Exploring the Use of Fruit Callus Culture as a Model System to Study Color Development and Cell Wall Remodeling during Strawberry Fruit Ripening

Cell cultures derived from strawberry fruit at different developmental stages have been obtained to evaluate their potential use to study different aspects of strawberry ripening. Callus from leaf and cortical tissue of unripe-green, white, and mature-red strawberry fruits were induced in a medium supplemented with 11.3 µM 2,4-dichlorophenoxyacetic acid (2,4-D) under darkness. The transfer of the established callus from darkness to light induced the production of anthocyanin. The replacement of 2,4-D by abscisic acid (ABA) noticeably increased anthocyanin accumulation in green-fruit callus. Cell walls were isolated from the different fruit cell lines and from fruit receptacles at equivalent developmental stages and sequentially fractionated to obtain fractions enriched in soluble pectins, ester bound pectins, xyloglucans (XG), and matrix glycans tightly associated with cellulose microfibrils. These fractions were analyzed by cell wall carbohydrate microarrays. In fruit receptacle samples, pectins were abundant in all fractions, including those enriched in matrix glycans. The amount of pectin increased from green to white stage, and later these carbohydrates were solubilized in red fruit. Apparently, XG content was similar in white and red fruit, but the proportion of galactosylated XG increased in red fruit. Cell wall fractions from callus cultures were enriched in extensin and displayed a minor amount of pectins. Stronger signals of extensin Abs were detected in sodium carbonate fraction, suggesting that these proteins could be linked to pectins. Overall, the results obtained suggest that fruit cell lines could be used to analyze hormonal regulation of color development in strawberry but that the cell wall remodeling process associated with fruit softening might be masked by the high presence of extensin in callus cultures.

A grounded theory study of the perceptions and meanings associated with gastrostomies among parents of children with palliative needs

BACKGROUND

There is few literature on the difficulties and different meanings of gastrostomy tubes (GST) for parents of children with palliative needs, and what specific palliative care teams contribute to this process.

AIM

To explore the process of information in the decision of performing a gastrostomy and the meanings that parents of children with palliative needs build around them.

DESIGN

Semi-structured interviews which were transcribed and analysed using Grounded Theory.

SETTING/PARTICIPANTS

Parents and caretakers of children admitted in Paediatric Palliative Care Unit of Madrid Autonomous Community (Spain) whose children bore a gastrostomy device.

RESULTS

Two core categories arise ('Fight' and 'The child as a life-meaning generator'). In all the cases, the child supplied the meaning to go on, and the Palliative Care Unit (CPU) helped in the daily care of the child and solving problems derived from the handling of the GT.

CONCLUSIONS

It is necessary to improve the process of giving bad news and to introduce models of health care that focus on parents and child as the center of palliative care. It is also necessary to develop educational programs that enable continuity of care at home for children with palliative needs.

Predictive capacity of prodromal symptoms in first-episode psychosis of recent onset

BACKGROUND

Both the nature and number of a wide range of prodromal symptoms have been related to the severity and type of psychopathology in the psychotic phase. However, at present there is an incomplete picture focused mainly on the positive pre-psychotic dimension.

AIM

To characterize the prodromal phase retrospectively, examining the number and nature of prodromal symptoms as well as their relationship with psychopathology at the onset of first-episode psychosis.

METHODS

Retrospective study of 79 patients experiencing a first-episode psychosis of less than 1 year from the onset of full-blown psychosis. All patients were evaluated with a comprehensive battery of instruments including socio-demographic and clinical questionnaire, IRAOS interview, PANSS, stressful life events scale (PERI) and WAIS/WISC (vocabulary subtest). Bivariate associations and multiple regression analysis were performed.

RESULTS

Regression models revealed that several prodromal dimensions of IRAOS (delusions, affect, language, behaviour and non-hallucinatory disturbances of perception) predicted the onset of psychosis, with positive (22.4% of the variance) and disorganized (25.6% of the variance) dimensions being the most widely explained.

CONCLUSION

In addition to attenuated positive symptoms, other symptoms such as affective, behavioural and language disturbances should also be considered in the definitions criteria of at-high-risk people.

Expression of the β-1,3-glucanase gene bgn13.1 from Trichoderma harzianum in strawberry increases tolerance to crown rot diseases but interferes with plant growth

The expression of antifungal genes from Trichoderma harzianum, mainly chitinases, has been used to confer plant resistance to fungal diseases. However, the biotechnological potential of glucanase genes from Trichoderma has been scarcely assessed. In this research, transgenic strawberry plants expressing the β-1,3-glucanase gene bgn13.1 from T. harzianum, under the control of the CaMV35S promoter, have been generated. After acclimatization, five out of 12 independent lines analysed showed a stunted phenotype when growing in the greenhouse. Moreover, most of the lines displayed a reduced yield due to both a reduction in the number of fruit per plant and a lower fruit size. Several transgenic lines showing higher glucanase activity in leaves than control plants were selected for pathogenicity tests. When inoculated with Colletotrichum acutatum, one of the most important strawberry pathogens, transgenic lines showed lower anthracnose symptoms in leaf and crown than control. In the three lines selected, the percentage of plants showing anthracnose symptoms in crown decreased from 61 % to a mean value of 16.5 %, in control and transgenic lines, respectively. Some transgenic lines also showed an enhanced resistance to Rosellinia necatrix, a soil-borne pathogen causing root and crown rot in strawberry. These results indicate that bgn13.1 from T. harzianum can be used to increase strawberry tolerance to crown rot diseases, although its constitutive expression affects plant growth and fruit yield. Alternative strategies such as the use of tissue specific promoters might avoid the negative effects of bgn13.1 expression in plant performance.

Is the reflux disease questionnaire useful for identifying GERD according to the Montreal definition?

Background

Scales for aiding physicians diagnose gastro-oesophageal reflux disease (GERD) have not been evaluated in terms of their ability to discriminate between troublesome symptoms (TS) and non-troublesome symptoms (NTS). Our objective is to evaluate the ability of the Reflux Disease Questionnaire (RDQ) to identify GERD according to referral of TS, in patients without previous proton pump inhibitor (PPI) treatment and in patients on PPI treatment.

Methods

Patients consulting physicians because of heartburn or acid regurgitation were recruited at 926 primary-care centres in Spain. They were asked to complete several questionnaires including the RDQ, and to define which of their symptoms were troublesome. Information on drug treatment was collected by the physician. We performed a receiver operating characteristic (ROC) curve analysis to ascertain the RDQ's optimum cut-point for identifying TS.

Results

4574 patients were included, 1887 without PPI and 2596 on PPI treatment. Among those without PPI treatment, 1722 reported TS. The area under the curve (AUC) was 0.79 for the RDQ, and the optimum RDQ cut-point for identifying TS was 3.18 (sensitivity, 63.2%; specificity, 80.2%). A total of 2367 patients on PPI treatment reported TS, and the optimum RDQ cut-off value was 3.06 (sensitivity, 65.4%; specificity, 71.8%).

Conclusions

An RDQ score higher than 3 shows good sensitivity and specificity for differentiating TS from NTS among patients without PPI or on PPI treatment. The RDQ is useful in primary care for diagnosis of GERD based on the Montreal definition.

[Prevalence of obesity in the population assisted at primary health care services in Girona, 1995-1999]

OBJECTIVES

To estimate the prevalence of obesity and overweight in the population of Girona (Spain) between 1995 and 1999 and to divide the prevalences in geographical areas according to age and sex.

METHODS

Height and weight were directly measures in 24,554 health care consumers older than 14 years (10,595 men and 13,959 women) treated in four primary health care areas: Girona 1, Girona 4, Salt and Camprodon and in one primary health care center in the province of Girona. Body mas index (BMI) was calcuted by dividing weight in kilograms bye height in meters squared. Obesity was defined as grades II and III of Garrow's index (BMI >= 30 kg/m2) and overweight as degree I (25 kg/m2 >= BMI < 30 kg/m2). Because the sample was not randomized, the prevalences were adequately weighted. The comparison between prevalences in two different primary health care areas for each sex (in the same Garrow's index and age group) was carried out using a parametric test of differences in proportions (Student's t-test). A hierarchical logistic regression was used to compare prevalences in the same grade Garrow's index, controlling for age and sex.

RESULTS

The prevalence of obesity was estimated as 15.6% in men aged from 20-74 years (from 14.0% in Girona 1 to 22.4% in Camprodon) and 17.5% for women (15.6% in Girona 1, 22.7% in Camprodon). The weighted mean was 16.7%. The prevalence of overweight was 44% in men and 33% in women and the weighted mean was 37.8%. The prevalence of obesity was graduated with statistically significant differences between Girona 1, Salt, Girona 4, Camprodon and Sils.

CONCLUSIONS

The estimates of the prevalences of obesity and overweight obtained in this study were closer to those of other studies in similar populations than previously believed. Indeed, the prevalences may be similar to those of the European Union and, in some age groups, to those of the United States.

[Temporary disability: analysis strategies]

OBJECTIVES

To apply different regression models to estimate rate ratios for temporary sick-leave (TSL) which may occur several times in the same individual during a period, and the frequency is not constant for the observation period.

SUBJECTS AND METHODS

All workers employed more than 30 days between January 1st of 1992 and June 1st of 1995 were included into the population study. The following period was 1,259 days and the total number of workers included in the study was 2,306. During that period 2,649 TSL episodes were notified, which meant 85,947 lost days. Poisson regression, Generalised Estimating Equations (GEE) and Andersen-Gill modification of Cox regression modify by Wei (WLW) were applied.

RESULTS

The highest TSL incidence rates were seen in women, lesser than 30 years old, cleaners, maintenance workers and auxiliary nurses, and those involved in shiftwork. This profile was not modified after applying GEE and WLW regression models, although confidence intervals were widened.

CONCLUSIONS

TSL data does not fit Poisson regression assumptions, but GEE and WLW regression models do not appear as alternatives. Other conditional regression models would need to be explored to suitably analyse this data.