Cyclin D1 overexpression lacks prognostic significance in superficial urinary bladder cancer

The biological behaviour of urinary bladder neoplasms cannot be adequately predicted by histological criteria alone. Cyclin D1 is a cell-cycle regulating protein known to be overexpressed in a proportion of bladder carcinomas. To evaluate the prognostic significance of cyclin D1 expression and its relationship with tumour phenotype, 392 bladder carcinomas were analysed by immunohistochemistry. Clinical follow-up information was available in 337 patients with superficial bladder tumours (stages pTa/pT1). Cyclin D1 positivity was seen in 176 of 392 carcinomas. Cyclin D1 overexpression was strongly linked to papillary tumour growth, low stage, and low histological grade (p<0.005 each). Multivariate analysis showed that papillary tumour growth was the only parameter which was independently linked to cyclin D1 positivity. There was no significant difference in proliferative activity (Ki67 labelling index) between cyclin D1-negative and -positive tumours. Cyclin D1 positivity was not linked to the risk of recurrence or tumour progression, either in pTa or in pT1 carcinomas. It is concluded that cyclin D1 positivity distinguishes a large subgroup of papillary bladder tumours, but there is no evidence of prognostic significance for increased cyclin D1 expression.

A prospective study of risk-adapted therapy for large cell non-Hodgkin's lymphoma with VACOP-B followed by high-dose CBV and autologous progenitor cell transplantation for high-risk patients in remission

Several centres reported a favourable outcome after high-dose chemotherapy with autologous progenitor cell transplantation in selected patients with high-risk large cell non-Hodgkin's lymphoma in first remission. Based on these observations, we wanted to prospectively determine the outcome of a risk-adapted therapy for patients with large cell lymphoma. Patients aged 60 years or less received 12 weeks of VACOP-B chemotherapy. For high-risk patients in remission this was immediately followed by high-dose chemotherapy with cyclophosphamide, carmustine and etoposide and autologous progenitor cell transplantation. High-risk criteria were defined before the establishment of the International Index and included large cell lymphoma stage III or IV or mediastinal large lymphoma with sclerosis stage II or higher, and the presence of bulky tumours and/or an elevated LDH. 89 patients fulfilled the clinical selection criteria and were entered onto this multicentre study. 82 patients were evaluable after confirmation of large cell histology by pathology review. Of these, 51 were considered to be in the low-risk group and 31 in the high-risk group. The 3-year event-free survival for all patients was 68%. The 3-year event-free survival was 76% for the low-risk and 55% for the high-risk group (P = 0.061). Only 22/31 high-risk patients were able to receive the high-dose chemotherapy in first remission as intended. In conclusion, although our study demonstrated that a risk-adapted therapy for large cell lymphoma could be safely administered, the potential impact on outcome of the strategy chosen here is likely to be small.

Polysomies but not Y chromosome losses have prognostic significance in pTa/pT1 urinary bladder cancer

A disturbed cellular DNA content is of potential diagnostic and prognostic relevance in urinary bladder cancer. To evaluate the prognostic significance of individual chromosomal aberrations in superficial bladder cancer, specimens of 105 tumors (67 pTa, 38 pT1) were examined by fluorescence in situ hybridization (FISH). FISH allows quantitation of chromosomes on a cell by cell level. Centromere probes for the chromosomes Y, 1, and 17 were used. There was a strong association between polysomies of the chromosomes 1 (found in 46% of tumors) and 17 (40% of tumors, P < .0001). Polysomies (1 and 17) were significantly more frequent in pT1 than in pTa tumors (P < .0001 each). In pTa tumors, polysomies of both chromosomes were linked to a high risk of recurrences; polysomy 17 was associated with an increased risk of progression (P < .05 each). There was no significant association between polysomies and an unfavorable prognosis in pT1 carcinomas. Previous studies had suggested a prognostic role of Y losses in bladder cancer. However, Y losses were not linked to recurrences or tumor progression in pTa or pT1 tumors of 67 male patients. These data show that marked genetic differences exist between pTa and pT1 carcinomas. They also indicate that polysomies of different chromosomes may have prognostic relevance in pTa urinary bladder cancer.

Navigation through vector addition

During short foraging excursions away from their home, central place foragers update their position relative to their point of departure by processing signals generated by locomotion. They therefore can home along a self-generated vector without using learned references. In rodents and other mammals, this path integration process (dead reckoning) can occur on the basis of purely internal signals, such as vestibular or proprioceptive (re)afferences. We report here that hamsters are also capable of proceeding to a previously learned feeding site through vector information from locomotion only. The subjects compute the direction and distance to the goal by subtracting their current-position vector from the stored nest-to-goal vector. This computation pertains to locations per se and therefore occurs in absolute space, independently of landmark objects. If available, prominent visual cues merely serve to confirm the path planned through the addition of self-generated vectors, whereas visual as well as nonvisual references confirm that the subject has arrived at the goal site.

Selection and immunomagnetic purging of peripheral blood CD34+ cells for autologous transplantation in B-cell non-Hodgkin's lymphomas

BACKGROUND

Clonogenic tumor cells in the hematopoietic progenitor cell harvest may contribute to relapse after high dose therapy for B-cell malignancies. Purging of the HPC harvest requires large amounts of anti-B-cell antibodies, whereas CD34-selection enriches self renewing HPC's but malignant cells are still detectable in many CD34+ fractions.

PATIENTS AND METHODS

We examined the feasibility and safety of a CD34-selection followed by purging with anti B-cell antibodies in 11 patients with B-cell non-Hodgkin's lymphomas undergoing high-dose therapy with cyclophosphamide, BCNU and etoposide with retransfusion of autologous HPC's.

RESULTS

A mean number of 340 x 10(8) mononuclear cells was used for CD34-selection and immunomagnetic purging. CD34+ cells were enriched from a mean of 1.7% (range 0.2%-4.5%) to a mean of 68% (range 49%-87%) with a mean recovery of 27% (range 15%-43%). The mean number of retransfused CD34+ cells was 1.2 x 10(6)/kg (range 0.6-2.2 x 10(6)/kg) body weight with a median of 11 days (range 10-13 days) to neutrophil recovery of 0.5 x 10(9)/l and 17 days (range 13-25 days) to platelet recovery of 50 x 10(9)/l. Mean number of intravenous antibodies and inpatient days were 8 (range 0-14) and 22 (range 19-26) respectively. Major toxicity consisted in four septicemias.

CONCLUSIONS

CD34-selected and purged HPC's are safe and mediate rapid hematological recovery after high dose therapy for B-cell non-Hodgkin's lymphomas.

Double-wavelength superheterodyne interferometer for absolute ranging with submillimeter resolution: results obtained with a demonstration model by use of rough and reflective targets

The potential of double-wavelength interferometry is well known, especially regarding the capability of performing absolute distance measurements of rough targets with high resolutions. We describe the experimental results obtained with a demonstration model of a double-wavelength interferometer with superheterodyne detection. Our system, implemented with two four-quadrant detectors to improve the detection probability, has demonstrated the ability to reach resolutions of 0.2 mm at 5-m distances on rough targets in 50-ms integration time.

Pharmacodynamic and safety results of PEG-Hirudin in healthy volunteers

PEG-Hirudin, a chemically defined conjugate of recombinant hirudin and two molecules of polyethylene glycol (PEG)-5000 is a highly selective direct thrombin inhibitor with a significantly longer duration of action than non-conjugated recombinant hirudin permitting once daily subcutaneous administration. A series of placebo-controlled, randomized, Phase I clinical trials were conducted in 75 healthy volunteers to investigate the anticoagulant effects, safety and pharmacodynamics of PEG-Hirudin when administered intravenously as a bolus injection, infusion, and subcutaneously. After single i.v. injections of various doses of PEG-Hirudin (0.03-0.3 mg/kg) dose-dependent increases in anti-IIa activity and APTT were observed. Four hours after injection of 0.3 mg/kg, mean plasma concentration expressed in terms of anti-IIa activity was still 0.89 micrograms/ml, corresponding to a 1.8-fold prolongation of APTT. Continuous intravenous infusions of 0.01 and 0.02 mg/kg/h PEG-Hirudin resulted in maximum anti-IIa activities of 0.42 micrograms/ml and 0.77 micrograms/ml, respectively, at the end of a six-hour infusion period without having reached steady state at this time. After termination of the infusion, anticoagulant activity displayed an immediate exponential decrease. The anticoagulant activities of single subcutaneous doses of 0.05 to 0.6 mg/kg were studied in a further series of investigations and slow increases and prolonged durations of anti-IIa activity and APTT prolongation were found. Repeated, once daily subcutaneous administrations of 0.2 to 0.4 mg/kg for five days resulted in dose-dependent prolongations of APTT and increases in anti-IIa activity without completely reaching steady state conditions. In a further study, 0.3 mg/kg of PEG-Hirudin was given as an i.v. bolus injection followed by three repeated single daily s.c. injections. In this trial, the APTT was shorter than expected from previous studies; therefore, a direct comparison of various APTT reagents was made in the intravenous infusion trial. Of the APTT reagents tested, BioMérieux Silimat and IL-ellagic acid proved to be the most sensitive to PEG-Hirudin. The hirudin derivative PEG-Hirudin was tolerated very well without immuno-allergic side effects. In view of the significantly prolonged anticoagulant efficacy in comparison to non-conjugated r-hirudin, PEG-Hirudin is a promising compound especially for repeated once daily subcutaneous administration.

Cloning and characterization of dnaE, encoding the catalytic subunit of replicative DNA polymerase III, from Vibrio cholerae strain C6706

We report that Vibrio cholerae (Vc) contains a gene homologous to Escherichia coli dnaE, the structural gene for the alpha (catalytic) subunit of replicative DNA polymerase III (PolIII). Despite 24% amino acid (aa) differences in the encoded proteins, the Vc gene strongly complements an E. coli dnaE temperature sensitive (ts) mutant, indicating that all functional features essential for replication are conserved.

Defect in general priming conferred by linker region mutants of Escherichia coli dnaB

The dnaB gene of Escherichia coli encodes a bifunctional primase accessory protein/helicase necessary for chromosomal replication. Monomers of DnaB comprise two trypsin-resistant domains connected by a 45-amino-acid linker. To investigate the role of the linker in the structure and function of DnaB, we have purified and characterized three DnaB mutant proteins having single amino acid substitutions in the linker. We find that the mutant proteins retain the two-domain structure and assemble into hexamers that may be less stable than hexamers formed by wild-type DnaB. These mutant hexamers have hydrodynamic properties slightly different from those of the wild type, suggestive of a more open structure. The mutant proteins had reduced or absent ability to stimulate primase and also exhibited slight alterations in ATPase activity compared with the wild type. We conclude that the linker region promotes primase-DnaB interaction, but this effect may be indirect. We propose a model involving repositioning of N-terminal domains to explain the properties of the mutant proteins.

The storm before the qualm

More than half of all changes in organizations fail. But there is hope, suggests Rick Maurer, author of ¿Beyond the Wall of Resistance.¿ He says that it isn't resistance itself--since resistance is nothing more than people's need to protect themselves from harm--but how you handle it that creates the problem. Here in this exclusive excerpt, he argues that you shouldn't try to overcome resistance, but embrace it.

Excretion and metabolism of remikiren, a potent orally active inhibitor of primate renin

1. Following intravenous administration of 14C-remikiren to the male rat, 78% of the administered radioactivity was recovered in faeces, indicating high biliary elimination. Of the 25 +/- 0.1% of the dose recovered in urine, the majority (16.5% of dose) was intact drug. 2. After oral administration to the male rat the urinary recovery was markedly reduced (8.5 +/- 2.0% of dose), and virtually all of the material was excreted as an inactive hydrolysis product. Intact drug was non-detectable, suggesting extensive first-pass metabolism. 3. Perfusion of isolated rat liver confirmed high biliary elimination, coupled with extensive metabolism. Although intact remikiren was the major component in bile (20% of the 'dose'), the majority of the radioactivity was recovered as a series of mono- and di-hydroxylated metabolites. 4. When screened against human renin, only one of the metabolites in bile and urine (mono-hydroxylated in the t-butyl side chain, and synthesized as Ro 44-0444) showed comparable activity to remikiren. The remaining ten metabolites tested were at least one order of magnitude less active than the parent drug. 5. In comparative in vitro studies Ro 44-0444 was formed by rat, but not human or cynomolgus monkey, liver microsomes. The primate microsomes also produced more of the remaining mono- and di-hydroxy products, suggesting that metabolites make little contribution to the oral activity of remikiren which is observed in these species in vivo.

Path integration in mammals and its interaction with visual landmarks

During locomotion, mammals update their position with respect to a fixed point of reference, such as their point of departure, by processing inertial cues, proprioceptive feedback and stored motor commands generated during locomotion. This so-called path integration system (dead reckoning) allows the animal to return to its home, or to a familiar feeding place, even when external cues are absent or novel. However, without the use of external cues, the path integration process leads to rapid accumulation of errors involving both the direction and distance of the goal. Therefore, even nocturnal species such as hamsters and mice rely more on previously learned visual references than on the path integration system when the two types of information are in conflict. Recent studies investigate the extent to which path integration and familiar visual cues cooperate to optimize the navigational performance.

Short-term weekly chemotherapy followed by high-dose therapy with autologous bone marrow transplantation for lymphoblastic and Burkitt's lymphomas in adult patients

BACKGROUND

Type and duration of treatment for highly aggressive non-Hodgkin's lymphoma has been a matter of debate over the past decade. To determine the therapeutic efficacy of an abbreviated treatment regimen, 26 patients with newly-diagnosed highly aggressive lymphomas, 17 of them belonging to the International Working Formulation (IWF) group I and 9 with Burkitt's lymphoma (IWF J), were entered in a study using short-term weekly chemotherapy followed by high-dose therapy and autologous bone marrow transplantation.

PATIENTS AND METHODS

Besides histology, requirements for entry into to the study were age between 16 and 60 years, stage 1 bulky disease and elevated LDH or stage II to IV disease with or without bulk or elevated LDH, and an absence of HIV infection or CNS involvement at diagnosis. The treatment plan was 12 weeks of MACOP-B or VACOP-B chemotherapy followed by high dose therapy and autologous bone marrow transplantation in first complete remission.

RESULTS

Twenty patients (76%), 16 (62%) of those on MACOP-B or VACOP-B, 1 who had received 2 cycles of ProMACE-CytaBOM prior to MACOP-B and 3 after a first salvage regimen, achieved complete remissions. Seventeen patients (65%) were transplanted in first remission, and 15 (58%) after induction treatment with only MACOP-B or VACOP-B. Reasons for not being given high dose therapy and autologous bone marrow transplantation (ABMT) were failure to achieve complete remission in 6 patients, early relapse in 2 and severe pulmonary toxicity associated with chemotherapy in 1. The median time of follow-up was 45 months. At 3 years, the estimated event-free survival was 31% (CI 14%-50%) and the overall survival 48% (CI 25%-67%). There were no deaths from toxic effects of treatment. Pretreatment factors associated with relapse were stage III or IV disease, age over 30 years and bone marrow involvement. Logrank analysis showed that age was the only factor significantly associated with poor event-free survival.

CONCLUSION

Short-term weekly chemotherapy followed by high-dose therapy with the CBV regimen in first remission is not a higly effective treatment for advanced lymphoblastic and Burkitt's lymphomas. The 30% rate of failure to achieve partial remission after 6 weeks and/or complete response after 12 weeks of MACOP-B or VACOP-B treatment, as well as the 42% failure rate to undergo ABMT in first remission, suggest that more aggressive chemotherapy should be used in the beginning.

Optimizing distal landmarks: horizontal versus vertical structures and relation to background

During hoarding excursions, golden hamsters use distal landmarks and dead reckoning (updated signals derived from locomotion) to find their way back from a food source at the centre of a circular arena to their nest at the periphery. The preference for particular landmarks was assessed by setting landmark panoramas in conflict with dead reckoning. The hamsters tended to prefer horizontal landmarks to vertical ones when these landmarks were presented alone. However, in combination with a continuous background pattern including a single apex, vertical landmarks were more effective than horizontal ones. A panorama consisting of a vertical cylinder or bar and the background pattern was optimal provided the vertical landmark was aligned or superimposed on the apex of the background. The impact of a landmark panorama therefore depends on its particular components as well as on their mutual relationship.

Urease-specific monoclonal antibodies prevent Helicobacter felis infection in mice

Experiments were performed to determine the antigenic specificity of a monoclonal antibody (immunoglobulin A [IgA] 71) previously demonstrated to neutralize the ability of Helicobacter felis to colonize mice. Immunoprecipitation of radiolabeled H. felis outer membrane proteins with IgA 71 revealed specificity for a 62-kDa protein. Another of our monoclonal antibodies, IgG 40, precipitated a protein of similar molecular weight. IgA 71 but not IgG 40 also precipitated purified recombinant H. pylori urease. The antigenic specificity of both antibodies was confirmed to be urease by the ability of each to select Escherichia coli clones expressing the H. felis urease genes. The two antibodies were shown to bind nonoverlapping epitopes in a competition enzyme-linked immunosorbent assay. Both IgA 71 and IgG 40 could effectively neutralize H. felis infectivity by incubating the bacteria with the antibodies prior to oral administration to naive mice. The mechanism of protection does not appear to be inhibition of urease activity, as IgA 71 does not inhibit the conversion of urea to ammonia by H. pylori urease in vitro. These results support a protective role for the secretory humoral immune response in Helicobacter immunity and provide further evidence that the urease enzyme can serve as a protective antigen.

Golden hamsters on the eight-arm maze in light and darkness: the role of dead reckoning

This paper examines whether golden hamsters can rely on dead reckoning (getting positional information from updated signals generated during locomotion) on an eight-arm maze. Two groups of hamsters were tested: Group L under ordinary room light, Group D in darkness. To enhance the role of dead reckoning, each subject could climb from its own home cage onto the central platform of the maze. In a first experimental phase (15 trials), the L subjects learned to master the maze through developing a locomotor rule (arm chaining) after three to four trials. The D subjects developed arm chaining less readily and fluctuated more in their performance than did the L subjects. In a second experimental phase (15 trials), four arms were blocked at the beginning of each trial. In both experimental groups the performance decreased, yet remained well above chance level. Success and arm chaining were positively correlated in Phase 1 and negatively correlated with success in Phase 2. We assume that in Phase 2 the L subjects switched to the predominant use of visual cues, and the D subjects to dead reckoning.

[Primary malignant melanoma of the male urethra. Case report and discussion of the literature]

We report the case of a 77-year-old man who presented with a polypoid tumor in the distal urethra. It was excised, and a histological diagnosis of malignant melanoma was made. The patient had no history of previous cutaneous biopsies or suspicious pigmented lesions; therefore, the melanoma was considered to be primary in the urethra. The patient declined therapy and died 28 months later with local tumor progression. The autopsy revealed a widespread metastatic disease. The male urethra is rarely the primary site of a malignant melanoma. This event has so far been described in about 45 patients. The case is discussed in view of the pertinent literature.

[Low-grade MALT-type non-Hodgkin lymphoma of the stomach with local recurrence 14 years following resection. Demonstration of clonal identity using polymerase-chain-reaction (PCR)]

So-called low grade B-cell lymphomas of MALT type occurring mainly in the gastrointestinal tract but also in the salivary glands, the thyroid and the lungs are indolent neoplasms with a prolonged clinical course and persistent localized disease at the site of origin. This behaviour sets them apart from their nodal counterparts, which are frequently generalized from onset. Their recognition within and their separation from accompanying reactive processes (e.g. chronic gastritis) is important but may be difficult on morphology alone. In the immediate past there have been reports on regression of gastric MALT type lymphomas after eradication of Helicobacter pylori. We observed a 68-year-old male patient who underwent partial gastric resection for persistent ulcer disease in 1979. A histological diagnosis of pseudolymphoma was established at that time. In 1993 he again had gastrointestinal bleeding. Endoscopy revealed ulcerations at the anastomosis. Biopsies showed a monoclonal infiltrate of centrocytoid B-cells with typical lymphoepithelial lesions, suggesting the diagnosis of low grade B-cell lymphoma of MALT type which was seen focally in multiple biopsies randomly taken from the gastric remnant. Review of the 1979 specimen revealed identical lesions. Polymerase chain reaction (PCR) on both specimens demonstrated identical products of rearranged Ig-heavy chain genes, thus confirming the monoclonality and establishing the clonal relationship of both lesions. Staging revealed no extragastric disease. Two courses of chemotherapy did not affect the mucosal infiltrates. Although the patient had been under antacid medication and the presence of Helicobacter pylori could not be demonstrated, antimicrobial treatment was given, after which follow-up biopsies were free of tumor and bacteria after 4 months.(ABSTRACT TRUNCATED AT 250 WORDS)

The value of inferior petrosal sinus sampling in diagnosis and treatment of Cushing's disease

OBJECTIVE

While microsurgical selective adenomectomy is the best method available at present for the treatment of Cushing's disease, its success depends to a large degree on precise preoperative intrapituitary microadenoma localization. This study compares the results of intrapituitary adenoma localization obtained with inferior petrosal sampling, computerized tomography and magnetic resonance imaging with the adenoma localization as found at surgery.

DESIGN

The results of inferior petrosal sampling for intrapituitary localization of ACTH-producing pituitary adenomas were compared in a retrospective study with the results of computerized tomography, magnetic resonance imaging, surgical and pathological findings. Special attention was paid to the intersinus ACTH relation.

PATIENTS

Thirty-eight patients (33 women and 5 men) of 11-68 years of age suffering from pituitary-dependent Cushing's disease were studied. Patients with ectopic ACTH-secreting tumours and recurrent pituitary adenomas were excluded.

MEASUREMENTS

Blood samples were obtained simultaneously from both inferior petrosal sinuses and a peripheral vein before and 5, 10, 15 and 20 minutes after stimulation with 60 micrograms/m2 human corticotrophin-releasing hormone (hCRH).

RESULTS

Of the adenomas in our series, 42% had a diameter of 3 mm or less. Only 6 of 20 adenomas examined by computerized tomography and 11 of 29 examined by magnetic resonance imaging were identified correctly. Inferior petrosal sinus sampling produced significantly better results, particularly when combined with a stimulation test with hCRH: for 29 of 38 adenomas examined, the location was predicted correctly with these techniques. Analysis of the intersinus adrenocorticotrophin concentration ratio showed that the best right-central-left discrimination was obtained with values of 1.3 and 1.4.

CONCLUSIONS

We conclude that inferior petrosal sinus ACTH sampling after hCRH stimulation is the best method available for the intrapituitary localization of microadenomas causing Cushing's disease provided that the appropriate technique of blood sampling is used meticulously.

holE, the gene coding for the theta subunit of DNA polymerase III of Escherichia coli: characterization of a holE mutant and comparison with a dnaQ (epsilon-subunit) mutant

DNA polymerase III holoenzyme is a multiprotein complex responsible for the bulk of chromosomal replication in Escherichia coli and Salmonella typhimurium. The catalytic core of the holoenzyme is an alpha epsilon theta heterotrimer that incorporates both a polymerase subunit (alpha; dnaE) and a proofreading subunit (epsilon; dnaQ). The role of theta is unknown. Here, we describe a null mutation of holE, the gene for theta. A strain carrying this mutation was fully viable and displayed no mutant phenotype. In contrast, a dnaQ null mutant exhibited poor growth, chronic SOS induction, and an elevated spontaneous mutation rate, like dnaQ null mutants of S. typhimurium described previously. The poor growth was suppressible by a mutation affecting alpha which was identical to a suppressor mutation identified in S. typhimurium. A double mutant null for both holE and dnaQ was indistinguishable from the dnaQ single mutant. These results show that the theta subunit is dispensable in both dnaQ+ and mutant dnaQ backgrounds, and that the phenotype of epsilon mutants cannot be explained on the basis of interference with theta function.

Simple phagemid-based system for generating allele replacements in Escherichia coli

We describe a phagemid-based system for rapidly generating chromosomal allele replacements in two steps. The system utilizes simple vector-determined selection procedures for each step and requires only that the target strain be male and sup+ (nonsuppressing for amber mutations).