Increased incidence of breast cancer in southeast Netherlands between 1960 and 1989]

Trends in incidence, stage distribution and mortality of breast cancer were determined in the Southeastern Netherlands in 1960-1989. First and second primary breast cancers were analyzed separately. The incidence and mortality rates were age-standardised according to the European Standard Population. The incidence rate of first primary invasive breast cancer increased from 50 per 100,000 women per year in 1960-61 to 96 in 1988-89, and of second primary invasive breast cancer from 3.2 in 1965-66 to 7.8 in 1988-89. The incidence rate of first primary ductal carcinoma in situ (DCIS) increased from 0.3 per 100,000 women per year in 1975-76 to 2.8 in 1988-89 and of second primary DCIS from 0.06 in 1975-79 to 0.4 per 100,000 in 1985-89. The increase in first invasive primaries was observed in all age groups, but mostly at age 75 and over. The percentage with stage I tumours of the patients with a first primary invasive breast cancer increased from 7% in the sixties to 27% in the eighties, whereas the percentage of stage III and IV tumours combined, decreased from 39% in the sixties to 26% in the eighties. While age-adjusted incidence of first primaries almost doubled in the past thirty years, breast cancer mortality rose only slightly. However, breast cancer mortality showed a proportionate increase of total mortality from 4.5% in 1970-71 to 6.3% in 1988-89.(ABSTRACT TRUNCATED AT 250 WORDS)     

Incorporation of the major outer membrane protein of Neisseria gonorrhoeae in saponin-lipid complexes (iscoms): chemical analysis, some structural features, and comparison of their immunogenicity with three other antigen delivery systems.

We incorporated the major outer membrane protein (PI) of Neisseria gonorrhoeae into immunostimulating complexes (iscoms) and examined some analytical, physicochemical, and immunological properties of these structures. The immunogenicity was compared with that of three other PI-containing structures, i.e., liposomes, outer membrane complexes produced by the bacterium, and protein-detergent-adjuvant complexes. AIPO4 and dioctadecyldimethylammonium bromide were used as adjuvants. Our results show that iscoms are much more immunogenic than liposomes and protein-detergent complexes but are also much more toxic. The localization of PI in iscoms was investigated. Therefore, the chymotrypsin susceptibility of PI in iscoms was tested, and the incorporation of fragments of PI was determined. Amphiphilic fragments of PI were incorporated in iscoms, but hydrophilic and hydrophobic fragments were not. Chymotrypsin degradation of PI in iscoms indicated that the protein is exposed to the environment in a similar manner as PI in outer membrane complexes, i.e., with both termini anchored in the iscom.     

Targeting liposomes with protein drugs to the blood-brain barrier in vitro.

In this study, we aim to target pegylated liposomes loaded with horseradish peroxidase (HRP) and tagged with transferrin (Tf) to the BBB in vitro. Liposomes were prepared with the post-insertion technique: micelles of polyethylene glycol (PEG) and PEG-Tf were inserted into pre-formed liposomes containing HRP. Tf was measured indirectly by measuring iron via atomic absorption spectroscopy. All liposomes were around 100 nm in diameter, contained 5-13 microg HRP per mumol phospholipid and 63-74 Tf molecules per liposome (lipo Tf) or no Tf (lipo C). Brain capillary endothelial cells (BCEC) were incubated with liposomes at 4 degrees C (to determine binding) or at 37 degrees C (to determine association, i.e. binding+endocytosis) and the HRP activity, rather than the HRP amount was determined in cell lysates. Association of lipo Tf was two- to three-fold higher than association of lipo C. Surprisingly, the binding of lipo Tf at 4 degrees C was four-fold higher than the association of at 37 degrees C. Most likely this high binding and low endocytosis is explained by intracellular degradation of endocytosed HRP. In conclusion, we have shown targeting of liposomes loaded with protein or peptide drugs to the BCEC and more specifically to the lysosomes. This is an advantage for the treatment of lysosomal storage disease. However, drug targeting to other intracellular targets also results in intracellular degradation of the drug. Our experiments suggest that liposomes release some of their content within the BBB, making targeting of liposomes to the TfR on BCEC an attractive approach for brain drug delivery.     

Immunogenicity of meningococcal PorA formulations encapsulated in biodegradable microspheres.

The purpose of our study was to investigate the possibility to microencapsulate liposomes and meningococcal outer membrane vesicles (OMV), both containing neisserial pore protein A (PorA), in biodegradable dextran- and mannan-based microspheres and to study the immunogenicity of the encapsulated PorA formulations. PorA-liposomes and OMV were encapsulated in dextran- or mannan-based microspheres by using an aqueous two-phase system consisting of a polyethylene glycol solution and a methacrylated dextran or mannan solution. The formulations were characterized for size distribution, PorA structure and antigen recovery after release. Calcein-containing model liposomes were used to establish the encapsulation efficiency and release profiles from both types of microspheres. The immunogenicity of the PorA-containing formulations was determined in mice after subcutaneous immunization. Liposomes were encapsulated in dextran and mannan microspheres with a high efficiency (70-90%). Calcein liposomes, after a 5-day lag period, exhibited apparent zero-order release kinetics from both types of microspheres between Days 5 and 10 of incubation in vitro. The total release was 80 and 100% from mannan and dextran microspheres, respectively. The trimeric PorA conformation was preserved in the released liposomes and OMV and the antigen was partly recovered. The immunogenicity of PorA-liposomes and OMV encapsulated in dextran or mannan microspheres was preserved. In conclusion, PorA-liposomes and OMV could be encapsulated in dextran- and mannan-based microspheres with high efficiency. The immunogenicity of encapsulated antigen was preserved.     

Coupling of Metal Containing Homing Devices to Liposomes via a Maleimide Linker: Use of TCEP to Stabilize Thiol-groups without Scavenging Metals

Liposomes for drug delivery are often prepared with maleimide groups on the distal end of PEG to enable coupling of homing devices, such as antibodies, or other proteins. EDTA is used to stabilize the thiol group in the homing device for attachment to the maleimide. However, when using a homing device that contains a metal, EDTA inactivates this by scavenging of the metal. Holo-transferrin (Tf) containing two iron atoms (Fe³⁺), has a much higher affinity for the Tf receptor than apo-Tf (which does not contain any Fe³⁺). To couple Tf to a liposome, the introduction of a thiol group is necessary. During this process, by using N-succinimidyl S-acetylthioacetate (SATA), followed by 2–3 h coupling to the liposomes, Fe³⁺ is scavenged by EDTA. This causes a decreased affinity of Tf for its receptor, resulting in a decreased targeting efficiency of the liposomes.

Tris(2-carboxyethyl)phosphine (TCEP) hydrochloride is a sulfhydryl reductant that is often used in protein biochemistry. We found that TCEP (0.01 mM) does not scavenge Fe³⁺ from Tf and is able to protect thiol groups for the coupling to maleimide. Furthermore, TCEP does not interfere with the maleimide coupling itself.

In this communication, we describe the preparation of liposomes, focussing on the coupling of Tf to the maleimide linker at the distal end of PEG, without loosing Fe³⁺ from Tf. This method can be applied to other metal-containing homing devices as well.     

Different Pharmaceutical Products Need Similar Terminology

In the last decade, discussions on the development of the regulatory framework of generic versions of complex drugs such as biologicals and non-biological complex drugs have attracted broad attention. The terminology used is far from harmonized and can lead to multiple interpretations of legal texts, reflection papers, and guidance documents regarding market introduction as well as reimbursement. This article describes the meaning of relevant terms in different global regions (Europe, USA, WHO) and offers a proposal for a globally accepted terminology regarding (non-) biological complex drugs.     

Supported discharge service versus inpatient care evaluation (SITE): a randomised controlled trial comparing effectiveness of an intensive community care service versus inpatient treatment as usual for adolescents with severe psychiatric disorders: self-harm,functional impairment,and educational and clinical outcomes

Clinical guidelines recommend intensive community care service treatment (ICCS) to reduce adolescent psychiatric inpatient care. We have previously reported that the addition of ICCS led to a substantial decrease in hospital use and improved school re-integration. The aim of this study is to undertake a randomised controlled trial (RCT) comparing an inpatient admission followed by an early discharge supported by ICCS with usual inpatient admission (treatment as usual; TAU). In this paper, we report the impact of ICCS on self-harm and other clinical and educational outcomes. 106 patients aged 12–18 admitted for psychiatric inpatient care were randomised (1:1) to either ICCS or TAU. Six months after randomisation, we compared the two treatment arms on the number and severity of self-harm episodes, the functional impairment, severity of psychiatric symptoms, clinical improvement, reading and mathematical ability, weight, height and the use of psychological therapy and medication. At six-month follow-up, there were no differences between the two groups on most measures. Patients receiving ICCS were significantly less likely to report multiple episodes (five or more) of self-harm (OR = 0.18, 95% CI: 0.05–0.64). Patients admitted to private inpatient units spent on average 118.4 (95% CI: 28.2–208.6) fewer days in hospitals if they were in the ICCS group compared to TAU. The addition of ICCS to TAU may lower the risk of multiple self-harm and may reduce the duration of inpatient stay, especially in those patients admitted for private care. Early discharge with ICCS appears to be a viable alternative to standard inpatient treatment.

     

PEG shielded polymeric double-layered micelles for gene delivery.

A combination of A-B and B-C block copolymers was used to encapsulate DNA inside pEG coated particles, where A is a cationic block (poly(dimethylaminoethyl methacrylate), pDMAEMA) for DNA binding and condensation, B is a hydrophobic block (poly(butylmethacrylate), pBMA) and C is a polyethylene glycol (pEG) block. The AB and BC block copolymers were synthesized by transition metal mediated radical polymerization. The AB block copolymer had a fixed pBMA molecular weight of 3800 g/mol and a varying pDMAEMA molecular weight (from 22 to 65 kg/mol), the BC block copolymer had a fixed composition (pBMA 9000 g/mol; pEG 2000 g/mol). Plasmid DNA containing particles were made via a detergent dialysis method. By this method, particles of approximately 120 nm, as determined by dynamic light scattering (DLS), with a near neutral charge were formed, independent of the DMAEMA block size. DLS measurements and gel electrophoresis indicated that the particles were very stable in cell culture medium at 37 degrees C and resistant to anionic exchange by poly-l-aspartic acid. The particles were able to transfect COS-7 and OVCAR-3 cells with minor toxicity if incubated for 1 or 4 h; incubation for 24 h resulted in an increased toxicity. This paper shows that small polyplexes with near neutral charge can be obtained via a convenient detergent dialysis method using pDMAEMA-b-pBMA and pBMA-b-pEG. These particles may be interesting for in vivo experiments where particles with high positive charges have adverse interactions with blood components.     

How to Regulate Nonbiological Complex Drugs (NBCD) and Their Follow-on Versions: Points to Consider

The aim of this critical review is to reach a global consensus regarding the introduction of follow-on versions of nonbiological complex drugs (NBCD). A nonbiological complex drug is a medicinal product, not being a biological medicine, where the active substance is not a homo-molecular structure, but consists of different (closely related and often nanoparticulate) structures that cannot be isolated and fully quantitated, characterized and/or described by state of the art physicochemical analytical means and where the clinical meaning of the differences is not known. The composition, quality and in vivo performance of NBCD are highly dependent on manufacturing processes of both the active ingredient as well as in most cases the formulation. The challenges posed by the development of follow-on versions of NBCD are illustrated in this paper by discussing the ‘families’ of liposomes, iron–carbohydrate (‘iron–sugar’) drugs and glatiramoids. It is proposed that the same principles for the marketing authorization of copies of NBCD as for biosimilars be used: the need for animal and/or clinical data and the need to show similarity in quality, safety and efficacy. The regulatory approach of NBCD will have to take into consideration the specific characteristics of the drugs, their formulation and manufacturing process and the resulting critical attributes to achieve their desired quality, safety and efficacy. As with the biosimilars, for the NBCD product, family-specific methods should be evaluated and applied where scientifically proven, including sophisticated quality methods, pharmacodynamic markers and animal models. Concerning substitution and interchangeability of NBCD, it is also advisable to take biosimilars as an example, i.e. (1) substitution without the involvement of a healthcare professional should be discouraged to ensure traceability of the treatment of individual patients, (2) keep an individual patient on a specific treatment if the patient is doing well and only switch if unavoidable and (3) monitor the safety and efficacy of the new product if switching occurs.     

Towards more effective advanced drug delivery systems

This position paper discusses progress made and to be made with so-called advanced drug delivery systems, particularly but not exclusively those in the nanometre domain. The paper has resulted from discussions with a number of international experts in the field who shared their views on aspects of the subject, from the nomenclature used for such systems, the sometimes overwrought claims made in the era of nanotechnology, the complex nature of targeting delivery systems to specific destinations in vivo, the need for setting standards for the choice and characterisation of cell lines used in in vitro studies, to attention to the manufacturability, stability and analytical profiling of systems and more relevant studies on toxicology. The historical background to the development of many systems is emphasised. So too is the stochastic nature of many of the steps to successful access to and action in targets. A lacuna in the field is the lack of availability of data on a variety of carrier systems using the same models in vitro and in vivo using standard controls. The paper asserts that greater emphasis must also be paid to the effective levels of active attained in target organs, for without such crucial data it will be difficult for many experimental systems to enter the clinic. This means the use of diagnostic/imaging technologies to monitor targeted drug delivery and stratify patient groups, identifying patients with optimum chances for successful therapy. Last, but not least, the critical importance of the development of science bases for regulatory policies, scientific platforms overseeing the field and new paradigms of financing are discussed.