The totality of evidence approach in the development of AVT02 (adalimumab), a biosimilar to Humira

The development of a biosimilar is based on comparative structural, physicochemical, functional and clinical assessments. The sum of these analyses encompasses the 'totality of evidence', which demonstrates no clinically meaningful differences between the biosimilar and the reference product (RP). Once biosimilarity has been established, provided there is suitable scientific justification, clinical data may be extrapolated to other indications of the RP. AVT02 has been developed as a biosimilar to high-concentration, low-volume Humira (adalimumab), an anti-tumour necrosis factor-alpha monoclonal antibody approved for various chronic inflammatory indications. The totality of evidence for AVT02 is described, supporting its approval as an adalimumab biosimilar for all approved indications globally. Analytical similarity assessments using mass spectrometry methods demonstrated identical amino acid sequences for AVT02 and the RP, with high similarity in terms of primary structure, post-translational modifications and higher-order structural attributes. The mechanism of action was assessed by various cell-based potency assays and binding assays, and the results demonstrated that AVT02 is highly similar to the RP. No clinically meaningful differences in terms of purity, potency and safety were observed, and minor differences in a few physiochemical attributes did not impact the in vitro biologic activity and were not considered clinically relevant. Clinical similarity was demonstrated by comparing the pharmacokinetic, efficacy, safety and immunogenicity profiles of AVT02 with those of the RP. Clinical studies supported similar pharmacokinetic and comparable immunogenicity profiles between AVT02 and the RP in healthy participants and participants with moderate-to-severe chronic plaque psoriasis, with no new safety signals detected. The totality of evidence described demonstrates the biosimilarity of AVT02 to the RP, thereby fulfilling the scientific and regulatory requirements for AVT02 as a high-concentration biosimilar for the treatment of chronic plaque psoriasis and all approved indications of the RP.

Support practices by an interdisciplinary team in a palliative-care unit for relatives of patients in agonal phase

Background

In the absence of extant recommendations, the aim of this study was to formalise support practices used by an interdisciplinary team in a palliative-care unit (PCU) for the relatives of patients in the agonal phase preceding death. The secondary objective was to understand the expectations of relatives during this phase in terms of the support provided by professionals and volunteers.

Methods

Thirty-two people took part in this study; all were interviewed through focus groups (FGs). Each FG comprised one category of individuals working in the PCU: nurses, care- assistants, doctors, psychologists, other professionals, palliative-care volunteers, and relatives. Groups were surveyed using an interview guide, and the interviews were recorded and transcribed to enable identification and characterization of all practices. Care practices were classified into four categories: current consensual practices (i.e. performed by all team members), occasional consensual practices, non-consensual practices (performed by one or a few participants), and practices to be developed.

Results

In total, 215 practices were mentioned by professionals and palliative-care volunteers: 150 current consensual practices, 48 occasional consensual practices, 1 non-consensual practice, 16 practices yet to be developed, and 29 practices for relatives. Many practices were mentioned by different categories of participants; thus, after cross-checking, the number of practices decreased from 215 to 52. A list of practices deemed desirable by all was drawn up and then validated by the entire interprofessional team. These practices were organised around four themes: providing care and ensuring comfort; communicating, informing, and explaining; interacting; and mobilising interdisciplinary skills.

Conclusions

These results underline the importance of the quality of care provided to patients, the attention given to the relatives themselves, and they highlight the importance of the helping relationship. Following this study, which established a list of varied practices aimed at supporting the relatives of patients in agonal phase, it will be important to set up a broader study seeking to establish a consensus on these practices with an interprofessional group of experts from other PCUs using broad surveys and an adapted methodology. Such studies will make it possible to develop training modules for teams working with relatives.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12904-020-00680-4.

[Research ethics: French regulations and applications in radiation oncology]

French regulations about research ethics are based on the so-called Jardé law, which defines researches involving human beings. Researches involving human beings require the submission of research protocols to a committee for protection of persons with a precise list of documents to submit for a favourable opinion. This law describes different categories of researches and determines the ethical procedures to apply before setting up a research protocol. This issue of categorisation is central and must be taken into account by researchers from the beginning of the research process. Researches considered as not involving human beings also require a set of ethical precautions focused on patients' information and the collection of their non-opposition (due to the application of the General Data Protection Regulation adopted by the European Parliament). Thus, many regulations exist and they require a real work for researchers to meet these requirements in research ethics. This article aims to summarise French regulations. Selected examples are specifically taken into the field of radiation oncology research.

[Consensus approach: Prior to the construction of an evaluation scale of risk constipation patients hospitalized for nursing practice]

BACKGROUND

Constipation is a frequent issue during hospitalization. Multiple causes such as the existence of irregular habits, lack of exercise as well as medical history have been identified. Drugs such as strong painkillers, central nervous system therapies and treatments of the digestive tract are a major cause of constipation. Additionally, unbalanced diet, fluid deficiency, and anxiety may aggravate constipation. The consideration of all these risk factors being under the responsibility of nurses. The difficulty to take into account such a multifactorial aetiology in nursing practice and the fact that there is no easy to use and validated tool to assess the risk of constipation in current nurse practice has led us to consider the development of a Risk Assessment scale of Constipation in Patient Hospitalized (ERCoPH) to facilitate preventive management of this trouble. We present here the first step of the elaboration of this scale, the identification of risk factors through a consensus approach after a systematic literature review.

METHODS

The key informants consensus-based approach proposed by Pineault and Daveluy is based on five steps: (1) a literature review to identify risk factors for constipation; (2) the elaboration of a questionnaire containing the factors identified in the first step; (3) pre-select a panel of experts; (4) submission the questionnaire to the panel; (5) analysis the results of the consensus survey. Only factors that received a rating>6 by at least 80 % of the experts were retained.

RESULTS

The systematic literature review identified 69 risk factors submitted to the 23 experts of the panel. Fifteen risk factors were retained after analyzing the answers of the experts. The Scientific Committee added eight risk factors because of their importance in the literature and decided to group together some factors of the same domain.

CONCLUSION

A total of 19 risk factors were selected and grouped by major class (age, physical activity, medication, social data, food/hydration, medical and surgical history and environmental data). These factors have been tested among 300 patients enrolled in different clinical settings as part of the construction and validation of ERCoPH.

Kaliberreduktion der V. saphena magna und der V. femoralis communis nach CHIVA

Hintergrund: Das Ziel von CHIVA (Cure Con-servatrice et Hémodynamique de l‘Insuffisance Veineuse en Ambulatoire) ist der Erhalt der Stammvene als Drainageweg für das Blut der Seitenäste. Ziel der Arbeit ist es, zu prüfen, ob CHIVA möglicherweise eine Überlastung der tiefen Beinvene nach sich ziehen könnte.

Material und Methode: 557 Beine von 458 Pa-tienten wurden präoperativ mit Ultraschall untersucht. Dabei wurden die Durchmesser der V. femoralis (VFC) distal zum sapheno-femoralen Übergang und der V. saphena magna (VSM) 10–15 cm distal der Krosse gemessen. 383 Patienten mit 470 behandelten Beinen kamen zur Nachuntersuchung (84 % der be-handelten Patienten). Die beiden Durchmesser wurden erneut erhoben und mit dem präoperativen Durchmesser verglichen.

Ergebnisse: Die Durchmesser der VSM und der VFC sind signifikant unterschiedlich zwischen Männern und Frauen. In der VSM fand sich eine Kaliberreduktion von 6,1 mm präoperativ auf 4,5 mm postoperativ bei den Frauen und von 6,8 mm präoperativ auf 5,1 mm bei den Männern. Der Durchmesser in der VFC verringerte sich von 14,0 mm präoperativ auf 13,7 mm postoperativ bei den Frauen, sowie von 16,5 mm präoperativ auf 16,1 mm post-operativ bei den Männern. Diese Kaliberreduktionen sind statistisch signifikant.

Zusammenfassung: Es konnte eine signifikante Kaliberreduktion in der VFC nach CHIVA nachgewiesen werden, sodass gefolgert werden kann, dass zwei Monate nach der Operation das tiefe Venensystem nicht überlastet, son-dern es im Gegenteil entlastet wird.

Presentation of the vascular supply of the proximal ulna using a sequential plastination technique

PURPOSE

The purpose of this study was to demonstrate the peri- and intraosseous vascular supply of the proximal ulna.

METHODS

Eleven fresh human cadaveric elbows were sequentially plastinated beginning with arterial injection, followed by block and secondary slice plastination of the whole elbow. With this technique, we obtained completely transparent cadaveric slices in which the peri- and intraosseous vascular architecture could be studied.

RESULTS

Proximal ulna vascularization is due to an arterial network: a superior and inferior collateral ulnar artery and the profunda brachial artery climbing to the olecranon from proximal. An anterior artery and a posterior recurrent artery climb up distally to the medial parts of the ulna and an interosseous recurrent artery is responsible for the lateral and posterolateral proximal part of the ulna. The intraosseous vascularization is due to directly penetrating branches out of the posterior recurrent ulnar artery and a vascular plexus at the olecranon tip. In addition, we saw a major distal bone penetration branch coming from the recurrent posterior artery, climbing intraosseously without junction to the proximal penetrating branches.

CONCLUSION

The peri- and intraosseous vascularization of the proximal ulna was shown. A transitional zone of the intraosseous vascularization of the proximal ulna was detected.

On the dose calculation at the cellular level and its implications for the RBE of (99m)Tc and ¹²³I

PURPOSE

Based on the authors' previous findings concerning the radiotoxicity of(99m)Tc, the authors compared the cellular survival under the influence of this nuclide with that following exposure to the Auger electron emitter (123)I. To evaluate the relative biological effectiveness (RBE) of both radionuclides, knowledge of the absorbed dose is essential. Thus, the authors present the dose calculations and discuss the results based on different models of the radionuclide distribution. Both different target volumes and the influence of the uptake kinetics were considered.

METHODS

Rat thyroid PC Cl3 cells in culture were incubated with either(99m)Tc or (123)I or were irradiated using 200 kV x-rays in the presence or absence of perchlorate. The clonogenic cell survival was measured via colony formation. In addition, the intracellular radionuclide uptake was quantified. Single-cell dose calculations were based on Monte Carlo simulations performed using Geant4.

RESULTS

Compared with external radiation using x-rays (D37 = 2.6 Gy), the radionuclides (99m)Tc (D37 = 3.5 Gy), and (123)I (D37 = 3.8 Gy) were less toxic in the presence of perchlorate. In the absence of perchlorate, the amount of activity a37 that was necessary to reduce the surviving fraction (SF) to 0.37 was 22.8 times lower for (99m)Tc and 12.4 times lower for (123)I because of the dose increase caused by intracellular radionuclide accumulation. When the cell nucleus was considered as the target for the dose calculation, the authors found a RBE of 2.18 for (99m)Tc and RBE = 3.43 for (123)I. Meanwhile, regarding the dose to the entire cell, RBE = 0.75 for (99m)Tc and RBE = 1.87 for (123)I. The dose to the entire cell was chosen as the dose criterion because of the intracellular radionuclide accumulation, which was found to occur solely in the cytoplasm. The calculated number of intracellular decays per cell was (975 ± 109) decays/MBq for (99m)Tc and (221 ± 82) decays/MBq for (123)I.

CONCLUSIONS

The authors' data indicate that extra-nuclear targets to Auger electrons exist, which is obvious from our dose calculations. When considering the dose to the cell nucleus, the authors found an enhanced RBE for(99m)Tc and (123)I relative to acute x-ray irradiation and pure extracellular irradiation with both radionuclides. Surprisingly, the authors did not find any radionuclide accumulation in the cell nucleus, indicating that there are additional radiosensitive targets besides the DNA. In addition, the authors demonstrated the necessity of cellular dose calculations in radiobiological experiments using unsealed radionuclides and identified the relevant parameters.

Management program decreases postoperative nausea and vomiting in high-risk and in general surgical patients: a quality improvement cycle

BACKGROUND

Preventing postoperative nausea and vomiting (PONV) is a major priority for postsurgical patient care. Our objective was to assess the efficacy of a multimodal postoperative nausea and vomiting (PONV) approach, which was associated with a continuous quality improvement program, in maintaining a low PONV incidence in the PACU.

METHODS

Consecutive adult patients scheduled for surgery (ambulatory surgery or not) were prospectively included. PONV data were recorded in the PACU and over a 24-hour period. The management program was based on a multimodal approach with both changes in anesthetic techniques and anti-emetics, and on a three-stage protocol including: 1) phase I: institutional practice phase based on prospective observational study; 2) protocol implementation; 3) phase II: prospective observational study associated with feedback, scientific session and evaluation to guideline adherence. We used the Apfel risk scoring system to identify patients at high risk of PONV. Feedback with audit results and didactic sessions were scheduled quarterly in the Phase II.

RESULTS

Thirty-seven/395 (9.4%) and 151/3864 (3.9%) patients experienced PONV in the PACU during Phase I and Phase II respectively (P<0.001). Among the patients with an Apfel risk score that included at least two risk factors, 16.6% and 4.2% experienced PONV in the PACU during Phase I and Phase II respectively (P<0.001).

CONCLUSION

We highlight the association with a sharp decrease in PONV incidence over a one-year period and a multimodal PONV approach using feedback to clinicians associated with continuous quality improvement program.

Operative treatment and outcome of unstable distal radial fractures using a palmar T-miniplate at a non-specialized institution

Treatment options for displaced distal radial fractures are still a controversial topic of discussion. Although good results for the palmar plating of high-volume centers have been published, evidence of its successful use in smaller institutions is still lacking. We report the clinical and radiological results of the treatment for 84 distal radial fractures with a single 2.4-mm T-miniplate in an institution performing <30 procedures per year. According to the AO classification system, there were 30 A, 5 B, and 49 C fractures with a patients mean age of 64 years. After a minimum of 12-month follow-up, we found very good and good results according to the Gardland and Sarmiento scores and a DASH of 5.6. Only five patients were classified as having a moderate outcome. A remaining intra-articular step-off of more than 1 mm was seen in 15 patients. In a comparison of grip strength between the injured and uninjured hands, we saw a difference of 6.8 % less on the injured side. We saw two instances of tendon rupture and one of tendon irritation due to prominent dorsal screws and necessitating revision surgery. Flexor tendon irritation was noted in one patient, requiring a second operation. Modern treatment for distal radial fractures can be performed successfully and with good clinical outcome in smaller institutions. Based on the high and increasing incidence of distal radial fractures, there is no need to transfer these patients into high-volume centers. Level of evidence Case study, Level IV.

An anti-TNFR1 scFv-HSA fusion protein as selective antagonist of TNF action

IZI-06.1 is a humanized anti-TNFR1 single-chain fragment variable (scFv) that selectively inhibits binding of tumor necrosis factor (TNF) and lymphotoxin alpha to tumor necrosis factor receptor 1 (TNFR1) but not TNFR2. Recently, IZI-06.1 was converted into a fully human IgG1 antibody (ATROSAB) for the treatment of inflammatory diseases. Here, we compare the bivalent ATROSAB with a monovalent scFv-human serum albumin (HSA) fusion protein lacking any antibody-associated effector functions and possessing approximately only half the molecular mass of an IgG, which should facilitate accumulation in inflamed tissues. Furthermore, the half-life of the scFv should be strongly extended while maintaining monovalent binding, avoiding a possible signal transduction by receptor cross-linking in the absence of TNF. The scFv-HSA fusion protein was produced by stably transfected Chinese hamster ovary cells and purified by affinity chromatography. The fusion protein bound specifically to TNFR1 in enzyme-linked immunosorbent assay and TNFR1-transfected mouse embryonic fibroblasts. Affinity determined by quartz crystal microbalance was reduced compared with ATROSAB, which resulted also in a reduced inhibitory activity. Compared with the scFv fragment, the half-life of the fusion protein was significantly increased, although not reaching the long half-life of ATROSAB. In summary, the scFv-HSA may provide an alternative to the full-length IgG1 with the ability to selectively inhibit TNFR1 and exploiting the pharmacokinetic properties of albumin.

A multicenter phase II trial of weekly paclitaxel (wPC) and epirubicin (E) in first line metastatic breast cancer (MBC) and pronostic impact of VEGF level

Abstract #6122

Background : wPC and E are effective in the treatment of MBC. The main objective was to determine the efficacy of combined induction with wPC and E followed by consolidation with wPC. Secondary objective were to determine tolerance survivals and characterize antiangiogenic PC activity and predictive values of plasmatic neurotrophic and endothelial factors, in terms of neurotoxicity and efficacy.&#x2028; Methods : patients (pts) with RECIST measurable metastasis were recruited from april 2004 to may 2006 : ages (18-75 y) PS≤2, prior neoadjuvant adjuvant chemotherapy (NA-A CT) was permited if &gt;6 month. 3 cycles [wPC 80 mg/m² (D1, D8, D15, reinduction D28) and epirubicine 100 mg/m² D15], were followed by wPC (no week rest). VEGF, IL6, IL6SR, BDNF were measured in plasma at baseline and C2. Evaluation was performed after 3 induction cycles and every 3 month. A Simon optimal two-stage design was performed with 13 objective responses, allowing to accrue 25 more patients (28 responses expected).&#x2028; Results : 54 patients: median age 58.5 (30-75); 81% had surgery, 53.7% radiotherapy and 40.7% had NA-A CT, 46.3% hormonotherapy. Metastatic sites were nodes (36) lung (36) liver (28) bone (23). 100% PC and 90% E dose were administered at C2 and C3. 49 patients were evaluable for response; 3 patients withdrawn for taxol hypersensitivity, 1 early death (GIII asthenia and dyspnea), 1 investigator's decision. ITT analysis was performed: 33 responses (ORR: 61 %) Median OS was 30 months. During induction, 16 grade III, 27 grade IV and 3 febrile neutropenia were reported. There were 13 serious adverse events.&#x2028; Consolidation was mainly associated with neurotoxicity n=28 (20pts), GIII (n=1; 3.6%) GIV (n=1; 3.6%), astenia n=26 (18pts) ), GIII n=1; 3.8% GIV n=1; 3.8%and onycholysis n=15 (13pts) ), GIII n=2 ; 13.4% GIV n=1; 6.7%.&#x2028; High initial VEGF plasma levels were correlated with poor survival s (PFS, OS) with an univariate cox model (OR=1.954, 95%CI 0.944-4.043, p=0.071 ; HR 4.437, 95%CI 1.731-11.371, p=0.0019). Thresholds were determined. No correlation were observed between neurotoxicity and IL6, IL6SR and BDNF plasma levels.&#x2028; Conclusion : Despite the significant but manageable haematologic toxicity, PC + E showed a high efficacy. VEGF plasma levels are predictive of the outcome and should be tested as antiangiogenic drugs targeting factors.This work was supported in part by BMS.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6122.

Nutritional risk score is not sensitive enough to predict weight loss in diseased elderly subjects

OBJECTIVES

malnutrition is highly prevalent in diseased elderly people, especially in hospital departments, and weight loss also occurs during hospital stays. Among the tools proposed to define malnutrition and to screen persons at risk of malnutrition, the nutritional risk score (NRS) has been suggested as a simple tool.

DESIGN AND PARTICIPANTS

the aim of the present study was to test the validity of the NRS to predict weight changes 3 months after discharge. NRS and visual analogue scales for hunger, early satiety, thirst, fatigue and pain were performed in 106 patients aged 65 yrs and over, 67 treated for cancer, without overt malnutrition.

RESULTS

forty six patients lost more than 1 kg. None of the parameters tested was correlated with weight changes, except NRS which was weakly correlated (r=-0.22, P=0.037). However a 0 score at NRS was associated with weight changes ranging -9 to +5 kg. Furthermore, the 11 patients with a high NRS score and weight loss were in a clinical situation that made it very likely that they would lose weight. In conclusion, NRS is not a valid score to predict weight change.

Semiconductor waveguide source of counterpropagating twin photons

We experimentally demonstrate an integrated semiconductor source of counterpropagating twin photons in the telecom range. A pump beam impinging on top of an AlGaAs waveguide generates parametrically two counterpropagating, orthogonally polarized signal/idler guided modes. A 2 mm long waveguide emits at room temperature one average photon pair per pump pulse, with a spectral linewidth of 0.15 nm. The twin character of the emitted photons is ascertained through a time-correlation measurement. This work opens a route towards new guided-wave semiconductor quantum devices.

Clinical experience with 99mTc-MIBI scintimammography in patients with breast microcalcifications

The aim of this study was to evaluate whether 99mTc-MIBI scintimammography can improve the diagnostic value of mammography for the differentiation of benign and malignant breast microcalcifications. In 41 women presenting 45 clusters of microcalcifications, a 99mTc-MIBI scintimammography was performed before open biopsy. There were 24 malignant lesions (53%). The sensitivity (SE) and specificity (SP) of 99mTc-MIBI scintimammography were 58.3% and 81%, and the positive and negative predictive values (PPV, NPV) were 78% and 63%, respectively. SE and PPV increased for lesions over 10 mm and for the younger patients (under 50 years). No correlation was found between true positive uptake and breast cancer invasiveness: 69% (9/13) for invasive lesions and 45% (5/11) for noninvasive lesions (P = 0.48). 99mTc-MIBI scintimammography was more often positive in high grade than in low- or intermediate-grade ductal carcinoma in situ (P = 0.03). The results were analysed according to the morphologic aspect of the microcalcifications. 99mTc-MIBI scintimammography could not be used for routine evaluation of all the microcalcifications detected by mammography.

Counterpropagating twin photons by parametric fluorescence

An original geometry for parametric fluorescence is proposed and analyzed theoretically, in which counterpropagating twin photons are emitted in a thin waveguide. In this original down-conversion process, a dramatic decrease of the spectral signal bandwidth at degeneracy is expected, as compared to usual parametric fluorescence processes. The possibility of using the counterpropagating twin photons for quantum cryptography is emphasized. It is shown that the realization of a fibered semiconductor source of Einstein-Podolsky-Rosen photons is possible by this method.

Efficient second-harmonic generation in birefringently phase-matched GaAs/Al(2)O(3) waveguides

We report efficient second-harmonic generation of femtosecond pulses in birefringently phase-matched GaAs/Al(2)O(3) waveguides pumped at 2.01mum. By use of pump pulses of ~200-fs duration and type I interaction, practical second-harmonic average powers of up to ~650muW were obtained, with an average input power of ~50muW. Waveguides of four different widths and two different lengths were investigated, and a normalized conversion efficiency of greater than 1000%W(-1)cm(-2) was obtained for a 1-mm waveguide. Measurements of pump and second-harmonic spectra provided clear evidence of phase matching and depletion of the pump spectrum. The measured bandwidth of the second harmonic was ~1.3nm. From the measurements of transmitted pump power at the phase-matching wavelength, pump depletions of more than 80% were recorded.

A three-stage clinical trial design for rare disorders

Many clinical trials of uncommon diseases are underpowered because of the difficulty of recruiting adequate numbers of subjects. We propose a clinical trial design with improved statistical power compared to the traditional randomized trial for use in clinical trials of rare diseases. The three-stage clinical trial design consists of an initial randomized placebo-controlled stage, a randomized withdrawal stage for subjects who responded, and a third randomized stage for placebo non-responders who subsequently respond to treatment. Test level and power were assessed by computer-intensive exact calculations. The three-stage clinical trial design was found to be consistently superior to the traditional randomized trial design in all cases examined, with sample sizes typically reduced by 20 per cent to 30 per cent while maintaining comparable power. When a treatment clearly superior to placebo was considered, our design reached a power of 75 per cent with a sample of 21 patients compared with the 52 needed to attain this power when only a randomized controlled trial was used. In situations where patient numbers are limited, a three-stage clinical trial design may be a more powerful design than the traditional randomized trial for detecting clinical benefits.

Transport mechanisms of the large neutral amino acid L-phenylalanine in the human intestinal epithelial caco-2 cell line

The transepithelial transport and the intracellular accumulation of the large neutral amino acid L-phenylalanine (L-Phe) were studied in monolayers of Caco-2 cells, cultivated in a bicameral insert system, to characterize the mechanisms involved in the absorption of this essential amino acid by the human intestinal mucosa. In our model, L-Phe was transported selectively in the apical (AP)-to-basolateral (BL) direction. AP-to-BL transport of L-Phe was temperature dependent and Na(+) independent, increased in the absence of protein synthesis and showed competition with large neutral and cationic amino acids. By contrast, transport in the BL-to-AP direction mainly resulted from passive movement (probably paracellular passage and transcellular diffusion). L-Phe accumulation into Caco-2 cells was higher from the BL pole than from the AP pole and characterized by the incorporation of most of the accumulated molecules into newly synthesized proteins. In addition, L-Phe accumulation was Na(+) dependent from both poles, whereas only accumulation from the AP pole was sensitive to inhibition by both large neutral and cationic amino acids. These results suggest that the processes involved in AP-to-BL transport and AP accumulation of this amino acid are very different from those involved in BL-to-AP transport and BL accumulation.

Transport mechanisms of the imino acid L-proline in the human intestinal epithelial caco-2 cell line

The intestinal transport of L-proline (L-Pro) has been investigated in various animal species with the use of different tissue preparations. Because major qualitative differences have been observed among the species, it is difficult to extent the results obtained with animal models to humans. In addition, studies on human tissue are lacking because of difficulties in obtaining material for experiments. To characterize the mechanisms involved in the intestinal absorption of L-Pro in humans, the transport of this nonessential imino acid was studied in monolayers of human intestinal Caco-2 cells that were cultivated on microporous membranes. In this model, L-Pro was transported selectively in the apical (AP)-to-basolateral (BL) direction. This transport was significantly reduced by metabolic inhibitors and by an incubation at 4 degrees C; it was Na(+) dependent and showed competition with (methylamino)-alpha-isobutyric acid and L-hydroxyproline. By contrast, transport in the BL-to-AP direction resulted to a large extent from passive movement (paracellular passage and transcellular diffusion). L-Pro accumulation by Caco-2 cells was significantly greater from the AP pole than from the BL pole. About 30-50% of the accumulated molecules were incorporated into newly synthesized proteins in a process inhibited by cycloheximide, whereas the remainder were extensively metabolized into non-amino acid compounds. L-Pro accumulations from the AP and BL poles were both Na(+) dependent, but they exhibited different characteristics. AP accumulation was inhibited by competition with (methylamino)-alpha-isobutyric acid, L-hydroxyproline and, to a lesser extent, D-Pro, whereas BL accumulation was inhibited by competition with L-hydroxyproline, (methylamino)-alpha-isobutyric acid, alpha-aminoisobutyric acid, L-histidine and small neutral amino acids. The results indicate that AP-to-BL transport and AP accumulation of L-Pro exhibited very different characteristics than BL-to-AP transport and BL accumulation.

Effect of field strength on MR images: comparison of the same subject at 0.5, 1.0, and 1.5 T

To assess the effect of field strength on magnetic resonance (MR) images, the same healthy subject was imaged at three field strengths: 0.5, 1.0, and 1.5 T. Imaging was performed with three similarly equipped MR imagers of the same generation and from the same manufacturer. The same imaging sequences were used with identical parameters and without repetition time correction for field strength. Imaging was performed in four anatomic locations: the brain, lumbar spine, knee, and abdomen. Quantitative image analysis involved calculation of signal-to-noise ratio, contrast-to-noise ratio, and relative contrast; qualitative image analysis was performed by four readers blinded to field strength. The results of all of the examinations were considered to be of diagnostic value. In general, signal-to-noise ratio and contrast-to-noise ratio were lowest at 0.5 T and highest at 1.5 T; relative contrast was not related to field strength. At qualitative analysis, images obtained at 1.0 and 1.5 T were superior to images obtained at 0.5 T; qualitative differences were less important in locations where there is motion or high magnetic susceptibility differences between tissues (e.g., the spine and abdomen). However, excellent image quality was obtained with all three field strengths.

[Abdominal and pelvic segmented T1-weighted echo-planar imaging and MRI. Comparison with T1-TSE and T2-UTSE sequences]

PURPOSE

To assess, quantitatively and qualitatively, the diagnostic value of a segmented EPI T1W sequence compared to T1W and T2W TSE sequences.

MATERIAL AND METHODS

A prospective analysis of abdominal and pelvic MRI examinations of 70 patients (44 women, 26 men, mean age of 61 years), was performed on a 0.5 T supraconductive magnet with 15 mT/m gradients. The sequences were randomized and compared in a blinded fashion by 3 independent reviewers: TSE T1W (TR/TE = 500/12 ms, NSA = 6, turbo factor 5, 3:49 min), EPI T1W (TR/TE = 500/30 ms, NSA = 6, EPI factor = 7, 2:13 min) and UTSE T2W (TR/TE = 1600-2500/100, NSA = 6, turbo factor = 31, 2:20 min).

RESULTS

Quantitatively, no significant difference was found between T1W sequences for signal to noise ratio. The EPI T1W sequence had lower signal but stronger enhancement after gadolinium injection. Qualitatively, EPI T1W had significantly less flow artefacts (p < 0.001, wilcoxon test), and more chemical shift artifact (p < 0.01). For lesion detection, differences were not statistically significant between T1W sequences or between paired T1W and T2W sequences (sensitivity and specificity 84 and 86% for TSE T1W 76 and 86% for EPI T1W, 78 and 79% for UTSE T2W, 90 and 65% for TSE T1W-UTSE T2W, 88 and 65% for EPI T1W-UTSE T2W). Kappa concordance test (0.686) and Mac Nemar symmetry test (3.55) were high between T1W sequences.

CONCLUSION

The segmented EPI T1W sequence used had equivalent results compared to the TSE T1W sequence, it allows a 40% reduction in acquisition time and this without difference in the diagnostic performances of the reviewers.

Dietary specific sugars for serum protein enzymatic glycosylation in man

All glycoprotein sugars can theoretically derive from glucose. However, dietary specific sugars could represent preferential substrates or have regulatory roles in enzymatic glycosylation. This hypothesis was tested in man using stable isotopes. Healthy subjects ingested different amounts (150, 300, or 550 mg) of artificially 13C-enriched sugar (galactose, mannose, or glucose) diluted in 200 mL water containing 50 g 13C-poor sucrose. 13C enrichment of expired CO2 was monitored for 8 hours during indirect calorimetry. Serum glycoproteins were precipitated and delipidated at various intervals. Glycoprotein neutral sugars were obtained by acidic hydrolysis, purified by ion-exchange chromatography, derivatized to alditol acetates, and analyzed by gas chromatography-isotope ratio mass spectrometry. The oxidation rate for galactose and mannose was slower than the rate for glucose. Total oxidation over the 8-hour period was less than 10% of the ingested amount of galactose or mannose. Galactose and mannose were readily incorporated into glycoprotein glycans, in the native form or after interconversion, despite ingestion of a large excess of sucrose: glycoprotein sugar 13C enrichment was strongly higher after 13C-galactose or 13C-mannose than after 13C-glucose. Thus, the metabolism of these three sugars appears to be different. Specific dietary sugars could represent a new class of non essential nutrients displaying interesting metabolic roles. This could have practical consequences especially in parenteral nutrition, where glucose is currently the only sugar available for metabolism.

Emergency room visits of asthmatic children, relation to air pollution, weather, and airborne allergens

BACKGROUND

The worldwide increase in the incidence, prevalence, and severity of asthma may suggest that environmental factors play a role in these epidemiologic changes.

OBJECTIVE

To examine the correlations between air pollutants, weather conditions, airborne allergens, and the incidence of emergency room (ER) visits of children with acute asthma attacks.

DESIGN

One-year prospective study. Data of daily concentration of air pollutants, weather conditions, and selective airborne allergens were collected and compared with the number of ER visits of asthmatic children.

SUBJECTS

1076 asthmatic children (aged 1 to 18 years) who presented at the Pediatric ER between January 1 and December 31, 1993.

RESULTS

Correlations between fluctuations in ER visits of asthmatic children and various environmental parameters were more relevant for weekly than for daily values. Emergency room visits correlated positively with concentrations of NOx, SO2 and with high barometric pressure; and negatively with O3 concentration and minimal and maximal temperature. There were no significant correlations with concentrations of particulates, humidity, or airborne pollen and spores. An exceptionally high incidence of ER visits of asthmatic children was observed during September. This peak coincided with the beginning of the school year and the Jewish holidays. The correlations between ER visits and the environmental factors increased significantly when the September peak was excluded, revealing that 61% of the variance in ER visits was explained by NOx, SO2, and 03 concentrations, 46% by weather parameters, 66% by NOx, SO2 and barometric pressure, and 69% by the combination of air pollutants and weather parameters.

CONCLUSION

The major factors found to be associated with ER visits of asthmatic children were high NOx, high SO2, and high barometric pressure. Negative correlation was found between ER visits of asthmatic children and ozone concentrations. The particularly high number of ER visits at the beginning of the school year and the Jewish holidays was probably associated with an increase in the number of viral infections and/or emotional stress.

Adhesion of mammalian cells to polymer surfaces: from physical chemistry of surfaces to selective adhesion on defined patterns

The study of the adsorption of type I collagen from a solution containing Pluronic F68 has shown that the latter prevents collagen adsorption on polystyrene and does not prevent it on surface-oxidized polystyrene. This explains the control of mammalian cell adhesion by substrate surface hydrophobicity and composition of pre-conditioning solution. On that basis, selective adhesion of different types of mammalian cells (PC12 pheochromocytoma, MSC80 schwannoma, Hep G2 hepatoblastoma, rat hepatocytes) on patterned surfaces was achieved. Therefore tracks (width in the range of a few tens of microm) of reduced hydrophobicity were produced on polystyrene by photolithography and oxygen plasma treatment. After conditioning by a solution containing both Pluronic F68 and extracellular matrix protein (collagen, fibronectin), the latter adsorbed selectively on these paths thus allowing selective adhesion of the cells.

Surface emitted second-harmonic generation from a quasi-phase matched waveguide in an Al(x)Ga(1-x)As/Al(2)O(3) microcavity

A nonlinear Al(x)Ga(1-x)As waveguide consisting of a quasi-phase matched heterostructure embedded in a microcavity has been designed and fabricated. The microcavity resonator is formed by Al(2)O(3)/Al(0.32)Ga(0.68)As multilayer mirrors located above and below the waveguide core. The cavity resonantly enhances the surface emitting second-harmonic generation. The SH conversion efficiency has been measured for wavelengths between l = 1525 and 1575 nm. A simple waveguide loss measurement technique based on the SH autocorrelation of short optical pulses in a III-V waveguide is also demonstrated.

Evidence for a role for bulbospinal pathways in the spinal antinociceptive effect of systemically administered vapreotide in normal rats

Numerous neurotransmitters are involved in nociceptive transmission or regulation. Several reports have shown the analgesic effects of somatostatin and its analogues. Somatostatin, when given intrathecally, markedly reduced pain in cancer patients. Somatostatin analogues that possess a longer half-life time are more convenient for therapeutic use. Vapreotide, a somatostatin analogue, was shown to induce a long-lasting antinociceptive effect in rats. We studied the site and the mechanism of action of vapreotide in rats using the paw pressure test. Intrathecal administration of vapreotide induced no antinociception. Systemically administered vapreotide-induced antinociception was inhibited by several intrathecal (i.t.) administered antagonists (yohimbine, naloxone and to a lesser degree tropisetron). These results show a lack of spinal effect and suggest a supraspinal site of action with an involvement of noradrenergic and to a lesser degree serotonergic bulbospinal pathways. In addition, spinal opioid receptors also seen to be involved.

5.2-5.6-microm source tunable by frequency conversion in a GaAs-based waveguide

A tunable mid-IR source obtained by difference-frequency generation is demonstrated in a selectively oxidized GaAsAlAs multilayer waveguide. We designed the waveguide to present the required form birefringence for phase matching of the nonlinear interaction. We took special care to lower losses for the mid-IR radiation. IR tunability from 5.2 to 5.6 mum was achieved by variation of the waveguide temperature and one pump wavelength. IR output power as great as 0.12 muW was obtained with the product of two pump powers of 7 mW(2). Losses of ~50 cm(-1) were measured for the mid-IR radiation. These losses are attributed to surface scattering.

Availability of specific sugars for glycoconjugate biosynthesis: a need for further investigations in man

We review the metabolism of specific sugars used for protein glycosylation, focusing on the fate of exogenously provided sugars. Theoretically, all glycoprotein sugars can derive from glucose, but previous studies show that other exogenous sugars can be incorporated into glycoproteins. From data obtained in congenital galactosemia, exogenous galactose may be important for correct glycosylation. Contrary to galactose, the metabolism of other sugars seems to depend on insulin regulation: stimulation of their endogenous production in diabetic subjects might participate in some diabetic complications, precluding the need for an exogenous supply. The metabolic fate of these sugars is different according to the administration route and exogenous supply may be important either in enteral nutrition or in some clinical situations as has been suggested for sialic acid in the newborn. Data in man are too sparse to reach firm conclusions, implying a need for further investigations. Our preliminary results in animals and man demonstrate that stable isotope methodology allows one to trace glycoprotein sugar metabolism in nutritionally relevant conditions with accuracy and sensitivity, using doses of specific sugars well below toxic levels.

Influence of Substrate Hydrophobicity on the Adsorption of Collagen in the Presence of Pluronic F68, Albumin, or Calf Serum

The influence of Pluronic F68 [a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) copolymer surfactant], serum albumin (HSA), and fetal calf serum (FCS) on the adsorption of type I collagen by polymer substrates was investigated using radiolabeling and XPS analysis. Three different kinds of polystyrene substrates with increasing level of hydrophobicity were used. Change in the state of hydration of the sorbent and protein surfaces appears to be the main driving force for collagen adsorption. Pluronic F68 strongly reduces collagen adsorption, the reduction being more pronounced with higher substrate hydrophobicity. This explains why epithelial cell adhesion on substrates preconditioned with a solution of Pluronic F68 and collagen is strongly influenced by substrate hydrophobicity. Collagen adsorption is also reduced in the presence of HSA and FCS, but the reduction and its sensitivity to substrate hydrophobicity are lower than with Pluronic F68.

[Left ovarian vein syndrome]

Ovarian vein syndrome is classically described on the right side. Patients present with lumbar pain or renal colics due to a compression of the ureter between the external iliac artery and a dilated ovarian vein. We report an unusual case of left ovarian vein syndrome between a dilated ovarian vein and the psoas muscle, with a similar clinical presentation.

[Bladder adenomyomatosis. Apropos of a case of segmental involvement. Correlation ultrasonography-MRI]

Adenomyomatosis of the gall bladder is a classical but seldom recognized cause of gallbladder wall thickening. The authors review the imaging features of this disease and emphasize the value of ultrasound and MRI. Although considered a benign disease, some recently described cases of neoplastic transformation may warrant surgery.