Genome size variation and incidence of polyploidy in Scrophulariaceae sensu lato from the Iberian Peninsula

BACKGROUND AND AIMS

In the last decade, genomic studies using DNA markers have strongly influenced the current phylogeny of angiosperms. Genome size and ploidy level have contributed to this discussion, being considered important characters in biosystematics, ecology and population biology. Despite the recent increase in studies related to genome size evolution and polyploidy incidence, only a few are available for Scrophulariaceae. In this context, we assessed the value of genome size, mostly as a taxonomic marker, and the role of polyploidy as a process of genesis and maintenance of plant diversity in Scrophulariaceae sensu lato in the Iberian Peninsula.

METHODOLOGY

Large-scale analyses of genome size and ploidy-level variation across the Iberian Peninsula were performed using flow cytometry. One hundred and sixty-two populations of 59 distinct taxa were analysed. A bibliographic review on chromosome counts was also performed.

PRINCIPAL RESULTS

From the 59 sampled taxa, 51 represent first estimates of genome size. The majority of the Scrophulariaceae species presented very small to small genome sizes (2C ≤ 7.0 pg). Furthermore, in most of the analysed genera it was possible to use this character to separate several taxa, independently if these genera were homoploid or heteroploid. Also, some genome-related phenomena were detected, such as intraspecific variation of genome size in some genera and the possible occurrence of dysploidy in Verbascum spp. With respect to polyploidy, despite a few new DNA ploidy levels having been detected in Veronica, no multiple cytotypes have been found in any taxa.

CONCLUSIONS

This work contributed with important basic scientific knowledge on genome size and polyploid incidence in the Scrophulariaceae, providing important background information for subsequent studies, with several perspectives for future studies being opened.

Cytotype distribution at a diploid-hexaploid contact zone in Aster amellus (Asteraceae)

BACKGROUND AND AIMS

The present study aims to assess the diversity and distribution of cytotypes of Aster amellus in central and eastern Europe, contributing with data to improve understanding of the evolutionary dynamics of the contact zone between diploids and hexaploids of this polyploid complex.

METHODS

Large-scale cytotype screening of 4720 individuals collected in 229 populations was performed using 4',6-diamidino-2-phenylindole (DAPI) flow cytometry. Fine-scale cytotype screening was performed in the mixed-ploidy population. Reproductive variables, such as number of florets per flower head, seed set and seedling emergence, as well as ploidy level of seeds and seedlings were recorded in this population.

KEY RESULTS

The diploid-hexaploid contact zone is large and complex, reaching the Czech Republic in the west, Austria in the south, Poland in the north-east and Romania in the extreme east of the surveyed areas. Most populations presented only one cytotype, either diploid or hexaploid. In several areas of the contact zone both cytotypes were found to grow in parapatry. One mixed-ploidy population of diploids and hexaploids was detected for the first time, but no signs of hybridization were detected. In this population, diploids had a significantly lower reproductive success, and significantly higher production of intercytotype offspring, being in reproductive disadvantage in comparison with hexaploids.

CONCLUSIONS

The contact zone of diploid and hexaploid A. amellus in central and eastern Europe seems to be highly dynamic and diffuse, with both primary and secondary contacts being possible. The obtained results suggest the origin of hexaploids through diploids, overall supporting previous hypotheses that this species is autopolyploid. Data from the only mixed-ploidy population detected so far suggest that the minority cytotype exclusion is an important evolutionary mechanisms driving the prevalence of single-cytotype populations, and thus contributing to the current distributional patterns of the cytotypes of A. amellus.

Genes involved in lactose catabolism and organic acid production during growth of Lactobacillus delbrueckii UFV H2b20 in skimmed milk

There are three main reasons for using lactic acid bacteria (LAB) as starter cultures in industrial food fermentation processes: food preservation due to lactic acid production; flavour formation due to a range of organic molecules derived from sugar, lipid and protein catabolism; and probiotic properties attributed to some strains of LAB, mainly of lactobacilli. The aim of this study was to identify some genes involved in lactose metabolism of the probiotic Lactobacillus delbrueckii UFV H2b20, and analyse its organic acid production during growth in skimmed milk. The following genes were identified, encoding the respective enzymes: ldh – lactate dehydrogenase, adhE – Ldb1707 acetaldehyde dehydrogenase, and ccpA-pepR1 – catabolite control protein A. It was observed that L. delbrueckii UFV H2b20 cultivated in different media has the unexpected ability to catabolyse galactose, and to produce high amounts of succinic acid, which was absent in the beginning, raising doubts about the subspecies in question. The phylogenetic analyses showed that this strain can be compared physiologically to L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis, which are able to degrade lactose and can grow in milk. L. delbrueckii UFV H2b20 sequences have grouped with L. delbrueckii subsp. bulgaricus ATCC 11842 and L. delbrueckii subsp. bulgaricus ATCC BAA-365, strengthening the classification of this probiotic strain in the NCFM group proposed by a previous study. Additionally, L. delbrueckii UFV H2b20 presented an evolutionary pattern closer to that of probiotic Lactobacillus acidophilus NCFM, corroborating the suggestion that this strain might be considered as a new and unusual subspecies among L. delbrueckii subspecies, the first one identified as a probiotic. In addition, its unusual ability to metabolise galactose, which was significantly consumed in the fermentation medium, might be exploited to produce low-browning probiotic Mozzarella cheeses, a desirable property for pizza cheeses.

Unusual heterostyly: style dimorphism and self-incompatibility are not tightly associated in Lithodora and Glandora (Boraginaceae)

BACKGROUND AND AIMS

Heterostyly is a floral polymorphism characterized by the reciprocal position of stamens and stigmas in different flower morphs in a population. This reciprocal herkogamy is usually associated with an incompatibility system that prevents selfing and intra-morph fertilization, termed a heteromorphic incompatibility system. In different evolutionary models explaining heterostyly, it has been alternately argued that heteromorphic incompatibility either preceded or followed the evolution of reciprocal herkogamy. In some models, reciprocal herkogamy and incompatibility have been hypothesized to be linked together during the evolution of the heterostylous system.

METHODS

We examine the incompatibility systems in species with different stylar polymorphisms from the genera Lithodora and Glandora (Boraginaceae). We then test whether evolution towards reciprocal herkogamy is associated with the acquisition of incompatibility. To this end, a phylogeny of these genera and related species is reconstructed and the morphological and reproductive changes that occurred during the course of evolution are assessed.

KEY RESULTS

Both self-compatibility and self-incompatibility are found within the studied genera, along with different degrees of intra-morph compatibility. We report for the first time extensive variability among members of the genus Glandora and related species in terms of the presence or absence of intraspecies polymorphism and heteromorphic incompatibility. Overall, our results do not support a tight link between floral polymorphism and incompatibility systems.

CONCLUSIONS

The independent evolution of stylar polymorphism and incompatibility appears to have occurred in this group of plants. This refutes the canonical view that there is strong linkage between these reproductive traits.

Interaction among Arachis hypogaea L. (peanut) and beneficial soil microorganisms: how much is it known?

The leguminous crop Arachis hypogaea L. (peanut) is originally from South America and then was disseminated to tropical and subtropical regions. The dissemination of the crop resulted in peanut plants establishing a symbiotic nitrogen-fixing relationship with a wide diversity of indigenous soil bacteria. We present in this review, advances on the molecular basis for the crack-entry infection process involved in the peanut-rhizobia interaction, the diversity of rhizobial and fungal antagonistic bacteria associated with peanut plants, the effect of abiotic and biotic stresses on this interaction and the response of peanut to inoculation.

Pistil anatomy and pollen tube development in Polygala vayredae Costa (Polygalaceae)

Low seed ovule ratios have been observed in natural populations of Polygala vayredae Costa, a narrowly endemic species from the oriental pre-Pyrenees. To evaluate physical and nutritional constraints and pollen tube attrition in this endemic species, stigma and style anatomy, as well as pollen tube development along the pistil were investigated using light and fluorescence microscopy. The structural morphology of the stigmatic region was also examined with scanning electron microscopy. Pollen grains that reached the stigmatic papillae came into contact with a lipid-rich exudate and germinated easily. Although a large number of pollen grains reach the stigmatic papillae, few pollen tubes were able to grow into the style towards the ovary. The style was hollow, with the stylar channel beginning a few cells below the stigmatic papillae. Initially, the stylar channel area was small compared to other levels of the style, and was surrounded by lipid-rich, highly metabolic active cells. Furthermore, lipid-rich mucilage was detected inside the stylar channel. At subsequent style levels towards the ovary, no major reserves were detected histochemically. The reduced intercellular spaces below the stigmatic papillae and the reduced area of the stylar channel at its commencement are suggested to physically constrain the number of pollen tubes that can develop. In subsequent levels of the style, the stylar channel could physically support a larger number of pollen tubes, but the lack of nutritional reserves cannot be disregarded as a cause of pollen tube attrition. Finally, the number of pollen tubes entering the ovary was greater than the number of ovules, suggesting that interactions occurring at this level play a major role in the final reproductive outcome in this species.

First Report of Clover yellow vein virus in Grain Legumes in Spain

From 1999 to 2002, field surveys were conducted in the legume-growing areas of Spain including Ávila, Badajoz, Cádiz, Córdoba, León, Málaga, Murcia, Salamanca, and Zamora provinces. Leaf tissue from 35 asymptomatic and 224 virus symptomatic plants was sampled and analyzed by indirect-ELISA with a specific monoclonal antibody against the potyvirus group (Adgia, Elkhart, IN). All symptomatic plants of bean (Phaseolus vulgaris L.), broad bean (Vicia faba L.), lentils (Lens culinaris L.), and chickpea (Cicer arietinum L.) were positive for potyvirus infection. Identification as Bean yellow mosaic virus (BYMV) was obtained by double-antibody sandwich (DAS)-ELISA with a polyclonal antiserum (Loewe Biochemica Gmbh, Sauerlach, Germany). To analyze the genetic variability of BYMV Spanish isolates, 33 Spanish isolates were selected at random from our BYMV collection, and extracts from these plants were used with primers 1985 (5'-gagagaatgatacacatactgaa-3') and 1984 (5'-caaggtgagtggacaatgatgg-3') to amplify by immunocapture (IC)-reverse transcription (RT)-PCR a 524-nt fragment of the BYMV genome that includes the C-terminal 417 nt of the coat protein and 107 nt from the 3' untranslated region. The IC-RT-PCR products were cloned into pGEM-T easy vector (Promega, Madison, WI) and a minimum of three clones from each PCR amplification were sequenced. BLAST analysis showed that the sequences of 30 samples were 96 to 98% identical to BYMV, but three samples (GenBank Accession Nos. EU860364-66) from bean, broad bean, and lentils had a high (98%) identity with Clover yellow vein virus (ClYVV). Sequence alignments of the ClYVV Spanish isolates and 14 ClYVV isolates from the GenBank (Accession Nos. AB03308, AB004545, AB011819, AF185959, AF203536, D86044, S77521, D95538-94) were obtained using the Clustal X software. Genetic distances were estimated using the Kimura two-parameter method. Within-population and between-population nucleotide diversities were estimated from the genetic distances (2). ClYVV sequences were phylogenetically separated into two clades: one with the three isolates from Japan (Accession Nos. D89542, D89543, and D89544) and the other with the remaining isolates. Molecular clustering coincides with biology and serological variations of strains 1 and 2 (3). Phylogenetic distances were independent of geographic origin, host, or time of sampling. The nucleotide diversity value among populations (0.18) was higher than within the subpopulations (0.017 and 0.029). dNS/dS in the ClYVV population was 0.031 (<1) and we can conclude that negative selection is occurring in the gene in study and that the population of ClYVV present in Spain is homogenous. In Spain, ClYVV was reported infecting borage (Borago officinalis L.) (1). To our knowledge, this is the first report of natural infection of bean, broad bean, and lentils with ClYVV in Spain. ClYVV might cause important economic losses in grain legumes since it causes an important viral disease of legumes worldwide. References: (1) M. Luis-Arteaga et al. Plant Pathol. 45:38, 1996. (2) M. Nei and T. Gojobori. Mol. Biol. Evol. 3:418, 1986. (3) T. Sasaya et al. Virology 87:1014, 1987.

Effect of pollination on floral longevity and costs of delaying fertilization in the out-crossing Polygala vayredae Costa (Polygalaceae)

BACKGROUND AND AIMS

The effect of pollination on flower life span has been widely studied, but so far little attention has been paid to the reproductive consequences of delayed pollination in plants with long floral life spans. In the present study, Polygala vayredae was used to answer the following questions. (1) How does male and female success affect the floral longevity of individual flowers? (2) How does delaying fertilization affect the female fitness of this species?

METHODS

Floral longevity was studied after experimental pollinations involving male and/or female accomplishment, bagging and open pollination. The reproductive costs of a delay in the moment of fertilization were evaluated through fruit set, seed-ovule ratio and seed weight, after pollination of flowers that had been bagged for 2-18 d.

KEY RESULTS

Senescence of the flowers of P. vayredae was activated by pollen reception on the stigmatic papillae, while pollen removal had no effect on floral longevity. Nonetheless, a minimum longevity of 8 d was detected, even after successful pollination and pollen dissemination. This period may be involved with the enhancement of male accrual rates, as the female accomplishment is generally achieved after the first visit. Floral life span of open-pollinated flowers was variable and negatively correlated with pollinator visitation rates. Delayed pollination had a major impact on the reproductive success of the plant, with fruit set, seed-ovule ratio and seed weight being significantly diminished with the increase of flower age at the moment of fertilization.

CONCLUSIONS

A strong relationship between pollination and floral longevity was observed. Flowers revealed the ability to extend or reduce their longevity, within some limits, in response to the abundance of efficient pollinators (i.e. reproductive fulfilment rates). Furthermore, with scarce or unpredictable pollinators, a long floral life span could maintain the opportunity for fertilization but would also have reproductive costs on production of offspring. Reduced female fitness late in the flower's life could shift the cost-benefit balance towards a shorter life span, partially counteracting the selection for longer floral life span potentially mediated by scarce pollination services.

How does secondary pollen presentation affect the fitness of Polygala vayredae (Polygalaceae)?

Secondary pollen presentation is the relocation and presentation of pollen in floral structures (termed pollen presenters) other than the anthers. These pollen presenters are often found close to the stigma and have been hypothesized to increase the accuracy of pollen transfer, although no experimental studies have been done. We examined the function of the pollen presenter and its efficiency in pollen dispersal, female fitness, and the degree of interference created by self-pollen in the shrublet Polygala vayredae, an insect-pollinated species with secondary pollen presentation. Herkogamy, a mechanism generally involved in the reduction of self-interference, was also evaluated. Significant pollen was lost (49% of total pollen) during the secondary relocation in the pollen presenter. However, pollen was exported from the pollen presenter, and subsequent pollen losses were similar to those in species with primary pollen presentation. Despite the presence of a self-incompatibility system, the numbers of developed pollen tubes as well as fruit and seed production were significantly reduced by the self-pollen interference created at the stigmatic papillae level. The extent of herkogamy correlated positively with female fitness. The secondary pollen presentation mechanism may in fact be an accurate system for pollen transport, but it may also have its costs. Further comparative studies involving species with primary and secondary pollen presentation are needed to fully understand the advantages and disadvantages of secondary pollen presentation.

Distribution of flower morphs, ploidy level and sexual reproduction of the invasive weed Oxalis pes-caprae in the western area of the Mediterranean region

BACKGROUND AND AIMS

Oxalis pes-caprae is a widespread invasive weed in regions with a Mediterranean climate. In its native habitat (southern Africa) this species has been reported as heterostylous with trimorphic flowers and a self- and morph-incompatible reproductive system. In most of the areas invaded, only a pentaploid short-styled morphotype that reproduces mainly asexually by bulbils is reported, but this has only been confirmed empirically. This study aims to analyse the floral morph proportions in a wide distribution area, test the sexual female success, and explain the causes of low sexual reproduction of this species in the western area of the Mediterranean Basin.

METHODS

Fifty-five populations of O. pes-caprae were sampled in the Iberian Peninsula and Morocco to evaluate the floral morph ratio and individual fruit set. In plants from a dimorphic population, hand-pollination experiments were performed to evaluate the effect of the pollen source on pollen tube growth through the style. The ploidy level and genome size of individuals of each floral morph were analysed using flow cytometry.

KEY RESULTS

From the populations studied 89.1 % were monomorphic, with most of them containing the short-styled (SS) floral morph, and 10.9 % were dimorphic containing long-styled (LS) and SS morphs. In some of these, isoplethy was verified but no fruit production was observed in any population. A sterile form was also recorded in several populations. Hand-pollination experiments revealed that pollen grains germinated over recipient stigmas. In intermorph crossings, pollen tubes were able to develop and fruit initiation was observed in some cases, while in intramorph pollinations, pollen tube development was sporadic and no fruit initiation was observed. All individuals within each floral form presented the same DNA ploidy level: SS plants were pentaploid and LS and the sterile form were tetraploid.

CONCLUSIONS

The low or null sexual reproduction success of this species in the area of invasion studied seems related with the high frequency of monomorphic populations, the unequal proportion of floral morphs in dimorphic populations and the presence of different ploidy levels between SS and LS morphs. The discovery of the occurrence of an LS floral morph and a sterile form, whose invading capacity in these areas is as yet unknown, will be valuable information for management programmes.

Glutamate Is Involved in Acid Stress Response in Bradyrhizobium sp. SEMIA 6144 (Arachis hypogaea L.) Microsymbiont

In the present study, the effect of acid stress on ammonium assimilation in Bradyrhizobium sp. SEMIA 6144 (Arachis hypogaea L.) microsymbiont was analyzed. The bacterial growth rate was decreased by 50%, and a significant increase in intracellular glutamate concentration was detected when the strain grew at acid pH (5.5). Assays of the enzymes involved in glutamate synthesis showed increased activities of glutamine synthetase (GS) and glutamate synthase (NADPH-GOGAT) under acid stress condition. This would support the contention that the GS/NADPH-GOGAT pathway contributes to the increase of glutamate synthesis as a compatible solute in response to acid stress.

Utilisation du rt-PA intraveineux dans l’ischémie cérébrale en Centre Hospitalier Général : l’expérience de l’Hôpital Saint-Jean de Perpignan

INTRODUCTION

Intravenous recombinant tissue plasminogen activator (rt-PA) has approval for use despite of its authorization for treatment of ischemic stroke within the 3-hour time window in 2003, is rarely used in community hospital (CH). It therefore remains questionable if the positive results of the key studies conducted in specialized centers may be extended to community hospitals less specialized in the management of stroke.

METHODS

We report the results of an observational cohort study including 39 patients treated with intravenous rt-Pa (according to the NINDS rt-PA stroke trail treatment protocol) at St Jean Hospital (Perpignan, France) between March 1, 2002 and August 31, 2005. Results are compared to those of the treated arm of the NINDS study.

RESULTS

1.2p.cent of ischemic stroke were treated with intravenous rt-Pa. Results are similar to those of the NINDS study: The outcome was favorable (modified Rankin score (mRS) with 0 or 1) for 44p.cent of the patients (as compared to 39p.cent in the NINDS study (X2 = 0.34; p = 0.5)) and there was no significant difference in term of death or outcome as assessed by mRS at 3 months (X2 = 0.09; p = 0.75 and X2 = 0.77; p = 0.75, respectively). No symptomatic hemmorrhagic transformation related to the use of rt-Pa was observed.

CONCLUSION

Our results indicate that rt-PA therapy for ischemic stroke may be as safe and effective in the setting of a community hospital as it is in specialized centers.

Isolation in cell culture and detection by PCR-based technology of IPNV-like virus from leucocytes of carrier turbot, Scophthalmus maximus (L.)

A non-destructive procedure was utilized to determine the infectious pancreatic necrosis virus (IPNV) status of an apparently healthy turbot broodstock. Blood samples were used to detect IPNV by reverse transcriptase-polymerase chain reaction (RT-PCR), Southern blot hybridization and nested PCR. In addition, viral isolation from turbot leucocytes was performed. Around 22% of the fish were IPNV positive by RT-PCR, and this increased to close to 60% when nested PCR was performed. The present report supports the use of blood samples for the detection of IPNV-like viruses in brood fish. In addition, we demonstrate that it is possible to isolate the virus from the blood of carrier fish, as a non-lethal detection method, although it is much less sensitive than RT-PCR and nested PCR as a IPNV-like strain was isolated from only five of the 15 blood sample pools assayed. The viral isolate was identified as type Dry Mills (genogroup I) by means of restriction fragment length polymorphisms and DNA sequencing.

[Meningioma of the olfactory groove: review of a series of 27 cases]

OBJECTIVE

To describe our experience with olfactory groove meningiomas, analysing their clinical and radiological form of presentation and their surgical treatment.

METHODS

The clinical records of 27 patients diagnosed of olfactory groove meningioma, extracted from the series of meningiomas operated on in our department since 1973, were retrospectively reviewed. Demographical data, the clinical presentation and duration of the symptoms before diagnosis were collected. Several radiological characteristics were also reviewed such as the tumour size, associated brain edema, type of contrast enhancement, presence of endostosis and invasion of the cranial base. The surgical resection grade, the histological type and the presence of recurrences in the follow-up were also analysed.

RESULTS

The average age at presentation was 59 years. Average duration of symptoms prior to diagnosis was 39 months. The most frequent symptom at presentation was higher function impairment (52%), The average maximum tumoral diameter was 6.2 cm. 61% of the patients presented moderate or severe brain edema, which was quite frequently bilateral (74%). Radiological endostosis was present in 37% of the cases, but there were no signs of bone invasion in any case. The approach used was the basal frontal, uni or bilateral. In all cases the grade of resection was Simpson II. The majority of the cases presented a typical histology. Over 80% of the cases presented a good recovery at discharge. None of the patients presented with a tumoral recurrence after an average radiological follow-up of 74 months.

CONCLUSIONS

The olfactory groove is an infrequent location for intracranial meningiomas, accounting for only 4.5% of all meningiomas in our experience. These tumours reach a big size due to the delay in diagnosis. Drilling of the cranial base does not seem necessary for preventing tumoral recurrence.

Microcosm studies on the persistence of peanut inoculant in acid soil and its interaction with indigenous soil micro-organisms

The effect of a native peanut (Arachis hypogaea) microsymbiont strain (streptomycin resistant mutant) introduced into acid soil on the indigenous micro-organism population as well as the survival of this isolate was studied. Although the isolate survived at a fairly low population level after the 3 month period of soil incubation, it maintained its antibiotic resistance. Slight changes in the total bacteria and fungi soil populations as a result of this inoculation were also detected.

Forearm bone density in long-term users of oral combined contraceptives and depot medroxyprogesterone acetate

OBJECTIVE

To compare the bone mineral density of users of combined oral contraceptives (OC) or depot medroxyprogesterone acetate (depot-MPA) with women who have never used a hormonal contraceptive method.

DESIGN

Cross-sectional study.

SETTING

Academic tertiary-care hospital.

PATIENT(S)

A total of 189 women, aged 30 to 34 years old, were allocated to three groups: 63 who had used OC for at least 2 years; 63 who had used depot-MPA for at least 2 years; and 63 control women who had never used hormonal contraceptives.

INTERVENTION(S)

Each woman's bone mineral density (BMD) was evaluated at the distal and ultradistal section of the radius of the nondominant forearm by the use of single x-ray absorptiometry.

MAIN OUTCOME MEASURE(S)

We obtained BMD measurements for each participant.

RESULT(S)

Independent of the period of use and the section of the forearm studied, we found no difference in BMD for OC or depot-MPA users when compared to women who had never used hormonal contraceptive methods. In addition, BMD was similar between OC users and depot-MPA users. The multiple linear regression analysis showed that the variables associated with BMD were weight, number of pregnancies, and the woman's occupation.

CONCLUSION(S)

Women aged 30 to 34 years who have used OC or depot-MPA have similar BMD as control women. These findings suggest that the use of OC or depot-MPA does not affect the BMD of women in this age group.

Diagnosis disclosure in a Portuguese oncological centre

The disclosure of a diagnosis of cancer to patients is a controversial matter. There have been major differences in practice concerning this issue through time and between cultures. A questionnaire was sent to the doctors of the Oporto Centre of the Portuguese Institute of Oncology in order to assess their attitudes. We received 45 responses (40%) from the 113 questionnaires sent. Of these, 32 (71%) said that they disclose the diagnosis as a general policy or at the patients' request, and 13 (29%) disclose it rarely or not at all. The most frequent reason indicated by these 13 physicians was that the disclosure might damage the patients psychologically. Forty-four (98%) doctors inform the family of the diagnosis. Thirty-nine (87%) think that patients are satisfied with the information provided. This study was carried out in one oncological centre only, so it is inappropriate to conclude that this is what happens throughout Portugal. As far as we know, this is the first study in Portugal addressing this area of practice. This subject is a very important topic of research both in Portugal and in other countries, as many published recommendations are not research based.

The effect upon the human vaginal histology of the long-term use of the injectable contraceptive Depo-Provera

The objective of the study was to evaluate the effect of long-term use of the injectable contraceptive depot medroxyprogesterone acetate (DMPA) on human vaginal histology. Twenty premenopausal women currently using DMPA as a contraceptive method for two and three years were compared with 20 regularly menstruating women, who never used Depo-Provera and/or other kind of hormonal contraceptive in the last 6 months prior to the study. Subjects and controls were matched by age (+/-1 year), body mass index (kg/m2) (+/-1.0), number of pregnancies (+/-1), age at first intercourse (+/-1 year), years of sexual activity (+/-1 year), and number of partners during their life (+/-1). Vaginal biopsies were performed in users at 90+/-7 days after the last injection and in nonusers at day 20-25 of the menstrual cycle. In addition, at the day of the biopsy a blood sample was collected to measure estradiol (in all women) and DMPA in users. The level of serum estradiol was significant lower in Depo-Provera users than in controls (p < 0.001). The thickness of the vaginal epithelium was not smaller among DMPA users than among controls, the mean count of Langerhans cells per mm of epithelium were almost identical in both groups, and no significant differences were found on the vaginal maturation indices. In conclusion, the use of Depo-Provera between two and three years did not affect vaginal thinning of the epithelium, Langerhans cell count or maturation index.

Beneficial effects of modest systemic hypothermia on locomotor function and histopathological damage following contusion-induced spinal cord injury in rats

OBJECT

Local spinal cord cooling (LSCC) is associated with beneficial effects when applied following ischemic or traumatic spinal cord injury (SCI). However, the clinical application of LSCC is associated with many technical difficulties such as the requirement of special cooling devices, emergency surgery, and complicated postoperative management. If hypothermia is to be considered for future application in the treatment of SCI, alternative approaches must be developed. The objectives of the present study were to evaluate 1) the relationship between systemic and epidural temperature after SCI; 2) the effects of modest systemic hypothermia on histopathological damage at 7 and 44 days post-SCI; and 3) the effects of modest systemic hypothermia on locomotor outcome at 44 days post-SCI.

METHODS

A spinal cord contusion (12.5 mm at T-10) was produced in adult rats that had been randomly divided into two groups. Group 1 rats (seven in Experiment 1; 12 in Experiment 2) received hypothermic treatment (epidural temperature 32-33 degrees C) 30 minutes postinjury for 4 hours; Group 2 rats (nine in Experiment 1; eight in Experiment 2) received normothermic treatment (epidural temperature 37 degrees C) 30 minutes postinjury for 4 hours. Blood pressure, blood gas levels, and temperatures (epidural and rectal) were monitored throughout the 4-hour treatment period. Twice weekly assessment of locomotor function was performed over a 6-week survival period by using the Basso-Beattie-Bresnahan locomotor rating scale. Seven (Experiment 1) and 44 (Experiment 2) days after injury, animals were killed, perfused, and their spinal cords were serially sectioned. The area of tissue damage was quantitatively analyzed from 16 longitudinal sections selected from the central core of the spinal cord.

CONCLUSIONS

The results showed that 1) modest changes in the epidural temperature of the spinal cord can be produced using systemic hypothermia; 2) modest systemic hypothermia (32-33 degrees C) significantly protects against locomotor deficits following traumatic SCI; and 3) modest systemic hypothermia (32-33 degrees C) reduces the area of tissue damage at both 7 and 44 days postinjury. Although additional research is needed to study the therapeutic window and long-term benefits of systemic hypothermia, these data support the possible use of modest systemic hypothermia in the treatment of acute SCI.

Methods to evaluate nodulation competitiveness between Sinorhizobium meliloti strains using melanin production as a marker

Three methods to evaluate the relative ability of different strains of Sinorhizobium meliloti to occupy nodules formed on alfalfa after co-inoculation were compare in this study. Results obtained using the three methods of evaluation together, provided insight into the relative nodulation competitiveness between two given sinorhizobial strains. A simple visual phenotypic marker, i.e., melanin production was used to distinguish individual strains in a given assay. As such, melanin producing strains were compared with melanin non-producing strains throughout this study. Method 1 required the use of an ELISA plate, took 35 min for the analysis of 40 nodules, and allowed strain identification by melanin production 2 days after nodule harvest. Method 2 required 3 h for the analysis of 40 nodules, used an ELISA plate, growth of bacteria on Petri dishes, and melanin production was analysed after 48 h of cell culture. Finally, method 3 involved the whole nodulated plant root, required less material than the above methods, and results were obtained after 24 h. Only method 2 was useful in determining if both a melanin producing strain and a melanin non-producing strain had occupied an individual nodule. Each of the three methods represented a rapid way of studying strain competition for field studies, using a natural trait as a marker.

First Detection of Faba bean necrotic yellow virus in Spain

Faba bean necrotic yellow virus (FBNYV) was not detected during 1994 to 1996 field surveys of faba beans (Vicia faba L.) in Spain (1). In 1997, however, one sample with symptoms of necrosis, collected in Baleares, was tested using ELISA (enzyme-linked immunosorbent assay) and was positive for both Tomato spotted wilt virus (TSWV) and FBNYV. FBNYV is a single-strand DNA virus that is transmitted by aphids and is the main virus disease of broad bean in North Africa and West Asia (2). During 1997 to 1999, faba bean plants with symptoms of necrosis, yellowing, small leaves, and stunting were collected from several fields in the Murcia Region (Spain) and were analyzed using ELISA. To detect FBNYV, we used monoclonal 2E9 supplied by H. J. Vetten (Institute of Plant Virology, Microbiology and Biosafety, BBA, Braunschweig, Germany). Of 700 samples analyzed, 34 were positive for FBNYV. Of the 34 positive samples, 12 tested positive, using commercial antiserum from Loewe, Inc. (Munich) for mixed infections with TSWV. FBNYV was transmitted to healthy faba bean plants by aphids (Acyrthosiphon pisum) in greenhouse experiments and was confirmed by ELISA. Preliminary epidemiological data showed a gradual increase in the number of plants infected with time in the same field. Aphid transmission of FBNYV to faba beans has established the disease in Spain and is a potential threat to other leguminous crops. This is the first report of a nanovirus in Europe. References: (1) J. Fresno et al. Plant Dis. 81:112, 1997. (2) L. Katul et al. Ann. Appl. Biol. 123:629, 1993.

Effects of salts on Debaryomyces hansenii and Saccharomyces cerevisiae under stress conditions

The effect of Na+ and K+ on growth and thermal death of Debaryomyces hansenii and Saccharomyces cerevisiae were compared under stress conditions as those commonly found in food environments. At the supraoptimal temperature of 34 degrees C both cations at concentrations of 0.5 M stimulated growth of D. hansenii, while K+ had no effect and Na+ inhibited growth of S. cerevisiae. At 8 degrees C, close to the minimum temperature for growth in both species, both cations inhibited both yeasts, this effect being more pronounced with Na+ in S. cerevisiae. At extreme pH values (7.8 and 3.5) both cations at concentrations of 0.25 M stimulated D. hansenii while Na+ inhibited S. cerevisiae. K+ inhibited this yeast at pH 3.5. Thermal inactivation rates, measured at 38 degrees C in D. hansenii and at 48 degrees C in S. cerevisiae, decreased in the presence of both cations. This protective effect could be observed in a wider range of concentrations in D. hansenii. These results call the attention to the fact that not all yeasts have the same behaviour on what concerns synergy or antagonism of salt together with other stress factors and should be taken into consideration in the establishment of food preservation procedures.

Forearm bone density in users of Depo-Provera as a contraceptive method

OBJECTIVE

To determine the influence of depot medroxyprogesterone acetate (MPA) on bone mineral density when used as a contraceptive method.

DESIGN

Cross-sectional study.

SETTING

Academic tertiary-care hospital.

PATIENT(S)

Fifty premenopausal women who had used depot MPA as a contraceptive method for > or =1 year and 50 women who had never used hormonal contraceptive methods.

INTERVENTION(S)

Bone mineral density was evaluated at the midshaft and at the distal radius of the nondominant forearm using single x-ray absorptiometry.

MAIN OUTCOME MEASURE(S)

Bone mineral density.

RESULT(S)

Bone mineral density at the midshaft of the forearm was lower in depot MPA users than in women who had never used hormonal contraceptive methods, but the difference was not statistically significant. At the distal portion, bone mineral density was significantly lower in the study group. The duration of depot MPA use was not related to bone mineral density.

CONCLUSION(S)

Women > or =35 years of age presented with a lower bone mineral density only at the distal portion of the forearm after the use of depot MPA for > or =1 year. However, this decrease was not related to the duration of depot MPA use. It is not possible to conclude that women who use depot MPA are at risk of osteoporosis.

Factor analysis and somatotyping, are these two physique classification methods comparable?

The aim of this study was to investigate the correspondence of physique structures estimated by the Heath-Carter anthropometric somatotyping method and a factor analysis based on the same set of 10 variables used by Heath-Carter. The investigation was carried out on a group of 200 healthy young adults of 20 years of age who were students of physical education. The mean somatotype was 2.7-4.6-3.0 for the males and 3.3-3.4-3.1 for the females. The 73% of the total variance in males and 75% in females were represented by three factors. They were identified as muscular, fatness and skeletal factors in the males, and in the females as muscular-trunk fatness, skeletal and limb fatness factors. A PCA gives different results depending on the measurements used for the calculation. The same set of variables as for the somatotyping method were used intentionally to extract the PCA factors and to evaluate the possible correspondence between these factors and the Heath-Carter components. On the basis of the correlation between the factors and the somatotype components, one can conclude that there is: (1) a high correspondence between endomorphy and fatness factors in both sexes; (2) that mesomorphy correlated positively with the muscular factor in males and negatively with the skeletal factor in both sexes; and (3) that ectomorphy was highly positively correlated with the skeletal factor and negatively with the other two factors in both sexes. Factors and somatotype components do not correspond exactly which leads to the following conclusions: (1) The three somatotype components cannot be identified as orthogonal factors in a factorial analysis based on the same measurements as for the somatotype, e.g. the ectomorphy component is not an independent factor in males or in females; (2) The muscle measurements and bone width used to estimate mesomorphy in somatotyping scored in two independent factors; and (3) The factor structure of the 10 measurements was sex dependent.

The risk of inadvertent intrauterine device insertion in women carriers of endocervical Chlamydia trachomatis

The most important complication attributed to the use of intrauterine device (IUD) is pelvic inflammatory disease (PID), often associated with Neisseria or Chlamydia infection. Consequently, the IUD should not be inserted in women at risk of infection or with symptoms of endocervicitis. To evaluate the effectiveness of such a policy, a systematic investigation of Chlamydia and Neisseria was carried out among 407 contraceptive acceptors. Twenty-seven cases were positive for Chlamydia and none were positive for Neisseria. There were no statistical differences in the proportion of women with and without Chlamydia who had vulvovaginal or cervical signs or symptoms, although twice as many women had pain at pelvic exam in the Chlamydia-infected group. In 29 women in whom infection was clinically suspected, two were found to be infected with Chlamydia. IUD were not inserted in women suspected of having infection, but 19 of 327 IUD acceptors were subsequently found to have a positive Chlamydia test result. Two women returned with symptoms of PID and 17 were asymptomatic, but all were treated. PID was not suspected in any other subject. These results reinforce the need for careful selection of IUD acceptors and for thorough counseling for symptoms of PID and the need for immediate consultation.

[Application of RUG-T18 classification system to elderly patients admitted to a university hospital]

BACKGROUND

Among case mix classifications, the best for hospitalized elders is the Resource Utilization Groups (RUG) system, which allows a better location of patients, resource administration and the design of health care strategies for elderly people.

AIM

To report the results of RUG-T18 classification of elderly patients admitted to an university hospital.

PATIENTS AND METHODS

RUG-T18 classification was applied to 210 patients aged 75.2 +/- 7.2 years old, 108 male, admitted to the Clinical Hospital of the Catholic University of Chile.

RESULTS

The clinical classification of assessed patients was rehabilitation in 50.9% of cases, special care in 10.5%, clinically complex in 37.1% and reduced physical functions in 0.5%. None had behavioral alterations. There were no differences between subjects older or younger than 75 years old. Daily life activities showed that help was required for sphincter control in 46% of patients, for feeding in 44% and for mobilization in 64% (28% of patients required help from two or more people). Geriatric assessment showed that, since 1993, the proportion of elders with greater functional derangement increased from 18 to 28%, and the proportion of those with mental disturbances from 4 to 12%, specially among those over 75 years old.

CONCLUSIONS

Most elders admitted to the hospital are classified in the superior categories of the RUG-T18 system and have severe mental and functional limitations. These patients require a multidisciplinary approach with a great emphasis in rehabilitation.

[Ambulatory geriatric assessment of 2116 in poor elderly]

BACKGROUND

Geriatric assessment quantifies medical, functional, mental and social capabilities and alterations of elders and is the first step to initiate specific intervention programs.

AIM

To report the initial geriatric assessment of a program aimed to help poor elders living in Metropolitan Santiago.

SUBJECTS AND METHODS

Two thousand one hundred sixteen free living subjects aged 65 to 99 years old (711 males) were subjected to an assessment using a simple geriatric score validated abroad and used previously in Chile. The resulting score ranges from 0 (better) to 5 (worst).

RESULTS

Eighty eight percent of elders did not have problems in the functional evaluation. Subjects over 75 years old needed occasional support for the daily activities with higher frequency than younger subjects (12 and 5.4% respectively, p < 0.001) and had a higher frequency of major functional limitations (7.8 and 3.2% respectively, p < 0.001). Mental assessment was considered normal in 89.4% of subjects. Those over 75 years old had a higher frequency of memory disturbances (11.4 and 6.5% respectively) and cognitive alterations (4.6 and 1.8% respectively). Indefinite social support could be received by 84% of subjects, but 7.4% did not have access to this resource.

CONCLUSIONS

Geriatric assessment of poor elders gives useful information to identify those subjects that require community help.

Biochemical alterations in Bradyrhizobium sp USDA 3187 induced by the fungicide Mancozeb

We have previously shown that fungicide Mancozeb causes a 50% decrease in Bradyhizobium sp USDA 3187 growth rate and affects the bacteria-root symbiotic interaction. In order to elucidate the fungicide toxicity mechanism we determined the effects of Mancozeb on cell chemical composition, glutathione (GSH) content (molecule involved in the detoxification process), glutathione S-transferase (GST) activity and on polyamine, exopolysaccharides, capsular polysaccharides and lipopolysaccharides. Mancozeb produced biochemical alterations in membrane composition, polysaccharides and polyamines. In spite of the increment of GSH content and GST activity, they are not enough to prevent the growth diminution.

Response of Azospirillum brasilense Cd to sodium chloride stress

Growth of Azospirillum brasilense Cd in the presence of different NaCl concentrations showed that it tolerates up to 200 mM NaCl in the medium, without appreciable decline in growth rate. At 300 mM NaCl, a decrease of 66% in growth was observed at 24 h of culture. At 48 h of culture, bacteria in the presence of 300 mM NaCl reached the maximum optical density value that was attained at 12 h by control cultures. This investigation was designed to elucidate the effect of saline stress on Azospirillum brasilense Cd and the physiologic mechanism involved in its possible salinity tolerance. For this reason, studies of other osmolytes, as well as of putrescine metabolism and protein patterns were done with bacteria grown with this NaCl concentration in the medium, at 24 and at 48 hours. A. brasilense responded to saline stress elevating the intracellular concentration of glutamate at 24 h, and of K+ at 48 h. Glucan pattern, putrescine metabolism, and total and periplasmic protein patterns of the treated group showed several changes with respect to the control. In spite of the several cellular functions affected by saline stress, the results imply that A. brasilense Cd shows salinity tolerance in these experimental conditions.

Remission of hairy cell leukemia without treatment

A patient is described with hairy cell leukemia, in whom a remission occurred spontaneously or in association with Legionnaires or subsequent HIV infection. Possible pathophysiological mechanisms are reviewed. Currently it is seventeen years since the diagnosis of hairy cell leukemia and fourteen years since the infusion of HIV infected blood. Hairy cell leukemia has yet to return and HIV infection has not progressed to AIDS.

Giant intrasacral schwannomas: report of six cases

Only 4 of the 30 previously reported cases of giant sacral schwannomas have been studied with Magnetic Resonance Imaging (MRI). We are reporting 6 more cases, 5 of which had MRI studies. There were 5 women and 1 man (average age 45 years) with long lasting symptoms consisting of lumbosacral and radicular pain accompanied by urinary disturbances and dysaesthetic sensations in the lower limbs. CT clearly defined sacral bone involvement but poorly demonstrated intraspinal tumour extension which was more evident in MRI studies. MRI also clearly showed the intrapelvic extension of the tumour, its relationship with the neighbouring structures and the dumbbell growth pattern due to tumour extension through sacral foramina which are important data for making a pro-operative diagnosis and surgical planning. Surgical treatment consisted of piecemeal tumour resection through a posterior approach in four cases. Two patients underwent operation through an abdominal transperitoneal approach followed by a sacral laminectomy. Total intracapsular resection was apparently achieved in 5 cases. Through an average follow-up period of 9.2 years and despite a rather conservative approach, the recurrence rate has been very low in our series and only one patient had to be re-operated on for tumour recurrence.

[Comparative study of institutionalized and non-institutionalized nonagenarians]

BACKGROUND

The 1992 census showed that 10,470 people over 90 years old lived in Santiago and we do not have information about their general medical status.

AIM

To evaluate and compare quality of life and functional status of free living and institutionalized nonagenarians in Santiago.

SUBJECTS AND METHODS

During 24 months, 241 people of 90 years or older were interviewed. One hundred twenty seven (96 female) lived in their own homes and 114 (108 female) lived in institutions. The geriatric evaluation scale, validated in previous studies, was used as the assessment instrument.

RESULTS

Mean age of subjects was 94 years old (range 90 to 106). Eight percent of subjects were bedridden. No differences in general condition, fecal or urinary continence, nutritional status, blood pressure, cognition, sight and hearing acuity, were observed between free living and institutionalized subjects. Free living elders had a significantly higher number of brothers or offspring and 90% were happy with the place where they lived.

CONCLUSIONS

Most nonagenarians in Santiago are in good general medical conditions. Probably, the decision to become institutionalized depends more on lack of family support than on worse medical, functional or mental conditions.

Lipid-laden macrophage infiltration of human adenocarcinoma in vivo associated with taxol and GCSF treatment

This brief report illustrates the presence of lipid-laden macrophages in proximity to metastatic adenocarcinoma cells within the bone marrow of a patient receiving taxol and GCSF therapy. The pathophysiological mechanism is uncertain. Taxol, which is associated with macrophage function in vitro, may have been responsible for the recruitment of macrophages in this patient. GCSF could have contributed as well; however, GCSF usually has little effect on monocytes and macrophages.

Virus Diseases of Broad Bean in Spain

Broad bean (Vicia faba L.) plants showing symptoms suggestive of viral infection, such as stunting, leaf roll, mosaic, chlorosis, necrosis, and yellowing, were observed in the Andalucia, Baleares, Cataluna, and Murcia regions of Spain. A 4-year field survey showed the presence of five viruses: bean leaf roll luteovirus (BLRV), beet western yellows luteovirus (BWYV), bean yellow mosaic potyvirus (BYMV), tomato spotted wilt tospovirus (TSWV), and cucumber mosaic cucumovirus (CMV). Identity of viruses was first determined by enzyme-linked immunosorbent assay and confirmed by at least one other method, such as inoculation to plant hosts, electron microscopy, molecular hybridization, or immunocapture-reverse transcriptase-polymerase chain reaction. Of the 250 samples assayed, 93 were positive for BYMV, 21 for BLRV, 10 for BWYV, 30 for TSWV, and 2 for CMV. Faba bean necrotic yellow virus (a single-strand DNA virus) and broad bean mottle bromovirus, which are widely distributed in the Mediterranean basin, were not detected in the samples analyzed. BYMV was distributed in all regions, whereas TSWV was restricted only to Mediterranean areas. To our knowledge, this is the first report of viruses infecting broad bean in Spain.