Improvement of the Pour Plate Method by Separate Sterilization of Agar and Other Medium Components and Reduction of the Agar Concentration

Although the pour plate method is widely employed in microbiological quality control, it has certain drawbacks, including having to melt the culture medium before seeding. In this study, the preparation of the culture medium was modified by using a lower concentration of agar (10 g/L), which was separated from the nutrients during sterilization. The new protocol was assessed in media frequently used in microbiological quality control of food, cosmetics, and pharmaceutical products, with tryptic soy agar (TSA), Sabouraud 4% dextrose agar (SDA), and violet red bile glucose agar (VRBG). In comparison with the conventionally produced media, the modifications significantly improved the growth of Saccharomyces cerevisiae in SDA, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Typhimurium, and Candida albicans in TSA and Escherichia coli ATCC 8739 and ATCC 25922 and S. Typhimurium in VRBG. The modified VRBG was also more selective for Pseudomonas aeruginosa. Regarding physicochemical properties, a significantly lower pH was observed in TSA and VRBG and lower strength values in TSA. Sterilizing agar separately from the other components of the medium and reducing the agar concentration to 10 g/L can improve microorganism growth and enhance the selectivity of differential media in the pour plate method. These modifications could facilitate the automation of this culture technique. IMPORTANCE In the era of rapid microbiological methods, there is a need to improve long-established culture techniques. Drawbacks of the pour plate method include having to melt each medium separately before seeding. For this technique, we demonstrate that separating the agar from the other components of commonly used media during sterilization and reducing the agar concentration to 10 g/L can enhance microbial growth. The new protocol could have advantages in routine laboratory practice because less agar is required and the same molten agar suspension can be used to prepare different media. Moreover, these modifications could facilitate the automation of the pour plate method.

Improvement of Mueller-Kauffman Tetrathionate-Novobiocin (MKTTn) enrichment medium for the detection of Salmonella enterica by the addition of ex situ-generated tetrathionate

The detection of Salmonella in food is based on the use of a selective enrichment broth such as Muller-Kauffman Tetrathionate-Novobiocin (MKTTn), in which tetrathionate plays a key role by providing Salmonella with a growth advantage. As sodium tetrathionate is unstable, it is generated in situ by the addition of iodine (Lugol's solution) before seeding. This step is cumbersome as the solution is easily spilled, compromising the performance of the medium and hindering the work of technicians. The aim of this study was to optimize MKTTn broth by generating tetrathionate ex situ through an external reaction between iodine and thiosulphate followed by lyophilization. Quality control procedures were performed to compare the modified and original media, testing pure productivity (enrichment with 50-120 CFU of Salmonella Thyphimurim ATCC 14028 and Salmonella Enteritidis ATCC 13076 and plating on Xylose Lysine Deoxycholate agar, XLD), mixed productivity (50-120 CFU of Salmonella strains and Pseudomonas aeruginosa and Escherichia coli at ≥10⁴ CFU and XLD plating) and selectivity (≥10⁴ CFU of P. aeruginosa and Enterococcus faecalis and plating on Tryptone Casein Soy agar, TSA). The modified MKTTn medium (S/L) performed comparably with the original medium in terms of growth of both Salmonella strains (>300 colonies in XLD), alone or with P. aeruginosa and E. coli. Quantitative assays showed no statistically significant differences in the number of colonies grown on XLD after 10^-5 dilution (p = 0.7015 with S. Thyphimurim ATCC 14028 and p = 0.2387 with S. enteritidis ATCC 13076; ANOVA test). MKTTn medium (S/L) was also selective against E. coli (≤100 colonies) and E. faecalis (<10 colonies). These results suggest that adding tetrathionate as a lyophilisate (S/L) is a feasible alternative to the use of Lugol's solution for the preparation of MKTTn enrichment broth and does not affect the properties of the medium.

LOXL2-mediated H3K4 oxidation reduces chromatin accessibility in triple-negative breast cancer cells

Oxidation of H3 at lysine 4 (H3K4ox) by lysyl oxidase-like 2 (LOXL2) generates an H3 modification with an unknown physiological function. We find that LOXL2 and H3K4ox are higher in triple-negative breast cancer (TNBC) cell lines and patient-derived xenografts (PDXs) than those from other breast cancer subtypes. ChIP-seq revealed that H3K4ox is located primarily in heterochromatin, where it is involved in chromatin compaction. Knocking down LOXL2 reduces H3K4ox levels and causes chromatin decompaction, resulting in a sustained activation of the DNA damage response (DDR) and increased susceptibility to anticancer agents. This critical role that LOXL2 and oxidized H3 play in chromatin compaction and DDR suggests that functionally targeting LOXL2 could be a way to sensitize TNBC cells to conventional therapy.

Adherence to oral anticoagulants in patients with atrial fibrillation-a population-based retrospective cohort study linking health information systems in the Valencia region, Spain: a study protocol

INTRODUCTION

Adherence to oral anticoagulation (OAC) treatment, vitamin K antagonists or new oral anticoagulants, is an essential element for effectiveness. Information on adherence to OAC in atrial fibrillation (AF) and the impact of adherence on clinical outcomes using real-world data barely exists. We aim to describe the patterns of adherence to OAC over time in patients with AF, estimate the associated factors and their impact on clinical events, and assess the same issues with conventional measures of primary and secondary adherence-proportion of days covered (PDC) and persistence-in routine clinical practice.

METHODS AND ANALYSIS

This is a population-based retrospective cohort study including all patients with AF treated with OAC from 2010 to date in Valencia, Spain; data will be obtained from diverse electronic records of the Valencia Health Agency.

PRIMARY OUTCOME MEASURE

adherence trajectories.

SECONDARY OUTCOMES

(1) primary non-adherence; (2) secondary adherence: (a) PDC, (b) persistence. Clinical outcomes: hospitalisation for haemorrhagic or thromboembolic events and death during follow-up.

ANALYSIS

(1) description of baseline characteristics, adherence patterns (trajectory models or latent class growth analysis models) and conventional adherence measures; (2) logistic or Cox multivariate regression models, to assess the associations between adherence measures and the covariates, and logistic multinomial regression models, to identify characteristics associated with each trajectory; (3) Cox proportional hazard models, to assess the relationship between adherence and clinical outcomes, with propensity score adjustment applied to further control for potential confounders; (4) to estimate the importance of different healthcare levels in the variations of adherence, logistic or Cox multilevel regression models.

ETHICS AND DISSEMINATION

This study has been approved by the corresponding Clinical Research Ethics Committee. We plan to disseminate the project's findings through peer-reviewed publications and presentations at relevant health conferences. Policy reports will also be prepared in order to promote the translation of our findings into policy and clinical practice.

Prevalence of osteoporotic fracture risk factors and antiosteoporotic treatments in the Valencia region, Spain. The baseline characteristics of the ESOSVAL cohort

This study provides information on the prevalence of the most important risk factors for osteoporosis and osteoporotic fracture in a large sample of women and men from the Valencia region and also provides the FRAX 10-year major and hip fracture risks for this population, as well as data about the use of diagnostic tests and antiosteoporotic treatments.

INTRODUCTION

The purpose of this study was to describe demographic characteristics, osteoporosis risk factors, the 10-year risk of osteoporotic fracture, and the use of densitometry and antiosteoporotic treatments in the Valencia region, Spain.

METHODS

A cross-sectional study using the ESOSVAL cohort baseline data was conducted. We analyze the data from 5,310 women and 5,725 men aged 50 and over who attended to 272 collaborating primary care centers in 2009-2010. We collected the demographic, anthropometric, clinical, and pharmacy data from the electronic medical record.

RESULTS

The mean age of participants was 64.3 years old for women and 65.6 years old for men. The most frequent fracture risk factors were sedentary life (22.2 %) and previous fracture (15.8 %) in women and low calcium intake (21.4 %) and current smoker (20.9 %) in men. According to FRAX(®), the 10-year risk of presenting a major fracture was 5.5 % for the women and 2.8 % for the men. The 10-year risk for hip fracture was 1.9 and 1.1 % for the women and the men, respectively; 23.8 % of the women and 5.2 % of the men had a densitometry test, 27.7 % of the women and 3.5 % of the men were taking calcium and/or vitamin D supplements, and 28.2 % of the women (22.0 % in the 50-64 age group) and 2.3 % of the men were taking antiosteoporotic drugs.

CONCLUSIONS

The prevalence of certain fracture risk factors not included in the FRAX tool (sedentary life, falls, low calcium intake) is high. In young women, their low risks estimated by FRAX contrast with the high figures for densitometry testing and treatment.

Agreement between semi-automatic radiographic morphometry and Genant semi-quantitative method in the assessment of vertebral fractures

Semi-automatic morphometry is highly reproducible and not time intensive; however, no study has evaluated agreement between semi-automated morphometric methods and the Genant semi-quantitative method performed as a rule by radiologists. Our study shows substantial agreement between both methods; however, semi-automatic morphometry upgrades mild deformities and overestimates the prevalence of fractures.

INTRODUCTION

The aim of this study was to evaluate the agreement between radiologists using the Genant semi-quantitative (SQ) method and semi-automated morphometry in the diagnosis of vertebral fractures in post-menopausal women.

METHODS

Cross-sectional study was conducted in 2006-2007 in an age-stratified population-based sample of 824 post-menopausal women over the age of 50. From this population two sets of 95 and 50 X-ray were randomly extracted to test inter-rater agreement and agreement between SQ and semi-automated morphometry, and vertebral fractures were classified according to both methods. The Genant method was used to homogenise the diagnosis of fractures. Agreement was evaluated with weighted kappa. We evaluated each vertebral body independently and also the whole vertebral column (T4-L4) classifying women into the worst grade of fracture. For the qualitative interpretation of the agreement, we used the criteria described by Landis and Koch (Biometrics 33:159-174, 1977).

RESULTS

The radiologists' agreement was 98.4% (Kappa, 0.75; 95% CI, 0.42-0.89). Agreement between semi-automated morphometry and SQ reached 97.6% and Kappa was 0.86 (95% CI, 0.66-0.94). In the whole evaluation of the spine semi-automated morphometry overestimates, the prevalence of fractures compared with the radiologists were 15.8% of women with fractures and 7.4% of women with moderate-severe fractures by semi-automated morphometry vs. 8.4% and 3.2% by the SQ method. The negative predictive value for MorphoXpress was 99% while the positive was 40%.

CONCLUSIONS

Semi-automated morphometry shows high reliability and a substantial agreement with the SQ approach but overestimates the prevalence of fractures. Its role in routine clinical practice is limited because positive results should be reassessed by qualitative or semi-quantitative methods.

[Medication errors in a tertiary hospital with three different drug delivery systems]

OBJECTIVE

To estimate the proportion of medication errors in a tertiary hospital, global and for each delivery medication system, to describe the error types and the implied medications, and to analyze the factors associated to the same ones.

METHODS

Errors were identified from direct observation of 2,242 opportunities for error (administered doses or prescribed doses not given) by 6 couples of observers. Delivery medication systems were stock in ward, unit dose with electronic prescription and unit dose with computerized transcription. Logistic regression was used to evaluate the association between errors and certain factors.

RESULTS

The medication error rate was of 7.2% (CI 95%: 6.1-8.3), and 4.4% (CI 95%: 3.6-5.3) of them reached the patient. For delivery systems, the error rate was of 9.5% (CI 95%: 7.4-11.9) for stock in ward, 7.8% (CI 95%: 5.9-10.0) for electronic prescription and 4.7% (CI 95%: 3.4-6.4) for computerized transcription. The highest error frequency was observed in the administration phase (58.4%) and the omitted dose was the most prevalent error (31.7%). The error rate was associated to the pharmacotherapeutic process, the schedule of administration and the unit of hospitalization.

CONCLUSIONS

In one of each 14 opportunities for error a medication error takes place. The different delivery medication systems have different error rates.

[Variations in the use of hospital resources in treating patients with chronic obstructive pulmonary disease]

AIM

To analyze factors associated with the length of stay and pharmaceuticals expense for patients admitted with chronic obstructive pulmonary disease (COPD) and to evaluate whether treatment by different physicians means greater or less use of hospital resources.

METHODS

We retrospectively studied a cohort of 1033 COPD patients admitted to the Hospital de Mataró, Catalonia, Spain, during the years 1996 through 1998 in order to analyze factors associated with length of stay and pharmaceuticals use. We used the Minimum Basic Data Set, laboratory databases, and pharmacy single-dose database. We also analyzed the differences among patients treated by different physicians and developed multiple linear regression models to evaluate differences in treatment between one physician and another.

RESULTS

The length of stay increased with patient age, the number of times admitted, the presence of atrial fibrillation or respiratory insufficiency, ventilatory alterations, chronicity, a forced expiratory volume in 1 second less than 50% of predicted, and treatment by certain physicians. Medication costs showed a similar pattern. Although the characteristics of patients treated by different physicians were quite homogeneous, the median length of stay varied from 9 to 11 days depending on the physician, while the median cost for medication varied from;43.62 to;54.39 (from $41.07 to $51.21). After removing the effects of several covariables by multiple regression analysis, an effect of physician persisted.

CONCLUSIONS

Significant differences in length of hospital stay and consumption of pharmaceuticals are related to attending physician and continue to have an important effect after controlling for the differences in the severity of patient status.

[Abstruse comparisons in abstracts of clinical trials in Spanish medical journals]

BACKGROUND

To describe the frequency of abstracts of clinical trials whose information does not allow to assess the clinical relevance of the comparisons made.

METHOD

Review of 64 trials published in the journals Atención Primaria and Medicina Clínica. Abstracts were defined as quantitative or qualitative abtruse when it was not possible to identify the numerical values used in the comparison or when scales were included without specifying their range and clinical implications, respectively.

RESULTS

43.7% of abstracts were deemed quantitively abstruse, and 75% of 8 including scales were deemed qualitatively abstruse.

CONCLUSIONS

Abstracts of clinical trials should present results in a way that makes it possible to evaluate

The influence of apo E phenotypes on the plasma triglycerides response to hormonal replacement therapy during the menopause

OBJECTIVE

To study the influence of apo E phenotype in plasma lipids, especially in triglycerides levels, in menopausal women receiving hormonal replacement therapy (HRT).

METHODS

One hundred and ten postmenopausal women were studied. Plasma total cholesterol (TC), HDL-C and triglycerides (TG) were measured before and after 3 months of HRT and the apo E phenotype was determined. According to the apo E phenotype the sample was divided into three groups: E2/E3 (n=28), E3/E3 (n=96) and E4/E3 (n=25).

RESULTS

In the pre-treatment state, higher plasma levels of TC and TC/HDL-C ratio were observed in women with phenotype E3/E4 (P<0.0001 and P<0.02, respectively), while higher plasma TG levels were found in the apo E2/E3 group (P<0.0001). After HRT, women with phenotype E3/E4 showed higher levels of TC and TC/HDL-C ratio (P<0.0001 and P<0.006, respectively). The apo E2/E3 phenotype group showed increased levels of TG (P<0.0001). In the multivariant analysis the changes of TG after HRT were related to the type of treatment used (P<0.001), age (P=0.05) and the apo E phenotype (E2/E3).

CONCLUSION

Women with phenotype E2/E3 have higher plasma TG levels and show a significant post HRT increase compared with the other phenotypes. Other factors with a lower impact on TG levels are age and progestagen association.

[Delay in the performance of diagnostic tests and unnecessary hospital stays in lung cancer]

OBJECTIVES

To report among hospitalised patients the proportion of admissions and inappropriate stays, causes for inappropriateness and length in diagnosis delay. To analyse the relationship between patient's characteristics, length of stay and inappropriate use of hospitalization; to evaluate the association between requesting diagnostic tests, stay prolongation and unnecessary use of hospitalization.

METHODS

Prospective cohort of 118 admitted patients because of bronchopulmonary cancer at a university teaching hospital. Length of stay, inappropriate stays and delays in diagnostic tests were analysed.

RESULTS

The mean hospital stay was 16.3 days, with 74.2% of unnecessary stays and relevant intrahospital diagnostic delays, with over five days for obtaining a chest X-ray, almost seven for a computerized tomography, and eight to have pathology results available. The proportion of inappropriate stays was associated with the number and type of requested tests.

CONCLUSIONS

The results of this study suggest a number of possibilities to improve care quality to patients with suspect of lung cancer, both avoiding unnecessary admissions and shortening diagnostic delays. Also, care costs are reduced and hospital beds are reserved for those patients whose clinical status warrant hospital admission.

Outpatient management of upper digestive hemorrhage not associated with portal hypertension: a large prospective cohort

OBJECTIVES

To evaluate the safety of outpatient management of upper GI hemorrhage (UGIH) not associated with portal hypertension.

METHODS

A prospective cohort of 983 subjects who went to the Accident & Emergency Department (A&ED) of a University hospital in Valencia (Spain), for UGIH not associated with portal hypertension during 1994 to 1997 were evaluated. After evaluation in the A&ED, 216 patients (22%) were discharged and referred for outpatient follow-up, but 15 patients could not be located thus, reducing the follow-up to 201 subjects. The main outcome measures were rebleeding within 10 days, emergency surgery within 15 days, and mortality for any cause during the 30 days after the initial hemorrhaging episode.

RESULTS

UGIH in subjects under outpatient care were less severe than those subjects in the hospitalized group. Hemorrhaging recurred in 7.3% of inpatients versus 0.5% of outpatients (p < 0.01); emergency surgery was required in 5.6% of the hospitalized patients and 0.5% of the outpatients (p < 0.01); a total of 20 deaths occurred in the hospitalized group (2.6%), while three (1.5%) occurred in outpatients (p = 0.26). After adjusting for several significant risk factors, outpatient management was not associated with outcomes that were worse.

CONCLUSIONS

Treatment under an outpatient regime is a safe alternative for a large percentage of selected patients with UGIH not associated with portal hypertension.

Activation of Raf-1 is defective in annexin 6 overexpressing Chinese hamster ovary cells

Annexin 6 is a Ca2+-dependent phospholipid-binding protein involved in membrane trafficking. In this study we demonstrate the association of Raf-1 with recombinant rat annexin 6. Raf-annexin 6 interaction was shown to be independent of cell activation by epidermal growth factor (EGF) or phorbol esters (12-O-tetradecanoyl-phorbol-13-acetate (TPA)). A stable Chinese hamster ovary (CHO)-anx6 cell line overexpressing annexin 6 was established to examine the function of annexin 6. In these cells, no increase of Ras-GTP levels, induced by EGF or TPA, was detected. In addition, the activity of Raf was completely inhibited, whereas the mitogen-activated protein kinase-P was unaffected.

Inappropriate use of an accident and emergency department: magnitude, associated factors, and reasons--an approach with explicit criteria

BACKGROUND

We evaluate the appropriateness of medical visits to the accident and emergency department (A&ED) of a university hospital using an instrument based on explicit and objective criteria, analyze the association between inappropriate visits and certain factors, and identify reasons for inappropriate use.

METHODS

This concurrent review of a random sample of 2,980 adult medical patients' visits to the A&ED of the hospital of Elche uses the Hospital Urgencies Appropriateness Protocol, an instrument based on explicit criteria. We analyze the association between inappropriate use and specific factors, and provide a descriptive analysis of reasons for inappropriate use assigned by A&ED staff.

RESULTS

Of the total number, 882 (29.6%) of the visits were evaluated as inappropriate. Inappropriate use was associated with younger patients, use of own means of transportation, referral by the hospital, certain months of the year, and certain diagnostic groups of lesser severity. The most frequent reasons for inappropriate use were the patients' greater trust in the hospital than primary care (451 [51.1%]), inappropriate use of services by patients (160 [18.1%]), and inappropriate referrals by primary care physicians (142 [16.1%]).

CONCLUSION

Inappropriate use represents an important percentage of use of the A&ED. Many reasons contribute to it, although foremost among them is patient preference (and the convenience and accessibility) of these services compared with primary care.

[Factors associated with the use and adaptation of hospitalization in people over than 64 years of age]

BACKGROUND

Some social, medical or functional aspects are associated with a greater use of health care resources, although this does not necessarily imply an inappropriate usage of the same. The aim of this research is that of ascertaining the influence of health condition on hospital stays and inappropriate stays among the population over 64 years of age.

METHODS

A cohort representative of the population over age 64 in the Judicial District of Toledo (n = 3214) whose health condition had been previously evaluated was studied over an eighteen-month period identifying the income and length of stays at the public hospitals, the appropriateness of which was evaluated by the Appropriateness Evaluation Protocol. Associations analyzed were those of the cohort socio-demographic characteristics, health condition-related variables and morbidity with frequency and hospitalization rates and with inappropriate stays and admissions.

RESULTS

During the 18 months of study 410 individuals were hospitalized, who generated 546 admissions (frequency rate = 17.0 admissions/100 rooms) and 7015 stay days (hospitalization rate = 218.3 stays/100 rooms), 18.9% of the admissions and 49.9% of the stays were evaluated as inappropriate. Hospitalization was associated with a worse health condition, institutionalization, male sex, certain pathologies and previous health services usage. Patients characteristics were not associated with the percentage of inappropriate stays. 97.5% of inappropriate stays were attributed to hospital scheduling problems and physicians' practices.

CONCLUSIONS

Socio-demographic factors, morbidity, health condition and previous health service usage are shown as good hospitalization predictors for senior citizens, but these factors are not related to inappropriate hospitalization usage.

[Management of research in healthcare centers. An exploration through nominal group dynamics]

OBJECTIVES

To determine the opinions of hospital and other research organizations managers concerning three questions: 1) the desirability of healthcare centers' managing biomedical research as a specific product; 2) the characteristics that define a "research management" culture as opposed to the current "administration of research" culture and 3) the management instruments needed to implement a "research management" culture.

MATERIALS AND METHODS

A meeting was held with 14 experts from healthcare centers or research organizations from Barcelona, Madrid and Valencia to discuss the three questions and evaluate the relative importance of items comprising the last two with a score system from 1 (little relevance) to 9 (extremely relevant).

RESULTS

The group was in favor of healthcare centers' managing research as a specific and differentiated product. Keys to achieving a management culture (items scoring higher than 7 with the above system) included the development of a culture to evaluate work and external auditing, transversal support and sharing infrastructures and intellectual capital, specific accounting, unified management, prioritization of research lines and capacity for cooperation, and strategic alliances between centers. Management instruments deemed essential (items scoring 7 or higher with the above system) were: support to research foundations or other organizational formulae to ensure autonomy, specific budgetary control, development of support structures and contractual formulae to support autonomy, creativity and researchers' accountability.

CONCLUSIONS

Research conducted in healthcare centers should be managed just as any other product derived from the center's activities. Key points to success are prioritization, evaluation and clear assignation of responsibilities, which requires organizational structures with greater flexibility and specific information systems.

[Drug expenditure in primary care: associated variables and allocation of drug budgets according to health district]

OBJECTIVES

Identify factors explaining variability in prescribing costs after reviewing ecological data related to costs and socio-demographic characteristics of the health care zones in the autonomous region of Valencia, and explore the usefulness of using the model to set prescribing budgets in basic healthcare zones.

MATERIALS AND METHODS

An ecological analysis of the value socio-demographic characteristics and use of healthcare services to explain prescribing costs in 1997. Development of a prediction model based on multiple linear regression in data for prescribing costs in 1997 and validation in data for 1998.

RESULTS

Factors that correlated positively with prescribing costs were the percentage of inhabitants over the age of 80, the death rate, the percentage of inhabitants with only primary education or less, the percentage of inhabitants between the ages of 65 and 79 and the distance from the capital city. A multivariate model including the death rate, the percentage of inhabitants 80 years of age and older, the number of cars per 100 inhabitants and number of visits per inhabitant accounted for 44.5% of the variations in prescribing costs in 1997 and 32% in 1998.

CONCLUSIONS

Socio-demographic factors and certain variables associated with health care utilization can be applied, within certain limitations, to set prescribing budgets in basic healthcare zones.

[Evolution of childhood hospitalization in Spain. Variation among autonomous communities]

BACKGROUND

To describe trends in children hospitalization in Spain during 1985-1994 and its variability among regions.

METHODS

Description between 1985 and 1994, by autonomous regions, of the evolution in the rates of available beds, discharges, stays and visits and average length of stay, from data provided by the health care centres with inpatient statistics.

RESULTS

The average length of stay decreased 23.9%, but there was a 4.5% increase in bed availability, a 39.5% increase in the discharges rate and 36.8% in the visits rate. Regions showed large differences in all indicators, that trends to converge in beds availability and discharges, but not in length of stay and visits rate.

CONCLUSIONS

There has been an increase in hospital performance with strong variation among regions. Differences tends to reduce in some indicators but not in others.

PC12 cells have caveolae that contain TrkA. Caveolae-disrupting drugs inhibit nerve growth factor-induced, but not epidermal growth factor-induced, MAPK phosphorylation

Nerve growth factor (NGF) induces survival and differentiation of the neural crest-derived PC12 cell line. Caveolae are cholesterol-enriched, caveolin-containing plasma membrane microdomains involved in vesicular transport and signal transduction. Here we demonstrate the presence of caveolae in PC12 cells and their involvement in NGF signaling. Our results showed the expression of caveolin-1 by Western blot and confocal immuno-microscopy. The presence of plasma membrane caveolae was directly shown by rapid-freeze deep-etching electron microscopy. Moreover, combined deep-etching and immunogold techniques revealed the presence of the NGF receptor TrkA in the caveolae of PC12 cells. These data together with the cofractionation of Shc, Ras, caveolin, and TrkA in the caveolae fraction supported a role for these plasma membrane microdomains in NGF signaling. To approach this hypothesis, caveolae were disrupted by treatment of PC12 cells with cholesterol binding drugs. Either filipin or cyclodextrin treatment increased basal levels of MAPK phosphorylation. In contrast, pretreatment of PC12 cells with these drugs inhibited the NGF- but not the epidermal growth factor-induced MAPK phosphorylation without affecting the TrkA autophosphorylation. Taken together, our results demonstrate the presence of caveolae in PC12 cells, which contain the high affinity NGF receptor TrkA, and the specific involvement of these cholesterol-enriched plasma membrane microdomains in the propagation of the NGF-induced signal.

[Declaring conflict of interest in scientific publications. Time for the spotlights and stenographers in the backroom of research financed by the industry?]

The term conflict of interests is applied to those situations in which the research validity and integrity may be influenced by a secondary interest, typically an economic benefit, but also an ideological, personal or professional interest. In this work we describe some ways of conflict of interests--particularly those related with the publication of clinical and epidemiological research supported by the industry--and the regulation of this problem from medical journals, including references to the situation in Spain. The conflict of interest is not synonymous of scientific fraud neither malpraxis in research, but in the medical literature there exists enough evidence to consider it as an important source of biases. The usual form of facing the conflict of interests is to make it public, so that readers can judge its importance. The editorial policies of the Spanish journals are, in general, far from giving importance to this problem, an aspect which could favor an attitude of the investigators, to maintain funding or to obtain new contracts, unnecessarily subordinated to the interests of the companies.

Epidermal growth factor-mediated caveolin recruitment to early endosomes and MAPK activation. Role of cholesterol and actin cytoskeleton

The endocytic compartment of eukaryotic cells is a complex intracellular structure involved in sorting, processing, and degradation of a great variety of internalized molecules. Recently, the uptake through caveolae has emerged as an alternative internalization pathway, which seems to be directly related with some signal transduction pathways. However, the mechanisms, molecules, and structures regulating the transport of caveolin from the cell surface into the endocytic compartment are largely unknown. In this study, normal quiescent fibroblasts (normal rat kidney (NRK)) were used to demonstrate that epidermal growth factor causes partial redistribution of caveolin from the cell surface into a cellubrevin early endocytic compartment. Treatment of NRK cells with cytochalasin D or latrunculin A inhibits this pathway and the concomitant activation of Mek and mitotic-activated protein (MAP) kinase; however, if cells were pre-treated with filipin, cytochalasin D does not inhibit the phosphorylation of MAP kinase induced by epidermal growth factor. From these results we conclude that in NRK cells the intact actin cytoskeleton is necessary for the EGF-mediated transport of caveolin from the cell surface into the early endocytic compartment and the activation of MAP kinase pathway.

[Outpatient care of upper gastrointestinal hemorrhage not related to portal hypertension]

BACKGROUND

The handling of upper gastrointestinal hemorrhage (UGH) usually includes the hospitalization of all patients, regardless of severity and prognosis. The aim of this paper is to assess the security of the outpatient control of some UGH, after their assessment in the hospital emergency room.

PATIENTS AND METHODS

Prospective cohort of 533 patients who attended over 1994 and 1995 hospital emergency room for an episode of UGH not linked to portal hypertension. After clinical and endoscopical assessment in the emergency department, 422 cases (79%) were admitted and 111 (21%) discharged for outpatient care. An analysis is presented of the characteristics of both groups, their clinical outcomes and a multivariate analysis to assess the factors associated with the decision to admit the patient.

RESULTS

Outpatients were young, with less comorbidity and better haemodynamic status than hospitalized patients. Most of outpatient cases UGH was due to gastroduodenitis, oesophagitis and Mallory-Weiss syndrome, as opposed to the greater importance of peptic ulcer in those admitted. All outpatients presented clean lesions or haematic remains. 25 (5.9%) hospitalized patients presented rebleeding, vs. only 1 (0.9%) outpatient (p < 0.05). When more severity cases were excluded from hospital group, the differences were not significant. All cases with active bleeding, severe haemodynamic repercussion or without endoscopy were admitted. For the remainder, the decision to admit was associated with the presence of bleeding stigmata, haemodynamic repercussion, some causes of hemorrhage, older age, and urea levels.

CONCLUSIONS

Although the scarce sample do not permit definitive conclusions, results guide towards that a substantial part of UGH not linked to portal hypertension may be monitored without hospitalizing the patient, thereby minimizing care costs and increasing the productive capacity of the hospital, without increasing risks for the patient.

Inter-hospital variations in caesarean sections. A risk adjusted comparison in the Valencia public hospitals

BACKGROUND

The aim of this study was to describe the variability in caesarean rates in the public hospitals in the Valencia Region, Spain, and to analyse the association between caesarean sections and clinical and extra-clinical factors.

METHODS

Analysis of data contained in the Minimum Basic Data Set (MBDS) compiled for all births in 11 public hospitals in Valencia during 1994-1995 (n=36 819). Bivariate and multivariate analyses were used to evaluate the association between caesarean section rates and specific risk factors. The multivariate model was used to construct predictions about caesarean rates for each hospital, for comparison with rates observed.

RESULTS

Caesarean rates were 17.6% (inter-hospital range: 14.7% to 25.0%), with ample variability between hospitals in the diagnosis of maternal-fetal risk factors (particularly dystocia and fetal distress), and the indication for caesarean in the presence of these factors. Multivariate analysis showed that maternal-fetal risk factors correlated strongly with caesarean section, although extra-clinical factors, such as the day of the week, also correlated positively. After adjusting for the risk factors, the inter-hospital variation in caesarean rates persisted.

CONCLUSIONS

Although certain limitations (imprecision of some diagnoses and information biases in the MBDS) make it impossible to establish unequivocal conclusions, results show a high degree of variability among hospitals when opting for caesarean section. This variability cannot be justified by differences in obstetric risks.

Nerve growth factor activation of the extracellular signal-regulated kinase pathway is modulated by Ca(2+) and calmodulin

Nerve growth factor is a member of the neurotrophin family of trophic factors that have been reported to be essential for the survival and development of sympathetic neurons and a subset of sensory neurons. Nerve growth factor exerts its effects mainly by interaction with the specific receptor TrkA, which leads to the activation of several intracellular signaling pathways. Once activated, TrkA also allows for a rapid and moderate increase in intracellular calcium levels, which would contribute to the effects triggered by nerve growth factor in neurons. In this report, we analyzed the relationship of calcium to the activation of the Ras/extracellular signal-regulated kinase pathway in PC12 cells. We observed that calcium and calmodulin are both necessary for the acute activation of extracellular signal-regulated kinases after TrkA stimulation. We analyzed the elements of the pathway that lead to this activation, and we observed that calmodulin antagonists completely block the initial Raf-1 activation without affecting the function of upstream elements, such as Ras, Grb2, Shc, and Trk. We have broadened our study to other stimuli that activate extracellular signal-regulated kinases through tyrosine kinase receptors, and we have observed that calmodulin also modulates the activation of such kinases after epidermal growth factor receptor stimulation in PC12 cells and after TrkB stimulation in cultured chicken embryo motoneurons. Calmodulin seems to regulate the full activation of Raf-1 after Ras activation, since functional Ras is necessary for Raf-1 activation after nerve growth factor stimulation and calmodulin-Sepharose is able to precipitate Raf-1 in a calcium-dependent manner.

[Factors related to functional outcomes and quality of life after knee arthroplasty]

BACKGROUND

The aim of this work was to describe the early evolution of functional capacity and health related quality of life (HRQL) in patients in rehabilitation after knee arthroplasty, and to identify predictive factors of better outcomes.

PATIENTS AND METHODS

Prospective cohort of 141 patients with knee arthroplasty which immediately after the intervention were referred to the rehabilitation unit. The functional capacity (Knee Society Score, KSS) and the HRQL (Medical Outcomes Study Survey Form 36, MOS SF36) were administrated in the first visit and at 3 months of follow-up. Changes between the interval and factors associated to better outcomes were analysed with nonparametric test and multivariate analyses.

RESULTS

Patients with knee arthroplasty experienced an important improvement in the KSS score and in 6 dimensions of the MOS-SF36 (except emotional role and general health). Worst functional status and quality of life at the time of starting rehabilitation, rheumatoid arthritis diagnosis and gender (women) were associated with worse prognosis. Age, comorbidity, study level, work situation, social help, live alone and ambulatory treatment were not associated with outcomes.

CONCLUSIONS

Patients in rehabilitation after knee arthroplasty improve their functional status and quality of life. The identification of factors with worst prognosis could be useful to modify treatments in some patient's groups.

[Patient classification systems in intermediate and long-term stay institutions: evolution and future perspectives]

The importance of long term care sector is increasingly growing. Actually, the use of patient classification systems is a useful tool for the planning and management of health services for chronic and geriatric patients. Despite being much less known, patient classification systems have had a richer and earlier development in the long term care sector than in the acute care sector. Thus, one could could see the evolution from classifications based on the assessment of functional dependency to classifications progressively including variables corresponding to clinical complexity, and finally to complex systems such as RUG-III. Patient classification systems were first utilised as tools for the financing of long term centres, based on the patients' characteristics. Later, their applications have spread out to objectives related to the management of centres, assessment of quality of care, staff allocation level, control of access and national policies. In Spain, the only experience in the use of a patient classification system is the one used by the Catalan Health Care Administration which uses a classification for the financing of their centres.

[The quality assessment from the minimum basic hospital discharge data set]

INTRODUCTION

Risk adjustment is essential before comparing patient outcomes across hospitals. With this aim several risk adjustment systems have been developed, including the well-known diagnosis related groups.

MATERIAL AND METHODS

Narrative review on risk assessment framework from administrative databases, including data quality and system pitfalls.

RESULTS

The risk adjustment systems developed for cost-control aims to group different patient typologies in relation to the predicted use of resources with the aim to develop incentives to cost-reduction; the systems developed for measuring effectiveness have the objective to assess the health care quality. Both systems are useful for clinical, management and health public uses, but they have several pitfalls and their results should be interpreted cautiously.

CONCLUSIONS

Managers and physicians should consider the risk adjustment systems as a valuable resource for decision-making and reducing uncertainty, but not as the scientific referee of hospital quality or hospital efficiency.

[Inappropriate use of pediatric hospitalization]

OBJECTIVE

Our aim was to identify the inappropriate utilization of pediatric hospitalization, its reasons and associated factors.

PATIENTS AND METHODS

Three hundred twenty-three medical records were randomly selected among the patients aged 6 months to 14 years and hospitalized in 1995 in a public hospital of the Community of Valencia. The validated Spanish version of the "Pediatric Appropriateness Evaluation Protocol" was retrospectively applied. The proportions of inappropriate admissions and stays and their reasons were estimated and their association with certain factors analyzed.

RESULTS

Of the admissions 17.7% (95% CI: 13.5-21.8) and 15.5% of the stays (95% CI: 11.5-19.4) were considered inappropriate. The most frequent reason for inappropriate admission was that diagnostic and therapeutic needs might have been solved by ambulatory care. Inappropriate stays were in mot cases (70%) due to that doctors did not pay attention to keeping the patient in the hospital although acute care was no longer needed. Female patients, non-elective admissions, admissions by general pediatricians or traumatology and weekend stays had significantly higher proportions of inappropriate utilization.

CONCLUSIONS

A considerable proportion of inappropriate admissions and stays was observed, although it is in the lower range of those observed in other studies in pediatric patients. The most frequent reasons were attributed to an excessively conservative medical practice.

[Accident and emergency department inappropriate utilization. An evaluation with explicit criteria]

BACKGROUND

Several studies have shown a growth in the number of visits to accident and emergency (A&E) hospital departments with a high proportion of inappropriate utilization. Methods to identify improper use based on implicit criteria limit the comparisons between hospitals. The aim of this study is to know the proportion of inappropriate attendance's in an A&E department and their associated factors, using a method with objective criteria.

METHODS

An instrument based on diagnosis-independent explicit criteria was used to identify inappropriate visits in a random sample of 1845 14-year-old greater patients attended to A&E medical services, and the factors associated with improper demand were analysed.

RESULTS

The proportion of inappropriate attendance's was of the 26,8% (495/1. 845). The unadjusted analysis show that the smaller age, absence of comorbidity, spontaneous visit and some diagnostic groups (diseases of the skin, muscle-skeletal, mental, and bad defined symptoms) were associated to a greater proportion of improper use. Upon adjusting the variables through logistics regression, the age, associated pathology, the spontaneous attendance's and diagnostic groups, maintained the association with improper use, but other variables as woman gender, and night hours were also associated to inappropriate utilization.

CONCLUSIONS

At least the fourth part of the attendance's in the A&E medical services do not require urgent attention. Inappropriate utilization is associated to characteristic of the patient and the attended process.

[Chronic comorbidity and homogeneity in diagnostic related groups]

OBJECTIVE

[corrected] One of the ways to compare the efficiency of different hospitals and services is to evaluate Diagnostic Related Groups (DRGs), with the hypothesis that patients in the same RDG will present homogeneous behavior with respect to length of stay. The object of this study was to evaluate in the context os the National Health System the internal variability of specific DRGs in terms of the patients' comorbidity.

METHODS

On the basis of various comorbidity scores measured with the Charlson index (ChI), we analyzed length of stay, inhospital mortality and emergency readmissions at 30 and 365 days in 106.673 hospitalizations (excluding subjects younger than 17 years of age, and obstetrics and psychiatric patients) in 12 hospitals, and in 17 DRGs selected on the basis of their greater frequency and comorbidity.

RESULTS

In the aggregated analysis, length of stay (from 8.5 days in patients with no comorbidity to 17.0 days in patients with scores higher than 4) and inhospital mortality rates (from 3.7% in patients with no comorbidity to 17.6% in patients with highest score) increased significantly with each level of the Charlson index. The readmission rate at 30 days rose from 4.7% to 10.9% also in step with increases in comorbidity scores. Readmissions at one year varied from 14.8% in patients with scores of 0 to 35.2% in patients with scores of 3-4, and dropped to 27.9% in patients with scores higher than 4. When analysing different DRGs, 8 of the 17 groups studied showed a significantly higher length of stay with increased comorbidity scores. Some DRGs also showed intra-group variability with respect to mortality and readmission, particularly at 365 days.

CONCLUSIONS

Some DRGs show significant internal variability in terms of comorbidity that may be generating a false worse evaluation of the efficiency of hospitals that treat patients with higher comorbidity.

[Inappropriate utilization of pediatric hospitalization. Validation of the pediatric appropriateness evaluation protocol Spanish version]

OBJECTIVE

To validate the Spanish version of the Pediatric Appropriateness Evaluation Protocol (PAEP).

METHODS

The protocol was applied by two independent reviewers to a sample of 104 clinical records of pediatric patients (age 6 months to 14 years) admitted to a general hospital in the Valentian Community. Reliability was tested by comparing their results. Validity was tested by comparing the results of one reviewer with the judgment of three pediatricians. The following measures were calculated: overall agreement (IO), specific agreement (IE), Cohen's κ, inappropriate use ratio, and, to evaluate the predictive value, sensitivity, specificity and positive and negative predictive value.

RESULTS

Interobserver reliability was high: the IO for admissions was 94.2% and 96.2% for days of care. The IE was 66.7% and 75% respectively, and κ showed values of excellent agreement: 0.77 (95% CI 0.59-0.94) for admissions and 0.83 (95% CI 0.68-0.99) for days of care. Validity was moderate: the IO for admissions was 92.35, and 90.4% for days of care. The IE was 60% and 58.3% respectively, and κ showed values of good agreement: 0.70 (95% CI 0.51-0.90) for admissions and 0.68 (95% CI 0.50-0.86) for days of care. Inappropriate use ratio was 1.13 for admissions and 0.73 for days of care. The sensitivity and specificity were high for admissions (80% and 94% respectively), while sensitivity was lower for days of care (64% and 98%). Regarding the prevalence of inappropriate use of this study, the positive predictive value ranged between 71% and 88%, and the negative predictive value ranged between 97% and 91%.

CONCLUSIONS

PAEP has a high reliability, moderate validity and good predictive value face to clinical judgment, and it is a useful instrument for assessing the inappropriate utilization of pediatric hospitalization.

[Validity of the Hospital Emergency Suitability Protocol]

BACKGROUND

Different studies rate the proportional number of visits unsuited to the HER services at 20%-80% of all. This wide range is due, in good part, to no consensus existing as to the definition of the term "emergency" and the ideal degree of assistance for dealing with each possible situation which leads to the use of subjective judgments for evaluating unsuitability. The purpose of this study is that of developing and validating an objective tools for pinpointing unsuitable hospital emergencies.

METHOD

Based on a conceptual framework which included as dimensions the seriousness of the clinical condition of the patient in question, the intensity of the services rendered and some situations which would warrant spontaneous visits being suitable, the Hospital Emergency Suitability Protocol (HESP), a tool entailing explicit criteria for assessing the suitability of the visits to the HER's, and a random sample of 100 emergency room clinical histories, the reliability thereof of observers on an individual and group basis and the validity of judgment and predictive validity thereof as regarding the opinion of experts having been analyzed.

RESULTS

The HESP revealed itself to provide an excellent reliability rate of observers on an individual and group basis (indexes of agreement fond of 99%-100%; kappa statistic of 0.97-1.00), and judgment validity on the borderline between moderate and low (index of agreement found of 68%, kappa statistic 0.39). This low level of agreement is due to the fact that the HESP functions like a highly specific (the inappropriate cases accord to the clinical judgment are evaluated as inappropriate) yet not highly sensitive tool (solely 59% of the cases which the HESP considered to be suitable were evaluated as such by the clinical judgments).

CONCLUSIONS

The HESP acts as a highly reliable tool capable of pinpointing the most clearly unsuitable fraction of the inappropriate visits to the HER's. These characteristics make it useful for drawing comparisons among hospitals and for long-range follow-up or monitoring of actions for lowering the percentages of unsuitable use.