to a specific metabolic acidosis. We speculate that larger amounts of irrigant absorption may cause a more severe metabolic acidosis. As the constellation of independently pH regulating variables appears to be typical for TURP, this acidosis could be named "TURP-acidosis." IMPLICATIONS: We measured acid base status in 20 patients undergoing transurethral resection of the prostate comparing a larger fluid absorption group with a minor or no fluid absorption group. We postulate the development of a typical metabolic transurethral resection of the prostate-acidosis caused by irrigant absorption.

Randomized trial of radiofrequency lumbar facet denervation for chronic low back pain.

STUDY DESIGN: A prospective double-blind randomized trial in 31 patients. OBJECTIVES: To assess the clinical efficacy of percutaneous radiofrequency denervation of the lumbar zygapophysial joints in reducing pain, functional disability, and physical impairment in patients with back pain originating from the lumbar zygapophysial joints. SUMMARY OF BACKGROUND DATA: Chronic low back pain is a major health problem in the industrialized world. A treatment option is percutaneous radiofrequency denervation of the lumbar zygapophysial joints. Its clinical efficacy has never been formally tested in a controlled trial. METHODS: Thirty-one patients with a history of at least 1 year of chronic low back pain were selected on the basis of a positive response to a diagnostic nerve blockade and subsequently randomly assigned to one of two treatment groups. Each patient in the radiofrequency treatment group (15 patients) received an 80 C radiofrequency lesion of the dorsal ramus of the segmental nerve roots L3, L4, and L5. Patients in the control group (n = 16) underwent an the same procedure but without use of a radiofrequency current. Both the treating physician and the patients were blinded to the group assignment. Before treatment, physical impairment, rating of pain, the degree of disability, and quality of life were assessed by a blinded investigator. RESULTS: Eight weeks after treatment, there were 10 success patients in the radiofrequency group (n = 15) and 6 in the sham group (n = 16). The unadjusted odds ratio was 3.3 (P = 0.05, not significant), and the adjusted odds ratio was 4.8 (P < 0.05, significant). The differences in effect on the visual analog scale scores, global perceived effect, and the Oswestry disability scale were statistically significant. Three, 6, and 12 months after treatment, there were significantly more success patients in the radiofrequency group compared with the sham group. CONCLUSIONS: Radiofrequency lumbar zygapophysial joint denervation results in a significant alleviation of pain and functional disability in a select group of patients with chronic low back pain, both on a short-term and a long-term basis.

A nonspecific, single-stranded nuclease activity with characteristics of a topoisomerase found in a major grass pollen allergen: possible biological significance.

The major allergen from timothy grass pollen, Phlp5b (Phleum pratense), was shown to exhibit ribonuclease activity. It turned out that the C-terminal portion of this molecule was the biologically active domain. Here evidence is presented that the allergen is a single-stranded, sugar-nonspecific nuclease with topoisomerase activity. An isomerase-specific active site was identified, and a non-active mutant was constructed by site directed mutagenesis, and showed no nucleolytic activity. In contrast to the wild type (WT), the mutant did not dimerize. Although the binding capacity of IgE antibodies toward the mutant was reduced as compared to the WT, the allergenic activity was retained. We conclude that the allergen Phlp5b is a single-stranded nuclease with an unusual topoisomerase-like activity. This biological activity is not by itself connected to the allergenicity of the molecule. Whether the enzymatic activity is responsible for the induction of the allergic sensitization and inflammation remains an open question.

Electrical spinal cord stimulation in reflex sympathetic dystrophy: retrospective analysis of 23 patients.

OBJECT: The aim of the study was to assess retrospectively the clinical efficacy and possible adverse effects of electrical spinal cord stimulation (SCS) for the treatment of patients with reflex sympathetic dystrophy (RSD). METHODS: Twenty-three patients who suffered severe pain due to RSD were included in the study. The SCS system was implanted only after a positive 1-week test period. The visual analog scale (VAS) score for pain (1-10) was obtained in all patients prior to treatment, 1 month postimplantation, and at last follow up. At final follow-up examination, patients were asked to rate the effect of their treatment on the 7-point global perceived effect scale. Eighteen (78%) of 23 patients treated between 1991 and 1997 reported improvement during the test period. Permanent implantation of SCS system was not performed in the other five patients. Complications occurred in nine (50%) of 18 patients. The system was removed in three patients after implantation (17%). At the end of follow up (mean 32 months) 15 patients still had an implanted system. The mean pain score had decreased from 7.9 to 5.4 (p<0.001). In the other eight patients the pain score had not changed significantly. In 13 patients (57%) in whom the SCS system was implanted, clinical status had much improved or improved; these cases were regarded as successful. CONCLUSIONS: In this retrospective series, the majority of patients with RSD reported a subjective improvement after implantation of an SCS system.

Crystallization and preliminary diffraction data of a major pollen allergen. Crystal growth separates a low molecular weight form with elevated biological activity.

Group V major allergen Phl p 5b of timothy grass pollen induces allergic rhinitis and bronchial asthma in 90% of grass pollen-allergic patients. In addition to its allergenicity ribonuclease activity has recently been attributed to this 29-kDa protein. The allergen was expressed in Escherichia coli and subsequently purified. Spontaneous conversion of these preparations to a mixture of various forms with molecular sizes between 10 and 29 kDa was consistently observed. Surprisingly, crystals could be grown from this heterogenous preparation. Single crystals, redissolved and analyzed by SDS-polyacrylamide gel electrophoresis and immunoblot, yielded one distinct low molecular weight protein, which was identified by amino acid sequencing as the C-terminal 13-kDa portion of the allergen. Histamine release assays with single crystal solutions using basophils of an allergic patient demonstrated allergenicity comparable with that of the holo-allergen. By contrast, RNase activity of the crystallized C-terminal form was 23 times higher than that of the full-length parent allergen. Crystals were used to collect preliminary diffraction data; the space group was evaluated to I4122 with cell dimensions of a = 87.7 A, b = 87.7 A, and c = 59.6 A. We conclude that preferential crystal growth of the 13-kDa form is indicative of a compact conformation of this particular C-terminal portion of the allergen. Thus, we show here that protein crystallization is not only a prerequisite for structural analyses, but it also can provide a unique separation technique to localize the functional domain of a major allergen.

Systematic screening for pharmacokinetic interactions during drug development.

The possible involvement of a new chemical entity in pharmacokinetic drug interactions is an important safety issue. Not all relevant drug combinations for evaluation of the interactive potential of a new drug can be examined. Therefore, experiments should be selected to provide information which is valid not only for the interaction investigated, but which can be extrapolated to other comedications. In this respect the typical approaches currently used, including interaction studies with high risk drugs and compounds frequently given as comedication, or studies involving standard inhibitors and standard substrates are unsatisfactory. A better approach is to characterize drugs according to their effects on the underlying pharmacokinetic processes. Indeed, recent progress in understanding drug interaction mechanisms and in the development and refinement of in vitro test systems enables in many cases experiments to be designed which predict the occurrence of drug interactions. This paper illustrates systematic investigational procedures based on mechanism of interaction. Interaction mechanisms involving drug absorption, distribution, metabolism, and/or excretion are briefly summarized. Detailed proposals are derived which allow identification of the possible role of a new drug in interaction mechanisms for which valid test systems are available. Emphasis is placed on the rational selection of experiments with optimal cost-effectiveness. In vitro methods are integrated in the schemes wherever possible. In addition, it is proposed that pharmacoepidemiological screening, starting in phase II of drug development, be used to identify those relevant drug interactions missed by the mechanism-based approach. As exemplified by several recently discovered interactions it should be possible, by implementation of the proposed procedure, to avoid most serious unexpected adverse effects due to pharmacokinetic drug interactions.

Activation of 2-aminofluorene by prostaglandin endoperoxide H synthase-2.

Prostaglandin endoperoxide H synthase is the key enzyme in the conversion of arachidonic acid to tissue prostanoids. Two isoforms of prostaglandin endoperoxide H synthase have been identified: PHS-1 is constitutively expressed in most tissues under normal physiological conditions and PHS-2 is expressed in response to inflammatory agents, tumor promotors, and other agents related to mitogenesis. Previous work demonstrated that PHS-1 can activate arylamine carcinogens. We report here that PHS-2 can also activate an arylamine carcinogen to form DNA adducts. This is shown by: (1) use of purified ovine PHS-2 to form DNA adducts; (2) increased DNA adduct formation, PHS-2 mRNA, and PHS-2 protein after treatment of HUVEC cells with the PHS-2 inducer PMA; and (3) transient expression of PHS-2 cDNA in COS-1 cells gave rise to both elevations of PHS-2 enzyme protein and DNA adduct formation. Finally, two PHS inhibitors, aspirin and indomethacin, showed significant inhibition of PHS-2-mediated DNA adduct formation.

Early hematological toxicity of adjuvant perioperative intraportal and intravenous chemotherapy with fluorouracil, mitomycin and heparin in colorectal cancer. Swiss Group for Clinical Cancer Research.

BACKGROUND: From 1987 to 1993 the Swiss Group for Clinical Cancer Research (SAKK) performed a randomized phase III adjuvant trial in patients with colorectal adenocarcinoma with the objective of comparing intraportal versus intravenous perioperative chemotherapy. PATIENTS AND METHODS: Patients younger than 75 years had a curative en bloc resection of their cancer and were then randomized into three arms: 1. adjuvant perioperative portal liver infusion with fluorouracil, mitomycin and heparin, 2. adjuvant subclavian intravenous infusion with the same regimen and 3. no adjuvant treatment. The hematological toxicity was evaluated by hemoglobin determination and leucocyte and thrombocyte counting before and during ten days after surgery. RESULTS: Hemoglobin showed a median decrease of 22% in the control group. This decrease is aggravated significantly by 3% through the chemotherapy. Leucocytes showed a median decrease of 7% in the control group. Perioperative chemotherapy caused a significantly higher median drop; 23% when given into the liver through the portal vein and 34% when given systemically through a subclavian catheter. Thrombocytes revealed a median decrease of 25% in the control group. Chemotherapy was not associated with a significant additional drop. CONCLUSIONS: Adjuvant perioperative chemotherapy with fluorouracil, mitomycin and Heparin as given in this study is associated with a significant mild drop in hemoglobin and leucocytes during the first 10 postoperative days. If drug dose increases are planned in future trials the addition of hematopoietic growth factors might be considered.