A budget impact model and a cost-utility analysis of reducer device (Neovasc) in patients with refractory angina

Background

Refractory angina (RA) is a chronic condition characterized by the presence of debilitating angina symptoms due to established reversible ischemia in the presence of obstructive coronary artery disease (CAD). Treatments for this condition have undergone major developments in recent decades; however, the treatment for RA remains a challenge for medicine. In this sense, the Coronary Sinus Reducer System (CSRS) stands as the last line of therapy for ineligible patients for revascularization with reversible ischemia. The purpose of this report is to evaluate the potential burden on the National Health Service (NHS) and measure the health effects in terms of both quantity (life years) and quality-of-life aspects related to the reducer.

Methods

Two different economic evaluation models were developed as part of the analysis. The budget impact was developed to estimate the potential burden on the NHS from incremental uptake of the use of the reducer in the target population. The utility cost analysis compares and evaluates the quality of life and health resource use and costs between the two alternatives, based on the research of Gallone et al. A deterministic and probabilistic sensitivity analysis was carried out to characterize the uncertainty around the parameters of the model.

Results

In the budget impact analysis (BIA), the reducer is shown to be more expensive in the first 2 years of the model, due to the gradual uptake in the market and the cost of the device. Starting from the third year, assuming maintenance of effectiveness, there are savings in terms of resource absorption in direct healthcare costs arising from hospitalizations, emergency department accesses, coronarography, and visits avoided.

Conclusion

The BIA and cost-effectiveness model show that the reducer device, despite an increase in resources absorbed in the first years of implementation and use, has the potential to result in increased quality of life in patients with RA. These costs are largely offset in the short term by the improved clinical outcomes achievable leading to savings from the third year onward in the BIA and a dominance ratio in the cost-utility analysis.

Il burden clinico ed economico delle complicanze della cute peristomale: un’analisi di Activity Based Costing

Introduction:

An ostomy is a procedure in which an opening is made in the abdominal wall to establish a communication between the intestinal or urinary system and the external environment. Peristomal skin complications pose a constant challenge for the majority of individuals with a stoma, as they represent the most common postoperative complication. The aim of this study was to develop an economic evaluation model for assessing the costs associated with peristomal skin complications.

Methods:

In order to identify these costs, a survey was conducted in collaboration with the Coloplast Ostomy Forum group with the aim of mapping and documenting the timelines and all activities in the management of these complications. The data obtained from the survey were subsequently analyzed using the Activity Based Costing methodology.

Results:

The results of this analysis clearly indicate that the expenditure for initial visits is higher compared to subsequent ones, and that severe peristomal skin complications impose a greater economic burden than less severe complications. Specifically, the average total cost for managing severe peristomal skin complications amounts to € 104.6.

Conclusion:

This kind of analysis could provide support to decision-makers in dealing with a more accurate estimate of costs related to healthcare processes, aiming to implement rates able to “cover” the overall cost of certain healthcare activities. Specifically, there is currently no specific rate aimed at defining the value associated with the care and management of this type of complication, so this study confirms that this is an economic challenge that the National Health Service must address.

Analysis of heterogeneity of the different health technology assessment reports produced on the transcatheter aortic valve implantation in patients with severe aortic valve stenosis at low surgical risk

Background

Symptomatic severe aortic stenosis is a congenital or acquired aortic valve disease that occurs when the aortic valve of the heart narrows. It represents the most common valvular disease in adults and generally has a degenerative nature. Transcatheter aortic valve implantation (TAVI), due to its non-invasive approach, has become the standard treatment in patients who are ineligible to surgery or at high surgical risk, and it is also increasingly being performed in patients at intermediate to low surgical risk. The aim is to analyze the heterogeneity and explore the limitations of current health technology assessments (HTAs) on TAVI.

Methods

For the purpose of this analysis, a review of the literature based on manual research was performed. A population, intervention, comparators, and outcome (PICO) model was used to gather the HTA reports assessing TAVI in the treatment of patients affected by symptomatic severe aortic valve stenosis at low surgical risk. Furthermore, a manual search has been developed to also include assessments from the Haute Autorité de Santé.

Results

At the end of the investigation, a certain degree of heterogeneity in the evidence factored and in the recommendations on the technology has emerged. Relative to the clinical domains, the main drivers for the disparity are found in the type of evidence considered and in the use or not of the grading of recommendations, assessment, development, and evaluation (GRADE) methodology to evaluate the quality of the clinical evidence included. Another element concerns the chosen device generation assessed within the evaluation. In order to perform the economic evaluation, a cost-utility analysis and a budget impact model were developed. Despite some elements of heterogeneity, the economic assessments demonstrate a favorable or dominant cost-effectiveness profile for TAVI compared with surgical aortic valve replacement (SAVR).

Conclusion

Despite the presence of heterogeneity elements both in clinical and economic domains, HTA agencies reached the same recommendations on the use of TAVI. It emerged the need for a centralized vision on the "strong" domains, which means giving up freedom to local bodies to adapt to their context on the "soft" ones. This approach could have the potential to strengthen the role of HTA in Europe by ensuring faster decision-making and equity of access to health innovations and reduce the heterogeneity in the assessment methods.

Comparing the COVID-19-related PTSD symptoms between psychiatric patients and healthy subjects: an observational retrospective study from Northern Italy

COVID-19 pandemic had a great impact on mental health, both in the general population and psychiatric patients. Little is known about the difference between these two populations in perceiving the pandemic as a traumatic event. The aim of the study was to compare psychiatric patients and healthy controls (HC) in terms of change over time of post-traumatic (PTSD) symptoms. Demographic and clinical variables were collected. Impact of Event Scale Revised (IES-R) scores were registered at T1 as lockdown period (March-April 2020) and T2 as restarting (May-June 2020). Descriptive analyses and linear regression models were performed. A total of 166 outpatients and 57 HC were recruited. Time (F = 15.76; p < 0.001) and diagnosis (F = 4.94; p < 0.001) had a significant effect on the change of IES-R scores, which resulted T1 > T2 (p < 0.001), except for subjects affected by Obsessive-Compulsive Disorder (OCD). Overall, IES-R scores were < in patients than in HC (p = 0.02), particularly in the schizophrenia (SKZ) subgroup (p < 0.001). IES-R scores of subjects with personality disorders (PDs) resulted to be > HC, although not statistically significant. The lockdown period was perceived as more traumatic than the reopening phase by both groups, with the exception of OCD patients, probably because of the clinical worsening associated with the urge of control against risks of contamination. Overall, HC reported more PTSD symptoms than psychiatric patients did, particularly SKZ ones. PD patients, in contrast, may be more vulnerable to PTSD symptoms probably as a result of poor coping skills. Together with OCD patients, subjects with PDs may need closer monitoring during the different phases of the pandemic. Trial Registration: ClinicalTrials.gov Identifier: NCT04694482.

O-286 Bisphenol A in blood serum and follicular fluid of women undergoing to cycle of IVF living in areas with different environmental impact. (EcoFoodFertility Project)

Study question

Bisphenol A (BPA) is a constituent of polycarbonate and epoxy resin plastics and is also a by-product of combustion of plastics, resulting harmful for health.

Summary answer

To evaluate the presence of BPA in the blood and Follicular Fluids, in women, subjected to IVF cycles, living in areas with different environmental impact.

What is known already

BPA is used in the production of polycarbonate plastics and epoxy resins. 1,3,5-triphenylbenzene is a tracer for burning plastic and has been related to levels of bisphenol A in the air, so the actual release of bisphenol A to the atmosphere could result from burning the plastic. Bisphenol A belongs to the group of endocrine disruptors.

Little is known about the effects of BPA on human female reproduction. BPA levels appear to be inversely related to the number of oocytes retrieved in IVF cycles, and it also appears to negatively affect the ovulatory peak of estradiol.

Study design, size, duration

In the frame of EcoFoodFertility project a cross sectional study conducted in Campania Region (Southern Italy), between January 2019 and December 2020, 74 women, no smokers, no chronic diseases, not exposed to occupational risk factors. living for at least 5 years in areas with low environmental impact (LEI, 31 women), Alto-Medio Sele in province of Salerno and high environmental impact (HEI, 43 women), so-called “Land of Fires” in province of Naples, were selected.

Participants/materials, setting, methods

Participants have a normal ovarian reserve, average age 32.05 + 3.49, with infertility duration between 26 and 39 months and at the first experience of an IVF cycle. ELISA was used for measuring bisphenol A in blood and Follicular Fluids (FFs), expressed in ng/ mL. 5 mL glass tubes, without additives, not siliconized and kept in a horizontal position were used. FFs were bloodless with a negative albumin test.

Main results and the role of chance

Differents levels of BPA were found in all processed samples.

In the LEI (Low Environmental Impact) group, serum levels vary from a minimum of 3.1 ng/mL to a maximum of 7.7 ng/mL (4.1 ± 1.6) and the Follicular Fluids levels vary from a minimum of 7,1 ng/mL to a maximum of 55.3 ng/mL (13.8 ± 10.9).

In the HEI (High Environmental Impact) group, serum levels vary from a minimum of 69.2 ng/mL to a maximum of 167.8 ng/mL (95.5 ± 24.3) and Follicular Fluids levels vary from a minimum of 4.2 ng/mL to a maximum of 34.3 ng/mL (19.9 ± 9.2).

Statistical processing of the data shows a highly significant variation in serum levels (p &lt; 0.0001) with higher values in the HEI group (95.5 ± 24.3) than in the LEI group (4.1 ± 1.6).

A moderately significant change (p &lt; 0.01) for Follicular Fluids levels, higher in the HEI group (19.9 ± 9.2) than in the LEI group (13.8 ± 10.9).

Furthermore, the data did not show any correspondence between serum and Follicular Fluids for any of the participants tested.

Limitations, reasons for caution

The ELISA method for the determination of BPA seems suitable to us, however, the subject requires further biomonitoring studies, with a larger sample and greater selection of participants, to better understand the effects of BPA and its metabolites in FF and in other districts of the female reproductive system.

Wider implications of the findings

The results indicate that the greater bioaccumulation in women of the HEI group appears consistent with the environmental condition of the area and with the comparative studies already carried out within the EcoFoodFertility project. This is further evidence that pollution in this area can interfere with female fertility and beyond.

Trial registration number

G003

Transition memories: experiences of trans adult women with hormone therapy and their beliefs on the usage of hormone blockers to suppress puberty

PURPOSE

In recent years, an increasing number of specialized gender clinics have been prescribing gonadotropin-releasing hormone (GnRH) analogs to adolescents diagnosed with gender dysphoria (GD) to suppress puberty. This paper presents qualitative research on the hormone therapy (HT) experiences of older trans-people and their views on puberty suppression. The main aim of this research was to explore the psychological aspects of hormonal treatments for gender non-conforming adults, including the controversial use of puberty suppression treatments.

METHODS

Using a semi-structured interview format, ten adult trans-women were interviewed (mean age: 37.4) to explore their personal histories regarding GD onset and development, their HT experiences, and their views on the use of GnRH analogs to suppress puberty in trans-children and adolescents.

RESULTS

the interview transcripts were analyzed using the consensual qualitative research method from which several themes emerged: the onset of GD, childhood experiences, experiences with puberty and HT, views on the puberty suspension procedure, and the effects of this suspension on gender identity and sexuality.

CONCLUSIONS

The interviews showed that overall, the participants valued the new treatment protocol due to the opportunity to prevent the severe body dysphoria and social phobia trans-people experience with puberty. It seems that the risk of social isolation and psychological suffering is increased by the general lack of acceptance and stigma toward trans-identities in the Italian society. However, during gender transitions, they highlight the need to focus more on internal and psychological aspects, rather than over-emphasize physical appearance. This study gives a voice to an under-represented group regarding the use of GnRH analogs to suppress puberty in trans-individuals, and collected firsthand insights on this controversial treatment and its recommendations in professional international guidelines.

Beta 2-microglobulin Removal by Synthetic Dialysis Membranes. Mechanisms and Kinetics of the Molecule

Beta 2-microglobulin (ß2-m) accumulation represents a possible complication of long term dialysis. It is therefore important to evaluate the capacity of removal of this molecule from the patient by different dialysis membranes. The present study is aimed at evaluating the mechanisms involved in ß2-m removal by three different synthetic membranes: a) highly asymmetric hydrophobic polysulfone (Biosulfane, NMC), b) moderately asymmetric and hydrophobic polysulfone (PS600, Fresenius), c) Polyacylonitrile (AN69HF, Hospal). The adsorption capacity and sieving coefficients of the three membranes for native and labeled ß2-m were studied in vitro utilizing human blood. The amount adsorbed by the membrane was measured by the elution of the molecule obtained with a detergent solution. Clearances, total removal and membrane adsorption were studied in six patients treated in a randomized sequence with the three membranes. For this purpose, plasma and dialysate measurements as well as total collection of spent dialysate and ß2-m elution from the used dialyzers were carried out. Ex novo generation of ß2-m did not take place during in vitro circulation. The molecule was removed by the studied membranes both by filtration and adsorption. The Biosulfane membrane removed ß2-m mostly by adsorption while the PS600 membrane removed ß2-m almost entirely by filtration. Intermediate behaviour was shown by AN69 membrane. Similar quantities of ß2-m were removed from the patients with the three membranes. Total removal could only be precisely measured by adding the quantity of ß2-m eluted from the membrane to the amount recovered in the spent dialysate. Out of total removal, adsorption was more than 90% with Biosulfane, while only 5% with the PS600. These findings contribute to the understanding of the discrepancy found between the clearance measured from the plasma side and that measured from the dialysate side. In conclusion, clearance and sieving measurements for ß2-m cannot be correctly performed unless the capacity of adsorption of the membrane is taken into account.

Evaluation of Critical Differences of CEA and CA15.3 Levels in Serial Samples from Patients Operated for Breast Cancer

In the present investigation we evaluated the variability of tumor marker levels in the follow-up of patients without evidence of disease after resection of primary breast cancer. CEA and CA15.3 were measured using commercially available methods in serial blood samples collected from 170 patients. The coefficient of variation among all samples from each patient, which accounts for the total variability (analytical variability + biological variability), was widely scattered (from 4 to 99% for CEA; from 4 to 52% for CA15.3). The critical difference was calculated using the formula designed by Eraser [CD = 2.77. (CVa2 + CVb2)1/2]. It ranged from 11 to 276 for CEA and from 11 to 144 for CA15.3. From the present findings we conclude that:

1) it is possible to identify individually tailored decision criteria to evaluate tumor marker variations in the follow-up of breast cancer patients;

2) in a considerable number of cases the non-tumor-related variability is too high to allow the early identification of minor tumor marker variations that are of clinical relevance.

Abstract P2-05-05: Not presented

This abstract was not presented at the symposium.

Dialytic Performance Evaluation of Rexeed™: a New Polysulfone-based Dialyzer with Improved Flow Distributions

New dialyzers are designed to optimize the convective and diffusive components of solute transport. Asahi Kasei Medical Co., Ltd. has developed a new high flux dialyzer series called Rexeed™ with improved flow distributions. We evaluated the in vivo dialytic performance of two dialyzers of the Rexeed™ series: Rexeed-18A and Rexeed-25A (1.8 m2 and 2.5 m2).

We calculated the clearance for urea, creatinine, phosphate and b2-microglobulin both in high flux dialysis (HFD) and in 15 liter postidiluitional on-line hemodiafiltration (HDF) mode.

With n=3 patients in high flux HD at blood flow 450, 400, 350 and 250 ml/min we found remarkably high clearance for urea (347±4%,305±0%,288±5%,230±3%, for Rexeed-18A and 361±3%,329±0%,313±1%,234±3% for Rexeed-25A), creatinine (282±10%,234±0%, 221±8%, 174±8%, for Rexeed-18A and 276±6%,245±0%,226±9%,172±13% for Rexeed-25A), phosphate (347±0%,316±0%,275±4%,202±16%, for Rexeed-18A and 364±3%,365±0%,286±3%,224±2% for Rexeed-25A) and b2-microglobulin (133±21%,124±0%,118±12%,98±11%, for Rexeed-18A and 159±8%,169±0%,157±8%,129±7% for Rexeed-25A)

With n=2 patients in HDF at blood flow 300 ml/min we found remarkably high clearance for urea (268±2%, for Rexeed-18A and 283±2% for Rexeed-25A), creatinine (183±6% for Rexeed-18A and 205±9% for Rexeed-25A), phosphate (245±3%, for Rexeed-18A and 270±2% for Rexeed-25A) and b2-microglobulin (166±12%, for Rexeed-18A and 192±4% for Rexeed-25A).

Our preliminary evaluation describes the characteristics and the performances of a new polysulfone-based hemodialyzer series called Rexeed™. Several innovative features have been implemented by the manufacturer. These constructive approaches seem to have produced a positive effect on the dialyzer performance at the bedside.

Interchangeability and Diagnostic Accuracy of Two Assays for Total and Free Prostate-Specific Antigen: Two not Always Related Items

The variation between different PSA assays seems to influence the interpretation of individual PSA values and the clinical decisions about prostate cancer. One reason for this variability could be the different reactivity of antibodies for the various molecular forms of serum PSA; as a result, samples containing the same amount of tPSA but different proportions of fPSA can produce very different values. In this study, serum samples were collected prospectively from 152 consecutive patients referred to 2 institutions (Regional Hospital, Venice, 90 subjects; San Bortolo Hospital, Vicenza, 62 subjects) for PSA elevation and/or symptoms. Serum samples were assessed according to the manufacturers’ instructions on the following 2 analyzers: the Immulite 2000 assay (Diagnostic Products Corporation, Los Angeles, USA), which measures tPSA and fPSA, and the ADVIA Centaur (Bayer Diagnostics, Tarrytown, USA), which assays tPSA and cPSA. cPSA values were transformed into fPSA by the equation fPSA=tPSA-cPSA. When taking Immulite tPSA and f/tPSA values as 100%, ADVIA Centaur values were 92.6% and 122%, respectively, which means that 20% of patients would be classified differently according to the traditional biopsy cutoff. In conclusion, there are considerable differences between the 2 methods, which could affect clinical decisions.

Abstract P1-05-30: Genomic and microenvironmental intra-tumor heterogeneity in DCIS

Intra-tumor heterogeneity drives neoplastic progression by supplying the fuel for natural selection among neoplastic cells. It also complicates screening and treatment of neoplasms. We hypothesize that the degree of intra-tumor heterogeneity in DCIS should predict which tumors are likely to become invasive and metastatic. We initiated a pilot project to test this hypothesis by comparing 9 cases of pure DCIS to 9 cases of DCIS with adjacent invasive disease. For each case, we sequenced the exome from two spatially distinct regions of DCIS as well as normal tissue taken from a lymph node with no tumor involvement. This required the development of new methods to extract high quality sequencing data from small amounts of DNA extracted from FFPE samples. We calculated the genetic divergence between the two tumor regions, defined as percent of the sequenced regions of the genome showing differences between the two samples that had sufficient sequencing coverage and quality scores for confident scoring. We also employed automated imaging analysis to score microenvironmental differences between the two tumor regions. These microenvironmental measures are based on ecological methods for measuring organismal interactions and habitats. We will present initial data on differences in phenotypic and genotypic intra-tumor heterogeneity comparing pure DCIS to DCIS associated with invasive breast cancer. Our methods can be readily translated to large tissue banks of FFPE samples from DCIS.

Citation Format: Fortunato A, King L, Mallo D, Kovacheva V, Yuan Y, Boddy A, Graham T, Aktipis A, Mardis ER, Hall A, Marks JR, Hwang S, Maley CC. Genomic and microenvironmental intra-tumor heterogeneity in DCIS [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-30.

A new simplified methodology for studying the coupled fluid-structure interaction in a weakened basilar artery

In this paper, we study the fluid-structure interaction in a weakened basilar artery. The aim is to study how the wall shear stress changes in space and time because of the weakening, because spatial and temporal changes are thought to be possible causes of aneurysm and vascular deseases. The arterial wall, in its natural configuration, is modeled as a hyperelastic cylinder, inhomogeneous along its axis, in order to simulate the axis-symmetric weakening. The fluid is studied exploiting a recent approach for quasi-one-dimensional flows in slowly varying ducts, which allows to write the averaged equations of mass and energy balance on the basis of the velocity profile in a straight duct. The unknowns are the wall pressure, the average velocity, and the wall radial displacement. The problem is solved in two parts: first, the stationary non-linear coupled problem is solved, and an intermediate configuration is obtained. Then, we study the variation of the basic unknowns about the intermediate configuration, considering time dependence over the cardiac cycles. The results suggest that, with a 10% reduction of the main elastic modulus, the shear stress in the weakened zone changes its sign and doubles the maximum stress value detected in the healthy zone. Copyright © 2015 John Wiley & Sons, Ltd.

An ultra-rapid cryo-technique for complex organisms

The soil nematode Caenorhabditis elegans is an excellent research model in cell biology, human disease and developmental studies. In this study, a novel cryopreservation technique based on a rapid cooling procedure, previously established for juveniles, was applied to adult-worms. Here we demonstrated that adults of C. elegans, a complex metazoan organism, survive to a rapid cooling and storage in liquid nitrogen (-196 °C) with a very high survival percentage (85%). The procedure relies on a Low CryoProtectant Technique (LCPT) and Ultra Rapid Cooling (URC). The high cooling rate is achieved through the reduction of sample volumes and the effectiveness of a nylon carrier. Our technique complies with the requirements for vitrification to occur. The main distinctive characters of this cryopreservation technique compared to other methods, e.g. Slow Freezing and Vitrification, are presented. Our results show that this cryopreservation method is valid for both unicellular and multicellular organisms; it is suitable for short or long time storage in liquid-nitrogen. This technique promises to be a unique and simpler method for cryostorage of cells, organisms and tissues.

A pilot study on the effect of a symbiotic mixture in irritable bowel syndrome: an open-label, partially controlled, 6-month extension of a previously published trial

BACKGROUND

In recent years, the efficacy of probiotics has received considerable attention in the treatment for irritable bowel syndrome (IBS). In this regard, a symbiotic mixture (Probinul(®)) has shown beneficial effects. The aim of this study was to extend the previously published 4-week randomized, double-blinded, placebo-controlled study of this symbiotic mixture.

METHODS

This is an open-label prospective, partially controlled, 6-month extension period pilot study in which patients continued to receive the symbiotic mixture (Group 1) or were switched from placebo to symbiotic mixture (Group 2) using cyclic administration (last 2 weeks/month). The primary endpoints were the overall satisfactory relief of bloating and flatulence (assessed as proportions of responders). The secondary endpoints were evaluation of the symptom severity scores (bloating, flatulence, pain and urgency) and bowel function scores (frequency, consistency and incomplete evacuation).

RESULTS

Twenty-six IBS patients completed the 6-month extension period (13 patients in Group 1 and 13 patients in Group 2). In the per-protocol analysis, the proportions of responders across time were not significantly different in the groups but in Group 2, there was an increased percentage of responders for flatulence (p = 0.07). In addition, the score of flatulence was reduced significantly during the 6-month treatment period in Group 2 (p < 0.05), while no other significant differences were detected.

CONCLUSIONS

Treatment with this symbiotic mixture was associated with persistence of relief from flatulence or new reduction in flatulence in the present 6-month long extension study. These results need to be more comprehensively assessed in large, long-term, randomized, placebo-controlled studies.

The impact of cold on photosynthesis in genotypes of Coffea spp.--photosystem sensitivity, photoprotective mechanisms and gene expression

Environmental constraints disturb plant metabolism and are often associated with photosynthetic impairments and yield reductions. Among them, low positive temperatures are of up most importance in tropical plant species, namely in Coffea spp. in which some acclimation ability has been reported. To further explain cold tolerance, the impacts on photosynthetic functioning and the expression of photosynthetic-related genes were analyzed. The experiments were carried out along a period of slow cold imposition (to allow acclimation), after chilling (4°C) exposure and in the following rewarming period, using 1.5-year-old coffee seedlings of 5 genotypes with different cold sensitivity: Coffea canephora cv. Apoatã, Coffea arabica cv. Catuaí, Coffea dewevrei and 2 hybrids, Icatu (C. arabica×C. canephora) and Piatã (C. dewevrei×C. arabica). All genotypes suffered a significant leaf area loss only after chilling exposure, with Icatu showing the lowest impact, a first indication of a higher cold tolerance, contrasting with Apoatã and C. dewevrei. During cold exposure, net photosynthesis and Chl a fluorescence parameters were strongly affected in all genotypes, but stomatal limitations were not detected. However, the extent of mesophyll limitation, reflecting regulatory mechanisms and/or damage, was genotype dependent. Overnight retention of zeaxanthin was common to Coffea genotypes, but the accumulation of photoprotective pigments was highest in Icatu. That down-regulated photochemical events but efficiently protected the photosynthetic structures, as shown, e.g., by the lowest impacts on A(max) and PSI activity and the strongest reinforcement of PSII activity, the latter possibly reflecting the presence of a photoprotective cycle around PSII in Icatu (and Catuaí). Concomitant to these protection mechanisms, Icatu was the sole genotype to present simultaneous upregulation of caCP22, caPI and caCytf, related to, respectively, PSII, PSI and to the complex Cytb(6)/f, which could promote better repair ability, contributing to the maintenance of efficient thylakoid functioning. We conclude that Icatu showed the best acclimation ability among the studied genotypes, mostly due to a better upregulation of photoprotection and repair mechanisms. We confirmed the presence of important variability in Coffea spp. that could be exploited in breeding programs, which should be assisted by useful markers of cold tolerance, namely the upregulation of antioxidative molecules, the expression of selected genes and PSI sensitivity.

Sequential convective therapies (SCT): a prospective study on feasibility, safety, adequacy and tolerance of on-line hemofiltration and hemodiafiltration in sequence

Sequential dialysis techniques (i.e pure ultrafiltration followed by dialysis) have been used in the past, due to their capability to remove large volumes of fluids without inducing hemodynamic instability. The disadvantages of inadequate efficiency and lack of technology lead to the decline of such methods. Hemofiltration (HF) and hemodiafiltration (HDF) are recently being utilized in a greater proportion thanks to on-line fluid preparation systems. Each process (HF and HDF) has its own benefits in the removal of small, medium and high-molecular weight substances and in hemodynamic stability. Sequential convective therapies (SCT) such as hemofiltration-hemodiafiltration in sequence (HF-HDF) may combine the benefits and eliminate the disadvantages of each method and should be studied in order to explore their potential application in modern dialysis. Furthermore they can be easily applied nowadays, due to the development of new sophisticated dialysis machines. In order to evaluate the feasibility, safety, efficiency and tolerance of different SCT methods we studied 3 schedules: SCT1: 1h pre-dilution HF followed by 3h of post-dilution HDF (in the HF mode we lost 25% of the total fluid that had to be removed). SCT2: 1h pre-dilution HF followed by 3h of post-dilution HDF (in the HF mode we lost 50% of the total fluid that had to be removed). SCT3: 2h pre-dilution HF followed by 2h of post-dilution HDF (in the HF mode we lost 50% of the total fluid that had to be removed). We studied 6 chronic hemodialysis patients using the same machine (AK200 ULTRA), with on-line fluid preparation system and the same type of dialyzer (Polyflux 210). SCT schedules were compared to on-line HF, on-line HDF and high flux dialysis performed with the same dialyzers. The treatments resulted safe, easy, feasible and well tolerated with an improved hemodynamic response to high volume convective therapies. Adequacy of treatment was satisfactory in all SCT schedules while middle molecular weight solute clearance and removal resulted higher in treatments with higher convective component. SCT might represent an interesting option for the future especially in patients with hemodynamic instability and requirements for interventions during treatment.

A linear dominance hierarchy among clones in chimeras of the social amoeba Dictyostelium discoideum

Amoebae from different clones of Dictyostelium discoideum aggregate into a common slug, which migrates towards light for dispersal, then forms a fruiting body consisting of a somatic, dead stalk, holding up a head of living spores. Contributions of two clones in a chimera to spore and stalk are often unequal, with one clone taking advantage of the other's stalk contribution. To determine whether there was a hierarchy of exploitation among clones, we competed all possible pairs among seven clones and measured their relative representation in the prespore and prestalk stages and in the final spore stage. We found a clear linear hierarchy at the final spore stage, but not at earlier stages. These results suggest that there is either a single principal mechanism or additive effects for differential contribution to the spore, and that it involves more than spore/stalk competition.

Co-occurrence in nature of different clones of the social amoeba, Dictyostelium discoideum

The social amoeba, Dictyostelium discoideum, produces a multicellular fruiting body and has become a model system for cell-cell interactions such as signalling, adhesion and development. However, unlike most multicellular organisms, it forms by aggregation of cells and, in the laboratory, forms genetic chimeras where there may be competition among clones. Here we show that chimera formation is also likely in nature, because different clones commonly co-occur on a very small scale. This suggests that D. discoideum will likely have evolved strategies for competing in chimeras, and that the function of some developmental genes will be competitive. Natural chimerism also makes D. discoideum a good model organism for the investigation of issues relating to coexistence and conflict between cells.

Rapid deposition of extensin during the elicitation of grapevine callus cultures is specifically catalyzed by a 40-kilodalton peroxidase

Elicitation or peroxide stimulation of grape (Vitis vinifera L. cv Touriga) vine callus cultures results in the rapid and selective in situ insolubilization of an abundant and ionically bound cell wall protein-denominated GvP1. Surface-enhanced laser desorption/ionization/time of flight-mass spectrometry analysis, the amino acid composition, and the N-terminal sequence of purified GvP1 identified it as an 89.9-kD extensin. Analysis of cell walls following the in situ insolubilization of GvP1 indicates large and specific increases in the major amino acids of GvP1 as compared with the amino acids present in salt-eluted cell walls. We calculate that following deposition, covalently bound GvP1 contributes up to 4% to 5% of the cell wall dry weight. The deposition of GvP1 in situ requires peroxide and endogenous peroxidase activity. Isoelectric focusing of saline eluates of callus revealed only a few basic peroxidases that were all isolated or purified to electrophoretic homogeneity. In vitro and in situ assays of extensin cross-linking activity using GvP1 and peroxidases showed that a 40-kD peroxidase cross-linked GvP1 within minutes, whereas other grapevine peroxidases had no significant activity with GvP1. Internal peptide sequences indicated this extensin peroxidase (EP) is a member of the class III peroxidases. We conclude that we have identified and purified an EP from grapevine callus that is responsible for the catalysis of GvP1 deposition in situ during elicitation. Our results suggest that GvP1 and this EP play an important combined role in grapevine cell wall defense.

Tumor markers in breast cancer monitoring should be scheduled according to initial stage and follow-up time: a prospective study on 859 patients

PURPOSE

The purpose of this study was to identify and standardize optimal decision criteria for maximizing the effectiveness of tumor markers in clinical use during the follow-up of patients operated on for breast cancer.

MATERIALS AND METHODS

The study was prospectively performed on 859 patients enrolled in 10 institutions. A total of 13,337 determinations of CEA and 14,330 determinations of CA15.3 were available. The median number of samples per patient was 16 for CEA and 17 for CA15.3. The median follow-up was 7 years. Receiver-operating characteristic analysis was used to evaluate the ability of CEA and CA15.3 to discriminate relapses from patients who had no evidence of disease. The diagnostic performances of the two markers were evaluated using decision criteria based on both dichotomic cut-off points and dynamic variations among serial samples.

RESULTS

We selected decision levels corresponding to preset levels of 90% and 99% specificity. Patients with CEA and/or CA15.3 levels above the cut-off values were considered positive only if a 1.5-fold increase occurred among the last sample and the mean of the first three samples. According to the different cut-offs used, specificity ranged from 94% to 99% and sensitivity from 48% to 63%. We calculated predictive values using the prevalence expected with reference to the stage of primary tumor and the length of follow-up. Positive predictive values ranged from 1.6% to 93.7%, and negative predictive values from 88.9% to 100%, according to the clinical scenarios and the decision criteria used. The choice of the decision criteria significantly affected positive predictive values within each patient subset. Differences related to time from surgery were still remarkable for every decision criteria (i.e., positive predictive values ranged from 36.6% to 2.8% in node-negative patients according to the year of observation, although the same cut-off point was used).

DISCUSSION

The results of the present prospective study show that different decision criteria may provide different diagnostic performances for the same tumor marker and in the same patient. Therefore, we suggest that different decision criteria be settled and used according to the clinical goals.

Defensive role of secretion of ectal mandibular glands of the wasp Polistes dominulus

Ectal mandibular glands of insects are exocrine glands localized in the anterior-lateral region of the head, close to the base of the mandibles. In social wasps, the gland is composed of secretory cells and a reservoir into which the secretion accumulates. At the time of emission the secretion flows onto a specialized cuticular area on the outside of the base of the mandibles. Secretion of Polistes dominulus is emitted only when wasps are greatly disturbed or in the presence of predators, and its function seems to be mainly defensive. Morphometric studies did not reveal any size differences between the glands of the queens and those of the workers. GC-MS analyses of the glands identified 32 compounds, mainly acids and aldehydes in the range C2-C18. The overall odor, caused by the mixture of aldehydes, is distinct. Workers do not respond strongly to the odor. The secretion probably serves as a warning signal to vertebrate predators.

Use of Dufour's gland secretion in nest defence and brood nutrition by hover wasps (Hymenoptera, Stenogastrinae)

Social wasps of the subfamily Stenogastrinae produce an abdominal secretion that is used in two distinct biological contexts. First, the secretion plays an important role in larval nutrition where it serves as a substrate in which food is placed by the adults for eventual consumption by the larvae. Second, in several species, females apply the same secretion to the substrate on which their nests are constructed, where it constitutes a sticky barrier that defends the immature brood from predation by ants. This paper describes for the first time ant guard construction behaviour of three species of stenogastrine wasps belonging to the genera Eustenogaster and Liostenogaster. The identification of compounds making up these secretions was also performed by gas chromatography-mass spectrometry. Ant guards and brood secretions were similar, with saturated and unsaturated long chain hydrocarbons and alcohols as major components. We further confirm that the glandular source of abdominal secretion is the Dufour's gland. This gland contains the same hydrocarbons, and in the same proportions as ant guards and brood secretion. We discuss the fundamental importance of Dufour's gland secretion in the social life of these wasps by comparing species with and without ant guards within the subfamily.

Ectal mandibular gland in Polistes dominulus (Christ) (Hymenoptera, vespidae): ultrastructural modifications over the secretory cycle

An ultrastructural study was carried out on the secretory activity of the ectal mandibular gland in the wasp Polistes dominulus (foundress and worker females as well as males). Secretory activity in foundresses proceeds slowly during hibernation and early spring, becoming prominent in late spring and then falling sharply during the summer. This sequential pattern of ultrastructural modifications follows a functional, annual cycle. However, by comparing the subcellular changes in the gland with colonial development, it appears that secretory activity fits in with the specie's social cycle rather than merely following the seasons. The highest levels of secretory activity correspond to the early, critical breeding phases, while activity slows down with an increase in colony protection, based on both primary (passive) and secondary (active) defenses, with the emergence of the workers. These correlations suggest that the ectal mandibular gland secretory product in P. dominulus is involved in chemical nest defense.

Antiandrogen drugs lower serum prostate-specific antigen (PSA) levels in hirsute subjects: evidence that serum PSA is a marker of androgen action in women

Assay by ultrasensitive methods of serum prostate-specific antigen (PSA) recently demonstrated that many women have detectable levels of this molecule. Interestingly, serum PSA concentrations were higher in hirsute than in nonhirsute subjects, suggesting that, also in females, PSA may be regulated by androgens. To establish the potential for this assay as a biochemical marker of androgen action in women, we studied 40 hirsute subjects recruited in a double-blind, placebo-controlled, 6-month trial assessing the effects of 3 different antiandrogen drugs: spironolactone, flutamide, or finasteride. In each subject, serum PSA, free testosterone, and 3alpha-androstanediol glucuronide were determined at baseline and at the end of treatments. At baseline, PSA concentrations were higher in these 40 women than in 19 nonhirsute healthy controls (12.9+/-1.5 vs. 4.9+/-0.7 pg/mL, P = 0.03) and significantly correlated with serum free testosterone (r = 0.37, P<0.005). After treatments, the 29 hirsute subjects given active drugs showed significant reduction of serum PSA levels (7.2+/-1.4 vs. 14.7+/-3.0 pg/mL, P = 0.002). This phenomenon was correlated to baseline PSA values. No change was found in the placebo group. In conclusion, serum PSA is increased in many hirsute women. A 6-month course of antiandrogen treatments with spironolactone, flutamide, or finasteride determines a reduction of PSA levels in these subjects. These results suggest that serum PSA is a biochemical marker of androgen action in tissues of female subjects.

Efficacy of 7 day lansoprazole-based triple therapy for Helicobacter pylori infection in elderly patients

BACKGROUND

The prevalence of Helicobacter pylori increases with age. However, data regarding the effects of anti-H. pylori treatments in the elderly are very scarce.

METHODS

To evaluate the effect of three lansoprazole-based, 7 day, triple-therapy regimens on H. pylori eradication rates, symptomatology, chronic gastritis activity and serological markers of H. pylori infection in elderly subjects, we studied 150 symptomatic patients over 60 years of age with H. pylori-positive duodenal ulcer (DU, n = 34), gastric ulcer (GU, n= 19) or chronic gastritis (CG, n = 97). Patients were consecutively treated with one of the following regimens: (A) lansoprazole (LNS) 30 mg b.i.d. + clarithromycin (CLR) 250 mg b.i.d. + metronidazole (MTR) 250 mg q.i.d.; (B) LNS 30mg b.i.d. + amoxycillin (AMOX) 1 g b.i.d. + MTR 250 mg q.i.d.; and (C) LNS 30 mg b.i.d. + CLR 250 mg b.i.d. + AMOX 1 g b.i.d.

RESULTS

Two months after therapy, the eradication rates of the three treatments, expressed using both intention-to-treat and per-protocol analyses were, respectively; group A, 86 and 91.5%; group B, 80 and 87%; group C, 82 and 89.1%. After therapy, a significant reduction in epigastric pain (P<0.001), heartburn (P=0.02), dyspepsia (P<0.001) and vomiting (P< 0.005) was observed independently of the success of H. pylori eradication. A significantly higher percentage of asymptomatic patients were in the GU-DU group than in CG group (87.7 vs 70.0%, P= 0.032). After therapy, 33 subjects still suffered from symptoms. Persistence of symptoms was significantly associated with an endoscopic diagnosis of oesophagitis and not with H. pylori infection. Patients cured of H. pylori infection showed a significant decrease in the histological activity of both antral and body gastritis (P< 0.0001), a significant drop in immunoglobulin (Ig) G anti-H. pylori antibodies (P< 0.0001) and pepsinogen (PG) C (P<0.0001) and an increase in the PGA/PGC ratio (P<0.0001).

CONCLUSIONS

The 7 day, lansoprazole-based triple therapy was well tolerated and highly effective in the cure of H. pylori infection, the reduction of symptoms, chronic gastritis activity and serum levels of IgG anti-H. pylori antibodies and PGC. Persistence of symptoms after therapy was significantly higher in CG than GU and DU patients and was significantly associated with oesophagitis.

Hemodynamic correlates of atrial natriuretic peptide concentration in unselected patients with heart disease of different etiologies

BACKGROUND

Although a large number of studies have investigated the relationship between atrial natriuretic peptide (ANP) concentrations and circulatory abnormalities, it is presently unsettled as to whether this parameter provides valuable information in unselected patients with heart disease of different etiologies regardless of the presence of left ventricular dysfunction or heart failure.

AIM OF THE STUDY

The aim was to evaluate the correlation between ANP, hemodynamics and parameters of ventricular function in a large series of consecutive patients and to define the predictive value of ANP for the identification of specific circulatory abnormalities.

METHODS

Cardiac catheterization was performed in 167 consecutive patients (62% males; mean age 62 yrs; range 18-85) and ANP serum levels were determined concomitantly by single antibody immune assay. Underlying etiology was: ischemic (67), valvular (72), idiopathic (12) and miscellaneous (16). Data management included: comparison of patients according to ANP values > or < 50% percentile of the cumulative distribution curve (i.e. 140 pg/ml); analysis of ANP concentrations according to the presence of normal or abnormal ventricular filling pressures; correlation between hemodynamic parameters and ANP concentrations; correlation of ANP with ventricular function in the whole population and in subgroups; calculation of sensitivity and specificity of ANP for the identification of abnormal filling pressures.

RESULTS

Mean ANP concentration was 181 +/- 139 pg/ml. Patients with ANP < 140 had significantly lower right-sided pressures but similar ventricular volumes and ejection fractions. By multivariate analysis, the single independent predictor of ANP was wedge pressure (p < 0.0001). Regarding etiology, severe mitral regurgitation was associated with the highest ANP levels (259 +/- 122 pg/ml), although the difference was not significant. The presence of abnormal left and right ventricular filling pressures was associated with significantly higher levels of ANP (p < 0.0001). A level of 125 pg/ml proved to be fairly sensitive (79%) but poorly specific (66%) for the detection of an abnormal wedge pressure. ANP was related to ventricular function only in the small subgroup of patients with dilated cardiomyopathy, where a significant negative correlation was found with both left ventricular (r = -0.72; p = 0.008) and right ventricular ejection fraction (-0.71; p = 0.01).

CONCLUSIONS

In unselected cardiac patients, ANP is confirmed to be a marker of left ventricular filling pressure in spite of poor specificity. Ventricular function appears to be related to ANP concentrations only in the subgroup of patients with pure heart-muscle disease.

Heterogeneity of the zona pellucida carbohydrate distribution in human oocytes failing to fertilize in vitro

The mammalian zona pellucida contains several glycoproteins whose oligosaccharide moieties are known to play a key role in the interaction with spermatozoa. Since zona pellucida defects may represent one of the most likely causes of failed fertilization in human in-vitro reproduction, we have studied the carbohydrate composition and distribution over the human zona pellucida by means of lectins. Donated, not inseminated cumulus-oocyte complexes, from cohorts with high fertilization rates, and fertilization-failed oocytes from cohorts inseminated with proven fertile donor semen, were analysed using 11 fluorescein-labelled lectins, on deplasticized semi-thin epoxy sections. Results showed that wheat germ agglutinin (WGA), Maclura pomifera (MPA) and Pisum sativum (PSA) bound to the extracellular matrix bordering the zona pellucida-corona radiata interface of cumulus-oocytes complexes, while the zona pellucida was labelled by WGA, Concanavalin A (ConA) and PSA. WGA labelling and correlative electron microscopy on the cumulus-oocyte complexes demonstrated that this lectin is a useful tool to trace the cortical granule distribution in the human oocyte. Surprisingly, in the failed-fertilized oocytes the zona pellucida was also labelled by MPA and showed three different patterns: (i) labelling of the zona pellucida outer surface; (ii) uniform labelling; (iii) labelling of an outer zona pellucida layer with variable thickness. Comparative analysis of WGA and MPA labelling on single failed-fertilized oocytes demonstrated that MPA zona pellucida patterns are not related to the cortical reaction. The nature and meaning of the MPA pattern of failed-fertilized oocytes were discussed in the light of zona pellucida defects impairing sperm receptivity.

Beta 2-microglobulin removal by synthetic dialysis membranes. Mechanisms and kinetics of the molecule

Beta 2-microglobulin (beta 2-m) accumulation represents a possible complication of long term dialysis. It is therefore important to evaluate the capacity of removal of this molecule from the patient by different dialysis membranes. The present study is aimed at evaluating the mechanisms involved in beta 2-m removal by three different synthetic membranes: a) highly asymmetric hydrophobic polysulfone (Biosulfane, NMC), b) moderately asymmetric and hydrophobic polysulfone (PS600, Fresenius), c) Polyacylonitrile (AN69HF, Hospal). The adsorption capacity and sieving coefficients of the three membranes for native and labeled beta 2-m were studied in vitro utilizing human blood. The amount adsorbed by the membrane was measured by the elution of the molecule obtained with a detergent solution. Clearances, total removal and membrane adsorption were studied in six patients treated in a randomized sequence with the three membranes. For this purpose, plasma and dialysate measurements as well as total collection of spent dialysate and beta 2-m elution from the used dialyzers were carried out. Ex novo generation of beta 2-m did not take place during in vitro circulation. The molecule was removed by the studied membranes both by filtration and adsorption. The Biosulfane membrane removed beta 2-m mostly by adsorption while the PS600 membrane removed beta 2-m almost entirely by filtration. Intermediate behaviour was shown by AN69 membrane. Similar quantities of beta 2-m were removed from the patients with the three membranes. Total removal could only be precisely measured by adding the quantity of beta 2-m eluted from the membrane to the amount recovered in the spent dialysate. Out of total removal, adsorption was more than 90% with Biosulfane, while only 5% with the PS600. These findings contribute to the understanding of the discrepancy found between the clearance measured from the plasma side and that measured from the dialysate side. In conclusion, clearance and sieving measurements for beta 2-m cannot be correctly performed unless the capacity of adsorption of the membrane is taken into account.

Culture of fetal erythroid progenitor cells from maternal blood for non-invasive prenatal genetic diagnosis

Fetal committed erythroid progenitors CFU-E and M-BFU-E released into the maternal circulation during pregnancy are ideal candidates for in vitro proliferation since their lifespan is short and they can form colonies of 100-1000 cells in a semi-solid medium. In order to propagate these cells with a high rate of purity, a strategy was devised based on their prior enrichment with biotin-labelled human erythropoietin ligand and magnetic sorting before culturing in a suitable medium. Eight euploid pregnancies investigated in order to address this issue produced fetal clones in cultures with 18 per cent purity as assessed by polymerase chain reaction (PCR) analysis for Y-specific sequences, immunocytochemical staining for fetal gamma-globin, and fluorescence in situ hybridization (FISH) study. The CFU-E-type colony was the most represented progenitor, followed by M-BFU-E, and only occasionally was the detection of CFU-GEMM recorded. The retrospective diagnosis of two cases of fetal Down's syndrome by culturing fetal cells from maternal blood was accomplished for the first time. FISH analysis disclosed a strong presence of fetal trisomic cells (70 per cent and 40 per cent in the two cases). This strong presence would suggest a preferential leakage into maternal blood. The overall results of this study demonstrate that fetal cells can be cultured in vitro with reliable reproducibility, thus making the prospect of a non-invasive prenatal genetic diagnosis realistic.

A soluble sperm factor gates Ca(2+)-activated K+ channels in human oocytes

PURPOSE

Our goal was to study the activation current in physiologically competent metaphase II human oocytes, i.e., not previously exposed to spermatozoa or aged in vitro, and, in particular, to determine whether a soluble sperm factor triggers a fertilization current comparable to that observed with intact spermatozoa and to characterize the current involved.

METHODS

The whole-cell voltage-clamp technique was used on spare metaphase II oocytes, obtained with patient consent from IVF programs. In this configuration a soluble fraction from human spermatozoa was microinjected, and the current recorded.

RESULTS

Metaphase II human oocytes generate bell-shaped outward currents of 400-1000 pA (X = 706 +/- 322; n = 10), following injection of a cytosolic extract from human spermatozoa. The amount of sperm extract injected was less than 10% of the total oocyte volume and was equivalent to 1-10 spermatozoa. A similar current was generated following exposure to 20 microM of the calcium ionophore A23187 (n = 10). The steady-state conductance of the oocyte increased from 10 to 19.8 nS (n = 10) following injection of the sperm factor and from 5.3 to 27.7 nS following ionophore exposure. Both sperm factor- and ionophore-induced currents were reduced in amplitude when the unfertilized oocyte was preexposed to 25-75 microM iberiotoxin (n = 8) and eliminated at a concentration of 100 microM iberiotoxin.

CONCLUSIONS

The data support the hypothesis of a soluble sperm factor involved in the activation of human oocytes and shows that the initial activation response in the human oocyte is the gating of Ca(2+)-activated K+ channels.

[Acute changes in the hemodynamic profile and circulating levels of atrial natriuretic peptide induced by dobutamine in severe heart failure]

METHODS

Sixteen patients (15 males, 1 female; mean age 63 years, range 45-78) with severe heart failure (NYHA class III = 5; class IV = 11) secondary to ischemic heart disease (8), dilated cardiomyopathy (5) and valvular heart disease (3), were evaluated for eligibility to intermittent Dobutamine (D) treatment. As a part of this evaluation, they were submitted to an acute dose-ranging test with D, up to 10 micrograms/Kg/min under hemodynamic and electrocardiographic monitoring. By inclusion criteria, all patients had:-cardiac index (CI) < 2.2 L/min/m2;-pulmonary wedge pressure (WP) > 18 mmHg;-left ventricular ejection fraction (EF) < 30%. At each step of the procedure, hemodynamic measurements and blood sampling for atrial natriuretic peptide (ANP) concentration were performed.

RESULTS

Peak effect, defined as the dose corresponding to the maximum increase in CI, was reached at a mean of 7.8 +/- 0.5 micrograms/Kg/min. CI increased from 1.7 +/- 0.3 to 2.53 +/- 0.7 L/min/m2 (p < 0.001) and ANP decreased from 234 +/- 112 to 173 +/- 118 pg/ml (p < 0.001). Correspondingly, heart rate, stroke volume index and stroke work index increased, while right atrial pressure (RAP), mean pulmonary artery pressure (PAP), WP, systemic and pulmonary vascular resistance all significantly decreased. Mean arterial pressure was not affected. Changes in ANP concentration correlate significantly with changes in WP and in PAP (r = 0.65, p < 0.05 and r = 0.89, p < 0.001, respectively), but not with changes in RAP (r = 0.26, p = 0.34). Patients showing an increase > 40% in CI or a CI > or = 2.5 L/min/m2 at peak effect (responders) had significantly lower baseline PAP with respect to non-responders. Besides PAP, baseline ANP levels, end-systolic pressure/volume ratio and ejection fraction were also independent predictors of response. The test did not induce complex arrhythmias and was well tolerated in all patients.

CONCLUSIONS

Patients with severe heart failure retain the ability to respond to acute administration of D. with a significant improvement in their hemodynamic profile. Response to D. administration is predicted by lower baseline pulmonary pressure and ANP levels and a lesser degree of left ventricular dysfunction. Despite high baseline ANP concentration, a significant decrease is obtained which parallels the decrease in pulmonary artery and pulmonary wedge pressure, but is not related to changes in right atrial pressure. These findings suggest that changes in left ventricular performance induced by D. are the major determinants of the decrease in ANP concentration in this clinical setting.

Helicobacter pylori infection in asymptomatic elderly subjects living at home or in a nursing home: effects on gastric function and nutritional status

Age and close living conditions are known to be risk factors for the acquisition of Helicobacter pylori (HP) infection. It is unknown whether institutionalization of asymptomatic, elderly subjects is an additional risk factor and whether gastric function and nutritional status are affected by the HP infection. The study sample comprised 102 subjects over 65 years of age: 52 living in a nursing home and 50 at home. No subject had symptoms or previous pathology related to the upper digestive tract. In all subjects, serum levels of specific anti-HP antibodies were determined. Gastric function was evaluated by levels of pepsinogen A (PGA), pepsinogen C (PGC) and gastrin. The nutritional status of the subject was evaluated by measuring: albumin, haemoglobin, iron, ferritin, transferrin, vitamin B12, and folic acid in blood, and body mass index and mid-arm muscle area. The prevalence of anti-HP antibodies was 86.5% in institutionalized subjects (men: 100%; women:76.6%, p <0.05) and 82.0% in subjects living at home (men:86.3%; women:76.3%). No differences between the two groups were observed in levels of serum anti-HP antibodies and PGC was identified. In neither group were differences observed between serum positive (HP + ve) and negative (HP - ve) subjects with respect to the biohumoral and anthropometric indices of nutritional status. We conclude: (1) the seroprevalence of the HP infection was high (82-86%) in asymptomatic elderly patients living either at home or in an institution; (2) the presence of specific IgG anti-HP antibodies in asymptomatic elderly individuals, at home or in a nursing home, was not associated with changes in PGA levels in institutionalized subjects; (3) nutritional indices were not influenced by the presence of anti-HP antibodies.

Vasopressin, atrial natriuretic factor and renal water homeostasis in premature newborn infants with respiratory distress syndrome

Arginine vasopressin (AVP), human atrial natriuretic peptide (hANP), and body fluid and electrolyte balance were examined during the first five days of life in eleven premature infants (birthweight 1610 +/- 240 g, gestation 30 +/- 1 weeks) receiving mechanical ventilation for respiratory distress syndrome (RDS). Plasma hANP and urine AVP concentrations were determined by radioimmunoassay on the first, third and fifth days. Arginine vasopressin urine levels remained constantly elevated during the study period (mean +/- SD 13.5 +/- 7.8 day 1, 12.0 +/- 9.9 day 3, 13.2 +/- 5.1 ng/l day 5, p = n.s.), while plasma hANP was significantly increased on the third day (626 +/- 495 vs. 298 +/- 240 pg/ml on day 1, p < .05). Urine sodium concentration, urine osmolality and osmolality and osmolar clearance were elevated significantly as well on day 3, p < .05, and correlated to hANP levels. Body weight decreased during the study by 8.2% on the third day and by 11.3% of birthweight on the fifth day. A significant increase in creatinine clearance occurred after the third day (p < .01), while free water clearance remained essentially the same during the first five days of life. We speculate that an increase in plasma hANP concentration on day 3 of life results in a natriuresis and osmolar diuresis without correlations or temporal relationships to hypervasopressinemia of the premature neonate with RDS.

Tumor markers in breast cancer follow-up: a potentially useful parameter still awaiting definitive assessment. Forza Operativa Nazionale sul Carcinoma Mammario (FONCaM)

BACKGROUND

Although tumor markers are frequently used in the follow-up of patients with breast cancer, two points are still being debated: 1) their cost/effectiveness has been neither demonstrated nor disproved; 2) the reliability of the currently used dichotomous division into a positive/negative cut-off should be definitely validated. Dynamic criteria of interpretation based on serial serum samples would probably be more effective for early detection of relapse.

PATIENTS AND METHODS

The aim of the present study was to compare the dichotomous cut-off based decision criteria to a dynamic serial sample based assessment of tumor markers. Since 1989, 794 patients have been followed in 11 institutions. CEA and CA15.3 were measured once a month for three months before every clinical examination. The present paper concerns the evaluation variability in 405 patients without evidence of disease in the first three institutions joining the study.

RESULTS

In patients without evidence of disease, the coefficient of variation of all samples for every patient showed a median value of 19 for CEA and 21 for CA15.3. Variability was negatively associated with the antigen level and was most likely due to the analytical component. This was also confirmed by the significant difference in variability among the three institutions evaluated. The median value of the critical difference was 53% for CEA and 57% for CA15.3.

CONCLUSIONS

1) Individually tailored dynamic decision criteria are applicable in about 50% of the cases. 2) The problem of improving the precision of tumor marker assays in the low dose range must be urgently addressed to the manufacturers of tumor markers by the scientific community in order to apply individually tailored decision criteria for patients in whom the serum level of biological markers is low.

A morphological and functional study of fusibility in round-headed spermatozoa in the human

OBJECTIVE

To study the molecular origin and functionality of the plasma membrane of round-head spermatozoa in the human.

DESIGN

Clinical and laboratory study.

SETTING

Patients in a clinical and academic environment.

PATIENTS

Men with round-head spermatozoa.

RESULTS

Pisum sativum lectin homogeneously stains the surface of round sperm; however, the staining pattern and transmission electron microscopy show that the plasma membrane does not alter after exposure to the calcium ionophore A23187. In a clinical program, round-head spermatozoa injected subzonally into metaphase II oocytes with or without pretreatment with the fusogen polyethylene glycol did not bind or fuse to the oocyte surface.

CONCLUSION

The data suggests that plasma membrane fusion in human gametes is regulated by specific surface molecules and that exposure of these molecules on the sperm surface cannot be triggered by elevating intracellular calcium alone.

Single umbilical artery: a Doppler flow velocity study of four cases

We measured the pulsatility index of the umbilical artery in four fetuses identified as having a single umbilical artery. A pulsed color Doppler ultrasound machine was used and measurements were performed at 4-week intervals following the first diagnosis of single umbilical artery (week 22-34). The pulsatility index was derived from the mean of five consecutive measurements at the umbilical insertion of the cord, taking care to obtain the Doppler signal with an incidence angle between +45 degrees and -15 degrees. All measurements were taken during periods of fetal inactivity. The pulsatility index at 22, 26, 30, 34 and 38 weeks in these pregnancies did not differ significantly from the mean values registered in normal pregnancies. The four women gave birth to babies of normal weight: two were healthy, one suffered from bladder extrophy and hemispondyly, the other had bilateral dilatation of the renal pelves, megalocystis, megalourethra and an imperforate anus.

Variability of tumor markers in the follow-up of patients radically resected for breast cancer

The biological and analytical components of variability of tumor markers should be distinguished from the variations due to tumor progression. The aim of the present study was to evaluate tumor marker variability in the follow-up of patients resected for breast cancer. So far, we have carried out 2,085 CEA and 2,550 CA 15-3 determinations in 435 patients. The total variability of both CEA and CA 15-3 was widely scattered among different subjects (CEA coefficient of variation 0-105%; CA 15-3 coefficient of variation 0-89.2%). The biological variability of CA 15-3, which was calculated in a limited number of cases, was scattered between 0 and 23% and was higher than the intra-assay variability. From these findings we conclude that when evaluating serial marker assays the intra-individual variability should be assayed initially to obtain a reference value of individual variability in relapse-free conditions.

Anti-Thy-1 antibody responses evoked by Thy-1 antigen expressed in transfected mouse mastocytoma cells and rat fibroblast

The mouse genomic Thy-1.1 gene was isolated from a phage library constructed from AKR/J (Thy-1.1) mouse DNA. Partial nucleotide sequence analysis of the coding region showed that it has only a single nucleotide difference from the Thy-1.2 gene, namely that amino acid 89 reads CGA (Arg) in Thy-1.1 and CAA (Glu) in Thy-1.2, corresponding to the amino acid substitutions previously identified. It was subcloned into an SV-40 derived vector for transfection. Transient transfection into HeLa cells gave 2% positive staining by immunofluorescence. The gene in this vector was also co-transfected into L cells and mastocytoma cells (both of Thy-1.2 strain origin) together with the Agpt gene. L-cell clones selected for transformation proved almost negative for Thy-1.1 expression, and any positive clones gradually lost Thy-1.1 antigen expression in culture. On the contrary, all clones of mastocytoma transformants gave a high level of expression after more than 3 months in culture. The mastocytoma transformants were used to study the immunogenicity of Thy-1.1 molecules expressed on transfected cells. They evoked clear anti-Thy-1.1 plaque-forming cell (PFC) responses both in vivo and in vitro. The mastocytoma transformants also proved able to induce a T-dependent anti-Thy-1.1 antibody response in a cell transfer experiment. The immunogenicity of Thy-1.2 molecules on rat fibroblasts was also studied after transfection with a Thy-1.2 gene cosmid. Although Thy-1.2 expression was very low, these transfectants elicited a clear anti-Thy-1.2 PFC response from AKR spleen cells hyperimmunized against CBA thymocytes.

[Myelofibrosis caused by cancer: presentation of a clinical case with a very difficult diagnosis]

Fibrosis of the bone marrow or myelofibrosis, is a connective tissue response of the bone marrow, giving rise to alterations of various nature. From an etiological point of view, it may be divided into primitive or secondary forms. Since the therapeutic implications differ, it is important to make a correct differential diagnosis between the 2 forms. With this in mind, particular importance must be given to myelofibrosis secondary to neoplastic metastasis since it frequently presents with a clinical and hematological picture and bone marrow morphology typical of acute or chronic idiopathic myelofibrosis. In such a situation the particular course of the disease and the description fibrosis-sclerosis of the bone marrow are highly suggestive of myelofibrosis secondary to neoplastic metastasis. On the basis of these considerations, we found it interesting to report a case which came under our observations. The patient in this case presented a complex differential diagnosis which offered us the occasion to review and highlight the clinical and histological criteria fundamental to the 2 forms. The patient, a 40 year old woman, presented with a clinical picture typical of myelofibrosis following surgery for a cystic ovary. For 3 years she had felt violent bone pains and had progressively declined in her physical state to the point of cachexia. A careful histological exam of the bone marrow revealed metastasis from the gastric tumor thus giving a clear diagnosis of secondary myelofibrosis.